Video bitstream encapsulation, decoding and access method and apparatus - Patent Application 20070122967

Abstract

An embodiment of the present disclosure provides a method and apparatus for encapsulating, decoding, and accessing a video bitstream. The method includes the steps of: encapsulating information of a library random access point (LRAP) sample in a first video bitstream into a media container file in which the first video bitstream is encapsulated; and encapsulating information of a library picture sample of the LRAP sample into the media container file, the library picture sample being a reference picture sample of the LRAP sample. The method solves the problem that a video coding method using a library picture as a reference picture in the related art cannot efficiently access and process a video bitstream including a reference picture sample, leading to complex processing. By directly encapsulating information of the LRAP sample into the media container file, the LRAP sample that can be a random access point and the library picture sample it refers to can be easily recognized, and the LRAP sample can be easily recognized without wasting transmission bandwidth while satisfying compression efficiency, thereby reducing processing complexity.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This disclosure claims priority to Chinese patent application CN202111309701.X, filed on November 6, 2021, entitled "Method and Apparatus for Encapsulating, Decoding, and Accessing Video Bitstream," the entire contents of which are incorporated herein by reference.

[0002] TECHNICAL FIELD Embodiments of the present disclosure relate to the field of communications, and more particularly to methods and apparatus for encapsulating, decoding, and accessing video bitstreams. [Background technology]

[0003] Conventional video codecs are hybrid coding framework technologies that utilize block partitioning-based temporal and spatial prediction, where spatial prediction is achieved using intra (I) prediction from the current picture, and temporal prediction is achieved using block-level inter (P) or bidirectional inter (B) prediction. Typically, the coding cost of an intra (I) coded block is significantly higher than that of an inter (P) coded block, which in turn is higher than that of a bidirectional inter (B) coded block.

[0004] A picture consisting only of intra-coded blocks is called an intra-coded picture, or I-picture. An Intra Random Access Point (IRAP) picture is an I-picture that ensures that pictures following the IRAP picture in decoding and display order do not refer to any pictures preceding the IRAP picture in decoding order.

[0005] 1 is a schematic diagram of an Intra Random Access Point (IRAP) in the related art. As shown in FIG. 1, an Intra Random Access Point (IRAP) picture can provide an access point to a video bitstream, and all pictures following the IRAP picture in decoding and display order can be decoded correctly.

[0006] However, the video bitstream random access functionality provided by IRAP pictures comes at a cost, as the coding cost and number of bits occupied by intra-coded I-pictures are typically significantly higher than that of inter-coded P-pictures or bidirectional inter-coded B-pictures.

[0007] The Audio Video coding Standard Work group of China (AVS) has introduced a large span video coding technology based on library pictures and reference library pictures (RL pictures) into its new generation video coding standard (AVS3 video coding).

[0008] In AVS3 video coding, a library picture is a long-term reference picture with temporal correlation across random access points, and a RL picture is a P or B picture that performs inter-prediction decoding using only library pictures as reference pictures in AVS3 video coding.Related experiments have demonstrated that performing inter-prediction or bidirectional inter-prediction using library pictures as reference pictures can significantly improve video coding efficiency in many applications, such as video surveillance and video conferencing.

[0009] In the related art, a video encoding method that uses library pictures as reference pictures is unable to efficiently access and process video bitstreams containing reference picture samples, resulting in complex processing. However, no solution has yet been proposed. Summary of the Invention [Problem to be solved by the invention]

[0010] The embodiments of the present disclosure provide a method and apparatus for encapsulating, decoding, and accessing a video bitstream to at least solve the problem that, in related art, a video encoding method that uses a library picture as a reference picture is unable to efficiently access and process a video bitstream containing reference library picture samples, and the processing is complicated. [Means for solving the problem]

[0011] According to one embodiment of the present disclosure, encapsulating information of Library Random Access Point (LRAP) samples in the first video bitstream into a media container file in which the first video bitstream is encapsulated; encapsulating information of library picture samples of the LRAP sample in the media container file, wherein the library picture samples are reference picture samples of the LRAP sample.

[0012] According to another embodiment of the present disclosure, recognizing, in a media container file in which a first video bitstream is encapsulated, Library Random Access Point (LRAP) samples in the first video bitstream; recognizing library picture samples of the LRAP samples in the media container file; decoding the library picture samples; and decoding the LRAP samples using the library picture samples as reference picture samples.

[0013] According to another embodiment of the present disclosure, obtaining a library random access point (LRAP) picture in a first video bitstream and obtaining a library picture of the LRAP picture; decoding the LRAP picture using the library picture as a reference picture; performing random access of the first video bitstream at the decoded LRAP picture.

[0014] According to another embodiment of the present disclosure, a first encapsulation module configured to encapsulate information of library random access point (LRAP) samples in the first video bitstream into a media container file in which the first video bitstream is encapsulated; a second encapsulation module configured to encapsulate information of library picture samples of the LRAP sample into the media container file, the library picture samples being reference picture samples of the LRAP sample.

[0015] According to another embodiment of the present disclosure, a first recognition module configured to recognize Library Random Access Point (LRAP) samples in a first video bitstream in a media container file in which the first video bitstream is encapsulated; a second recognition module configured to recognize library picture samples of the LRAP samples in the media container file; a first decoding module configured to decode the library picture samples; a second decoding module configured to decode the LRAP samples using the library picture samples as reference picture samples.

[0016] According to another embodiment of the present disclosure, an acquisition module configured to acquire a library random access point (LRAP) picture in a first video bitstream and acquire a library picture of the LRAP picture; a third decoding module configured to decode the LRAP picture using the library picture as a reference picture; an execution module configured to perform random access of the first video bitstream in the decoded LRAP picture.

[0017] According to yet another embodiment of the present disclosure, there is further provided an electronic device including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to perform the steps of any one of the method embodiments described above by executing the computer program. [Effects of the Invention]

[0018] According to an embodiment of the present disclosure, information about library random access point (LRAP) samples in a first video bitstream is encapsulated in a media container file in which the first video bitstream is encapsulated, and information about library picture samples of the LRAP samples is encapsulated in the media container file, and the library picture samples are reference picture samples of the LRAP samples. This solves the problem that video encoding methods in related art that use library pictures as reference pictures are unable to efficiently access and process video bitstreams containing reference picture samples, resulting in complex processing.

[0019] By directly encapsulating the information of LRAP samples in a media container file, it is possible to easily identify LRAP samples that can be used as random access points and the library picture samples they refer to, thereby achieving compression efficiency without wasting transmission bandwidth and reducing processing complexity. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram of an intra-random access point (IRAP) in the related art. [Figure 2] FIG. 2 is a block diagram illustrating the hardware structure of a mobile terminal in a video bitstream encapsulation method according to an embodiment of the present disclosure. [Figure 3] 1 is a flowchart of a video bitstream encapsulation method according to an embodiment of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram of a library random access point (LRAP) according to an embodiment of the present disclosure. [Figure 5] 1 is a flowchart of a media container file encapsulation method according to an alternative embodiment of the present disclosure. [Figure 6] FIG. 1 is a schematic diagram of an LRAP sample group and an LRAP sample group description according to an embodiment of the present disclosure. [Figure 7] 1 is a flowchart of a video bitstream decoding method according to an embodiment of the present disclosure. [Figure 8] 1 is a flowchart of a video bitstream decoding method according to an exemplary embodiment of the present disclosure. [Figure 9] 1 is a flowchart of a video bitstream access method according to an embodiment of the present disclosure. [Figure 10] FIG. 1 is a schematic diagram of an LRAP index segment according to an embodiment of the present disclosure. [Figure 11] 1 is a flowchart 1 of random access based on LRAP pictures according to an embodiment of the present disclosure. [Figure 12] 10 is a flowchart 2 of random access based on LRAP pictures according to an embodiment of the present disclosure. [Figure 13] FIG. 1 is a block diagram of a video bitstream encapsulation device according to an embodiment of the present disclosure. [Figure 14] FIG. 1 is a block diagram of a video bitstream decoding device according to an embodiment of the present disclosure. [Figure 15] 1 is a block diagram of a video bitstream access device according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0022] In addition, terms such as "first" and "second" in the specification, claims and drawings of the present disclosure are intended to distinguish between similar objects and are not intended to describe a specific order or chronological order.

