Methods, apparatus, and systems for efficient integration of metadata into a bitstream for utility signals

Abstract

Methods, apparatus, programs, and storage media for improving annotation of waveform data are provided. The method includes obtaining a bitstream comprising one or more coded packets of waveform data. A metadata header is inserted into the bitstream to generate a combined bitstream, wherein the metadata header is related to the waveform data. The metadata header indicates a feature type value and the feature type value comprises a value corresponding to a common feature of a subset of the one or more coded packets associated with the metadata header.

Description

[0001] Dolby International AB October 28, 2025

[0002] D24147 WOOl

[0003] METHODS, APPARATUS, AND SYSTEMS FOR EFFICIENT INTEGRATION OF METADATA INTO A BITSTREAM FOR UTILITY SIGNALS

[0004] CROSS-REFERENCE TO RELATED APPLICATIONS

[0005] This application claims priority of the following priority application: U.S. Provisional Application No. 63 / 713,238, filed October 29, 2024; European Patent Application No.: 24210353.9, filed November 1, 2024, U.S. Provisional Application No. 63 / 825,035, filed June 17, 2025 and U.S. Provisional Application No. 63 / 882,068, filed 15 September, 2025, each of which is hereby incorporated by reference in its entirety.

[0006] TECHNICAL FIELD

[0007] The present disclosure relates to methods and devices for inserting metadata into a bitstream for allowing extraction of a part of the bitstream.

[0008] BACKGROUND

[0009] Utility signals with waveform characteristics are prevalent in various domains, such as biomedical, industrial, and communication systems. These signals, which often carry vital information, are typically continuous functions that vary over time, representing physical phenomena or measurements. Waveform signals are particularly significant in applications where the time-domain or frequency-domain behavior of the signal reveals important insights.

[0010] For instance, in biomedical engineering, waveform signals such as electrocardiograms (ECG), electroencephalograms (EEG), and electromyograms (EMG) are essential for diagnosing and monitoring physiological conditions. These biomedical signals exhibit unique waveform patterns that correspond to the electrical activity of the heart, brain, and muscles, respectively. The shape, amplitude, and frequency of these waveforms provide critical information about the health and functioning of various body systems. Dolby International AB October 28, 2025

[0011] D24147 WOOl

[0012] Accurate analysis and interpretation of waveform signals are crucial for applications such as medical diagnostics, process control, and telecommunications. For example, anomalies in a biomedical waveform may indicate the presence of a disorder, while variations in industrial sensor waveforms could suggest mechanical failure. Therefore, understanding and processing these waveform signals is a foundational aspect of signal analysis in many technical fields.

[0013] While biomedical signals may be sometimes inspected directly by a clinician, they are very often used to estimate some performance parameters (e.g., estimation of hearth rate from a photoplethismography (PPG) signal, computation of pulse wave velocity from simultaneous observations of ECG signals and PPG signals, etc.). Furthermore, there is an emerging use case where large data sets of medical signals are used to train deep neural networks, which may be able to provide more advanced insights (e.g., estimation of metabolic age, estimation of cardiovascular age, etc.). These types of use cases are highly relevant in a context of wearables and fitness. In addition, large collections of medical signals are used for research studies performed in a clinical context (e.g., clinical trials of treatments, observational studies, etc.). To reduce storage requirements for such datasets and to facilitate manipulations of such dataset, it may be required to compress these signals. The encoded signals may be stored in a database and retrieved at some point to perform tasks on these signals, where these tasks may remain unknown during the signal acquisition and during encoding. Furthermore, a large dataset of medical signals may be composed of lossy coded signals encoded with different compression rates. It may be therefore required to perform selection of a subset of such signals, for example by selecting only these signals, which include a certain type of feature.

[0014] Further, utility signals, such as biomedical signals are often accompanied by side information that may be characterizing the context of capture or may be added later during the analysis of the captured signals.

[0015] Thus, there is a need for an efficient handling of said side information to enable fast and automated processing of the utility signals depending on the particular use case. Dolby International AB October 28, 2025

[0016] D24147 WOOl

[0017] SUMMARY

[0018] In view of the above, the present disclosure provides methods, apparatus, and programs, as well as computer-readable storage media for inserting metadata into a bitstream and for selectively decoding the bitstream based on the metadata.

[0019] According to an aspect of the disclosure, a method of inserting a metadata header into a bitstream is provided. The bitstream comprising one or more coded packets of waveform data may be obtained. The metadata header may be inserted into the bitstream to generate a combined bitstream. The metadata header may be related to the waveform data (e.g., it may be based on the waveform data or / and on auxiliary data recorded in connection with the waveform data). The metadata header may include a feature type value. The feature type value may include a value corresponding to a common feature of the coded packets associated with the metadata header.

[0020] By inserting metadata in the bitstream, the bitstream may be scanned for the metadata without decoding the encoded waveform data. A selective decoding process may be performed based on the content of the metadata. Thereby, processing of relevant parts of the waveform data may be improved.

[0021] In some embodiments, obtaining the bitstream may include receiving the waveform data, e.g., from a sensor or from a device connected to a sensor. Further, the waveform data may be encoded to generate the bitstream.

[0022] Alternatively, obtaining the bitstream may include receiving the bitstream, e.g., by a device that has encoded the waveform data. Optionally, the one or more coded packets may be decoded to obtain the waveform data.

[0023] In some embodiments, the metadata header may further include a length value. The length value may indicate a number (a quantity) of packets of the one or more coded packets associated with the metadata header. Therefore, the association may be defined by the length value and the feature type value may indicate the reason for the association. The common feature may be determined based on the waveform data. The common feature may be one or more of a plurality of predefined common features. The plurality of predefined common features may vary depending on a signal type of the waveform data. The predefined common features may indicate a condition (e.g., an abnormality, a specific pattern etc.) associated with part of the waveform data corresponding to the coded packets associated with the metadata header. If the common Dolby International AB October 28, 2025

[0024] D24147 WOOl feature is determined based on the encoded waveform data (i.e., the bitstream is received and the coded packets are not decoded) a neural network suitable for operating on encoded waveform data may be used to analyze the coded packets for determining the common feature.

[0025] In some embodiments, inserting the metadata header into the bitstream may include inserting the metadata header at a position related to the number of packets (i.e. the subset of packets) associated with the metadata header. The position may be in front of the number of packets in a decoding order or reading order of the bitstream and the metadata header may be included in a packet different from the number of packets associated with the metadata header. Therefore, the metadata may be transported by its own packet type in the bitstream. Alternatively, the metadata header may be part of a first coded packet with which the metadata header is associated with. The first coded packet may be understood as a first packet in a decoding or reading order of the bitstream. The metadata header may therefore be part of a packet header of the coded packet including the encoded waveform data.

[0026] In some embodiments, the one or more coded packets may be a plurality of coded packets and the metadata header may include a first metadata header and a second metadata header. The first metadata header may be associated with a first subset of the plurality of coded packets and the second metadata header may be associated with a second subset of the plurality of coded packets. The first subset and the second subset may overlap, the first subset and the second subset may be disjunct, or the second subset may be a subset of the first subset. If the second subset is a subset of the first subset, the first and second metadata header may part of a same packet, i.e., a sperate packet or a coded packet including the waveform data, depending on the implementation.

[0027] In some embodiments, the metadata header may include a feature set packet and a feature packet. The feature set packet may indicate the feature type value and optionally a feature start value. The feature start value may indicate a position of the feature packet.

[0028] With this configuration, the feature set packet may be queried for a specific common feature. If the querying process returns a positive result, a selective decoding process may be started at the feature packet, i.e., by jumping to the feature packet based on the feature start value associated with the feature packet.

[0029] In some embodiments, the feature packet may additionally comprise a timestamp for indicating the starting time of the waveform data corresponding to the one or more coded packets associated Dolby International AB October 28, 2025

[0030] D24147 WOOl with the feature packet. The starting time may correspond to a time at which the waveform data has been generated or encoded.

[0031] In some embodiments, the feature set packet may additionally indicate a length value (feature length value). The length value may indicate a number of (quantity of) packets of the one or more coded packets associated with the feature packet or a duration (e.g., in milliseconds) of the waveform data corresponding to the one or more coded packets associated with the feature packet.

[0032] Alternatively, the feature set packet may not indicate a length value, but the metadata header may comprise a second feature packet. The feature packet and the second feature packet together may indicate a quantity of packets of the one or more coded packets associated with the feature packet. For example, the feature packet may be a leading packet of the one or more coded packets and the second feature packet may be a tailing packet of the one or more coded packets. The second feature packet may further include a timestamp and the timestamp may indicate the end time of the waveform data corresponding to the one or more coded packets associated with the feature packet. The timestamp of the second feature packet may be defined in the same way as the timestamp of the feature packet. Therefore, the feature packet and the second feature packet may be used to determine a duration (e.g. in seconds, minutes etc.) of waveform data corresponding to the one or more coded packets. Additionally, both timestamps may be used for aligning the waveform data corresponding to the one or more coded packets with other waveform data.

[0033] In some embodiments, inserting the metadata header into the bitstream may include inserting the feature packet at a position related to the number of packets (i.e. the subset of the one or more packets) associated with the feature packet and inserting or updating the feature set packet based on the number of packets associated with the feature packet. The feature set packet is located at a starting position of the combined bitstream (i.e., one of the first packets in the bitstream). The position of the feature packet may be in front of the number of packets in a decoding order or reading order of the combined bitstream.

[0034] In some embodiments, the one or more coded packets may be a plurality of coded packets and the feature packet may include a first feature packet and a second feature packet. The first feature packet may be associated with a first subset of the plurality of coded packets and the second feature packet may be associated with a second subset of the plurality of coded packets. The Dolby International AB October 28, 2025

[0035] D24147 WOOl feature set packet may indicate the feature type value and / or the length value and / or the feature start value for each of the first subset of the plurality of coded packets and second subset of the plurality of coded packets.

[0036] In some embodiments, the first subset and the second subset may overlap, the first subset and the second subset may be disjunct, or the second subset may be a subset of the first subset.

[0037] In some embodiments, the metadata header may only include a feature set packet (i.e., no feature packets). In this case, the feature type value in the feature set packet may be associated with substantially the whole bitstream (i.e., all packets containing waveform data). A feature set packet with this configuration may be indicated by a flag.

[0038] In some embodiments, the feature set packet may include the feature type value, or an annotation channel of the bitstream comprises the feature type value and the feature set packet points to the feature type value in the annotation channel.

[0039] In some embodiments, the feature type value may include a string (e.g., an individual string set typed by a user) or a pointer to a predefined string (e.g., a pointer to a predefined list of medical conditions for specific waveform data).

[0040] In some embodiments, the waveform data represents continuous measurements by a sensor. While the measurements may be continuous, the waveform data may include discontinuities, e.g., due to a sensor failure or a sensor disposition. The waveform data may be biomedical waveform data or waveform data representing mechanical motion. Specifically, the waveform data may represent signals by a seismometer or an accelerometer. Further, the biomedical waveform data may be any one of electrocardiography data, electroencephalography data, electromyography data, electrooculogram data, electroretinogram data, electrogastrogram data or photoplethysmogram data.

[0041] In some embodiments, the method may further include receiving auxiliary data. In this case, the common feature may be alternatively or additionally determined based on the auxiliary data. Therefore, a condition common to a specific subset of coded packets (i.e., the corresponding waveform data) may be determined based on the waveform data itself and / or based on the auxiliary data. The auxiliary data may include data associated with the generation of the waveform data. The auxiliary data may include static data or dynamic data. The static data may include a device type or a sensor type. The dynamic data may include auxiliary measurement data Dolby International AB October 28, 2025

[0042] D24147 WOOl for the waveform data. The auxiliary measurement data may have a slow change rate in comparison to the waveform data. The auxiliary measurement data may be any one of a time stamp, a temperature, a location, an elevation, a humidity and an orientation.

[0043] In some embodiments, encoding the waveform data to generate the bitstream may be based on a core encoder for source encoding of the waveform data. Any suitable core encoder may be used. Encoding the waveform data to generate the bitstream may include splitting the waveform data based on time and / or frequency and generating the one or more coded packets based on the split waveform data.

[0044] In some embodiments, the waveform data may be multichannel waveform data, i.e., the waveform data may include at least two channels with waveform data. In this case, encoding the waveform data to generate the bitstream may include encoding each channel of the multichannel waveform data to generate encoded channel signals and distribute the encoded channel signals into the one or more coded packets to generate the bitstream. The packets containing the waveform data of the different channels may for example be differentiable by different labels attached to the packets.

[0045] In some embodiments, decoding the one or more coded packets to obtain waveform data may be based on a core decoder for source decoding of the one or more coded packets.

[0046] In some embodiments, the metadata header further may include a label, wherein the label indicates a label of a coded packet with which the metadata header is associated.

