Video encoder, video decoder, methods for encoding and decoding and video data stream realizing a compact indication of properties of SEI messages

Abstract

A video decoder (200) for decoding a video data stream having a video comprising a plurality of pictures stored therein according to an embodiment is provided.The video decoder (200) is configured to receive the video data stream. Moreover, the video decoder (200) is configured to decode the video from the video data stream. The video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. Furthermore, the video data stream comprises a size indication. If the size indication is equal to a predefined value, the one or more messages are exactly one message and the payload of the packet comprises the payload of the exactly one message.

Description

[0001] Video Encoder, Video Decoder, Methods for Encoding and Decoding and Video Data Stream realizing a Compact Indication of Properties of SEI Messages

[0002] Description

[0003] The present invention relates to video encoding and video decoding and, in particular, to a video encoder, to a video decoder, to methods for encoding and decoding and to a video data stream realizing a compact indication of properties of SEI messages.

[0004] In the following, an introduction to VCL partitioning according to the state-of-the-art is described (VCL = video coding layer).

[0005] Typically, in video coding, a coding process of picture samples requires smaller partitions, where samples are divided into some rectangular areas for joint processing such as prediction or transform coding. Therefore, a picture is partitioned into blocks of a particular size that is constant during encoding of the video sequence.

[0006] In some prior art, Coding Tree Units (CTUs) are processed in raster scan order, starting with the topleft CTU, processing CTUs in the picture line-wise, down to the bottom-right CTU.

[0007] The coded CTU data is organized into a kind of container called slice. Originally, in former video coding standards, slice means a segment comprising one or more consecutive CTUs of a picture. Slices are employed for a segmentation of coded data. From another point of view, the complete picture can also be defined as one big segment and hence, historically, the term slice is still applied. Besides the coded picture samples, slices also comprise additional information related to the coding process of the slice itself which is placed into a so-called slice header.

[0008] According to the state-of-the-art, a VCE (video coding layer) also comprises techniques for fragmentation and spatial partitioning. Such partitioning may, e.g., be applied in video coding for various reasons, among which are processing load-balancing in parallelization, CTU size matching in network transmission, error-mitigation etc.

[0009] Other examples relate to Rol (Rol = Region of Interest) encodings, where there is for example a region in the middle of the picture that viewers can select e.g. with a zoom in operation (decoding only the Rol), or gradual decoder refresh (GDR) in which intra data (that is typically put into one frame of a video sequence) is temporally distributed over several successive frames, e.g. as a column of intra blocks that swipes over the picture plane and resets the temporal prediction chain locally in the same fashion as an intra picture does it for the whole picture plane. For the latter, two regions

[0010] FH251023PCT-2025353027.DOCX exist in each picture, one that is recently reset and one that is potentially affected by errors and error propagation.

[0011] The object of the present invention is to provide improved concepts for video encoding and video decoding.

[0012] The object of the present invention is solved by the subject-matter of the independent claims.

[0013] A video encoder according to an embodiment is provided. The video encoder is configured to encode a video comprising a plurality of pictures into a video data stream. Moreover, the video encoder is configured to generate the video data stream such that the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. Furthermore, the video encoder is configured to generate the video data stream such that the video data stream comprises a size indication. If the size indication is equal to a predefined value, the one or more messages are exactly one message and the payload of the packet comprises the payload of the exactly one message.

[0014] Moreover, according to an embodiment, a video encoder for encoding a video into a video data stream is provided. The video encoder is configured to generate the video data stream such that the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. The video encoder is configured to generate the video data stream such that the packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

[0015] Furthermore, a video decoder for decoding a video data stream having a video comprising a plurality of pictures stored therein according to an embodiment is provided.. The video decoder is configured to receive the video data stream. Moreover, the video decoder is configured to decode the video from the video data stream. The video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. Furthermore, the video data stream comprises a size indication. If the size indication is equal to a predefined value, the one or more messages are exactly one message and the payload of the packet comprises the payload of the exactly one message.

[0016] Moreover, a video decoder for receiving a video data stream having a video stored therein according to an embodiment is provided. The video decoder is configured to decode the video from the video data stream. The video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages. The packet

[0017] FH251023PCT-2025353027.DOCX comprises properties information comprising information on the two or more messages being encapsulated by the packet.

[0018] Furthermore, a video data stream according to an embodiment is provided. The video data stream has a video comprising a plurality of pictures encoded therein. Moreover, the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. The video data stream comprises a size indication. If the size indication is equal to a predefined value, the one or more messages are exactly one message and the payload of the packet comprises the payload of the exactly one message.

[0019] Moreover, a video data stream according to an embodiment is provided. The video data stream has a video comprising a plurality of pictures encoded therein. Moreover, the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages. The packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

[0020] Moreover, a method for encoding a video comprising a plurality of pictures into a video data stream according to an embodiment is provided. The method comprises generating the video data stream such that the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. Furthermore, the method comprises generating the video data stream such that the video data stream comprises a size indication,

[0021] If the size indication is equal to a predefined value, the one or more messages are exactly one message, and the payload of the packet comprises the payload of the exactly one message.