[0023] The method embodiments provided by the embodiments of the present disclosure may be implemented in a mobile terminal, a computer terminal, or a similar computing device. Taking the implementation in a mobile terminal as an example, FIG. 2 is a block diagram of a hardware structure of a mobile terminal for the video bitstream encapsulation method according to the embodiments of the present disclosure. As shown in FIG. 2, the mobile terminal may include one or more processors 102 (only one is shown in FIG. 2 ) (the processor 102 may include, but is not limited to, a processing device such as a microprocessor (MCU) or a programmable logic device (FPGA)) and a memory 104 for storing data. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108.

[0024] As will be appreciated by those skilled in the art, the structure shown in Figure 2 is merely exemplary and is not intended to limit the structure of the mobile terminal. For example, the mobile terminal may include more or fewer components than those shown in Figure 2, or may have a different configuration than that shown in Figure 2.

[0025] The memory 104 is used to store computer programs, for example, software programs and modules of application software such as a computer program corresponding to the video bitstream encapsulation method in the embodiments of the present disclosure, and the processor 102 performs various function applications and service chain address pool slice processing, i.e., realizes the above-mentioned method, by executing the computer programs stored in the memory 104. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, for example, one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory.

[0026] In some embodiments, memory 104 may further include memory located remotely from processor 102, which may be connected to the mobile terminal via a network, examples of which include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0027] The transmission device 106 is used to transmit and receive data via a network. An example of the network may include a wireless network provided by a communication supplier of the mobile terminal. In one example, the transmission device 106 may include a network adapter (abbreviated as a network interface controller, NIC) that is connected to other network devices via a base station and can communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (abbreviated as RF) module that communicates with the Internet wirelessly.

[0028] In this embodiment, a video bitstream encapsulation method is provided, which is executed in the above mobile terminal or network architecture. Figure 3 is a flowchart of the video bitstream encapsulation method according to the embodiment of the present disclosure. As shown in Figure 3, the flow includes the following steps S302 and S304:

[0029] In step S302, information of library random access point (LRAP) samples in a primary video bitstream is encapsulated into a media container file in which the primary video bitstream is encapsulated.

[0030] In step S304, information of library picture samples of the LRAP sample is encapsulated in the media container file, where the library picture samples are reference picture samples of the LRAP sample.

[0031] The above steps S302 to S304 solve the problem that in the related art, a video coding method that uses a library picture as a reference picture is unable to efficiently access and process a video bitstream containing reference picture samples, resulting in complex processing. By directly encapsulating the LRAP sample information in a media container file, it becomes easier to identify LRAP samples that can be used as random access points and the library picture samples they reference, thereby satisfying compression efficiency without wasting transmission bandwidth and reducing processing complexity.

[0032] In one embodiment, the media container file includes an LRAP sample group and / or an LRAP sample group description containing information of the LRAP samples in the first video bitstream, or includes a synchronization sample data box containing information of the LRAP samples in the first video bitstream, or includes a stream access point (abbreviated as SAP) sample group containing information of the LRAP samples in the first video bitstream, or includes a segment index data box indicating information of the LRAP samples in the first video bitstream that are included in a segment of encoded video data of the first video bitstream.

[0033] In another embodiment, the media container file includes an LRAP sample group and / or an LRAP sample group description containing information about library picture samples of the LRAP sample, or includes a synchronization sample data box containing information about library picture samples of the LRAP sample, or includes an SAP sample group containing information about library picture samples of the LRAP sample, or includes a segment index data box indicating information about library picture samples of the LRAP sample included in a segment of coded video data of the first video bitstream.

[0034] In one alternative embodiment, a second video bitstream containing library picture samples of said LRAP samples may be encapsulated in the media container file.

[0035] In one embodiment, the information of the LRAP sample may include at least one of an index of the LRAP sample, a stream access point type of the LRAP sample, a number of library picture samples of the LRAP sample, and a number of library picture samples of the LRAP sample.

[0036] In one embodiment, the information of the library picture sample may include at least one of a track identifier corresponding to the library picture sample and a library picture sample number.

[0037] In this embodiment, a video bitstream is a binary data stream consisting of coded pictures. A video sequence is the highest-layer syntax structure of a video bitstream. A video sequence starts with a sequence header, and a sequence end code or video edit code indicates the end of a video sequence. A sequence header can appear repeatedly in the bitstream and is called a repeated sequence header. Each sequence header is followed by one or more coded pictures, and each picture should be preceded by a picture header. Coded pictures are arranged in bitstream order, which should be the same as the decoding order. The decoding order may be different from the display order.

[0038] The "library bitstream flag" (library_stream_flag) in the sequence header indicates the basic stream type of the video coding bitstream, and a value of "0" indicates that the current bitstream is a primary bitstream. A primary bitstream is a bitstream that can be decoded by referring to library pictures provided by bitstreams other than the current bitstream. A value of "1" indicates that the current bitstream is a library bitstream. A library bitstream contains only bitstreams of library pictures. Among them, library pictures are not used for display output and can be referenced by pictures in other bitstreams.

[0039] The "library picture enable flag" (library_picture_enable_flag) in the sequence header indicates whether or not there are inter-predicted pictures in the video sequence of the primary bitstream that use library pictures as reference pictures. A value of "1" indicates that there may be inter-predicted pictures in the video sequence that use library pictures as reference pictures, and a value of "0" indicates that there should not be inter-predicted pictures in the video sequence that use library pictures as reference pictures.

[0040] The "library picture index flag" (library_index_flag[list][rpls][i]) and "referenced library picture index" (referenced_library_picture_index[list][rpls][i]) in the sequence header or picture header are intended to indicate whether a reference picture in the reference picture queue is a library picture, and the library picture index as a reference picture, respectively.

[0041] If a video sequence contains an inter-predicted picture (P picture or B picture) that uses a library picture as a reference picture, and if the reference picture queue of the inter-predicted picture contains only library pictures, the inter-predicted picture is a Reference Library (abbreviated as RL) picture that performs inter-prediction decoding using only library pictures as reference pictures.

[0042] The "random access accurate decoding flag" (random_access_decodable_flag) in the inter-prediction picture header indicates whether the current picture refers only to pictures that follow the sequence header corresponding to the current picture in decoding order and have the random access accurate decoding flag value set to "1." Among them, the corresponding sequence header is the most recent sequence header that precedes the current picture in decoding order. If the random access accurate decoding flag of the current picture has a value of 0, the current picture may not be accurately decoded if a random access occurs to the corresponding sequence header.