[0047] In some embodiments, the method may further include inserting a configuration header into the combined bitstream. The configuration header may include a signal type value indicative of a signal type and / or a sampling rate of data of all one or more coded packets in the combined bitstream. The configuration header further comprises a packet length of the one or more coded packets. Therefore, the configuration header may include data common to all packets or all packets of a sub-stream in the bitstream. A sub-stream may be used to allow the data transport of different waveform types (and / or of different sensors) in the same bitstream.

[0048] In some embodiments, the method may further include providing the combined bitstream for further processing. The further processing may include storing the combined bitstream or transmitting the combined bitstream. Dolby International AB October 28, 2025

[0049] D24147 WOOl

[0050] According to another aspect of the disclosure, a method of extracting a subset of data from a combined bitstream is provided. The combined bitstream may be received. The combined bitstream may include a plurality of coded packets corresponding to waveform data and one or more metadata headers, each associated with a subset of the plurality of coded packets. A subset of the plurality of coded packets may be extracted based on the associated metadata header. Each metadata header may indicate a feature type value and the feature type value may comprises a value corresponding to a common feature of the subset of the plurality of coded packets associated with the metadata header.

[0051] Thereby, a specific part of interest of the bitstream, i.e., a part of the waveform data having a specific feature, may be extracted without processing / decoding other coded packets of the bitstream.

[0052] In some embodiments, each metadata header may further include a length value. The length value may indicate a number of (quantity of) packets of the one or more coded packets associated with the metadata header. Therefore, the association may be defined by the length value and the feature type value may indicate the reason for the association. The common feature may be determined based on the waveform data. The common feature may be one or more of a plurality of predefined common features. The plurality of predefined common features may vary depending on a signal type of the waveform data. The predefined common features may indicate a condition (e.g., an abnormality, a specific pattern etc.) associated with part of the waveform data corresponding to the coded packets associated with the metadata header.

[0053] In some embodiments, extracting the subset of the plurality of coded packets based on the associated metadata header may include determining the subset of the plurality of coded packets based on the common feature in the associated metadata header and extracting the subset of the plurality of coded packets. A common feature of interest may be determined by a human or automatically and the one or more metadata header in the bitstream may be read to compare the common feature included in the metadata header to the common feature of interest. Optionally, the extracted subset of the plurality of coded packets may be decoded to obtain decoded waveform data. Decoding the subset of the plurality of coded packets to obtain the decoded waveform data may be based on a core decoder for source decoding of the subset of the plurality of coded packets. Dolby International AB October 28, 2025

[0054] D24147 WOOl

[0055] In some embodiments, each metadata header may be positioned at a position related to the subset of the plurality of packets with which the metadata header is associated. The position may be in front of the respective subset in a decoding order or reading order of the bitstream and the metadata header may be included in a packet different from the number of packets associated with the metadata header. Therefore, the metadata may be transported by its own packet type in the bitstream. Alternatively, the metadata header may be part of a first coded packet with which the metadata header is associated with. The first coded packet may be understood as a first packet in a decoding or reading order of the bitstream. The metadata header may therefore be part of a packet header of the coded packet including the encoded waveform data.

[0056] In some embodiments, the one or more metadata headers may include a first metadata header and a second metadata header. The first metadata header may be associated with a first subset of the plurality of coded packets and the second metadata header may be associated with a second subset of the plurality of coded packets. The first subset and the second subset may overlap, the first subset and the second subset may be disjunct, or the second subset may be a subset of the first subset. If the second subset is a subset of the first subset, the first and second metadata header may part of a same packet, i.e., a sperate packet or a coded packet including the waveform data, depending on the implementation.

[0057] In some embodiments, each metadata header may include a feature set packet and, for each subset of the plurality of coded packets, a feature packet. Each feature set packet may indicate the feature type value and optionally a feature start value for the corresponding subset of the plurality of coded packets. The feature type value may include a value corresponding to a common feature of the subset of the plurality of coded packets associated with the feature packet. The feature start value may indicate a position of the feature packet associated with the subset of the plurality of coded packets.

[0058] With this configuration, the feature set packet may be queried for a specific common feature. If the querying process returns a positive result, a selective decoding process may be started at the feature packet, i.e., by jumping to the feature packet based on the feature start value associated with the feature packet.

[0059] In some embodiments, each feature packet may additionally comprise a timestamp for indicating the starting time of the waveform data corresponding to the subset of the plurality of coded Dolby International AB October 28, 2025

[0060] D24147 WOOl packets associated with the feature packet. The starting time may correspond to a time at which the waveform data has been generated or encoded.

[0061] In some embodiments, the feature set packet may additionally indicate a length value for each subset of the plurality of coded packets. The length value may indicate a number of (quantity of) packets of the subset of the plurality of coded packets associated with the feature packet or a duration (e.g., in milliseconds) of the waveform data corresponding to the subset of the plurality of coded packets associated with the feature packet.

[0062] Alternatively, the feature set packet may not indicate a length value, but the metadata header may comprise a second feature packet. The feature packet and the second feature packet together may indicate a quantity of packets of the subset of the plurality of coded packets associated with the feature packet. For example, the feature packet may be a leading packet of the subset of the plurality of coded packets and the second feature packet may be a tailing packet of the subset of the plurality of coded packets. The second feature packet may further include a second timestamp and the second timestamp may indicate the end time of the waveform data corresponding to the subset of the plurality of coded packets associated with the feature packet. The second timestamp of the second feature packet may be defined in the same way as the timestamp of the feature packet. Therefore, the feature packet and the second feature packet may be used to determine a duration (e.g. in seconds, minutes etc.) of waveform data corresponding to the one or more coded packets. Additionally, both timestamps may be used for aligning the waveform data corresponding to the subset of the plurality of coded packets with other waveform data.

[0063] In some embodiments, inserting the metadata header into the bitstream may include inserting the feature packet at a position related to the subset of the plurality of coded packets associated with the feature packet and inserting or updating the feature set packet based on the subset of the plurality of coded packets associated with the feature packet. The feature set packet is located at a starting position of the combined bitstream (i.e., one of the first packets in the bitstream). The position of the feature packet may be in front of the subset of the plurality of coded packets in a decoding order or reading order of the combined bitstream.

[0064] In some embodiments, the subsets may overlap, the subsets may be disjunct, or a second subset may be a subset of a first subset. Dolby International AB October 28, 2025

[0065] D24147 WOOl

[0066] In some embodiments, the metadata header may only include a feature set packet (i.e., no feature packets). In this case, the feature type value in the feature set packet may be associated with substantially the whole bitstream (i.e., all packets containing waveform data). A feature set packet with this configuration may be indicated by a flag.

[0067] In some embodiments, the feature set packet may include the feature type value, or an annotation channel of the bitstream comprises the feature type value and the feature set packet points to the feature type value in the annotation channel.

[0068] In some embodiments, the feature type value may include a string (e.g., an individual string set typed by a user) or a pointer to a predefined string (e.g., a pointer to a predefined list of medical conditions for specific waveform data).

[0069] In some embodiments, the waveform data represents continuous measurements by a sensor. While the measurements may be continuous, the waveform data may include discontinuities, e.g., due to a sensor failure or a sensor disposition. The waveform data may be biomedical waveform data or waveform data representing mechanical motion. Specifically, the waveform data may represent signals by a seismometer or an accelerometer. Further, the biomedical waveform data may be any one of electrocardiography data, electroencephalography data, electromyography data, electrooculogram data, electroretinogram data, electrogastrogram data or photoplethysmogram data.

[0070] In some embodiments, the metadata header further may include a label, wherein the label indicates a label of a coded packet with which the metadata header is associated.

[0071] In some embodiments, the combined bitstream may further include a configuration header. The configuration header may include a signal type value indicative of a signal type and / or a sampling rate of data of all one or more coded packets in the combined bitstream. The configuration header further comprises a packet length of the one or more coded packets. Therefore, the configuration header may include data common to all packets or all packets of a sub-stream in the bitstream.

[0072] In some embodiments, the method may further include providing the extracted subset of the plurality of coded packets for further processing. The further processing may include analyzing the decoded waveform data (if the extracted subset is decoded) or using the extracted subset for training or inference of a neural network. If the extracted subset is not decoded, the neural network may be suitable for operating with encoded waveform data. Dolby International AB October 28, 2025

[0073] D24147 WOOl

[0074] In some embodiments, extracting the subset of the plurality of coded packets based on the associated metadata header may include determining the subset of the plurality of coded packets based on the common feature in the associated metadata header and solely decoding the subset of the plurality of coded packets to obtain decoded waveform data.

[0075] In some embodiments, determining the subset of the plurality of coded packets based on the common feature in the associated metadata header may include querying the feature type value in the feature set packet for the common feature. Then, the subset of the plurality of coded packets may be determined based on the feature start value and optionally the associated length value. Solely decoding the subset of the plurality of coded packets to obtain decoded waveform data then may include starting decoding at the feature packet associated with the common feature.

[0076] In some embodiments, the method may further include removing the one or more metadata headers from the bitstream.

[0077] Thereby, metadata can be removed, if for example an analysis of the waveform data indicates that the common feature included in the metadata header is incorrect.

[0078] Aspects of the present disclosure may be implemented via an apparatus. The apparatus may include a processor and memory coupled to the processor. The processor may be adapted carry out the method according to aspects and embodiments of the present disclosure.

[0079] Aspects of the present disclosure may be implemented via a program. When instructions of the program are executed by a processor, the processor may carry out aspects and embodiments of the present disclosure. A computer-readable storage medium may store the program. Such computer-readable storage media may include memory devices such as those described herein, including but not limited to random access memory (RAM) devices, read-only memory (ROM) devices, etc.. Accordingly, some innovative aspects of the subject matter described in this disclosure can be implemented via one or more computer-readable storage media having software stored thereon.

[0080] It will be appreciated that apparatus features and method steps may be interchanged in many ways. In particular, the details of the disclosed method(s) can be realized by the corresponding apparatus (or system), and vice versa, as the skilled person will appreciate. Moreover, any of the above statements made with respect to the method(s) are understood to likewise apply to the corresponding apparatus (or system), and vice versa. Dolby International AB October 28, 2025

[0081] D24147 WOOl

[0082] BRIEF DESCRIPTION OF DRAWINGS

[0083] Example embodiments of the disclosure are explained below with reference to the accompanying drawings, wherein

[0084] Fig- 1 is a flowchart illustrating a method of inserting a metadata header into a bitstream according to embodiments of the disclosure,

[0085] Fig- 2 is a flowchart illustrating an example implementation of a method of inserting a metadata header into a bitstream according to embodiments of the disclosure,

[0086] Fig. 3 schematically illustrates an example for insertion of a metadata header into a bitstream according to embodiments of the disclosure,

[0087] Fig. 4 schematically illustrates another example for insertion of a metadata header into a bitstream according to embodiments of the disclosure,

[0088] Fig- 5 is a flowchart illustrating another example implementation of a method of inserting a metadata header into a bitstream according to embodiments of the disclosure,

[0089] Fig. 6 schematically illustrates another example for insertion of a metadata header into a bitstream according to embodiments of the disclosure,

[0090] Figs. 7 A and B schematically illustrate a bitstream including one or more metadata headers according to embodiments of the disclosure,

[0091] Fig. 8 schematically illustrates a bitstream including an alternative metadata header format according to embodiments of the disclosure,

[0092] Fig. 9 is a flowchart illustrating a method of extracting a subset of data from a bitstream based on the included metadata header according to embodiments of the disclosure,

[0093] Fig. 10 schematically illustrates an example for selectively decoding a bitstream according to embodiments of the disclosure,

[0094] Fig. 11 schematically illustrates an example of an apparatus for insertion of a metadata header into a bitstream or for extracting a subset of data from the bitstream according to embodiments of the disclosure, and Dolby International AB October 28, 2025

[0095] D24147 WOOl

[0096] Fig. 12 schematically illustrates an example of a transmission device according to embodiments of the disclosure.

[0097] DETAILED DESCRIPTION

[0098] The International Telecommunication Union (“ITU”) is an assembly of experts from around the world that work together to develop international standards known as ITU-T Recommendations. These standards enable improved interoperability of communication signals in the global infrastructure of information networks and communication devices, allowing such networks and devices to more easily communicate and operate together. Recognizing the need for a standardized codec for biomedical waveform data, in April 2024 the ITU-T issued a call for proposals for a new ITU-T Recommendation on the coding of biomedical waveform data. One or more of the embodiments disclosed herein describe methods, apparatuses, and systems developed to meet one or more requirements specified in the ITU-T call for proposals for improved coding, compression, storage, transmission, reception, and / or decoding of such signals.

[0099] Technical benefits of one or more of the embodiments disclosed herein enable a standardized lossy, lossless, and / or near-lossless coding format including a transmission-syntax specifically developed for biomedical waveform data, and facilitate clinical neurophysiology data exchange. Such data may include time-based neurophysiology signal data and associated video recordings, if present, from electroencephalography (EEG), video-electroencephalography (VEEG), electromyography (EMG), evoked potentials (EP), polysomnograms (PSGs), electrocardiograms (ECGs), and other types of neurophysiology signals. Additional non-exhaustive examples of biomedical waveform data include photoplethysmogram (PPG). One or more of the embodiments described herein therefore provide features for a standardized codec which facilitates interoperable processing of biomedical waveform data by a wide range of devices.