[0022] Furthermore, a method for decoding a video data stream having a video comprising a plurality of pictures stored therein according to an embodiment is provided. The method comprises receiving the video data stream, and decoding the video from the video data stream. The video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. Moreover, the video data stream comprises a size indication.

[0023] If the size indication is equal to a predefined value, the one or more messages are exactly one message, and the payload of the packet comprises the payload of the exactly one message.

[0024] Moreover, a method for encoding a video comprising a plurality of pictures into a video data stream according to an embodiment is provided. The method comprises generating the video data stream

[0025] FH251023PCT-2025353027.DOCX such that the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages. Generating the video data stream is conducted such that the packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

[0026] Furthermore, a method for decoding a video data stream having a video comprising a plurality of pictures stored therein according to an embodiment is provided. The method comprises receiving the video data stream, and decoding the video from the video data stream. The video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. Moreover, the video data stream comprises a size indication.

[0027] If the size indication is equal to a predefined value, the one or more messages are exactly one message, and the payload of the packet comprises the payload of the exactly one message.

[0028] Furthermore, a method for decoding a video data stream having a video comprising a plurality of pictures stored therein according to an embodiment is provided. The method comprises receiving the video data stream, and decoding the video from the video data stream. The video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages. The packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

[0029] Moreover, a computer program for implementing the above-described methods when being executed on a computer or signal processor according to an embodiment is provided.

[0030] Preferred embodiments are provided in the dependent claims.

[0031] In the following, embodiments of the present invention are described in detail with reference to the figures, in which:

[0032] Fig. 1 illustrates a video encoder for encoding a video into a video data stream according to an embodiment.

[0033] Fig. 2 illustrates a video decoder for receiving a video data stream having a video stored therein according to an embodiment.

[0034] Fig. 3 illustrates a video encoder.

[0035] FH251023PCT-2025353027.DOCX Fig. 4 illustrates a video decoder.

[0036] Fig. 5 illustrates the relationship between the reconstructed signal, e.g., the reconstructed picture, on the one hand, and the combination of the prediction residual signal as signaled in the data stream, and the prediction signal, on the other hand.

[0037] Fig. 1 illustrates a video encoder 100 for encoding a video into a video data stream according to an embodiment.

[0038] The video encoder 100 is configured to generate the video data stream such that the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. Furthermore, the video encoder 100 is configured to generate the video data stream such that the video data stream comprises a size indication.

[0039] If the size indication is equal to a predefined value, the one or more messages are exactly one message and the payload of the packet comprises the payload of the exactly one message.

[0040] According to an embodiment, if the size indication is equal to the predefined value, a size of the payload of the exactly one message may, e.g., depend on a size of a payload of the packet and may, e.g., depend on a size of a header or on a size of metadata information of the exactly one message.

[0041] In an embodiment, if the size indication is equal to the predefined value, the size of the payload of the exactly one message may, e.g., be equal to a size of the payload of the packet minus the size of the header or minus the size of the metadata information of the exactly one message.

[0042] According to an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the packet is a NAL unit. The video encoder 100 may, e.g., be configured to generate the video data stream such that the one or more messages are one or more SEI messages.

[0043] In an embodiment, the size indication may, e.g., be an integer value; or he size indication may, e.g., be a flag.

[0044] FH251023PCT-2025353027.DOCX According to an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that a header or metadata information of one of the one or more messages comprises the size indication.

[0045] In an embodiment, if the size indication is different from the predefined value, the size indication indicates a size of a payload of one of the one or more messages, or indicates the size of the payload of said one of the one or more messages minus a predefined value or plus a predefined value, or indicates a length in bytes of the syntax element that indicates the size of the payload of the one or more messages encapsulated in the same NAL unit.

[0046] According to an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the predefined value is 0.

[0047] If the size indication is equal to 0, the one or more messages are exactly one message, the payload of the packet comprises the payload of the exactly one message, the size of the payload of the exactly one message is equal to a size of a payload of the packet minus a size of a header or minus a size of metadata information of the exactly one message;

[0048] If the size indication is different from 0, the size indication indicates a size of a pay load of one of the one or more messages minus 1.

[0049] In an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the size indication applies to two or more messages being encapsulated by the packet.

[0050] According to an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the size indication is an 8 bit information (payload_size_byte_plusl) or is a 16 bit information (lsei_payload_size_16bits_plusl).

[0051] In an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the packet is a NAL unit. The video encoder 100 may, e.g., be configured to generate the video data stream such that the one or more messages are one or more SEI messages.

[0052] If the size indication is equal to the predefined value,

[0053] FH251023PCT-2025353027.DOCX the size of the payload payloadSize of the exactly one message is equal to NAL unit payload size minus a first constant number (e.g., 4) and the NAL unit contains a single SEI message payload.