[0043] A Library Random Access Point (LRAP) picture is defined as a Reference Library (RL) picture that satisfies the following property: given all library pictures as reference pictures, all pictures following the LRAP picture in decoding and display order can be correctly decoded.

[0044] An LRAP picture is a temporally predicted picture that references only library pictures. An LRAP picture may be coded as an inter-predicted P picture or a bidirectionally inter-predicted B picture. However, unlike conventional temporally predicted P or B pictures, an LRAP picture can constitute a random access point (RAP) in a video bitstream.

[0045] A Library Random Access Point (LRAP) picture should ensure that all pictures that follow it in decoding order and display order do not reference any pictures that precede the LRAP picture in decoding order or display order.

[0046] When performing a video bitstream random access operation on an LRAP picture, the associated library picture must first be decoded and used for reference, but not for display output. When performing a random access operation, accessing the LRAP picture and its associated library picture can ensure accurate decoding of the LRAP picture and pictures that follow it in display order.

[0047] A Library Random Access Point (LRAP) picture is defined as having a Library Random Access Point Type (LRAP_Type), where LRAP_type is a non-negative integer that indicates the Stream Access Point Type (SAP_type) corresponding to the LRAP picture if the LRAP picture does not depend on a library picture. If LRAP_type takes a value in the range 1 to 3, other type values ​​are reserved.

[0048] Among them, the type of stream access point (SAP) depends on the pictures that follow the LRAP picture in decoding order and can be correctly decoded, and their arrangement in display order. The stream access point type SAP_type is explained as follows:

[0049] Type 1: Corresponds to a "Closed GoP Random Access Point" and indicates that all pictures following the Library Random Access Point (LRAP) picture in decoding order can be correctly decoded.

[0050] Type 2: "Closed Group of Pictures (GoP) Random Access Point" indicates that all pictures following the Library Random Access Point (LRAP) picture in decoding order can be correctly decoded. At the same time, the first picture in video sequence decoding order from the LRAP picture is not the first picture in display order.

[0051] Type 3: "Open GoP Random Access Point", which indicates that some pictures that follow the Library Random Access Point (LRAP) picture in decoding order but precede the LRAP picture in display order cannot be correctly decoded.

[0052] In one exemplary embodiment, the elementary streams defined in the video bitstream are: a main bitstream, which is a video bitstream that can be decoded and output by referring to library pictures provided by other bitstreams; a library bitstream containing only video bits of library pictures, which are not used for display output but may be referenced by pictures in other bitstreams;

[0053] 4 is a schematic diagram of a library random access point (LRAP) according to an embodiment of the present disclosure. As shown in FIG. 4, a video sequence starts with a sequence header followed by one or more consecutive coded pictures. A video sequence of a library bitstream only includes library pictures. A video sequence of a primary bitstream may include P pictures, B pictures, and RL pictures. A P picture may include a library picture and multiple reference pictures that precede (past) the current picture in display order.

[0054] A B picture may have a library picture, multiple reference pictures that precede the current picture in display order (past), and multiple reference pictures that follow the current picture in display order (future). A RL picture can only have library pictures as reference pictures.

[0055] As shown in FIG. 4, the first decoded picture after the sequence header of the ith video sequence in the primary bitstream is an RL picture, and [i,1] It is marked as RL [i,1] uses only library pictures as reference pictures. [i,1] The range of reference pictures for all pictures following a picture is defined as RL [i,1] Picture, display order is RL [i,1] The picture following the picture and the RL [i,1] Once the picture is limited to the library pictures it references and all the referenced library pictures are obtained, the RL [i,1] All pictures following the picture can be decoded correctly. [i,1] The picture is a Library Random Access Point (LRAP) picture with "LRAP_type=1" in the video bitstream.

[0056] As shown in Figure 4, if there is another RL picture in the ith video sequence of the primary bitstream, and the RL [i,2] It is marked as RL [i,2] uses only library pictures as reference pictures. [i,2] The range of reference pictures for all pictures following a picture is defined as RL [i,2] Picture, display order is RL [i,2] The picture following the picture and the RL [i,2] If we limit the library pictures that a picture references to and obtain all of the referenced library pictures, all of the pictures that follow the RL[i,1] picture in decoding order can be decoded correctly.

[0057] At the same time, R.L. [i,2] RL in which pictures are displayed in the video sequence [i,2] It is not the first picture from the picture (for example, picture P in FIG. 6) [i,2] The display order is RL [i,2] (preceding the picture) and RL [i,1] The picture is a Library Random Access Point (LRAP) picture with "LRAP_type=2" in the video bitstream.

[0058] As shown in Figure 4, if there is another RL picture in the ith video sequence of the primary bitstream, and the RL [i,3] It is marked as RL [i,3] uses only library pictures as reference pictures. For example, picture P in FIG. [i,3] As shown, the decoding order is RL [i,3] It follows the picture but the display order is RL [i,3] There are several pictures preceding the picture P [i,3] The decoding order or display order is RL [i,3] Referencing the picture preceding the picture, RL [i,3] When a picture performs video bitstream random access, picture P [i,3] Therefore, RL [i,3] The picture is a Library Random Access Point (LRAP) picture with "LRAP_type=3" in the video bitstream.

[0059] As shown in Figure 4, if there is another RL picture in the ith video sequence of the primary bitstream, and the RL [i,4] It is marked as RL [i,4] uses only library pictures as reference pictures. For example, picture P in FIG. [i,4] As shown above, both the decoding order and the display order are RL [i,4] There are several pictures that follow the picture P [i,4] The decoding order or display order is RL [i,4] Referencing the picture preceding the picture, RL[i,4] Picture to Picture P [i,4] cannot be decoded correctly, and RL [i,4] Random access of the video bitstream is not possible in the picture. [i,4] The picture is not a Library Random Access Point (LRAP) picture in the video bitstream.

[0060] International Standard Organization (ISO) Basic Media File Format (ISOBMFF) The ISO Basic Media File Format defines a general structure for time-based media container files (e.g., video and audio) and can serve as the basis for other media file formats, such as the MPEG-4 Part 14 container format (MP4) and the 3GPP file format (3GPP). The ISO Basic Media File Format supports local editing and playback of media, and network transmission over a variety of streaming mechanisms, including dynamically adaptive streaming based on the Real-time Transport Protocol (RTP) and HyperText Transfer Protocol (HTTP).

[0061] This embodiment is used for encapsulating and processing video bitstream data, and allows the video bitstream to be encapsulated in an ISOBMFF container file. The ISO basic media file format consists of a number of data boxes, each of which has a type and length and can be regarded as a data object.

[0062] A data box may contain other data boxes, and is called a container data box. An ISO basic media file has only one file type "ftyp" data box, which is a file format flag. An ISO basic media file has only one movie "moov" data box, which contains media metadata information. A movie data box usually contains one or more tracks, and each track is stored in a track "trak" data box.

[0063] There are several types of tracks, such as media tracks and metadata tracks. The media data of an ISO basic media file is contained in the media data "mdat" data box, and the structure of the media data is described by metadata.

[0064] In one exemplary embodiment, the track type in which the media container file encapsulates the video bitstream is: a main bitstream track representing a main bitstream in a video bitstream by encapsulating non-library pictures in the video bitstream coded pictures in its samples and / or sample entries, and which may reference a library bitstream track; It represents a library bitstream in a video bitstream by encapsulating library pictures in the video bitstream coded pictures in its samples and / or sample entries, and includes a library bitstream track that the main bitstream track references via an "a3lr" track.