[0100] In order to enable easy parsing of bitstreams that comprise encoded waveform data of utility signals without decoding the complete bitstream, metadata is introduced that allows “tagging” of certain information, such as distinctive features available in the coded signal. Said metadata may be added during encoding or at a later stage. A bitstream with the added metadata may enable a more efficient review of an expert / doctor of the waveform data afterwards, as the areas of interest may be quickly identified through inspection of the metadata. Further, the bitstream with added Dolby International AB October 28, 2025

[0101] D24147 WOOl metadata may enable an efficient training of a neural network for determining certain conditions in a signal, i.e. identifying a stroke based on a waveform indicative of heart activity.

[0102] A utility signal in the context of the present disclosure may be a signal that is captured with purpose different from playing it out to a human observer / listener. For example, a smartwatch capturing a PPG signal may also capture the signal from its accelerometer (i.e., a mechanical signal), and the acceleration signal may be then used to aid filtering of the PPG signal.

[0103] The Figures (Figs.) and the following description relate to preferred embodiments by way of illustration only. It should be noted that from the following discussion, alternative embodiments of the structures and methods disclosed herein will be readily recognized as viable alternatives that may be employed without departing from the principles of what is claimed.

[0104] Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying figures. It is noted that wherever practicable similar or like reference numbers may be used in the figures and may indicate similar or like functionality. The figures depict embodiments of the disclosed system (or method) for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein.

[0105] Insertion of the metadata header

[0106] Fig. 1 depicts a flowchart of a method 100 for inserting metadata into a bitstream.

[0107] In step S101, a bitstream is obtained. The bitstream comprises one or more coded packets of waveform data.

[0108] The waveform data may be any waveform data captured or generated by a sensor, i.e. a continuous stream of data. Specifically, the waveform data may be based on mechanical motion or may indicate a biomedical signal of a body. Without any intended limitation, in the mechanical context, the waveform data may be data from a seismometer or an accelerometer.

[0109] A biomedical signal in the context of the present disclosure may be a signal that relates to physiological information, and the signal may be electrical, physical or biochemical. The biomedical signal may relate to biological systems and conditions, examples of which may include ECG data, EEG data, EMG data, and PPG data, or signals for blood sugar level, heart Dolby International AB October 28, 2025

[0110] D24147 WOOl rate, body temperature, respiratory rate and oxygen saturation. Further, a biomedical signal may comprise one or more channels of time domain biomedical signal samples. In other examples, the biomedical signals may relate to muscle and / or skin measurements. Any other medical signal and / or physical response would also be understood to be comprised by this definition.

[0111] Additionally, the waveform data may multichannel waveform data. In other words, a sensor or multiple sensors may generate correlated, but different types of waveform data simultaneously. In this case, the bitstream may comprise multiple sub-streams, each comprising the encoded waveform data corresponding to a channel of the multichannel waveform data. The coded packets may be associated to a particular sub-stream based on a label included in each coded packet.

[0112] The bitstream may have been generated by encoding the waveform data. In particular, the encoded waveform data may be distributed over multiple coded packets to enable transmission or storage of the bitstream.

[0113] In step SI 02, a metadata header is inserted into the bitstream to generate a combined bitstream, i.e., a bitstream comprising the coded packets and the metadata header. The metadata header is related to the waveform data, e.g., it may be based on the waveform data or / and on auxiliary data recorded in connection with the waveform data.

[0114] The metadata header may indicate a specific condition of a number of coded packets following the metadata header. The condition may be a feature common to the number of coded packets (the subset of coded packets) associated with the metadata header, in particular, a common feature of a part of the waveform data corresponding to the associated coded packets. The common feature may be specific to a type of the waveform data and may be limited to a number of predefined common features. For example, in the biomedical context, the common feature may be an abnormal heartrate. To indicate the common feature, the metadata header may comprise a feature type value. In other words, the metadata header indicates the feature type value and the feature type value comprises a value corresponding to the common feature of the coded packets associated with the metadata header.

[0115] The metadata header may comprise a feature set packet and one or more feature packets. The feature set packet may include the feature type value and a feature start value for each feature packet in the bitstream. The feature set packet may be located at the start of the bitstream, while Dolby International AB October 28, 2025

[0116] D24147 WOOl each feature packet may be located in front of the coded packets with which it is associated with. The feature start value may indicate a position of the feature packet. The feature packet may include a timestamp that may indicate the starting time of the waveform data corresponding to the one or more coded packets associated with the feature packet. The starting time may correspond to a time at which the waveform data has been generated or encoded.

[0117] Optionally, the feature set packet may indicate a length value (i.e., a feature length value). The length value may indicate a number of (quantity of) packets of the one or more coded packets associated with the feature packet or a duration of the waveform data corresponding to the one or more coded packets associated with the feature packet.

[0118] Alternatively, the feature set packet may not indicate a length value, but the metadata header may comprise a second feature packet. The feature packet and the second feature packet may together indicate a quantity of a number of (quantity of) packets of the one or more coded packets associated with the feature packet. To achieve this, the feature packet may be in front (in a decoding direction) of the one or more coded packets and the second feature packet may be behind (in a decoding direction) the one or more coded packets. The second feature packet may also include a timestamp and the timestamp may indicate the end time of the waveform data corresponding to the one or more coded packets associated with the feature packet. Thereby, it is possible to extract a length in number of (quantity of) packets and a duration of the waveform data corresponding to the one or more coded packets from the bitstream.

[0119] The feature set packet may include the indication of the length value, the feature type value and the feature start value in form of a list. In other words, for each group of packets (one or more packets) associated with a common feature (and the corresponding feature packet) the feature set packet may have a list entry, with corresponding length value and / or the feature type value and or the feature start value, depending on the implementation.

[0120] In yet an alternative implementation, the metadata header may only comprise the feature set packet with the feature type value. In this case, the feature set packet may be associated with substantially all packets (all packets including waveform data) of the bitstream.

[0121] The metadata header may be generated by analyzing the waveform data to determine the common feature. Analyzing the waveform data is understood as any suitable method for determining a specific condition in a part of the waveform data, e.g., an abnormal heartrate for a Dolby International AB October 28, 2025

[0122] D24147 WOOl biomedical waveform or a car crash based on acceleration waveform data. Said conditions may be determined by an algorithm, by a neural network trained to find said conditions and alternatively or additionally by human inspection.

[0123] In addition to obtaining the bitstream, auxiliary data may be received. Auxiliary data may be understood as any data generated in connection with the waveform data, e.g., by the sensor generating the waveform data. Auxiliary data may be static data, e.g., a sensor type of the sensor that generated the waveform data, or may be dynamic data, e.g., auxiliary measurement data. The auxiliary measurement data may be any data generated by the sensor in connection with generating the waveform data, e.g., a time stamp, a temperature, a location, an elevation, a humidity and an orientation. The dynamic data may have a slow change rate in comparison to the waveform data. In addition to the waveform data, the auxiliary data may be used additionally or alternatively for determining the common feature. For example, a location signal may help to identify an accident condition in acceleration waveform data.

[0124] Inserting the metadata header into the bitstream may be performed in different ways. In a first implementation, the metadata header is inserted in front of the number of coded packets (the subset of coded packets) the metadata header is associated with, i.e., the metadata header may be a packet different from the coded packets the metadata header is associated with. In a second implementation, the metadata header may be inserted into a first packet of the number of coded packets the metadata header is associated with. The first packet is understood as the first packet in a decoding or reading direction of the bitstream. Therefore, the metadata header is inserted as a header of a single packet. The header of the coded packet may be read without any decoding operation of the payload (i.e., the encoded waveform data).

[0125] In the implementation in which the metadata header includes the feature set packet and one or more feature packets, the feature set packet may be inserted at a start of the bitstream, if the feature set packet does not already exist. Further, the one or more feature packets may be inserted in front of the one or more coded packets with which they are associated with. For each inserted feature packet, the content of the feature set packet may be updated, i.e., a feature type value, a length value and a feature start value may be added for each inserted feature packet.

[0126] For example, a medical expert (or an algorithm or a trained neural network) may analyze a recorded waveform signal with a duration of 3 hours and determines that a 20 second portion of the signal corresponds to a medical condition, e.g., a heart disease. In this case, an individual Dolby International AB October 28, 2025

[0127] D24147 WOOl string or a predefined value may be added as feature type value to the feature set packet. The feature start value and the length value may be added automatically based on the determined 20 second portion. Additionally, the feature packet may be added to the bitstream (i.e. leading the coded packets corresponding to the 20 second portion of the waveform signal) and a start time of the 20 second portion may be included in the feature packet as a timestamp.

[0128] Later, e.g., at the extraction stage, another medical expert (or an algorithm or a trained neural network) may be able to immediately access the 20 second portion by using the information in the feature set packet and the feature packet, i.e., the 20 second portion may be decoded from the bitstream without touching the remaining portions of the bitstream and without any search effort.

[0129] In the implementation in which the metadata header only includes the feature set packet, the feature set packet may be inserted at the start of the bitstream, if not already existing, and the feature type value may be set in the feature set packet depending on the common feature of the coded packets in the bitstream.

[0130] The feature set packet may indicate the feature type value in different ways and may use different formats for the feature type value. For example, the feature type value may be directly included in the feature set packet. Alternatively, the feature set packet may point to a location of the feature type value, for example to a dedicated annotation channel of the bitstream. The feature type value may be an individual string, e.g., a string typed by a user. Alternatively, the feature type value may be fixed indices corresponding to a table of predefined strings, e.g., a table with a number of predefined medical conditions for a certain signal (waveform) type.

[0131] For enabling feature annotation during real-time processing of the bitstream, a feature may be flagged during real-time processing, e.g., by adding the feature and a flag to segment metadata that is positioned at the end of each segment of the bitstream. After real-time processing of the bitstream, the segment metadata may be read and the feature may be added to the bitstream by using the feature set packet and the feature packet as described above.

[0132] Inserting the metadata header may also be understood as a form of multiplexing, i.e., multiplexing the existing bitstream with the metadata header.

[0133] The metadata header may be inserted by a device comprising an encoder, e.g., a smartwatch. Alternatively, the metadata header may be inserted into the bitstream by a device independent from the encoder, e.g., a server receiving the bitstream from a device that generated the bitstream. Dolby International AB October 28, 2025

[0134] D24147 WOOl

[0135] The metadata header may not be encoded or may use a light codec, i.e., a codec for which decoding complexity is low. By inserting a metadata header into the bitstream that can be independently read without any decoding of the coded packets comprising the waveform data, large data sets of waveform data can be easily processed. For example, a medical practitioner may be able to inspect biomedical data efficiently, as relevant parts may already be marked by the metadata header. Additionally, automatic processing for collecting data for machine learning may also be simplified and more efficient, as relevant parts of the data can be identified without decoding the data first and may even be used as input for a neural network suitable for operating on encoded waveform data.

[0136] Multiple metadata headers may be inserted into the bitstream. Each metadata header may be associated with a subset of coded packets in the bitstream. The multiple subsets may be disjunct, may be overlapping, or a second subset may be a subset of a first subset.

[0137] In optional step SI 03, the combined bitstream, i.e., the bitstream comprising the one or more coded packets and the metadata header may be provided for further processing. For example, the combined bitstream may be stored on a non-volatile storage or may be transmitted. Then, the combined bitstream may be used as specified above.

[0138] Fig. 2 depicts a flowchart according to a first example method 200 for obtaining the bitstream.

[0139] In step S201, the waveform data is received. The waveform data may be received from a sensor generating the waveform data. Alternatively, the waveform data may be received from a device connected to a sensor. The waveform data may be raw measurement data of a sensor, i.e., measurement data without any further processing applied to the measurement data.

[0140] In step S202, the waveform data is encoded to generate the bitstream. In particular, any suitable waveform encoder may be used to encode the waveform data. Then, the encoded waveform data may be packaged in coded packets of equal or variable length to generate the bitstream.

[0141] Fig. 3 schematically illustrates an example for inserting metadata at a device with an encoder. A first sensor and a second sensor may generate two correlated waveforms, e.g. a PPG signal and a ECG signal. Additionally, auxiliary data is received, e.g., static data from a device that comprises sensor 1 and sensor 2. Therefore, a condition for a time segment of the waveform data may be determined based on the waveform data of the first sensor, the waveform data of the second sensor, and the auxiliary data. When a condition out of a predefined number of Dolby International AB October 28, 2025

[0142] D24147 WOOl conditions / common features is determined for a particular time segment of the waveform data a corresponding metadata header is generated and multiplexed / inserted at a position in the bitstream, e.g., the encoded waveform data of the first sensor and the second sensor, that is indicative of the start of the time segment. The metadata header may be associated with data packets corresponding to the waveform data of the first sensor, data packets corresponding to the waveform data of the second sensor, or both. The combined bitstream may then be transmitted or stored for further processing.