[0054] According to an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the packet is a NAL unit. The video encoder 100 may, e.g., be configured to generate the video data stream such that the one or more messages are one or more SEI messages.

[0055] If the size indication is equal to the predefined value, payloadSize = NAL unit payload size minus (a second constant number, e.g.

[0056] 2, + a number of payload type byte with a value equal to a third constant number, e.g. OxFF).

[0057] In an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the size indication is a payload size present flag. If the payload size present flag indicates a first value being the predefined value, payload size information indicating a size of a payload of one of the one more messages is not present in a header or in metadata information of said one of the one or more messages. If the payload size present flag indicates a second value being different from the predefined value, payload size information indicating a size of a payload of one of the one more messages is present in the header or in metadata information of said one of the one or more messages and indicates the size of the payload of said one of the one more messages.

[0058] According to an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the size indication is an 8 bit information (payload size byte) or is a 16 bit information (lsei_payload_size_ 16bits) .

[0059] In an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the packet is a NAL unit. The video encoder 100 may, e.g., be configured to generate the video data stream such that the one or more messages are one or more SEI messages. If the payload size present flag is equal to the second value being different from the predefined value, the payload size information is a size value which indicates the size of the payload of said one of the one or more messages. If the payload size present flag is equal to the predefined value, the size of the payload of said one of the one or more messages being exactly one message is equal to NAL unit payload size minus a first constant number (e.g., 4) and the NAL unit contains a single SEI message payload.

[0060] According to an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the payload size present flag and / or the payload size information apply to two or more messages being encapsulated by the packet.

[0061] FH251023PCT-2025353027.DOCX In an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the packet comprises properties information comprising information on the one or more messages being encapsulated by the packet.

[0062] According to an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the packet comprises the properties information comprising information on two or more messages being encapsulated by the packet.

[0063] In an embodiment, if the size indication is equal to the predefined value, a size of the payload of the exactly one message depends on a size of a payload of the packet and depends on a size of the properties information.

[0064] According to an embodiment, a video encoder 100 for encoding a video into a video data stream is provided. The video encoder 100 is configured to generate the video data stream such that the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. The video encoder 100 is configured to generate the video data stream such that the packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

[0065] According to an embodiment, the properties information may, e.g., comprise the size indication.

[0066] According to an embodiment, the video encoder 100 may, e.g., be configured to generate the video data stream such that the properties information comprises one or more of the following: information (e.g., sei_payload_size_length_in_bytes) indicating a length in bytes of the syntax element that indicates the size of the payload for each of the all sei_messages encapsulated in the same NAL unit; information (e.g., sei_affects_displayed_samples_flag) indicating whether processing / executing the SEI messages (all or at least one within the NAL unit) affects the decoded samples or display output (e.g., frame_packing, region_wise jacking, some kind of composition information, post filters); information (e.g., sei_same_scope_flag) indicating whether all SEI messages have the same scope (apply to the same amount of pictures / AUs);

[0067] FH251023PCT-2025353027.DOCX information (e.g., sei_applies_all_ols) indicating whether the SEI messages apply only to the current output layer set or all output layer sets (still applies when dropping a couple of layers); information (e.g., sei_essentiality_flag) indicating whether processing all contained SEI message is necessary to get a valid output or an output as intended by an encoder and / or indicating whether a receiver is expected to cease decoding or suppress picture output in case it cannot interpret all of the contained SEI messages; information (e.g., sei_preceding_vlc_nal_flag) indicating whether all contained SEI messages apply to the following VCL NAL units or to the preceding VCL NAL units; information (e.g., sei_post_encoding_flag) indicating whether all contained SEI messages have been generated or inserted into the video data stream by the video encoder 100 or by another device after encoding has been carried out (e.g., at a network device); information (e.g., sei_repetition_flag) indicating whether all contained SEI messages contain repeated SEI messages or whether the SEI messages are not a repetition (e.g., first time within the picture or access unit).

[0068] Fig. 2 illustrates a video decoder 200 for receiving a video data stream having a video stored therein according to an embodiment. The video decoder 200 is configured to decode the video from the video data stream.

[0069] The video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages. Furthermore, the video data stream comprises a size indication

[0070] If the size indication is equal to a predefined value, the one or more messages are exactly one message, and the payload of the packet comprises the payload of the exactly one message.

[0071] According to an embodiment, if the size indication is equal to the predefined value, a size of the payload of the exactly one message may, e.g., depend on a size of a payload of the packet and may, e.g., depend on a size of a header or on a size of metadata information of the exactly one message.

[0072] FH251023PCT-2025353027.DOCX In an embodiment, if the size indication is equal to the predefined value, the size of the payload of the exactly one message may, e.g., be equal to a size of the payload of the packet minus the size of the header or minus the size of the metadata information of the exactly one message.

[0073] According to an embodiment, the packet is a NAL unit. The one or more messages are one or more SEI messages.