[0065] A track reference of type "a3lr" may be included in the main bitstream track. If present, this track reference references an AVS3 library bitstream track from the main bitstream track.

[0066] In the syntactic structure of a media container file, a sample group groups samples in a media track according to a specific grouping criterion. The Sample To Group Box in the ISO Basic Media File Format indicates the sample group to which a sample belongs, and the Sample Group Description Box provides an associated description of that sample group.

[0067] 5 is a flowchart of a media container file encapsulation method according to an exemplary embodiment of the present disclosure. As shown in FIG. 5, the flow includes the following step S502:

[0068] In step S502, a library random access point (LRAP) sample group and / or an LRAP sample group description including information about library random access point (LRAP) samples in the first video bitstream and information about library picture samples of the LRAP samples are encapsulated in a media container file in which the first video bitstream is encapsulated.

[0069] The above step S502 solves the problem that the related art does not allow efficient access and processing of bitstreams or media container files containing reference library (RL) pictures or samples, and introduces unnecessary processing complexity.

[0070] In one embodiment, the above step S502 may specifically include a step of including a Library Random Access Point (LRAP) sample group in the media container file, the sample group including information of Library Random Access Point (LRAP) samples in the first video bitstream.

[0071] Library Random Access Point (LRAP) Sample Group The Library Random Access Point (LRAP) sample group indicates information about Library Random Access Point (LRAP) samples in a video bitstream and library picture samples as reference picture samples.

[0072] Members of a Library Random Access Point sample group (called LRAP samples) should meet the following conditions:

[0073] LRAP samples can only use library picture samples as reference picture samples, After decoding the reference library picture sample, decoding can be started from the LRAP sample, thereby accurately decoding the LRAP sample and all samples that follow it in display order.

[0074] An LRAP sample can only be used in combination with the library picture sample it references, and to create a decodable sample sequence, the library picture sample must be serially concatenated with the LRAP sample and the sample that follows it in display order.

[0075] syntax: class VisualLRAPEntry extend VisualSampleGroupEntry ('lrap') { unsigned int(3) LRAP_type; unsigned int(3) entry_count; unsigned int(2) reserved=0; int i; for (i=0;i <entry_count;i++) { unsigned int(9) library_sample_number; unsigned int(7) reserved=0;} }

[0076] Here, LRAP_type is a non-negative integer that indicates the stream access point type (SAP_type) that should be associated with the LRAP sample if the LRAP sample does not depend on a library picture sample. When LRAP_type is a value in the range of 1 to 3, other type values ​​are reserved.

[0077] entry_count is a non-negative integer indicating the number of library picture samples referenced by the LRAP sample in the group. A value of "001" in entry_count indicates that the number of library picture samples referenced by the LRAP sample in the group is 1, and values ​​"000" and "010" to "111" are reserved. When the value of entry_count is "000", the following table is empty, and in this case, the sample group does not provide information on library picture samples.

[0078] library_sample_number is a non-negative integer that provides the sample number of the library picture sample that the LRAP sample references in the group.

[0079] 6 is a schematic diagram of an LRAP sample group and an LRAP sample group description according to an embodiment of the present disclosure. As shown in FIG. 6, this embodiment defines a Library Random Access Point (LRAP) sample group and an LRAP sample group description with a group type of "lrap" in a media container file that encapsulates a video bitstream in order to simplify access to and processing of Library Random Access Point (LRAP) samples of the video bitstream.

[0080] In the ISO Basic Media File Format, the Sample Table Data Box or the Track Fragment Data Box of each Movie Fragment Data Box contains an LRAP Sample Group and an LRAP Sample Group Description, where the LRAP Sample Group Data Box provides positioning information (e.g., sample index) of each LRAP sample in the video bitstream and the LRAP Sample Group Entry to which each LRAP sample belongs.

[0081] The LRAP Sample Group Description Data Box provides description information of the LRAP samples in the same LRAP sample group entry, and includes at least one of the stream access point type of the LRAP sample, the number of library picture samples of the LRAP sample, and the library picture sample number of the LRAP sample.

[0082] The sync sample data box "stss" in the ISO Basic Media File Format provides a compact marking of sync samples in a video bitstream.

[0083] syntax: aligned(8) class SyncSampleBox extends FullBox('stss',version=0,0) { unsigned int(32) entry_count; int i; for (i=0;i <entry_count;i++){ unsigned int(32) sample_number; } }

[0084] In one embodiment, a media container file in which a first video bitstream is encapsulated encapsulates a synchronization sample data box containing information about library random access point (LRAP) samples in the first video bitstream and information about library picture samples of the LRAP samples.

[0085] The above steps solve the problem in the related art that bitstreams or media container files containing reference library (RL) pictures or samples cannot be efficiently accessed and processed, and introduce unnecessary processing complexity.

[0086] Stream Access Points (SAPs) in the ISO Basic Media File Format allow random access to a container of media streams, and SAP sample groups label samples with the indicated SAP type.

[0087] syntax: aligned(8) class SyncSampleBox class SAPEntry() extends SampleGroupDescriptionEntry('sap') { unsigned int(1) dependent_flag; unsigned int(3) reserved; unsigned int(4) SAP_type; }

[0088] In one embodiment, in a media container file in which a first video bitstream is encapsulated, the SAP sample group encapsulates a Stream Access Point (SAP) sample group that includes information of a Library Random Access Point (LRAP) sample in the first video bitstream and information of a library picture sample of the LRAP sample.

[0089] The above steps solve the problem in the related art that bitstreams or media container files containing reference library (RL) pictures or samples cannot be efficiently accessed and processed, and introduce unnecessary processing complexity.

[0090] 7 is a flowchart of a video bitstream decoding method according to an embodiment of the present disclosure. As shown in FIG. 7, the process includes the following steps S702, S704, S706, and S708.

[0091] In step S702, a library random access point (LRAP) sample in a primary video bitstream is recognized in a media container file in which the primary video bitstream is encapsulated.

[0092] In this embodiment, the above step S702 may specifically include a step of parsing LRAP sample groups and / or LRAP sample group descriptions in the media container file, where the LRAP sample groups and / or LRAP sample group descriptions contain information of the LRAP samples, and therefore the LRAP samples in the first video bitstream can be obtained based on the LRAP sample groups and / or LRAP sample group descriptions; or may include a step of parsing sync sample data boxes in the media container file, where the sync sample data boxes contain information of the LRAP samples, and therefore the LRAP samples in the first video bitstream can be obtained based on the sync sample data boxes; or may include a step of parsing stream access point (SAP) sample groups in the media container file, where the SAP sample groups contain information of the LRAP samples, and therefore the LRAP samples in the first video bitstream can be obtained based on the stream access point (SAP) sample groups; or may include a step of parsing segment index data boxes in the media container file, where the segment index data boxes indicate information of the LRAP samples, and therefore the LRAP samples in the first video bitstream can be obtained based on the segment index data boxes.

[0093] In step S704, library picture samples of the LRAP samples are identified in the media container file.