[0143] Fig. 4 schematically illustrates another example for inserting metadata at a device with an encoder. In this example waveform data is generated by a first sensor and the first sensor additionally outputs dynamic data, i.e., data varying over time, but with a slow change rate compared to the waveform data. Both the waveform data and the dynamic data may be used to determine the condition / common feature in a time segment of the waveform data, while only the waveform data may be encoded in the bitstream. Then the metadata header comprising the common feature may be generated and multiplexed with the encoded waveform data.

[0144] Fig. 5 depicts a flowchart according to a second example method 300 for obtaining the bitstream.

[0145] In step S301, the bitstream is received, i.e., a bitstream with encoded waveform data is received.

[0146] To be able to annotate the bitstream with the metadata header, the one or more coded packets in the bitstream may be either analyzed directly to determine the common feature or the encoded waveform data may be first decoded in optional step S302 and the decoded waveform data may be analyzed to determine the common feature. Decoding is understood as decoding the encoded waveform data in order to be able to analyze the waveform data for a specific condition common to a time segment of the waveform data. Analyzing the encoded waveform data directly may be based on a neural network suitable for operating on encoded waveform data.

[0147] An example for inserting a metadata header into a bitstream when the bitstream is received is depicted in Fig. 6. The bitstream may first be decoded by a suitable decoder. The decoded waveform data may then be analyzed for the common feature in a time segment of the waveform data. The metadata header may then be generated and comprises the common feature. In a multiplexing step, the metadata header is inserted in the received bitstream to generate the combined bitstream. Dolby International AB October 28, 2025

[0148] D24147 WOOl

[0149] In Figs. 7A and B, examples for a structure of the combined bitstream are illustrated, i.e. the structure of the bitstream after inserting one or more metadata headers as separate packets.

[0150] Fig. 7A depicts a bitstream example with a single metadata header. In this specific case, the metadata header is associated with 4 coded packets that follow in a decoding / reading direction of the bitstream. The coded packets associated with a metadata header may be denoted as a segment or a subset of coded packets in the bitstream.

[0151] Fig. 7B depicts an example with multiple metadata headers, i.e. metadata header 1 and metadata header 2. Two following coded packets are associated with metadata header 1, while four following coded packets are associated with metadata header 2. While this example depicts two disjunct segments / subsets of coded packets, the association functionality of the metadata headers is not restricted to disjunct segments / subsets. The segments / subsets may also be partially overlapping or one subset may be a subset of a second subset.

[0152] Fig. 8 depicts an example for a metadata header comprising a feature set packet and a feature packet. In this example, two packets are associated with the feature packet, and the corresponding feature type value, length value and feature start value are added to the feature set packet.

[0153] The bitstream may also comprise a configuration header. Contrary to the metadata header, the configuration header may always be the first packet in the bitstream in a decoding / reading order and the content may apply to all coded packets of the bitstream. The configuration header may comprise a signal type value indicative of a signal type and / or a sampling rate of data of all coded packets. The configuration header may further comprise a packet length of the coded packets. The packet length may indicate a fixed packet length or details of a variability of the packet length.

[0154] Data extraction based on the metadata header

[0155] Fig. 9 depicts a flowchart of a method 400 for extracting a subset of data from a combined bitstream.

[0156] In step S401, a combined bitstream is received. The combined bitstream comprises a plurality of coded packets and one or more metadata headers, each associated with a subset of the plurality of coded packets. For generation and the general format of the combined bitstream and the metadata headers it is referred to the description related to Figs. 1 to 8. Details already described with reference to these figures will not be repeated in the following description. Dolby International AB October 28, 2025

[0157] D24147 WOOl

[0158] The device receiving the combined bitstream may comprise a decoder for decoding coded packets and for reading the metadata headers in the bitstream. The combined bitstream may be received by loading it from a local memory or may be received from another device, e.g., from a server.

[0159] In step S402, a subset of the plurality of coded packets is extracted based on the associated metadata header. In particular, a receiver device may scan (without decoding) the combined bitstream for metadata headers. Then the content of the metadata headers may be read. In a next step, the content of the metadata header may be compared to a condition. A condition may be set by a medical practitioner, e.g., a medical practitioner may be interested in data related to a stroke. Alternatively, a condition comparison may be used to automatically find suitable training data for a neural network.

[0160] If a manual and / or automated comparison leads to a positive result, i.e. a specific condition is found in a metadata header, the coded packets associated with the metadata header are extracted. Notably, only the coded packets associated with the metadata header are extracted and the remaining bitstream is ignored. Thereby, a data extraction process can be efficiently implemented. Optionally, the extracted coded packets are decoded to retrieve decoded waveform data.

[0161] For the implementation in which the metadata header comprises a feature set packet and one or more feature packets, only the feature set packet at the beginning of the bitstream may be queried for a specific condition, i.e., by comparing the condition to each feature type value in the feature set packet. If a feature type value corresponding to the condition is found, a decoder may directly jump the corresponding feature packet (i.e., based on the feature start value) and decode the relevant coded packets (e.g., the subset of coded packets indicated by the length value or the subset of coded packets indicated by two feature packets). Additionally, timing data may be extracted from the timestamp in the feature packet, which may be used for analyzing the waveform data corresponding to the decoded packets. The timestamp may indicate time information of a first sample in time of the waveform data corresponding the number of coded packets (subset of coded packets) associated with a feature packet. Alternatively, the timestamp may indicate time information for an arbitrary sample of the waveform data and may also indicate a position of the sample in the waveform data, e.g., a number of the sample in the waveform data. Dolby International AB October 28, 2025

[0162] D24147 WOOl

[0163] For details regarding the waveform data, it is referred to the description of Figs. 1 to 8.

[0164] In optional step S403, the extracted coded packets may be provided for further processing. The further processing may comprise analyzing the decoded waveform data (i.e., if the extracted coded packets have been decoded) or using the extracted coded packets for training or inference of a neural network. If the extracted coded packets have not been decoded, a neural network suitable for processing encoded waveform data may be used.

[0165] Further, the method may include the removal of one or more of the metadata headers. For example, after analyzing the decoded waveform data, it may be concluded that the condition in the corresponding metadata header was inaccurate. Therefore, the metadata header may be removed to improve the accuracy of the metadata annotating the waveform data encoded in the combined bitstream. For the implementation in which the metadata header comprises the feature set packet and the feature packet, removing a metadata header may comprise removing the respective feature packet and removing the feature type value (and any other optional value corresponding to feature packet) in the feature set packet.

[0166] Fig. 10 depicts an example for extracting a subset of coded packets from a bitstream. The combined bitstream is received and forwarded to a module for metadata header extraction and to a core decoder for decoding the coded packets. Then the extracted metadata headers are analyzed for one or more conditions. If the condition comparison returns a positive result, a decoding instruction will be generated. The decoding instruction may instruct the core decoder to only decode the coded packets that are associated with the metadata headers for which the condition comparison returned a positive result. Then, the core decoder may output the decoded waveform data.

[0167] Format of the metadata header

[0168] In the following a detailed example for a format of the combined bitstream including the coded packets and the metadata header will be provided. The format is intended for a metadata header that is inserted as part of a first coded packet of the number of packets (the subset of packets) the metadata header is associated with or for a metadata header transported in a separate dedicated packet (or multiple separate dedicated packets). The specific example should however not be Dolby International AB October 28, 2025 D24147 WOOl construed to limit the subject-matter of the invention. Other formats for the combined bitstream may be used, depending on the implementation needs.

[0169] Basic Syntax

[0170] Tables 1 to 2 define an example of the general bitstream syntax, i.e., each packet in the bitstream may be defined by its type (msStreamPacketType), its label (msStreamPacketLabel), its length (msStreamPacketLength) and the payload (msStreamPacketPayload). Table 2 represents an example for allocating bits. Other bit allocations or other names for the variables may also be possible.

[0171] Table 1

[0172] Table 2 Dolby International AB October 28, 2025 D24147 WOOl msStreamPacketLabel For values of ‘ 1’ and higher, this element provides an indication of which packets in a stream belong together (so called sub-streams). In addition, packets with msStreamPacketLabel set to a value of ‘0’ apply to all sub-streams. msStreamPacketLength This element indicates the length of the msStreamPacketPayload() in Bytes. msStreamPacketPayload() The payload for the actual msStreamPacket. It consists of 1 or more payload frames.

[0173] Table 3 lists examples of different possible packet types in the bitstream, while Table 4 lists examples of the corresponding values. It is noted that only the packet type MS FRAME (grey marking) and optionally MS FEATURE may be needed for implementing the insertion of metadata, as packets of the packet type MS FRAME comprise the encoded waveform data and packets of the packet type MS FEATURE may comprise the metadata header, if the metadata is transported as a separate packet. Other packet types may be optional depending on the implementation needs. It is further noted that the list of packet types is not exhaustive and may be extended if needed. The association of value and packet type in Table 4 may also represent merely one option out of several possible mappings.

[0174] Table 3 Dolby International AB October 28, 2025

[0175] D24147 WOOl

[0176] Table 4 Dolby International AB October 28, 2025

[0177] D24147 WOOl

[0178] MS FRAME Syntax

[0179] Table 5 includes an example syntax for a packet of the type msFrame, i.e., the packet including the encoded waveform data. Each packet may define the signal type (msSignalType) of the payload data of the packet. An alternative syntax for msFrame is shown in Table 6. Table 8 provides a non-exhaustive list of examples of signal types in the biomedical context. The condition or common feature of a subset of packets may be set by the variable msFeatureType. msFeatureType may indicate the condition or common feature. If the packet indicates a signal type, msFeatureType may also vary depending on the signal type. Example conditions / common features and their corresponding values are listed in Tables 9 to 11, in the biomedical context. In addition, the packet may also indicate a number of packets which are associated with the common feature of msFeatureType. This may be accomplished by using the variables msSegmentStart and msFeatureSegmentLen . Further, the packet may comprise a flag msHasFeature to indicate that the payload of the packet has a feature defined by msFeatureType. Thereby, a device receiving the bitstream may be able to scan packets for the flag msHasFeature in order to investigate the feature defined by msFeatureType. Then, only the packets with a feature of interest may be decoded for further investigation or further processing.

[0180] Table 5 Dolby International AB October 28, 2025

[0181] D24147 WOOl Dolby International AB October 28, 2025

[0182] D24147 WOOl

[0183] Table 6

[0184] Additionally, if a dedicated packet is preferred to identify a feature, a new packet type can be introduced, e.g., MS FEATURE. This packet shall be inserted just prior to the msFeatureSegm entStart frame. An example syntax for this packet type is provided in Table 7.

[0185] Table 7

[0186] Table 8 Dolby International AB October 28, 2025 D24147 WOOl

[0187] List of variables msIndependentFrame Shall be set to 1 if the current frame is decodable without any additional information. msSignalType Indicates which type of signal the coded data is for. getLength() Calculates the payload segment length in samples. msNumFramesPerSegment Number of payload frames carried by an MS_FRAME payload

[0188] (segment). msSignalECG Coded Electrocardiography (ECG) data. msSignalEEG Coded Electroencephalography (EEG) data. msSignalEMG Coded Electromyography (EMG) data. msSignalPPG Coded Photopl ethy smogram (PPG) data. msHasFeature Indicates that this frame has data including a certain feature of interest. The flag may span various frames. msFeatureType Indicates a certain types of features of the signal. msNumFeatures Indicates the number of features available in the bitstream associated with msSignalType and msFeatureType. msF eatureSegment Indicates the presence of a feature segment associated with the feature msFeatureType. msSegmentStart Indicates the frame index of the start of a feature segment. The index is referring to the frame indexing within an MS FRAME segment of msNumFramesPerSegment payload frames. msF eatureSegmentLen Indicates the length of a feature segment in number of payload frames starting from msFeatur eSegmentStart. Dolby International AB October 28, 2025 D24147 WOOl

[0189] Table 9

[0190] Table 10

[0191] Table 11

[0192] Alternative Syntax

[0193] In the following, an alternative syntax for implementing the metadata header will be presented. In particular, the alternative syntax may be used if the metadata header comprises the feature set packet and one or more feature packets. Dolby International AB October 28, 2025

[0194] D24147 WOOl

[0195] Table 12 defines an example of a packet header, i.e., each packet in the bitstream may be defined by its type (stream_packet_type), its label (stream_packet_label) and its length (stream_packet_length). Depending on the stream_packet_type in the header, a packet may include different payloads.

[0196] Table 12

[0197] The following descriptors specify the parsing process of each syntax element:

[0198] - ae(v): context-adaptive arithmetic entropy-coded syntax element.

[0199] - b(8): byte having any pattern of bit string (8 bits).

[0200] - f(n): fixed-pattern bit string using n bits written (from left to right) with the left bit first.

[0201] - i(n): signed integer using n bits. When n is "v" in the syntax table, the number of bits varies in a manner dependent on the value of other syntax elements.

[0202] - se(v): signed integer O-th order Exp-Golomb-coded syntax element with the left bit first.