[0074] In an embodiment, the size indication may, e.g., be an integer value; or he size indication may, e.g., be a flag.

[0075] According to an embodiment, a header or metadata information of one of the one or more messages comprises the size indication.

[0076] In an embodiment, if the size indication is different from the predefined value, the size indication indicates a size of a payload of one of the one or more messages, or indicates the size of the payload of said one of the one or more messages minus a predefined value or plus a predefined value, or indicates a length in bytes of the syntax element that indicates the size of the payload of the one or more messages encapsulated in the same NAL unit.

[0077] According to an embodiment, the predefined value is 0,

[0078] If the size indication is equal to 0, the one or more messages are exactly one message, the payload of the packet comprises the payload of the exactly one message, the size of the payload of the exactly one message is equal to a size of a payload of the packet minus a size of a header or minus a size of metadata information of the exactly one message;

[0079] If the size indication is different from 0, the size indication indicates a size of a pay load of one of the one or more messages minus 1.

[0080] In an embodiment, the size indication applies to two or more messages being encapsulated by the packet.

[0081] FH251023PCT-2025353027.DOCX According to an embodiment, the size indication is an 8 bit information (payload_size_byte_plusl) or is a 16 bit information (lsei_payload_size_16bits_plusl).

[0082] In an embodiment, the packet is a NAL unit. The one or more messages are one or more SEI messages.

[0083] If the size indication is equal to the predefined value, the size of the payload payloadSize of the exactly one message is equal to

[0084] NAL unit payload size minus a first constant number (e.g., 4) and the NAL unit contains a single SEI message payload.

[0085] According to an embodiment, the packet is a NAL unit. The one or more messages are one or more SEI messages.

[0086] If the size indication is equal to the predefined value, payloadSize = NAL unit payload size minus (a second constant number, e.g.

[0087] 2, + a number of payload type byte with a value equal to a third constant number, e.g. OxFF).

[0088] In an embodiment, the size indication is a payload size present flag.

[0089] If the payload size present flag indicates a first value being the predefined value, payload size information indicating a size of a payload of one of the one more messages is not present in a header or in metadata information of said one of the one or more messages.

[0090] If the payload size present flag indicates a second value being different from the predefined value, payload size information indicating a size of a payload of one of the one more messages is present in the header or in metadata information of said one of the one or more messages and indicates the size of the payload of said one of the one more messages.

[0091] According to an embodiment, the size indication is an 8 bit information (payload size byte) or is a 16 bit information (lsei_payload_size_16bits).

[0092] In an embodiment, the packet is a NAL unit. The one or more messages are one or more SEI messages,

[0093] FH251023PCT-2025353027.DOCX If the payload size present flag is equal to the second value being different from the predefined value, the payload size information is a size value which indicates the size of the payload of said one of the one or more messages.

[0094] If the payload size present flag is equal to the predefined value, the size of the payload of said one of the one or more messages being exactly one message is equal to NAL unit payload size minus a first constant number (e.g., 4) and the NAL unit contains a single SEI message payload.

[0095] According to an embodiment, the payload size present flag and / or the payload size information apply to two or more messages being encapsulated by the packet.

[0096] In an embodiment, the packet comprises properties information comprising information on the one or more messages being encapsulated by the packet.

[0097] According to an embodiment, the packet comprises properties information comprising information on two or more messages being encapsulated by the packet.

[0098] In an embodiment, if the size indication is equal to the predefined value, a size of the payload of the exactly one message depends on a size of a payload of the packet and depends on a size of the properties information.

[0099] According to an embodiment, a video decoder 200 for receiving a video data stream having a video stored therein is provided. The video decoder 200 is configured to decode the video from the video data stream. The video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages. The packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

[0100] According to an embodiment, the properties information may, e.g., comprise the size indication.

[0101] According to an embodiment, the properties information comprises one or more of the following: information (e.g., sei_payload_size_length_in_bytes) indicating a length in bytes of the syntax element that indicates the size of the payload for each of the all sei_messages encapsulated in the same NAL unit; information (e.g., sei_affects_displayed_samples_flag) indicating whether processing / executing the SEI messages (all or at least one within the NAL unit) affects the

[0102] FH251023PCT-2025353027.DOCX decoded samples or display output (e.g., frame_packing, region_wise jacking, some kind of composition information, post fdters); information (e.g., sei_same_scope_flag) indicating whether all SEI messages have the same scope (apply to the same amount of pictures / AUs); information (e.g., sei_applies_all ls) indicating whether the SEI messages apply only to the current output layer set or all output layer sets (still applies when dropping a couple of layers); information (e.g., sei_essentiality_flag) indicating whether processing all contained SEI message is necessary to get a valid output or an output as intended by an encoder and / or indicating whether a receiver is expected to cease decoding or suppress picture output in case it cannot interpret all of the contained SEI messages. For example, in response to receiving said information (e.g., sei_essentiality_flag), the video decoder 200 is configured to cease decoding or suppress picture output in case it cannot interpret all of the contained SEI messages; information (e.g., sei receding_vlc al_flag) indicating whether all contained SEI messages apply to the following VCL NAL units or to the preceding VCL NAL units; information (e.g., sei jost_encoding_flag) indicating whether all contained SEI messages have been generated or inserted into the video data stream by a video encoder or by another device after encoding has been carried out (e.g., at a network device); information (e.g., sei_repetition_flag) indicating whether all contained SEI messages contain repeated SEI messages or whether the SEI messages are not a repetition (e.g., first time within the picture or access unit).