[0094] In this embodiment, the above step S704 may specifically include a step of analyzing an LRAP sample group and / or an LRAP sample group description in the media container file, which includes information on the library picture samples of the LRAP sample; or a step of analyzing a synchronization sample data box in the media container file, which includes information on the library picture samples of the LRAP sample; or a step of analyzing a stream access point (SAP) sample group in the media container file, which includes information on the library picture samples of the LRAP sample; or a step of analyzing a segment index data box in the media container file, which indicates information on the library picture samples of the LRAP sample included in a segment of coded video data of the first video bitstream, and the library picture samples of the LRAP sample can be recognized based on the information on the library picture samples.

[0095] In step S706, the library picture sample is decoded.

[0096] In this embodiment, the above step S706 may specifically include a step of decoding the library picture sample of the LRAP sample included in the second video bitstream encapsulated in the media container file based on information of the library picture sample of the LRAP sample.

[0097] In step S708, the LRAP samples are decoded using the library picture samples as reference picture samples.

[0098] The above steps S702 to S708 solve the problem that in the related art, in a video coding method that uses a library picture as a reference picture, it is not possible to efficiently access and process a video bitstream containing reference library picture samples, which results in complex processing and requires a large amount of download to complete decoding. By directly recognizing the LRAP samples that can be used as random access points and the library picture samples they reference from the media container file, decoding can be completed with a reduced amount of download.

[0099] In an embodiment of the present disclosure, the information of the LRAP sample may include at least one of an index of the LRAP sample, a flow access point type of the LRAP sample, a number of library picture samples of the LRAP sample, and a library picture sample number of the LRAP sample.

[0100] In an embodiment of the present disclosure, the information of the library picture sample may include at least one of a track identifier corresponding to the library picture sample and a library picture sample number.

[0101] 8 is a flowchart of a video bitstream decoding method according to an exemplary embodiment of the present disclosure. As shown in FIG. 8, the process includes the following steps S802, S804, and S806.

[0102] In step S802, library random access point (LRAP) samples in a first video bitstream and library picture samples of the LRAP samples are recognized by analyzing LRAP sample groups and / or LRAP sample group descriptions in a media container file in which the first video bitstream is encapsulated.

[0103] In step S804, the library picture sample is decoded.

[0104] In step S806, the LRAP samples are decoded using the library picture samples as reference picture samples.

[0105] The above steps S802 to S806 solve the problem that the related art is unable to efficiently access and process bitstreams or media container files containing reference library (RL) pictures or samples, and introduces unnecessary processing complexity.

[0106] In one embodiment, a problem that related art does not provide efficient access and processing for bitstreams or media container files containing reference library (RL) pictures or samples, resulting in unnecessary processing complexity, can be solved by analyzing synchronization sample data boxes in a media container file in which a first video bitstream is encapsulated, recognizing library random access point (LRAP) samples in the first video bitstream and library picture samples of the LRAP samples, decoding the library picture samples, and decoding the LRAP samples using the library picture samples as reference picture samples.

[0107] In one embodiment, a problem that related art does not provide efficient access and processing for bitstreams or media container files containing reference library (RL) pictures or samples, resulting in unnecessary processing complexity, can be solved by analyzing stream access point (SAP) sample groups in a media container file in which a first video bitstream is encapsulated, recognizing library random access point (LRAP) samples in the first video bitstream and library picture samples of the LRAP samples, decoding the library picture samples, and decoding the LRAP samples using the library picture samples as reference picture samples.

[0108] 9 is a flowchart of a video bitstream access method according to an embodiment of the present disclosure. As shown in FIG. 9, the flow includes the following steps S902, S904, and S906.

[0109] In step S902, obtain a library random access point (LRAP) picture in the primary video bitstream, and obtain a library picture of the LRAP picture.

[0110] In one embodiment, the step of obtaining a library random access point (LRAP) picture in the first video bitstream in step S902 above may include receiving a first segment of encoded video data of the first video bitstream that includes at least one LRAP picture, and / or the step of obtaining a library picture of the LRAP picture in step S902 may include receiving a second segment of encoded video data of a second video bitstream that includes a library picture, or receiving a third segment of encoded video data of the first video bitstream that includes the library picture.

[0111] In another embodiment, the above step S902 may specifically include receiving a fourth segment of coded video data of the first video bitstream, where a first sub-segment of the fourth segment includes the library picture and a second sub-segment of the fourth segment includes at least one LRAP picture, and the library picture can be obtained from the first sub-segment of the fourth segment and the LRAP picture can be obtained from the second sub-segment of the fourth segment.

[0112] In yet another embodiment, in the above step S902, the step of obtaining a library random access point (LRAP) picture in a first video bitstream may specifically include a step of receiving an index segment of encoded video data of the first video bitstream, the index segment indicating that an LRAP picture is present in a media segment of encoded video data of the first video bitstream.

[0113] And / or the step of obtaining a library picture of the LRAP picture in the above step S902 may specifically include a step of receiving an index segment of the coded video data of the first video bitstream indicating that the library picture is present in a media segment of the coded video data of the first video bitstream, or a step of receiving an index segment of the coded video data of a second video bitstream indicating that the library picture is present in a media segment of the coded video data of the second video bitstream.

[0114] In step S904, the LRAP picture is decoded using the library picture as a reference picture.

[0115] In step S906, random access of the primary video bitstream is performed at the decoded LRAP picture.

[0116] The above steps S902 to S906 solve the problem that in the related art, in the video encoding method using library pictures as reference pictures, it is not possible to efficiently access and process the video bitstream including the reference picture samples, resulting in complicated processing and low access frequency. By directly recognizing the LRAP pictures that can be used as random access points and the library pictures they refer to from the media container file, decoding can be completed on the premise of reducing the amount of download, and the amount of download can be reduced, and the compression efficiency is satisfied without wasting transmission bandwidth, and the random access frequency of the video bitstream can be increased and time delay can be reduced.

[0117] In one alternative embodiment, after step S904 above, the method may further include a step of decoding at least one non-random access point picture that follows the LRAP picture in decoding order and display order in the first video bitstream, wherein the at least one non-random access point picture does not use any picture that precedes the LRAP picture in decoding order or display order as a reference picture, making it easier to achieve random access.

[0118] LRAP Segment Index In the media container file syntax structure, the segment index is intended to provide compact index information for one media stream in a segment. The Segment Index Data Box in the ISO Basic Media File Format records how a segment is divided into one or more subsegments. A subsegment is defined by the media rendering time interval of the subsegment corresponding to the byte range of the subsegment. The segment index information may be encapsulated in the same file as the media content being indexed, or may be stored in a separate file.

[0119] Definition: The LRAP Segment Index Data Box indicates the presence of a Library Random Access Point (LRAP) in the subsegment it references, and if the media stream (track segment) referenced within the subsegment contains a Library Random Access Point (LRAP), then the subsegment contains and starts with a Library Random Access Point (LRAP).

[0120] Library Random Access Point (LRAP) samples (LRAP_type type 1, 2 or type 3) in a subsegment are marked as members of a sample group of "lrap" group type.

[0121] syntax: aligned(8) class LRAPSegmentIndexBox extends FullBox('lidx',version,0) { for(i=1;i<=reference_count;i++) { bit(1) reference_type; unsigned int(31) referenced_size; unsigned int(32) subsegment_duration; bit(1) starts_with_LRAP; unsigned int(3) LRAP_type; unsigned int(28) reserved=0; } }

[0122] Here, starts_with_LRAP indicates whether the referenced subsegment starts with a library random access point (LRAP), and LRAP_type indicates the LRAP_type type of the library random access point (LRAP) in the subsegment.