[0203] - st(v): null-terminated string encoded as universal coded character set (UCS) transmission format-8 (UTF-8) characters as specified in ISO / IEC 10646.

[0204] - u(n): unsigned integer using n bits. When n is "v" in the syntax table, the number of bits varies in a manner dependent on the value of other syntax elements.

[0205] - ue(v): unsigned integer O-th order Exp-Golomb-coded syntax element with the left bit first.

[0206] - ev(k,n,m): unsigned integer coded using escaped values. stream_packet_type Specifies the stream packet type, i.e., the type of RBSP data structure contained in the stream packet as specified in Table 13. Dolby International AB October 28, 2025

[0207] D24147 WOOl stream packet label Specifies a sub-stream indication. For values of 1 and higher, this element provides an indication of which packets in a stream belong together (so called sub-streams). In addition, packets with stream_packet_label set to a value of 0 apply to all sub-streams. stream packet length Indicates the length of the stream_packet_payload in bytes. It specifies the number pf RBSP bytes in the stream packet.

[0208] Table 13 lists examples of different possible packet types in the bitstream. It is noted that only the packet types IF SPT, DF SPT, FEATURE SPT and TIMESTAMP SPT (grey marking) may be needed for implementing feature annotation and feature extraction. Packet type IF SPT and DF SPT may comprise the encoded waveform data. Further, packet type TIMESTAMP SPT may correspond to the feature packet, while packet type FEATURE SPT may correspond to the feature set packet. For marking a feature in real-time, a segment containing the feature may be marked by storing the feature in segment metadata at the end of a segment. In this case, the packet type SEGMENT SPT may be needed. After real-time processing of the bitstream, the feature may also be marked by using the packet types TIMESTAMP SPT and FEATURE SPT. Other packet types may be optional depending on the implementation needs. It is further noted that the list of packet types is not exhaustive and may be extended if needed.

[0209] Table 13 Dolby International AB October 28, 2025

[0210] D24147 WOOl time stamp rbsp

[0211] An example of syntax for the timestamp is provided in Table 14, while examples of different time schemes and the associated values are defined in Table 15. Further, different timing use cases are defined in Table 16. Dolby International AB October 28, 2025 D24147 WOOl

[0212] Table 14 Dolby International AB October 28, 2025

[0213] D24147 WOOl

[0214] Table 15

[0215] Table 16

[0216] The timestamp shall be used for, but not limited to, the following cases:

[0217] • Indicating the timing information related to the generation of the sample of the signals (acqui siti on / recording)

[0218] • Indicating the timing information related to the generation of coded data (encoding time)

[0219] • Indicating the true signal length or period triggered by an event (e.g., in the presence of discontinuity triggered by an encoder event due to sensor interruption, displacement or restart)

[0220] • Enabling signal alignment across multiple channels and signal types to compensate any drifts.

[0221] Note that the timestamp insertion into the bitstream can occur in both the encoder (signal input) and bitstream input sides.

[0222] List of Variables ts wavefor m par am eter s et id Dolby International AB October 28, 2025

[0223] D24147 WOOl specifies the value of wps_waveform_parameter_set_id for the WPS in use. ts channel group id identifies the channel group to which the current timestamp belongs. When ts channel group id is not present, it is inferred to be equal to 0. A channel group may be used to transport signals of the same waveform type and sampling rate but with different parameters (e.g., coding parameters). ts type indicates the timestamp use case as specified in Table 16. ts tim e idx flag shall be set to 1 if a timestamp indexing by means of ts time idx is desired. ts time idx indicates the unique index of the timestamp packet related to feature set rbsp. ts time type indicates the time type as specified in Error! Reference source not found.15. ts offset type flag indicates the unit of ts time offset value. Shall be set to ‘0’ if the unit is miliseconds. Shall be set to ‘ 1 ’ if the unit is indicating the exact sample index. The desired floating-point time unit resolution in seconds shall be obtained using the underlying signal sampling frequency. ts time long is counted in seconds and the count starts on January 1st, 2025 at 00:00:00 UTC. ts time offset specifies an offset of time, added to ts time long, ts time short or ts_time_uxt, respectively, in unit signaled by ts_offest_type_flag. ts time short in seconds elapsed since last “ts time type = = TIME LONG”- update. ts time uxt specifies the Unix time. It is counted in seconds and the count starts on January 1st, 1970 at 00:00:00 UTC, the Unix epoch. ts time tai is specified according to ISO / IEC 23001-17. Dolby International AB October 28, 2025

[0224] D24147 WO01 ts_status_bits is specified according to the bits synchronization state, timestamp generation failure, timestamp is modified and reserved according to ISO / IEC 23001-17. ts_time_utc specifies the UTC timing information yyyy-mm- ddThh:mm:ss[.xxx]Z, e.g., the Unix epoch is stored as 1970-01- 01T00:00:00.000Z. ts tim e world flag indicates whether the timestamp is indicating a world clock or a

[0225] “relative” one. ts time long relative is counted in seconds and the count starts from the very first sample of the waveform of a coded waveform sequence (bitstream). ts_time_offset_relative specifies an offset of time, added to ts time long relative, in unit signaled by ts_offset_type_flag.

[0226] The time shall be set in a way that ts time flong, long relative, short, uxt] + ts_time_offset[_relative] indicates the time. If ts offset type flag is set to ‘O’, the indicated time is (1000 * ts time f. . . ] + ts time offsetf. . . ]) in miliseconds. The uniquely associated sample index shall be obtained by ( floor( 0.5 + time * sampling ^frequency / 1000 ) ). If ts offset type flag is set to T, the indicated time shall be calculated as (ts time f. . .] + ts time offsetf. . .] / sampling ^frequency) in seconds.

[0227] The time referring to the waveform indicates when the sample of following IF SPT or DF SPT with the same stream_packet_label has been recorded. Setting the stream_packet_label to ‘0’ shall indicate a timing information applied to all sub-streams. feature set rbsp

[0228] Table 17 shows the syntax for a feature set packet, while Table 18 specifies different feature annotation types, and Tables 19 to 21 provide examples for feature types if the annotation type is predefined (ft_feature_annotation_type=3 in Table 18). A combination of the variables ft feature annotation type and ft feature type enum (in combination with the signal type) may correspond to the feature type value as defined in the general description. If ft_feature_annotation_type=3, the feature type value may be directly extractable from the feature set packet by accessing a predefined table. For ft feature annotation type ={0,1 }, the feature Dolby International AB October 28, 2025 D24147 WOOl type value may correspond to an individual string (i.e., the string is not predefined), which has to be read from the feature set packet. The difference being that the value ‘0’ indicates that the feature type value is extracted from the specified string in the feature set packet and the value ‘ 1’ points to the location (e.g., path to a text file or an http site) outside of the bitstream, where the associated information on the feature type value is stored. For ft feature annotation type =2, the feature type value may be comprised in a dedicated channel of the bitstream, i.e., an annotation channel.

[0229] Table 17 Dolby International AB October 28, 2025

[0230] D24147 WOOl

[0231] Table 18

[0232] Table 19

[0233] Table 20

[0234] Table 21 Dolby International AB October 28, 2025 D24147 WOOl

[0235] List of Variables ft waveform parameter set id specifies the value of wps_waveform_parameter_set_id for the WPS in use. ft channel group id identifies the channel group to which the current feature set belongs. When ft channel group id is not present, it is inferred to be equal to 0. ft_num_features the number of features available in the bitstream. ft feature annotation type specifies the desired feature annotation type as indicated in Error! Reference source not found.. ft_annotation_str specifies an arbitrary feature type annotation string. ft_annotation_uri specifies the feature type annotation string in URI with syntax and semantics as specified in IETF Internet Standard 66. ft annotation channel id indicates the annotation channel index of the specified annotation channel ID (ac annotation channel id). Together with ft annotation channel wps id, they shall point to the annotation stored in the annotation channel data of the specified annotati on channel . ft_feature_type_enum indicates a certain type of features of the signal as indicated in the Tables 19 to 21 for different signal types. feat_extract() function specifies the feature type value after processing the input syntax elements ft annotation str, ft annotation uri, ft_annotation_channel_waveform_parameter_set_id, ft annotation channel id and ft feature type enum. ft feature marking present flag indicates the presence of a feature marking in the bitstream Dolby International AB October 28, 2025 D24147 WOOl associated with a feature. If set to ‘ 1’, the corresponding ft feature start and ft feature length denoting a feature segment, shall be set accordingly. The segments may overlap, or form disjunct segments or may be a subset of other segments. ft_feature_start indicates the timestamp index ts time idx of the start of a feature marking. ft feature length indicates the timestamp index ts time idx denoting the end of a feature marking defining the feature length. segment metadata rbsp

[0236] Table 22 may show the syntax for the segment metadata.

[0237] Table 22 Dolby International AB October 28, 2025

[0238] D24147 WOOl Dolby International AB October 28, 2025

[0239] D24147 WOOl

[0240] Segment metadata shall be used to obtain information on the coded data payload frame sizes (IF SPT, DF SPT) and distortion measure per bitstream segment.

[0241] • By default, a segment refers to the whole coded bitstream

[0242] • A segment is also defined as a single or multiple of random access intervals. A random access interval consists of a single or multiple of frame sequences. An frame sequence is a sequence of one IF SPT followed by zero or more DF SPT frames. In this case, a segment may refer to any partition resulting from the whole waveform partitioning, or it may refer to any arbitrary waveform excerpt based on a given user input or a particular waveform feature. Note a bitstream can be configured comprising only IF SPT frames.

[0243] The segment metadata packet is inserted at the end of each segment.

[0244] The distortion measure information shall be used for, but not limited to, the following cases:

[0245] • Indicating or classifying the segment’s coding behavior, i.e., lossless, near lossless (small distortion) or lossy

[0246] • Deriving other distortion measure metrics, e.g., percentage root mean square distortion (PRD), channel-normalized percentage root mean square distortion (CPRD)

[0247] • Enabling assessment of distortion at the decoder side without having access to the original signals. This use case is related to retrieval of lossy coded segments from a dataset by classifying and filtering of the segments in the context of further post-processing such as Al-based training

[0248] • Transcoding (encoding of decoded bitstream) from lossless to lossy or tandem coding. The resulting distortion shall be updated accordingly.

[0249] List of Variables sm channel group parameter set id specifies the value of cgps_channel_group_parameter_set_id for the CGPS in use. Dolby International AB October 28, 2025 D24147 WOOl sm channel group id identifies the channel group to which the current segment metadata belongs. When sm channel group id is not present, it is inferred to be equal to 0. sm has feature flag specifies the presence of a feature within a segment. sm num features minus one plus 1, specifies the number features within a segment. sm feature type specifies the feature type. sm feature segment marking flag indicates the presence of feature marking. sm feature segment start indicates the offset start of a feature marking in samples. sm feature segment length indicates the length of a feature marking in samples. sm payload extension flag shall be set to 1 to indicate the presence of a segment payload extension in the form of concatenated independent_frame_rbsp( ) and zero or more dependent_frame_rbsp( ) payload sequence(s). This utilizes the Golomb / Rice delta encoding syntax elements, i.e., sm_num_frames_per_segment, sm frame size, sm_delta_GR_param, sm abs delta and sm sign delta. In a specific transcoding case, where existing frame sequences (bitstream) are already available for processing, the Golomb / Rice syntax elements are determined by extracting the frame sizes / lengths from the stream_packet_header of respective payload packets. Given the transcoded bitstream, retreiving the original frame sequences is done by assigning a proper stream_packet_header (type, label, length) to individual payload rbsp, utilizing syntax elements within sm segment stat flag and Dolby International AB October 28, 2025 D24147 WOOl sm_payload_extension_flag. In all cases, the bitstream decoding to output the waveform shall be supported. sm_num_frames_per_sequence specifies the number of frames in a frame sequence. sm segment stat flag indicates whether an information on the frame sizes within a segment is present or not. sm num frames per segment indicates the number of payload frames carried in a segment. sm_frame_size[0] indicates the size / length of the first (n=0, IF SPT) coded data frame in the segment. Subsequent frame sizes (n>0) are encoded using the Golomb / Rice delta encoding method. sm delta GR param specifies the parameter that controls the Golomb / Rice delta encoding of subsequent sm frame sizefn]. It uses the fixed-length (FL) binarization process having cMax = 15, see clause Error! Reference source not found.. sm abs delta for a given iteration n, specifies the encoded absolute value of the difference between the n-th and (n-l)-th sm frame size values (encoded absolute delta value). It uses the un-truncated Rice (UTR) binarization process having cRiceParam = sm_delta_GR_param, see clause Error! Reference source not found.. The function decode(sm_abs_delta, sm_delta_GR_param) retrieves the symbolVal which is the absolute delta value, abs delta. Dolby International AB October 28, 2025 D24147 WO01 sm sign delta specifies the sign of abs delta. It uses the fixed- length (FL) binarization process having cMax = 1, see clause Error! Reference source not found.. sm distortion measures per channel flag indicates whether the per-channel distortion measure metadata is present or not in the bitstream. This shall indicate the coded data coding mode, a lossless codec shall set this to ‘O’. sm_num_distortion_measures_per_channel indicates the number of other per-channel distortion measures calculated for the segment. sm variance indicates the signal variance measured per channel in dB unit, 10 * loglO (variance). sm squared error indicates the signal squared error measured per channel in dB unit, 10 * log 10 (squared error). sm distortion measure type indicates other types of per-channel distortion measure calculated in a segment, e.g., maximum absolute error (MAE), maximum amplitude error (MAX), including it’ s unit. sm distortion measure indicates the per-channel distortion measure value. sm distortion measures in cg flag shall be set to zero if the measure of distortion per- channel group is not desired. This measure of distortion is active by default. sm num distortion measures in cg indicates the number of other per-channel group distortion measures calculated for the segment. sm variance cg indicates the signal variance measured per-channel group in dB unit, 10 * log 10 (channel group variance). sm squared error cg indicates the signal squared error measured per- channel group in dB unit, 10 * log 10 (channel group squared error). Dolby International AB October 28, 2025

[0250] D24147 WOOl sm distortion measure type cg indicates other types of per-channel group distortion measure calculated in a segment, e.g., maximum absolute error (MAE), maximum amplitude error (MAX), including it’ s unit. sm distortion measure cg indicates the per-channel group distortion measure value.