[0103] In an embodiment, the video decoder 200 is configured to decode the video from the video data stream and / or to parse the video data stream and / or to process the video data stream depending on the size indication.

[0104] Furthermore, a video data stream according to an embodiment is provided. The video data stream has a video comprising a plurality of pictures encoded therein. Moreover, the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet

[0105] FH251023PCT-2025353027.DOCX comprises a payload of each of one or more messages. The video data stream comprises a size indication.

[0106] Moreover, a video data stream according to an embodiment is provided. The video data stream has a video comprising a plurality of pictures encoded therein. Moreover, the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages. The packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

[0107] Furthermore, a system according to an embodiment is provided. The system comprises a video encoder as described above for encoding a video into a video data stream. Furthermore, the system comprises a video decoder as described above for decoding the video from the video data stream being generated by the video encoder.

[0108] The following description of the figures starts with a presentation of a description of an encoder and a decoder of a block-based predictive codec for coding pictures of a video in order to form an example for a coding framework into which embodiments of the present invention may be built in. The respective encoder and decoder are described with respect to Fig. 3 to Fig. 5. Thereinafter the description of embodiments of the concept of the present invention is presented along with a description as to how such concepts could be built into the encoder and decoder of Fig. 3 and Fig. 4, respectively, although the embodiments described with Fig. 1 to Fig. 2 and following, may also be used to form encoders and decoders not operating according to the coding framework underlying the encoder and decoder of Fig. 3 and Fig. 4.

[0109] Fig. 3 shows a video encoder, an apparatus for predict! vely coding a picture 12 into a data stream 14 exemplarily using transform-based residual coding. The apparatus, or encoder, is indicated using reference sign 10. Fig. 4 shows a corresponding video decoder 20, e.g., an apparatus 20 configured to predictively decode the picture 12’ from the data stream 14 also using transform-based residual decoding, wherein the apostrophe has been used to indicate that the picture 12’ as reconstructed by the decoder 20 deviates from picture 12 originally encoded by apparatus 10 in terms of coding loss introduced by a quantization of the prediction residual signal. Fig. 3 and Fig. 4 exemplarily use transform based prediction residual coding, although embodiments of the present application are not restricted to this kind of prediction residual coding. This is true for other details described with respect to Fig. 3 and Fig. 4, too, as will be outlined hereinafter.

[0110] The encoder 10 is configured to subject the prediction residual signal to spatial-to-spectral transformation and to encode the prediction residual signal, thus obtained, into the data stream 14.

[0111] FH251023PCT-2025353027.DOCX Likewise, the decoder 20 is configured to decode the prediction residual signal from the data stream 14 and subject the prediction residual signal thus obtained to spectral-to-spatial transformation.

[0112] Internally, the encoder 10 may comprise a prediction residual signal former 22 which generates a prediction residual 24 so as to measure a deviation of a prediction signal 26 from the original signal, e.g., from the picture 12. The prediction residual signal former 22 may, for instance, be a subtractor which subtracts the prediction signal from the original signal, e.g., from the picture 12. The encoder 10 then further comprises a transformer 28 which subjects the prediction residual signal 24 to a spatial-to-spectral transformation to obtain a spectral-domain prediction residual signal 24’ which is then subject to quantization by a quantizer 32, also comprised by the encoder 10. The thus quantized prediction residual signal 24” is coded into bitstream 14. To this end, encoder 10 may optionally comprise an entropy coder 34 which entropy codes the prediction residual signal as transformed and quantized into data stream 14. The prediction signal 26 is generated by a prediction stage 36 of encoder 10 on the basis of the prediction residual signal 24” encoded into, and decodable from, data stream 14. To this end, the prediction stage 36 may internally, as is shown in Fig. 3, comprise a dequantizer 38 which dequantizes prediction residual signal 24” so as to gain spectral-domain prediction residual signal 24”’, which corresponds to signal 24’ except for quantization loss, followed by an inverse transformer 40 which subjects the latter prediction residual signal 24”’ to an inverse transformation, e.g., a spectral-to-spatial transformation, to obtain prediction residual signal 24””, which corresponds to the original prediction residual signal 24 except for quantization loss. A combiner 42 of the prediction stage 36 then recombines, such as by addition, the prediction signal 26 and the prediction residual signal 24”” so as to obtain a reconstructed signal 46, e.g., a reconstruction of the original signal 12. Reconstructed signal 46 may correspond to signal 12’. A prediction module 44 of prediction stage 36 then generates the prediction signal 26 on the basis of signal 46 by using, for instance, spatial prediction, e.g., intra-picture prediction, and / or temporal prediction, e.g., inter-picture prediction.