[0123] LRAP Index Segment Dynamic Adaptive Streaming over HTTP (abbreviated as DASH) technology is compatible with different media formats such as audio, video, and text, and can provide high-quality streaming media services with multiple bit rates, frame rates, and resolutions. Among them, a Media Presentation Description (abbreviated as MPD) contains metadata required for a DASH client to provide a streaming media service to users, and is divided into multiple layers, including Period, Adaptation Set, Representation, and Segment, to accommodate different device playback capabilities and network bandwidth needs.

[0124] The Segment format defines the syntax and semantics of resources associated with HTTP-URLs in a Media Presentation Description (MPD). Among them, the Index Segments consist of a series of ISO Basic Media File Format data boxes and are intended to provide index information for media segments. An Index Segment may be associated with a single media segment or with all media segments in a representation.

[0125] 10 is a schematic diagram of an LRAP index segment according to an embodiment of the present disclosure. As shown in FIG. 10, the index segment provides indexes of all media segments of one representation in dynamic adaptive stream media. The index segment starts with one "styp" type data box, and each media segment in the representation is indexed by one or more segment index data boxes, and the segment indexes of each media segment are connected in order and indexed by the outermost segment index data box.

[0126] As shown in Figure 10, one of the media segments includes N consecutive sub-segments, each of which is indexed by a segment index data box of type "lidx". The "lidx" data box indicates whether the referenced sub-segment starts with a library random access point (LRAP) and the LRAP_type type of the library random access point (LRAP) in the sub-segment.

[0127] For LRAP random access, multiple user actions can trigger random access requests to a video bitstream. In broadcast and multicast services, channel switching triggers a random access operation to a video bitstream in another channel. In adaptive stream media sessions, trick plays such as drag play, fast forward / fast reverse play trigger a random access operation to a video bitstream in the current representation. Bitrate adaptive switching triggers a random access operation to a video bitstream in another representation.

[0128] By introducing the library random access point (LRAP) picture of this embodiment into a video bitstream and performing random access operations using it, random access operations can be realized with lower coding costs than intra-coded random access point (IRAP) pictures.

[0129] A video bitstream random access request typically indicates a desired position (time) in the video bitstream.

[0130] Preferably, the library random access point (LRAP) picture associated with the video bitstream random access is the library random access point (LRAP) picture that is temporally closest and appears before or at the desired position.

[0131] In one embodiment, Library Random Access Point (LRAP) samples associated with video bitstream random access and corresponding library picture samples can be identified by searching for samples included in a Library Random Access Point (LRAP) sample group.

[0132] Preferably, a segment associated with video bitstream random access refers to a segment containing at least one Library Random Access Point (LRAP) picture, where one Library Random Access Point (LRAP) picture is the Library Random Access Point (LRAP) picture that is temporally closest and appears before or at the desired position.

[0133] In one embodiment, a segment associated with a video bitstream random access can be identified by searching for a segment corresponding to a library random access point (LRAP) segment index, the segment including at least one library random access point (LRAP) picture associated with the video bitstream random access.

[0134] Preferably, a sub-segment associated with video bitstream random access refers to a sub-segment starting at a Library Random Access Point (LRAP) picture, which is the Library Random Access Point (LRAP) picture that is temporally closest and appears before or at the desired position.

[0135] In one embodiment, a sub-segment associated with a video bitstream random access can be identified by searching a sub-segment cited in a library random access point (LRAP) segment index, the sub-segment including a library random access point (LRAP) picture associated with the video bitstream random access.

[0136] 11 is a flowchart 1 of random access based on LRAP pictures according to an embodiment of the present disclosure. As shown in FIG. 11, the process includes the following steps S1102 to S1116.

[0137] In step S1102, in a stream media session, a media client (eg, a DASH client) requests a server to obtain an index segment, which provides an index of all media segments in a representation.

[0138] In step S1104, the server returns an index segment to the client. In this embodiment, the index segment consists of a series of LRAP Segment Index Boxes, which indicate whether a library random access point (LRAP) picture exists in a sub-segment referenced by the media segment and the random access point type (LRAP_type) of the library random access point (LRAP) picture.

[0139] In step S1106, the client receives a user-initiated video bitstream random access request. The client determines a desired position in the video bitstream based on the request. Preferably, the client identifies a segment associated with the video bitstream random access by searching a library random access point (LRAP) segment index provided by the index segment, the segment including at least one library random access point (LRAP) picture associated with the video bitstream random access.

[0140] Optionally, the index segment provides a library random access point (LRAP) segment index to identify a library picture corresponding to a library random access point (LRAP) associated with a video bitstream random access.

[0141] Optionally, library picture samples corresponding to library random access point (LRAP) samples associated with video bitstream random access can be identified by searching for samples included in a library random access point (LRAP) sample group.

[0142] In step S1108, the client requests the server to obtain a media segment of a library picture corresponding to a library random access point (LRAP) picture associated with video bitstream random access.

[0143] Alternatively, the client may request the server to obtain media segments in the same representation, ie, library pictures are encoded in the same video bitstream as library random access point (LRAP) pictures.

[0144] Alternatively, the client may request the server to obtain media segments in a different representation, ie, library pictures are encoded into a different video bitstream than library random access point (LRAP) pictures.

[0145] In step S1110, the server returns a media segment to the client, the segment including a library picture corresponding to a library random access point (LRAP) picture associated with a video bitstream random access.

[0146] In step S1112, the client requests the server to obtain the media segment associated with the video bitstream random access.

[0147] In step S1114, the server returns a media segment to the client, the segment including at least one video bitstream random access associated library random access point (LRAP) picture.

[0148] In step S1116, the client decodes the library random access point (LRAP) picture using the library picture as the only reference picture, and performs a random access operation on the decoded library random access point (LRAP) picture.

[0149] Preferably, at least one non-random access point picture that follows the library random access point (LRAP) picture in decoding order and display order is decoded, and the non-random access point picture does not reference any picture that precedes the library random access point (LRAP) picture in decoding order or display order.

[0150] 12 is a flowchart 2 of random access based on LRAP pictures according to an embodiment of the present disclosure. As shown in FIG. 12, the process includes the following steps S1202 to S1216.

[0151] In step S1202, optionally in a stream media session, a media client (eg, a DASH client) requests a server to obtain an index segment, which provides an index of all media segments in a representation.

[0152] In step S1204, the server returns an index segment to the client. In this embodiment, the index segment consists of a series of LRAP Segment Index Boxes, which indicate whether a library random access point (LRAP) picture exists in a subsegment referenced by the media segment and the random access point type (LRAP_type) of the library random access point (LRAP) picture.

[0153] In step S1206, the client receives a user-initiated video bitstream random access request. The client determines a desired position in the video bitstream based on the request. Preferably, the client identifies a segment and its subsegments associated with the video bitstream random access by searching a library random access point (LRAP) segment index provided by the index segment, where the subsegment starts from a library random access point (LRAP) picture associated with the video bitstream random access.

[0154] Optionally, the index segment provides a library random access point (LRAP) segment index to identify a library picture corresponding to a library random access point (LRAP) associated with a video bitstream random access.

[0155] Optionally, library picture samples corresponding to library random access point (LRAP) samples associated with video bitstream random access can be identified by searching for samples included in a library random access point (LRAP) sample group.

[0156] Optionally, a segment associated with the video bitstream random access and its sub-segments are identified by searching a library random access point (LRAP) segment index provided by the index segment, and the sub-segments include library pictures corresponding to the library random access point (LRAP) pictures associated with the video bitstream random access.