[0251] While methods of inserting metadata into a bitstream and using the metadata to selectively decode the bitstream have been described above, the disclosure likewise relates to corresponding apparatus, and the like. An embodiment providing such apparatus will be described next with reference to Fig. 11

[0252] As shown in Fig. 11, the apparatus 500 includes a processor 501 and memory 502. The memory 502 is configured to store program code. The processor 501 is configured to run instructions in the program code, so that the apparatus 500 performs the metadata insertion method or the selective decoding method in any one of the above embodiments and implementations. The processor 501 may also receive, among others, suitable input data (e.g., waveform data, auxiliary data, the bitstream or the combined bitstream) depending on use cases and / or implementations. The processor 501 may be adapted to carry out the methods / techniques (e.g., methods 100, 200, 300 and 400 as illustrated above with reference to Figs. 1, 2, 5 and 9, respectively) described throughout the present disclosure and to generate corresponding output data (e.g., a combined bitstream or decoded waveform data), depending on use cases and / or implementations. The apparatus may be part of a device comprising or connected to sensors, e.g., smart watch. The apparatus may further be part of a general-purpose computer, a server. Further, the apparatus may comprise the encoder and / or the decoder for encoding / decoding the waveform data.

[0253] Fig. 12 illustrates a transmission device 600. Transmission device 600 may comprise a variety of units, including a transmitter unit and / or a receiver unit and / or a coding unit. The coding unit may be composed of at least a processor configured to perform encoding and / or decoding processing. The coding unit may encode and / or decode data in accordance with the methods (e.g., methods 100, 200, 300 and 400 as illustrated above with reference to Figs. 1, 2, 5 and 9, respectively) throughout the present disclosure. Dolby International AB October 28, 2025

[0254] D24147 WOOl

[0255] Transmission device 600 may transmit the coded data in the form of a bitstream to a device or to a digital storage medium or through, for example, a network in the form of a file or streaming. The digital storage medium may include various storage mediums such as USB-C, USB, SD, CD, DVD, Blu-ray, HDD, SSD, and equivalent technologies. The digital storage medium may also be part of the coding unit of transmitter device 600.

[0256] Transmission device 600 may include an element for generating the bitstream and / or a media file and may include an element for transmission, e.g., through a variety of mediums (Bluetooth, broadcast / communication networks, Internet technologies and equivalents). The transmission may be implemented using a variety of technologies such as, for example, RF, light waves, infrared, Bluetooth, WiFi, and / or acoustic transmission devices.

[0257] Aspects of the systems described herein may be implemented in an appropriate computer-based sound processing network environment for processing digital or digitized audio files. Portions of the adaptive audio system may include one or more networks that comprise any desired number of individual machines, including one or more routers (not shown) that serve to buffer and route the data transmitted among the computers. Such a network may be built on various different network protocols, and may be the Internet, a Wide Area Network (WAN), a Local Area Network (LAN), or any combination thereof.

[0258] One or more of the components, blocks, processes or other functional components may be implemented through a computer program that controls execution of a processor-based computing device of the system. It should also be noted that the various functions disclosed herein may be described using any number of combinations of hardware, firmware, and / or as data and / or instructions embodied in various machine-readable or computer-readable media, in terms of their behavioral, register transfer, logic component, and / or other characteristics. Computer- readable media in which such formatted data and / or instructions may be embodied include, but are not limited to, physical (non-transitory), non-volatile storage media in various forms, such as optical, magnetic or semiconductor storage media.

[0259] While one or more implementations have been described by way of example and in terms of the specific embodiments, it is to be understood that one or more implementations are not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the Dolby International AB October 28, 2025

[0260] D24147 WOOl appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.

[0261] A computing device implementing the techniques described above can have the following example architecture. Other architectures are possible, including architectures with more or fewer components. In some implementations, the example architecture includes one or more processors (e.g., dual-core Intel® Xeon® Processors), one or more output devices (e.g., LCD), one or more network interfaces, one or more input devices (e.g., mouse, keyboard, touch-sensitive display) and one or more computer-readable mediums (e.g., RAM, ROM, SDRAM, hard disk, optical disk, flash memory, etc.). These components can exchange communications and data over one or more communication channels (e.g., buses), which can utilize various hardware and software for facilitating the transfer of data and control signals between components.

[0262] The term “computer-readable medium” refers to a medium that participates in providing instructions to processor for execution, including without limitation, non-volatile media (e.g., optical or magnetic disks), volatile media (e.g., memory) and transmission media. Transmission media includes, without limitation, coaxial cables, copper wire and fiber optics.

[0263] Computer-readable medium can further include operating system (e.g., a Linux® operating system), network communication module, audio interface manager, audio processing manager and live content distributor. Operating system can be multi-user, multiprocessing, multitasking, multithreading, real time, etc. Operating system performs basic tasks, including but not limited to: recognizing input from and providing output to network interfaces and / or devices; keeping track and managing files and directories on computer-readable mediums (e.g., memory or a storage device); controlling peripheral devices; and managing traffic on the one or more communication channels. Network communications module includes various components for establishing and maintaining network connections (e.g., software for implementing communication protocols, such as TCP / IP, HTTP, etc.).

[0264] Architecture can be implemented in a parallel processing or peer-to-peer infrastructure or on a single device with one or more processors. Software can include multiple software components or can be a single body of code.

[0265] The described features can be implemented advantageously in one or more computer programs that are executable on a programmable system including at least one programmable processor Dolby International AB October 28, 2025

[0266] D24147 WOOl coupled to receive data and instructions from, and to transmit data and instructions to, a data storage system, at least one input device, and at least one output device. A computer program is a set of instructions that can be used, directly or indirectly, in a computer to perform a certain activity or bring about a certain result. A computer program can be written in any form of programming language (e.g., Objective-C, Java), including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, a browser-based web application, or other unit suitable for use in a computing environment.

[0267] Suitable processors for the execution of a program of instructions include, by way of example, both general and special purpose microprocessors, and the sole processor or one of multiple processors or cores, of any kind of computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memories for storing instructions and data. Generally, a computer will also include, or be operatively coupled to communicate with, one or more mass storage devices for storing data files; such devices include magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and optical disks. Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices; magnetic disks such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, ASICs (application-specific integrated circuits).

[0268] To provide for interaction with a user, the features can be implemented on a computer having a display device such as a CRT (cathode ray tube) or LCD (liquid crystal display) monitor or a retina display device for displaying information to the user. The computer can have a touch surface input device (e.g., a touch screen) or a keyboard and a pointing device such as a mouse or a trackball by which the user can provide input to the computer. The computer can have a voice input device for receiving voice commands from the user.

[0269] The features can be implemented in a computer system that includes a back-end component, such as a data server, or that includes a middleware component, such as an application server or an Internet server, or that includes a front-end component, such as a client computer having a Dolby International AB October 28, 2025

[0270] D24147 WOOl graphical user interface or an Internet browser, or any combination of them. The components of the system can be connected by any form or medium of digital data communication such as a communication network. Examples of communication networks include, e.g., a LAN, a WAN, and the computers and networks forming the Internet.

[0271] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. In some embodiments, a server transmits data (e.g., an HTML page) to a client device (e.g., for purposes of displaying data to and receiving user input from a user interacting with the client device). Data generated at the client device (e.g., a result of the user interaction) can be received from the client device at the server.

[0272] A system of one or more computers can be configured to perform particular actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions.

[0273] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any inventions or of what may be claimed, but rather as descriptions of features specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0274] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be Dolby International AB October 28, 2025

[0275] D24147 WOOl understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0276] Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the present invention discussions utilizing terms such as “processing”, “computing”, “calculating”, “determining”, “analyzing” or the like, refer to the action and / or processes of a computer or computing system, or similar electronic computing devices, that manipulate and / or transform data represented as physical, such as electronic, quantities into other data similarly represented as physical quantities.

[0277] Reference throughout this invention to “one example embodiment”, “some example embodiments” or “an example embodiment” means that a particular feature, structure or characteristic described in connection with the example embodiment is included in at least one example embodiment of the present invention. Thus, appearances of the phrases “in one example embodiment”, “in some example embodiments” or “in an example embodiment” in various places throughout this invention are not necessarily all referring to the same example embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this invention, in one or more example embodiments.

[0278] As used herein, unless otherwise specified the use of the ordinal adjectives “first”, “second”, “third”, etc., to describe a common object, merely indicate that different instances of like objects are being referred to and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[0279] Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted”, “connected”, “supported”, and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings.

[0280] In the claims below and the description herein, any one of the terms comprising, comprised of or which comprises is an open term that means including at least the elements / features that follow, Dolby International AB October 28, 2025

[0281] D24147 WOOl but not excluding others. Thus, the term comprising, when used in the claims, should not be interpreted as being limitative to the means or elements or steps listed thereafter. For example, the scope of the expression a device comprising A and B should not be limited to devices consisting only of elements A and B. Any one of the terms including or which includes or that includes as used herein is also an open term that also means including at least the elements / features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising.

[0282] It should be appreciated that in the above description of example embodiments of the present invention, various features of the present invention are sometimes grouped together in a single example embodiment, Fig., or description thereof for the purpose of streamlining the present invention and aiding in the understanding of one or more of the various inventive aspects. This method of invention, however, is not to be interpreted as reflecting an intention that the claims require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed example embodiment. Thus, the claims following the Description are hereby expressly incorporated into this Description, with each claim standing on its own as a separate example embodiment of this invention.

[0283] Furthermore, while some example embodiments described herein include some but not other features included in other example embodiments, combinations of features of different example embodiments are meant to be within the scope of the present invention, and form different example embodiments, as would be understood by those skilled in the art. For example, in the following claims, any of the claimed example embodiments can be used in any combination.

[0284] In the description provided herein, numerous specific details are set forth. However, it is understood that example embodiments of the present invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0285] Thus, while there has been described what are believed to be the best modes of the present invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the present invention, and it is intended to claim all such changes and modifications as fall within the scope of the present invention. For example, any formulas given above are merely representative of procedures that may be used. Dolby International AB October 28, 2025

[0286] D24147 WOOl

[0287] Functionality may be added or deleted from the block diagrams and operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present disclosure.

[0288] Various aspects and implementations of the present disclosure may also be appreciated from the following enumerated example embodiments (EEEs), which are not claims.

[0289] EEE 1. A method of inserting a metadata header into a bitstream, the method comprising: obtaining the bitstream comprising one or more coded packets of waveform data; and inserting the metadata header into the bitstream to generate a combined bitstream, wherein the metadata header is related to the waveform data.

[0290] EEE 2. The method of EEE 1, wherein obtaining the bitstream comprises: receiving the waveform data; and encoding the waveform data to generate the bitstream.

[0291] EEE 3. The method of EEE 1, wherein obtaining the bitstream comprises receiving the bitstream.

[0292] EEE 4. The method of any previous EEE, wherein the metadata header comprises a feature type value and / or a length value, wherein the length value indicates a number of packets of the one or more coded packets associated with the metadata header and the feature type value comprises a value corresponding to a common feature of the coded packets associated with the metadata header.

[0293] EEE 5. The method of any previous EEE, wherein inserting the metadata header into the bitstream comprises inserting the metadata header at a position related to the number of packets associated with the metadata header.

[0294] EEE 6. The method of EEE 5, wherein the position is in front of the number of packets in a decoding order or reading order of the bitstream or the position is at the end of a segment of the bitstream in a decoding order or reading order of the bitstream, and the metadata header is comprised by a packet different from the number of packets associated with the metadata header.