[0113] Likewise, decoder 20, as shown in Fig. 4, may be internally composed of components corresponding to, and interconnected in a manner corresponding to, prediction stage 36. In particular, entropy decoder 50 of decoder 20 may entropy decode the quantized spectral -domain prediction residual signal 24” from the data stream, whereupon dequantizer 52, inverse transformer 54, combiner 56 and prediction module 58, interconnected and cooperating in the manner described above with respect to the modules of prediction stage 36, recover the reconstructed signal on the basis of prediction residual signal 24” so that, as shown in Fig. 4, the output of combiner 56 results in the reconstructed signal, namely picture 12’.

[0114] Although not specifically described above, it is readily clear that the encoder 10 may set some coding parameters including, for instance, prediction modes, motion parameters and the like, according to

[0115] FH251023PCT-2025353027.DOCX some optimization scheme such as, for instance, in a manner optimizing some rate and distortion related criterion, e.g., coding cost. For example, encoder 10 and decoder 20 and the corresponding modules 44, 58, respectively, may support different prediction modes such as intra-coding modes and inter-coding modes. The granularity at which encoder and decoder switch between these prediction mode types may correspond to a subdivision of picture 12 and 12’, respectively, into coding segments or coding blocks. In units of these coding segments, for instance, the picture may be subdivided into blocks being intra-coded and blocks being inter-coded. Intra-coded blocks are predicted on the basis of a spatial, already coded / decoded neighborhood of the respective block as is outlined in more detail below. Several intra-coding modes may exist and be selected for a respective intra-coded segment including directional or angular intra-coding modes according to which the respective segment is fdled by extrapolating the sample values of the neighborhood along a certain direction which is specific for the respective directional intra-coding mode, into the respective intra- coded segment. The intra-coding modes may, for instance, also comprise one or more further modes such as a DC coding mode, according to which the prediction for the respective intra-coded block assigns a DC value to all samples within the respective intra-coded segment, and / or a planar intra- coding mode according to which the prediction of the respective block is approximated or determined to be a spatial distribution of sample values described by a two-dimensional linear function over the sample positions of the respective intra-coded block with driving tilt and offset of the plane defined by the two-dimensional linear function on the basis of the neighboring samples. Compared thereto, inter-coded blocks may be predicted, for instance, temporally. For inter-coded blocks, motion vectors may be signaled within the data stream, the motion vectors indicating the spatial displacement of the portion of a previously coded picture of the video to which picture 12 belongs, at which the previously coded / decoded picture is sampled in order to obtain the prediction signal for the respective inter-coded block. This means, in addition to the residual signal coding comprised by data stream 14, such as the entropy-coded transform coefficient levels representing the quantized spectral-domain prediction residual signal 24”, data stream 14 may have encoded thereinto coding mode parameters for assigning the coding modes to the various blocks, prediction parameters for some of the blocks, such as motion parameters for inter-coded segments, and optional further parameters such as parameters for controlling and signaling the subdivision of picture 12 and 12’, respectively, into the segments. The decoder 20 uses these parameters to subdivide the picture in the same manner as the encoder did, to assign the same prediction modes to the segments, and to perform the same prediction to result in the same prediction signal.

[0116] Fig. 5 illustrates the relationship between the reconstructed signal, e.g., the reconstructed picture 12’, on the one hand, and the combination of the prediction residual signal 24”” as signaled in the data stream 14, and the prediction signal 26, on the other hand. As already denoted above, the combination may be an addition. The prediction signal 26 is illustrated in Fig. 5 as a subdivision of the picture area into intra-coded blocks which are illustratively indicated using hatching, and inter-coded blocks

[0117] FH251023PCT-2025353027.DOCX which are illustratively indicated not-hatched. The subdivision may be any subdivision, such as a regular subdivision of the picture area into rows and columns of square blocks or non-square blocks, or a multi-tree subdivision of picture 12 from a tree root block into a plurality of leaf blocks of varying size, such as a quadtree subdivision or the like, wherein a mixture thereof is illustrated in Fig. 5 in which the picture area is first subdivided into rows and columns of tree root blocks which are then further subdivided in accordance with a recursive multi -tree subdivisioning into one or more leaf blocks.

[0118] Again, data stream 14 may have an intra-coding mode coded thereinto for intra-coded blocks 80, which assigns one of several supported intra-coding modes to the respective intra-coded block 80. For inter-coded blocks 82, the data stream 14 may have one or more motion parameters coded thereinto. Generally speaking, inter-coded blocks 82 are not restricted to being temporally coded. Alternatively, inter-coded blocks 82 may be any block predicted from previously coded portions beyond the current picture 12 itself, such as previously coded pictures of a video to which picture 12 belongs, or picture of another view or an hierarchically lower layer in the case of encoder and decoder being scalable encoders and decoders, respectively.