[0157] In step S1208, the client requests the server to obtain a sub-segment of a library picture corresponding to a library random access point (LRAP) picture associated with video bitstream random access.

[0158] In step S1210, the server returns the sub-segment to the client, where the sub-segment includes a library picture corresponding to a library random access point (LRAP) picture associated with video bitstream random access.

[0159] In step S1212, the client requests the server to obtain a sub-segment associated with the video bitstream random access.

[0160] In step S1214, the server returns the sub-segment to the client, where the sub-segment starts from a library random access point (LRAP) picture associated with video bitstream random access.

[0161] In step S1216, the client decodes the library random access point (LRAP) picture using the library picture as the only reference picture, and performs a random access operation on the decoded library random access point (LRAP) picture.

[0162] Preferably, at least one non-random access point picture that follows the library random access point (LRAP) picture in decoding order and display order is decoded, and the non-random access point picture does not reference any picture that precedes the library random access point (LRAP) picture in decoding order or display order.

[0163] An embodiment of the present disclosure further provides a video bitstream encapsulation device, as shown in Figure 13, which is a block diagram of a video bitstream encapsulation device according to an embodiment of the present disclosure.

[0164] As shown in FIG. 13 , the apparatus includes a first encapsulation module 132 configured to encapsulate information of Library Random Access Point (LRAP) samples in a first video bitstream into a media container file in which the first video bitstream is encapsulated; a second encapsulation module 134 configured to encapsulate information of library picture samples of the LRAP sample in the media container file, the library picture samples being reference picture samples of the LRAP sample.

[0165] In one exemplary embodiment, the media container file contains LRAP sample groups and / or LRAP sample group descriptions containing information of LRAP samples in the first video bitstream, or a Sync Sample Data Box containing information of LRAP samples in the first video bitstream; or a Stream Access Point (SAP) sample group containing information of LRAP samples in the first video bitstream; or The segment index data box indicates information of LRAP samples in the first video bitstream that are included in a segment of the coded video data of the first video bitstream.

[0166] In one exemplary embodiment, the media container file includes an LRAP sample group and / or an LRAP sample group description containing information of library picture samples of the LRAP sample, or a Sync Sample Data Box containing information about a Library Picture Sample of the LRAP Sample; or a Stream Access Point (SAP) sample group containing information about library picture samples of the LRAP sample; or The segment index data box indicates information of library picture samples of the LRAP samples included in a segment of coded video data of the first video bitstream.

[0167] In one exemplary embodiment, the apparatus further includes a third encapsulation module configured to encapsulate a second video bitstream in the media container file, wherein the second video bitstream includes library picture samples of the LRAP samples.

[0168] In one exemplary embodiment, the information of the LRAP sample includes at least one of an index of the LRAP sample, a flow access point type of the LRAP sample, a number of library picture samples of the LRAP sample, and a number of library picture samples of the LRAP sample.

[0169] In one exemplary embodiment, the information of the library picture sample includes at least one of a track identifier corresponding to the library picture sample and a library picture sample number.

[0170] An embodiment of the present disclosure further provides a video bitstream decoding device. Figure 14 is a block diagram of a video bitstream decoding device according to an embodiment of the present disclosure.

[0171] As shown in FIG. 14, the apparatus includes a first recognition module 142 configured to recognize Library Random Access Point (LRAP) samples in a first video bitstream in a media container file in which the first video bitstream is encapsulated; a second recognition module 144 configured to recognize library picture samples of the LRAP samples in the media container file; a first decoding module 166 configured to decode the library picture samples; and a second decoding module 148 configured to decode the LRAP samples using the library picture samples as reference picture samples.

[0172] In one exemplary embodiment, the first recognition module 142 further comprises: Parsing LRAP sample groups and / or LRAP sample group descriptions in the media container file, which contain information about the LRAP samples, or Parsing a Sync Sample Data Box in the media container file containing information about the LRAP samples, or Parsing a Stream Access Point (SAP) sample group in the media container file that contains information about the LRAP samples, or The method is configured to analyze a segment index data box in the media container file, the segment index data box indicating information of the LRAP samples included in a segment of coded video data of the first video bitstream.

[0173] In one exemplary embodiment, the second recognition module 144 further comprises: Parsing LRAP sample groups and / or LRAP sample group descriptions in the media container file, which contain information about library picture samples of the LRAP samples, or Parsing a Sync Sample Data Box in the media container file containing information of Library Picture Samples of the LRAP samples, or Parsing a Stream Access Point (SAP) sample group in the media container file that contains information about library picture samples of the LRAP sample, or The segment index data box in the media container file is configured to parse a segment index data box indicating information of a library picture sample of the LRAP sample included in a segment of coded video data of the first video bitstream.

[0174] In one exemplary embodiment, the first decoding module 146 is further configured to decode, based on information of the library picture samples of the LRAP samples, library picture samples of the LRAP samples included in a second video bitstream encapsulated in the media container file.

[0175] In one exemplary embodiment, the information of the LRAP sample includes at least one of an index of the LRAP sample, a flow access point type of the LRAP sample, a number of library picture samples of the LRAP sample, and a number of library picture samples of the LRAP sample.

[0176] In one exemplary embodiment, the information of the library picture sample includes at least one of a track identifier corresponding to the library picture sample and a library picture sample number.

[0177] An embodiment of the present disclosure further provides a video bitstream access device. Figure 15 is a block diagram of a video bitstream access device according to an embodiment of the present disclosure.

[0178] As shown in FIG. 15 , the apparatus includes: an acquisition module 152 configured to acquire a library random access point (LRAP) picture in a first video bitstream and acquire a library picture of the LRAP picture; a third decoding module 154 configured to decode the LRAP picture using the library picture as a reference picture; and an execution module 156 configured to perform random access of the primary video bitstream at the decoded LRAP picture.

[0179] In one example embodiment, the capture module 152 is further configured to receive a first segment of coded video data of the first video bitstream, the first segment including at least one LRAP picture.

[0180] In one example embodiment, the capture module 152 further receives a second segment of coded video data of a second video bitstream that includes the library picture; or and configured to receive a third segment of encoded video data of the first video bitstream that includes the library picture.

[0181] In one example embodiment, the acquisition module 152 is further configured to receive a fourth segment of encoded video data of the first video bitstream, where a first sub-segment of the fourth segment includes the library picture and a second sub-segment of the fourth segment includes at least one LRAP picture.

[0182] In one example embodiment, the acquisition module 152 is further configured to receive an index segment of the coded video data of the first video bitstream that indicates that the LRAP picture is present in a media segment of the coded video data of the first video bitstream.

[0183] In one exemplary embodiment, the capture module 152 further comprises: receiving an index segment of the coded video data of the first video bitstream that indicates that the library picture is present in a media segment of the coded video data of the first video bitstream; or and configured to receive an index segment of coded video data of a second video bitstream that indicates that the library picture is present in a media segment of coded video data of the second video bitstream.

[0184] In one exemplary embodiment, the device further includes a fourth decoding module configured to decode at least one non-random access point picture that follows the LRAP picture in decoding order and display order in the first video bitstream, wherein the at least one non-random access point picture does not use as a reference picture any picture that precedes the LRAP picture in decoding order or display order.

[0185] An embodiment of the present application further provides a computer-readable storage medium having stored thereon a computer program configured, when executed, to perform the steps of any one of the method embodiments described above.