[0295] EEE 7. The method of EEE 5, wherein the metadata header is part of a first coded packet, in a decoding or reading order of the bitstream, with which the metadata header is associated with. Dolby International AB October 28, 2025

[0296] D24147 WOOl

[0297] EEE 8. The method of any previous EEE, wherein the one or more coded packets are a plurality of coded packets and the metadata header comprises a first metadata header and a second metadata header, wherein the first metadata header is associated with a first subset of the plurality of coded packets and the second metadata header is associated with a second subset of the plurality of coded packets.

[0298] EEE 9. The method of EEE 8, wherein the first subset and the second subset overlap, the first subset and the second subset are disjunct, or the second subset is a subset of the first subset.

[0299] EEE 10. The method of any one of EEEs 1 to 3, wherein the metadata header comprises a feature set packet and a feature packet, wherein the feature set packet indicates a feature type value and / or a feature start value, the feature type value comprises a value corresponding to a common feature of the coded packets associated with the feature packet and the feature start value indicates a position of the feature packet.

[0300] EEE 11. The method of EEE 10, wherein the feature packet comprises a timestamp and the timestamp indicates the starting time of the waveform data corresponding to the one or more coded packets associated with the feature packet.

[0301] EEE 12. The method of EEE 11, wherein the starting time corresponds to a time at which the waveform data has been generated or encoded.

[0302] EEE 13. The method of any one of EEEs 10 to 12, wherein the feature set packet indicates a length value, wherein the length value indicates a number of packets of the one or more coded packets associated with the feature packet or a duration of the waveform data corresponding to the one or more coded packets associated with the feature packet.

[0303] EEE 14. The method of any one of EEEs 10 to 12, wherein the metadata header comprises a second feature packet, wherein the feature packet and the second feature packet together indicate a length of a number of packets of the one or more coded packets associated with the feature packet.

[0304] EEE 15. The method of EEE 14, wherein the second feature packet comprises a timestamp and the timestamp indicates the end time of the waveform data corresponding to the one or more coded packets associated with the feature packet. Dolby International AB October 28, 2025

[0305] D24147 WOOl

[0306] EEE 16. The method of any one EEEs 10 to 15, wherein inserting the metadata header into the bitstream comprises inserting the feature packet at a position related to the number of packets associated with the feature packet and inserting or updating the feature set packet based on the number of packets associated with the feature packet, wherein the feature set packet is located at a starting position of the combined bitstream.

[0307] EEE 17. The method of EEE 16, wherein the position of the feature packet is in front of the number of packets in a decoding order or reading order of the combined bitstream.

[0308] EEE 18. The method of any one EEEs 10 to 17, wherein the one or more coded packets are a plurality of coded packets and the feature packet comprises a first feature packet and a second feature packet, wherein the first feature packet is associated with a first subset of the plurality of coded packets and the second feature packet is associated with a second subset of the plurality of coded packets; and wherein the feature set packet indicates the feature type value and / or the length value and / or the feature start value for each of the first subset of the plurality of coded packets and second subset of the plurality of coded packets.

[0309] EEE 19. The method of EEE 18, wherein the first subset and the second subset overlap, the first subset and the second subset are disjunct, or the second subset is a subset of the first subset.

[0310] EEE 20. The method of any one of EEEs 1 to 3, wherein the metadata header comprises a feature set packet, wherein the feature set packet indicates a feature type value, wherein the feature type value comprises a value corresponding to a common feature of the coded packets; and wherein the coded packets correspond to substantially the whole bitstream.

[0311] EEE 21. The method of any one of EEEs 10 to 20, wherein the feature set packet comprises the feature type value, or an annotation channel of the bitstream comprises the feature type value and the feature set packet points to the feature type value in the annotation channel.

[0312] EEE 22. The method of any one of EEEs 10 to 21, wherein the feature type value comprises a string or a pointer to a predefined string.

[0313] EEE 23. The method of EEE 4 or any one of EEEs 10 to 22 when depending on EEE 2, wherein the common feature is determined based on the waveform data. Dolby International AB October 28, 2025

[0314] D24147 WOOl

[0315] EEE 24. The method of EEEs 4 or any one of EEEs 10 to 22 when depending on EEE 3, wherein the common feature is determined directly on the one or more coded data packets; or wherein the method further comprises decoding the one or more coded packets to obtain the waveform data and determining the common feature based on the waveform data.

[0316] EEE 25. The method of EEEs 4 or any one of EEEs 10 to 24, wherein the common feature is one or more of a plurality of predefined common features.

[0317] EEE 26. The method of EEE 25, wherein the predefined common features indicate a condition associated with part of the waveform data corresponding to the coded packets associated with the metadata header.

[0318] EEE 27. The method of any previous EEE, wherein the waveform data represents continuous measurements by a sensor.

[0319] EEE 28. The method of any previous EEE, wherein the waveform data is biomedical waveform data or waveform data representing mechanical motion.

[0320] EEE 29. The method of EEE 28, wherein the waveform data represents signals by a seismometer or an accelerometer.

[0321] EEE 30. The method of EEE 28, wherein the biomedical waveform data is any one of electrocardiography data, electroencephalography data, electromyography data, electrooculogram data, electroretinogram data, electrogastrogram data or photoplethysmogram data.

[0322] EEE 31. The method of EEE 4 or any one of EEEs 10 to 29, wherein the method further comprises receiving auxiliary data and wherein the common feature is determined based on the auxiliary data.

[0323] EEE 32. The method of EEE 31, wherein the auxiliary data comprises data associated with the generation of the waveform data.

[0324] EEE 33. The method of EEE 31 or 32, wherein the auxiliary data comprises static data or dynamic data.

[0325] EEE 34. The method of EEE 33, wherein the static data comprises a device type or a sensor type. Dolby International AB October 28, 2025

[0326] D24147 WOOl

[0327] EEE 35. The method of EEE 33 or 34, wherein the dynamic data comprises auxiliary measurement data for the waveform data.

[0328] EEE 36. The method of EEE 35, wherein the auxiliary measurement data has a slow change rate in comparison to the waveform data.

[0329] EEE 37. The method of EEE 35 or 36, wherein the auxiliary measurement data is any one of a time stamp, a temperature, a location, an elevation, a humidity and an orientation.

[0330] EEE 38. The method of any previous EEE, wherein the waveform data is multichannel waveform data.

[0331] EEE 39. The method of EEE 2 or any one of EEEs 4 to 38 when depending on EEE 2, wherein encoding the waveform data to generate the bitstream is based on a core encoder for source encoding of the waveform data.

[0332] EEE 40. The method of EEE 38 when depending on EEE 2, wherein encoding the waveform data to generate the bitstream comprises encoding each channel of the multichannel waveform data to generate encoded channel signals and distribute the encoded channel signals into the one or more coded packets to generate the bitstream.

[0333] EEE 41. The method of EEE 2 or any one of EEEs 4 to 39 when depending on EEE 2, wherein encoding the waveform data to generate the bitstream comprises splitting the waveform data based on time and / or frequency and generating the one or more coded packets based on the split waveform data.

[0334] EEE 42. The method of EEE 24 or any one of EEEs 25 to 38 when depending on EEE 24, wherein decoding the one or more coded packets to obtain waveform data is based on a core decoder for source decoding of the one or more coded packets.

[0335] EEE 43. The method of any previous EEE, wherein the metadata header further comprises a label, wherein the label indicates a label of a coded packet with which the metadata header is associated.

[0336] EEE 44. The method of any previous EEE, wherein the method further comprises: inserting a configuration header into the combined bitstream, wherein the configuration header comprises a signal type value indicative of a signal type and / or a sampling rate of data of all one or more coded packets in the combined bitstream. Dolby International AB October 28, 2025

[0337] D24147 WOOl

[0338] EEE 45. The method of EEE 44, wherein the configuration header further comprises a packet length of the one or more coded packets.

[0339] EEE 46. The method of any previous EEE, wherein the method further comprises providing the combined bitstream for further processing.

[0340] EEE 47. The method of EEE 46, wherein the further processing comprises storing the combined bitstream or transmitting the combined bitstream.

[0341] EEE 48. A method of extracting a subset of data from a combined bitstream, the method comprising: receiving the combined bitstream, wherein the combined bitstream comprises a plurality of coded packets corresponding to waveform data and one or more metadata headers, each associated with a subset of the plurality of coded packets; and extracting a subset of the plurality of coded packets based on the associated metadata header.

[0342] EEE 49. The method of EEE 48, wherein each metadata header comprises a feature type value and / or a length value, wherein the length value indicates a number of packets of the plurality of coded packets associated with the metadata header and the feature type value comprises a value corresponding to a common feature of the coded packets associated with the metadata header.

[0343] EEE 50. The method of any one of EEEs 48 to 49, wherein each metadata header is positioned at a position related to the subset of the plurality of packets with which the metadata header is associated.

[0344] EEE 51. The method of EEE 50, wherein the position is in front of the respective subset in a decoding order or reading order of the bitstream, and each metadata header is comprised by a packet different from the subset of the plurality of packets associated with the respective metadata header.

[0345] EEE 52. The method of EEE 50, wherein each metadata header is part of a first coded packet of the respective subset, in a decoding or reading order of the bitstream, with which the respective metadata header is associated with. Dolby International AB October 28, 2025

[0346] D24147 WOOl

[0347] EEE 53. The method of any one of EEEs 48 to 51, wherein the one or more metadata headers comprises a first metadata header and a second metadata header, wherein the first metadata header is associated with a first subset of the plurality of coded packets and the second metadata header is associated with a second subset of the plurality of coded packets.

[0348] EEE 54. The method of EEE 53, wherein the first subset and the second subset overlap, the first subset and the second subset are disjunct, or the second subset is a subset of the first subset.

[0349] EEE 55. The method of EEE 48, wherein the metadata header comprises a feature set packet and a feature packet, wherein the feature set packet comprises a feature type value and / or a feature start value, wherein the feature type value comprises a value corresponding to a common feature of the coded packets associated with the feature packet and the feature start value indicates a position of the feature packet.

[0350] EEE 56. The method of EEE 55, wherein the feature packet comprises a timestamp and the timestamp indicates the starting time of the waveform data corresponding to the one or more coded packets associated with the feature packet.

[0351] EEE 57. The method of EEE 56, wherein the starting time corresponds to a time at which the waveform data has been generated or encoded.

[0352] EEE 58. The method of any one of EEEs 55 to 57, wherein the feature set packet indicates a length value, wherein the length value indicates a number of packets of the one or more coded packets associated with the feature packet or a duration of the waveform data corresponding to the one or more coded packets associated with the feature packet.

[0353] EEE 59. The method of any one of EEEs 55 to 57, wherein the metadata header comprises a second feature packet, wherein the feature packet and the second feature packet together indicate a length of a number of packets of the one or more coded packets associated with the feature packet.

[0354] EEE 60. The method of EEE 59, wherein the second feature packet comprises a timestamp and the timestamp indicates the end time of the waveform data corresponding to the one or more coded packets associated with the feature packet. Dolby International AB October 28, 2025

[0355] D24147 WOOl

[0356] EEE 6E The method of any one of EEEs 55 to 60, wherein the feature packet is positioned at a position related to the number of packets associated with the feature packet and the feature set packet is located at a starting position of the combined bitstream.

[0357] EEE 62. The method of EEE 61, wherein the position of the feature packet is in front of the number of packets in a decoding order or reading order of the combined bitstream.

[0358] EEE 63. The method of any one of EEEs 55 to 62, wherein the one or more coded packets are a plurality of coded packets and the feature packet comprises a first feature packet and a second feature packet, wherein the first feature packet is associated with a first subset of the plurality of coded packets and the second feature packet is associated with a second subset of the plurality of coded packets; and wherein the feature set packet comprises the feature type value and / or the length value and / or the feature start value for each of the first subset of the plurality of coded packets and second subset of the plurality of coded packets.

[0359] EEE 64. The method of EEE 63, wherein the first subset and the second subset overlap, the first subset and the second subset are disjunct, or the second subset is a subset of the first subset.

[0360] EEE 65. The method of EEE 48, wherein the metadata header comprises a feature set packet, wherein the feature set packet comprises a feature type value, wherein the feature type value comprises a value corresponding to a common feature of the coded packets; and wherein the coded packets correspond to substantially the whole bitstream.

[0361] EEE 66. The method of any one of EEEs 55 to 65, wherein the feature set packet comprises the feature type value, or an annotation channel of the bitstream comprises the feature type value and the feature set packet points to the feature type value in the annotation channel.

[0362] EEE 67. The method of any one of EEEs 55 to 66, wherein the feature type value comprises a string or a pointer to a predefined string.

[0363] EEE 68. The method of EEE 49 or any one of EEEs 55 to 67, wherein the common feature is one or more of a plurality of predefined common features.

[0364] EEE 69. The method of EEE 68, wherein the predefined common features indicate a condition associated with part of the waveform data corresponding to the coded packets associated with the metadata header. Dolby International AB October 28, 2025

[0365] D24147 WOOl

[0366] EEE 70. The method of EEE 49 or any one of EEEs 55 to 69, wherein extracting the subset of the plurality of coded packets based on the associated metadata header comprises: determining the subset of the plurality of coded packets based on the common feature in the associated metadata header; solely decoding the subset of the plurality of coded packets to obtain decoded waveform data.