[0119] The prediction residual signal 24”” in Fig. 5 is also illustrated as a subdivision of the picture area into blocks 84. These blocks might be called transform blocks in order to distinguish same from the coding blocks 80 and 82. In effect, Fig. 5 illustrates that encoder 10 and decoder 20 may use two different subdivisions of picture 12 and picture 12’, respectively, into blocks, namely one subdivisioning into coding blocks 80 and 82, respectively, and another subdivision into transform blocks 84. Both subdivisions might be the same, e.g., each coding block 80 and 82, may concurrently form a transform block 84, but Fig. 5 illustrates the case where, for instance, a subdivision into transform blocks 84 forms an extension of the subdivision into coding blocks 80, 82 so that any border between two blocks of blocks 80 and 82 overlays a border between two blocks 84, or alternatively speaking each block 80, 82 either coincides with one of the transform blocks 84 or coincides with a cluster of transform blocks 84. However, the subdivisions may also be determined or selected independent from each other so that transform blocks 84 could alternatively cross block borders between blocks 80, 82. As far as the subdivision into transform blocks 84 is concerned, similar statements are thus true as those brought forward with respect to the subdivision into blocks 80, 82, e.g., the blocks 84 may be the result of a regular subdivision of picture area into blocks (with or without arrangement into rows and columns), the result of a recursive multi-tree subdivisioning of the picture area, or a combination thereof or any other sort of blockation. Just as an aside, it is noted that blocks 80, 82 and 84 are not restricted to being of quadratic, rectangular or any other shape.

[0120] Fig. 5 further illustrates that the combination of the prediction signal 26 and the prediction residual signal 24”” directly results in the reconstructed signal 12’. However, it should be noted that more

[0121] FH251023PCT-2025353027.DOCX than one prediction signal 26 may be combined with the prediction residual signal 24”” to result into picture 12’ in accordance with alternative embodiments.

[0122] In Fig. 5, the transform blocks 84 shall have the following significance. Transformer 28 and inverse transformer 54 perform their transformations in units of these transform blocks 84. For instance, many codecs use some sort of DST or DCT for all transform blocks 84. Some codecs allow for skipping the transformation so that, for some of the transform blocks 84, the prediction residual signal is coded in the spatial domain directly. However, in accordance with embodiments described below, encoder 10 and decoder 20 are configured in such a manner that they support several transforms. For example, the transforms supported by encoder 10 and decoder 20 could comprise: o DCT-II (or DCT-III), where DCT stands for Discrete Cosine Transform o DST-IV, where DST stands for Discrete Sine Transform o DCT-IV o DST-VII o Identity Transformation (IT)

[0123] Naturally, while transformer 28 would support all of the forward transform versions of these transforms, the decoder 20 or inverse transformer 54 would support the corresponding backward or inverse versions thereof: o Inverse DCT-II (or inverse DCT-III) o Inverse DST-IV o Inverse DCT-IV o Inverse DST-VII o Identity Transformation (IT)

[0124] The subsequent description provides more details on which transforms could be supported by encoder 10 and decoder 20. In any case, it should be noted that the set of supported transforms may comprise merely one transform such as one spectral -to-spatial or spatial-to-spectral transform.

[0125] As already outlined above, Fig. 3 to Fig. 5 have been presented as an example where the inventive concept described further below may be implemented in order to form specific examples for encoders and decoders according to the present application. Insofar, the encoder and decoder of Fig. 3 and Fig.

[0126] 4, respectively, may represent possible implementations of the encoders and decoders described herein below. Fig. 3 and Fig. 4 are, however, only examples. An encoder according to embodiments of the present application may, however, perform block-based encoding of a picture 12 using the concept outlined in more detail below and being different from the encoder of Fig. 3 such as, for

[0127] FH251023PCT-2025353027.DOCX instance, in that same is no video encoder, but a still picture encoder, in that same does not support inter-prediction, or in that the sub-division into blocks 80 is performed in a manner different than exemplified in Fig. 5. Likewise, decoders according to embodiments of the present application may perform block-based decoding of picture 12’ from data stream 14 using the coding concept further outlined below, but may differ, for instance, from the decoder 20 of Fig. 4 in that same is no video decoder, but a still picture decoder, in that same does not support intra-prediction, or in that same sub-divides picture 12’ into blocks in a manner different than described with respect to Fig. 5 and / or in that same does not derive the prediction residual from the data stream 14 in transform domain, but in spatial domain, for instance.

[0128] Embodiments realize SEI message signalling improvements.

[0129] In the following, technologies for which embodiments may be employed are described.

[0130] SEI messages are an important signalling mechanism in video codecs such as H.264, H.265 and H.266 that allow in-bitstream transport of meta data and information. Some such messages are irrelevant for the decoding process, but some others are related to buffer and timing conformance testing and are therefore vital to ensure a standard conformance of a decoder. Embodiments relate to overcoming shortcomings of current SEI message signalling design in the respective standards as well as proposed solutions for future video coding standards.