[0186] In one exemplary embodiment, the computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB disk, a read-only memory (abbreviated as ROM), a random access memory (abbreviated as RAM), a removable hard disk, a magnetic disk, or an optical disk.

[0187] An embodiment of the present disclosure further provides an electronic device including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to perform the steps of any one of the method embodiments described above by executing the computer program.

[0188] In one exemplary embodiment, the electronic device may further include a transmission device connected to the processor and an input / output device connected to the processor.

[0189] For specific examples in this embodiment, reference can be made to the examples described in the above examples and exemplary embodiments, and therefore, the description thereof will be omitted in this embodiment.

[0190] As will be understood by those skilled in the art, each module or step of the present disclosure can be implemented by a general-purpose computing device, can be centralized in a single computing device, or can be distributed across a network of multiple computing devices, can be implemented by program code executable by a computing device, and can be stored in a storage device and executed by a computing device. It goes without saying that in some cases, the steps shown or described can be executed in a different order than shown here, or can be implemented by creating each of them in a separate integrated circuit module, or by creating multiple modules or steps in a single integrated circuit module. Thus, the present disclosure is not limited to any particular combination of hardware and software.

[0191] The above are only selective examples of the present disclosure, and do not limit the present application. Those skilled in the art can make various modifications and changes to the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the principle of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. encapsulating information of library random access point (LRAP) samples in a first video bitstream into a media container file in which the first video bitstream is encapsulated, wherein a reference library (RL) picture sample is defined as the LRAP sample, the reference library (RL) picture sample satisfying a property that once all library pictures are obtained as reference library pictures, all pictures following the LRAP sample in decoding order and display order can be correctly decoded; encapsulating information of library picture samples of the LRAP sample in the media container file, the library picture samples being reference picture samples of the LRAP sample. Video Bitstream Encapsulation Method.

2. The media container file is or comprising an LRAP sample group and / or an LRAP sample group description containing information of LRAP samples in the first video bitstream; a Sync Sample Data Box containing information of LRAP samples in the first video bitstream; or a Stream Access Point (SAP) sample group containing information of LRAP samples in the first video bitstream; or a segment index data box indicating information of LRAP samples in the first video bitstream included in a segment of coded video data of the first video bitstream; or or comprising an LRAP sample group and / or an LRAP sample group description containing information about the library picture samples of said LRAP sample; a Sync Sample Data Box containing information about a Library Picture Sample of said LRAP Sample; or a Stream Access Point (SAP) sample group containing information about library picture samples of the LRAP sample; or a segment index data box indicating information of a library picture sample of the LRAP sample included in a segment of the coded video data of the first video bitstream; The method of claim 1.

3. encapsulating a second video bitstream containing library picture samples of the LRAP samples in the media container file; 2. The method of claim 1 .

4. The information of the LRAP sample includes at least one of an index of the LRAP sample, a stream access point type of the LRAP sample, a number of library picture samples of the LRAP sample, and a number of library picture samples of the LRAP sample; or the information on the library picture sample includes at least one of a track identifier corresponding to the library picture sample and a library picture sample number; The method of claim 1.

5. a step of recognizing, in a media container file in which a first video bitstream is encapsulated, a library random access point (LRAP) sample in the first video bitstream, wherein a reference library (RL) picture sample is defined as the LRAP sample, the reference library (RL) picture sample satisfying the property that once all library pictures are obtained as reference library pictures, all pictures following the LRAP sample in decoding order and display order can be correctly decoded; recognizing library picture samples of the LRAP samples in the media container file; decoding the library picture samples; and decoding the LRAP samples using the library picture samples as reference picture samples. Video bitstream decoding method.

6. In a media container file in which a first video bitstream is encapsulated, the step of recognizing library random access point (LRAP) samples in the first video bitstream comprises: - parsing LRAP sample groups and / or LRAP sample group descriptions in the media container file, which contain information about the LRAP samples; or - parsing a Sync Sample Data Box in the media container file containing information of the LRAP samples; or parsing a Stream Access Point (SAP) sample group in the media container file, which contains information about the LRAP samples; or analyzing a segment index data box in the media container file indicating information of the LRAP samples included in a segment of coded video data of the first video bitstream; The method of claim 5.

7. The step of recognizing library picture samples of the LRAP samples in the media container file comprises: - parsing LRAP sample groups and / or LRAP sample group descriptions in the media container file, which contain information of library picture samples of the LRAP samples; or - parsing a Sync Sample Data Box in the media container file containing information of Library Picture Samples of the LRAP samples; or parsing a Stream Access Point (SAP) sample group in the media container file, which contains information of library picture samples of the LRAP samples; or analyzing a segment index data box in the media container file indicating information of library picture samples of the LRAP samples included in a segment of coded video data of the first video bitstream; 6. The method of claim 5.

8. The step of decoding the library picture samples comprises: decoding the library picture samples of the LRAP samples included in the second video bitstream encapsulated in the media container file based on information of the library picture samples of the LRAP samples; 8. The method of claim 7.

9. The information of the LRAP sample includes at least one of an index of the LRAP sample, a stream access point type of the LRAP sample, a number of library picture samples of the LRAP sample, and a number of library picture samples of the LRAP sample; or the information on the library picture sample includes at least one of a track identifier corresponding to the library picture sample and a library picture sample number; The method of claim 5.

10. obtaining a library random access point (LRAP) picture in a first video bitstream and obtaining a library picture of the LRAP picture, wherein a reference library (RL) picture that satisfies the property that once all library pictures are obtained as reference library pictures, all pictures that follow the LRAP picture in decoding order and display order can be correctly decoded is defined as the LRAP picture; decoding the LRAP picture using the library picture as a reference picture; performing random access of the first video bitstream at the decoded LRAP picture.

1. A video bitstream access method comprising:

11. The step of obtaining a library random access point (LRAP) picture in the first video bitstream includes: receiving a first segment of coded video data of a first video bitstream, the first segment including at least one LRAP picture; or receiving an index segment of the coded video data of the first video bitstream that indicates that the LRAP picture is present in a media segment of the coded video data of the first video bitstream; The method of claim 10.

12. The step of obtaining a library picture of the LRAP picture comprises: receiving a second segment of coded video data of a second video bitstream that includes the library picture; or receiving a third segment of encoded video data of the first video bitstream that includes the library picture; or receiving an index segment of the coded video data of the first video bitstream that indicates that the library picture is present in a media segment of the coded video data of the first video bitstream; or receiving an index segment of coded video data of a second video bitstream indicating that the library picture is present in a media segment of the coded video data of the second video bitstream; The method of claim 10.

13. The step of obtaining a library random access point (LRAP) picture in the first video bitstream and obtaining a library picture of the LRAP picture includes: receiving a fourth segment of encoded video data of the first video bitstream, wherein a first sub-segment of the fourth segment includes the library picture and a second sub-segment of the fourth segment includes at least one LRAP picture; 11. The method of claim 10.

14. After the step of decoding the LRAP picture using the library picture as a reference picture, decoding at least one non-random access point picture that follows the LRAP picture in decoding order and display order in the first video bitstream, wherein the at least one non-random access point picture does not use as a reference any picture that precedes the LRAP picture in decoding order or display order.

11. The method of claim 10.

15. An electronic device including a memory and a processor, The memory stores a computer program, The processor is configured to perform the method of any one of claims 1 to 14 by executing the computer program. electronic equipment.

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