[0367] EEE 71. The method of EEE 70, wherein determining the subset of the plurality of coded packets based on the common feature in the associated metadata header comprises: querying the feature type value in the feature set packet for the common feature; and determining the subset of the plurality of coded packets based on the feature start value and optionally the length value associated with the common feature.

[0368] EEE 72. The method of EEE 71, wherein solely decoding the subset of the plurality of coded packets to obtain decoded waveform data comprises starting decoding at the feature packet associated with the common feature.

[0369] EEE 73. The method of any one of EEEs 70 to 72, wherein solely decoding the subset of the plurality of coded packets to obtain the decoded waveform data is based on a core decoder for source decoding of the subset of the plurality of coded packets.

[0370] EEE 74. The method of any one of EEEs 48 to 73, wherein the waveform data represents continuous measurements by a sensor.

[0371] EEE 75. The method of any one of EEEs 48 to 74, wherein the waveform data is biomedical waveform data or waveform data representing mechanical motion.

[0372] EEE 76. The method of EEE 75, wherein the waveform data represents signals by a seismometer or an accelerometer.

[0373] EEE 77. The method of EEE 75 or 76, wherein the biomedical waveform data is any one of electrocardiography data, electroencephalography data, electromyography data, electrooculogram data, electroretinogram data, electrogastrogram data or photoplethysmogram data. Dolby International AB October 28, 2025

[0374] D24147 WOOl

[0375] EEE 78. The method of any one of EEEs 48 to 77, wherein each metadata header comprises a label, wherein the label indicates a label of a coded packet with which the metadata header is associated.

[0376] EEE 79. The method of any one of EEEs 48 to 78, wherein the combined bitstream further comprises a configuration header, wherein the configuration header comprises a signal type value indicative of a signal type and / or a sampling rate of data of all the plurality of coded packets in the combined bitstream.

[0377] EEE 80. The method of EEE 79, wherein the configuration header further comprises a packet length of the plurality of coded packets.

[0378] EEE 81. The method of any one of EEEs 70 to 73, wherein the method further comprises providing the decoded waveform data for further processing.

[0379] EEE 82. The method of EEE 81, wherein the further processing comprises analyzing the decoded waveform data or using the decoded waveform data for training or inference of a neural network.

[0380] EEE 83. The method according to any one of EEEs 48 to 69, wherein the method further comprises providing the extracted subset of the plurality of coded packets for training or inference of a neural network.

[0381] EEE 84. The method of any one of EEEs 48 to 83, wherein the method further comprises removing the one or more metadata headers from the bitstream.

[0382] EEE 85. An apparatus, comprising a processor and a memory coupled to the processor, wherein the processor is adapted to carry out the method according to any one of EEEs 1 to 84.

[0383] EEE 86. A computer program comprising instructions that, when executed by a processor, cause the processor to carry out the method according to any one of EEEs 1 to 84.

[0384] EEE 87. A computer-readable storage medium storing the computer program according to EEE 86.

Claims

Dolby International AB October 28, 2025 D24147 WOOlCLAIMS1. A method of inserting a metadata header into a bitstream, the method comprising: obtaining the bitstream comprising one or more coded packets of waveform data; and inserting the metadata header into the bitstream to generate a combined bitstream, wherein the metadata header is related to the waveform data; wherein the metadata header indicates a feature type value and the feature type value comprises a value corresponding to a common feature of a subset of the one or more coded packets associated with the metadata header.

2. The method of any previous claim, wherein the metadata header further indicates a length value, wherein the length value indicates a quantity of packets in the subset of the one or more coded packets associated with the metadata header.

3. The method of any previous claim, wherein inserting the metadata header into the bitstream comprises inserting the metadata header at a position related to the subset of the one or more coded packets associated with the metadata header.

4. The method of claim 3, wherein the position is in front of the subset of the one or more coded packets associated with the metadata header in a decoding order or reading order of the bitstream or the position is at the end of a segment of the bitstream in a decoding order or reading order of the bitstream, and the metadata header is comprised by a packet different from the subset of the one or more coded packets associated with the metadata header.

5. The method of claim 3, wherein the metadata header is part of a first coded packet, in a decoding or reading order of the bitstream, with which the metadata header is associated with.

6. The method of claim 1, wherein the metadata header comprises a feature set packet and a feature packet, wherein the feature set packet indicates the feature type value, and the feature packet is associated with the subset of the one or more coded packets.Dolby International AB October 28, 2025D24147 WOOl7. The method of claim 6, wherein the feature set packet further indicates a feature start value, and the feature start value indicates a position of the feature packet.

8. The method of claim 6, wherein the feature packet comprises a timestamp and the timestamp indicates the starting time of the waveform data corresponding to subset of the one or more coded packets associated with the feature packet.

9. The method of claim 8, wherein the starting time corresponds to a time at which the waveform data has been generated or encoded.

10. The method of any one of claims 6 to 9, wherein the feature set packet indicates a length value, wherein the length value indicates a quantity of packets in the subset of the one or more coded packets associated with the feature packet or a duration of the waveform data corresponding to the subset of the one or more coded packets associated with the feature packet.

11. The method of any one of claims 6 to 9, wherein the metadata header comprises a second feature packet, wherein the feature packet and the second feature packet together indicate a quantity of packets of subset of the one or more coded packets associated with the feature packet.

12. The method of claim 11, wherein the second feature packet comprises a timestamp and the timestamp indicates the end time of the waveform data corresponding to the subset of the one or more coded packets associated with the feature packet.

13. The method of any one claims 6 to 12, wherein inserting the metadata header into the bitstream comprises inserting the feature packet at a position related to the subset of the one or more coded packets associated with the feature packet and inserting or updating the feature set packet based on the subset of the one or more coded packets associated with the feature packet, wherein the feature set packet is located at a starting position of the combined bitstream.Dolby International AB October 28, 2025 D24147 WOOl14. The method of claim 13, wherein the position of the feature packet is in front of the subset of the one or more coded packets in a decoding order or reading order of the combined bitstream.

15. The method of claim 1, wherein the metadata header comprises a feature set packet, wherein the feature set packet indicates the feature type value; and wherein the one or more coded packets correspond to substantially the whole bitstream.

16. The method of any one of claims 6 to 15, wherein the feature set packet comprises the feature type value, or an annotation channel of the bitstream comprises the feature type value and the feature set packet points to the feature type value in the annotation channel.

17. The method of any one of claims 6 to 16, wherein the feature type value comprises a string or a pointer to a predefined string.

18. The method of any one of the previous claims, wherein the common feature is determined based on the waveform data.

19. The method of any one of claims 1 to 17, wherein the common feature is determined directly on the one or more coded data packets; or wherein the method further comprises decoding the one or more coded packets to obtain the waveform data and determining the common feature based on the waveform data.

20. The method of any one of the previous claims, wherein the common feature is one or more of a plurality of predefined common features.

21. The method of claim 20, wherein the predefined common features indicate a condition associated with part of the waveform data corresponding to the subset of the one or more coded packets associated with the metadata header.Dolby International AB October 28, 2025D24147 WOOl22. The method of any one of the previous claims, wherein the method further comprises receiving auxiliary data and wherein the common feature is determined based on the auxiliary data.

23. The method of claim 22, wherein the auxiliary data comprises data associated with the generation of the waveform data.

24. The method of claim 22 or 23, wherein the auxiliary data comprises static data or dynamic data.

25. The method of claim 24, wherein the static data comprises a device type or a sensor type.

26. The method of claim 24 or 25, wherein the dynamic data comprises auxiliary measurement data for the waveform data.

27. The method of claim 26, wherein the auxiliary measurement data has a slow change rate in comparison to the waveform data.

28. The method of claim 26 or 27, wherein the auxiliary measurement data is any one of a time stamp, a temperature, a location, an elevation, a humidity and an orientation.

29. A method of extracting a subset of data from a combined bitstream, the method comprising: receiving the combined bitstream, wherein the combined bitstream comprises a plurality of coded packets corresponding to waveform data and one or more metadata headers, each associated with a subset of the plurality of coded packets; and extracting a first subset of the plurality of coded packets based on the associated metadata header; wherein each metadata header indicates a feature type value and the feature type value comprises a value corresponding to a common feature of the subset of the plurality of coded packets associated with the metadata header.Dolby International AB October 28, 2025D24147 WOOl30. The method of claim 29, wherein each metadata header further indicates a length value, wherein the length value indicates a quantity of packets of the plurality of coded packets associated with the metadata header.

31. The method of any one of claims 29 to 30, wherein each metadata header is positioned at a position related to the subset of the plurality of packets with which the metadata header is associated.

32. The method of claim 31, wherein the position is in front of the respective subset in a decoding order or reading order of the bitstream, and each metadata header is comprised by a packet different from the subset of the plurality of packets associated with the respective metadata header.

33. The method of claim 31, wherein each metadata header is part of a first coded packet of the respective subset, in a decoding or reading order of the bitstream, with which the respective metadata header is associated with.

34. The method of claim 29, wherein the one or more metadata headers comprise a feature set packet and, for each subset of the plurality of coded packets, a feature packet, wherein the feature set packet indicates the feature type value for the corresponding subset of the plurality of coded packets, and wherein each feature packet is associated with one of the one or more subsets of the plurality of coded packets.

35. The method of claim 34, wherein the feature set packet further indicates a feature start value for the corresponding subset of the plurality of coded packets, and the feature start value indicates a position of the feature packet associated with the corresponding subset of the plurality of coded packets.

36. The method of claim 34, wherein each feature packet comprises a timestamp and the timestamp indicates the starting time of the waveform data corresponding to the subset of the plurality of coded packets associated with the feature packet.Dolby International AB October 28, 2025D24147 WOOl37. The method of claim 36, wherein the starting time corresponds to a time at which the waveform data has been generated or encoded.

38. The method of any one of claims 34 to 37, wherein the feature set packet indicates a length value for each subset of the plurality of coded packets, wherein the length value indicates a quantity of packets of the subset of the plurality of coded packets associated with the feature packet or a duration of the waveform data corresponding to the subset of the plurality of coded packets associated with the feature packet.

39. The method of any one of claims 34 to 37, wherein the one or more metadata headers comprises a second feature packet for each subset of the plurality of coded packets, wherein each feature packet and each second feature packet together indicate a quantity of packets of the subset of the plurality of coded packets associated with the feature packet.

40. The method of claim 39, wherein each second feature packet comprises a timestamp and the timestamp indicates the end time of the waveform data corresponding to the subset of the plurality of coded packets associated with the feature packet.

41. The method of any one of claims 34 to 40, wherein each feature packet is positioned at a position related to the subset of the plurality of coded packets associated with the feature packet and the feature set packet is located at a starting position of the combined bitstream.

42. The method of claim 41, wherein the position of each feature packet is in front of the associated subset of the plurality of coded packets in a decoding order or reading order of the combined bitstream.

43. The method of claim 29, wherein the one or more metadata headers comprises a feature set packet, wherein the feature set packet indicates the feature type value; and wherein the plurality of coded packets correspond to substantially the whole bitstream.Dolby International AB October 28, 2025D24147 WOOl44. The method of any one of claims 34 to 43, wherein the feature set packet comprises each feature type value, or an annotation channel of the bitstream comprises each feature type value and the feature set packet points to each feature type value in the annotation channel.

45. The method of any one of claims 34 to 44, wherein each feature type value comprises a string or a pointer to a predefined string.

46. The method of any one of claims 29 to 45, wherein the common feature is one or more of a plurality of predefined common features.

47. The method of claim 46, wherein the predefined common features indicate a condition associated with part of the waveform data corresponding to the subset of the plurality of coded packets associated with the metadata header.

48. The method of any one of claims 29 to 45, wherein extracting the first subset of the plurality of coded packets based on the associated metadata header comprises: determining the first subset of the plurality of coded packets based on the common feature in the associated metadata header; solely decoding the first subset of the plurality of coded packets to obtain decoded waveform data.

49. The method of claim 48 when depending on claim 34, wherein determining the first subset of the plurality of coded packets based on the common feature in the associated metadata header comprises: querying the feature type value in the feature set packet for the common feature; and determining the first subset of the plurality of coded packets based on the feature start value.

50. The method of claim 49 when depending on claim 38, wherein determining the first subset of the plurality of coded packets is further based on the length value associated with the common feature.Dolby International AB October 28, 2025 D24147 WOOl51. The method of claim 49 or 50, wherein solely decoding the first subset of the plurality of coded packets to obtain decoded waveform data comprises starting decoding at the feature packet associated with the common feature.

52. An apparatus, comprising a processor and a memory coupled to the processor, wherein the processor is adapted to carry out the method according to any one of claims 1 to 51.

53. A computer program comprising instructions that, when executed by a processor, cause the processor to carry out the method according to any one of claims 1 to 51.

54. A computer-readable storage medium storing the computer program according to claim 53.

Images