[0131] The SEI message design in H.264 and H.265 is basically similar to the design in H.266 which is given in the following. A special NAL unit syntax is defined that carried one or more messages within. This syntax can be carried as NAL unit of two types with either precedes or follows the applicable VCL NAL units.

[0132] VVC Supplemental enhancement information message syntax

[0133] FH251023PCT-2025353027.DOCX

[0134] With the following semantics:

[0135] VVC Supplemental enhancement information message semantics

[0136] Each SEI message consists of the variables specifying the type payloadType and size payloadSize of the SEI message payload. SEI message payloads are specified in Annex D. The derived SEI message payload size payloadSize is specified in bytes and shall be equal to the number of RBSP bytes in the SEI message payload.

[0137] NOTE - The NAL unit byte sequence containing the SEI message might include one or more emulation prevention bytes (represented by emulation_prevention_three_byte syntax elements). Since the payload size of an SEI message is specified in RBSP bytes, the quantity of emulation prevention bytes is not included in the size payloadSize of an SEI payload. payload_type_byte is a byte of the payload type of an SEI message. payload_size_byte is a byte of the payload size of an SEI message.

[0138] Currently, as a technology under discussion (TUC), the following design for SEI messages in future video coding standards is documented.

[0139] TUC Supplemental enhancement information message syntax

[0140] With the following semantics:

[0141] TUC Earge Supplemental enhancement information message semantics

[0142] FH251023PCT-2025353027.DOCX Each Large SEI message consists of the variables specifying the type payloadType and size payloadSize of the large SEI message payload. Large SEI message payloads are specified in Annex D. The derived Large SEI message payload size payloadSize is specified in bytes and shall be equal to the number of RBSP bytes in the Large SEI message payload.

[0143] NOTE - The NAL unit byte sequence containing the Large SEI message might include one or more emulation prevention bytes (represented by emulation_prevention_three_byte syntax elements). Since the payload size of a Large SEI message is specified in RBSP bytes, the quantity of emulation prevention bytes is not included in the size payloadSize of a Large SEI payload. lsei_position indicates if the SEI message corresponds to the PREFIX SEI NUT and SUFFIX_SEI_NUT. lsei_position equal 0 indicates that the SEI message is treated as PREFIX SEI NUT. lsei_position equal 1 indicates that the SEI message is treated as SUFFIX_SEI_NUT. Values 3 and 4 of Isei position are reserved for future use and shall be ignored. lsei_relevance indicates the relevance of the SEI message for the target application. lsei_relevance ranges from 0 to 3, 0 being the least relevant and 3 being the most relevant.

[0144] NOTE - The relevance of an SEI message is an arbitrary decision and its use is to be specified by the target application. lsei_reserved is revered for future use and shall be ignored. lsei_payload_type_byte is a byte of the payload type of a large SEI message. payloadType =

[0145] Isei payload type byte. lsei_payload_size_16bits is the payload size in bits of a large SEI message. payloadSize = lsei_payload_size_16bits.

[0146] It should be noted that the TUC design could also be used to indicate the payload size in byte, which is the approach used in the remainder of the document.

[0147] Either one of the above NAL units syntax structures carries the one or more SEI message payloads as follows (taken from H.266):

[0148] A.1.1 General SEI payload syntax

[0149] FH251023PCT-2025353027.DOCX

[0150] FH251023PCT-2025353027.DOCX

[0151] With the following semantics:

[0152] A.1.2 General SEI payload semantics sei_reserved_payload_extension_data shall not be present in bitstreams conforming to this version of this Specification. However, decoders conforming to this version of this Specification shall ignore the presence and value of sei_reserved_payload_extension_data. When present, the length, in bits, of sei_reserved_payload_extension_data is equal to

[0153] 8 * payloadSize - nEarlierBits - nPayloadZeroBits - 1, where nEarlierBits is the number of bits in the sei_payload( ) syntax structure that precede the sci rcscrvcdjiayload cxtcnsion data syntax element, and nPayloadZeroBits is the number of sei_payload_bit_equal_to_zero syntax elements at the end of the sei_payload( ) syntax structure.

[0154] If more_data_in_payload( ) is TRUE after the parsing of the SEI message syntax structure (e.g., the buffering_period( ) syntax structure) and nPayloadZeroBits is not equal to 7, PayloadBits is set equal to 8 * payloadSize - nPayloadZeroBits - 1; otherwise, PayloadBits is set equal to 8 * payloadSize. payload bit equal to one shall be equal to 1. payload bit equal to zero shall be equal to 0.

[0155] FH251023PCT-2025353027.DOCX NOTE 1 - SEI messages with the same value of payloadType are conceptually the same SEI message regardless of whether they are contained in prefix or suffix SEI NAL units.

[0156] NOTE 2 - For SEI messages specified in this Specification and the VSEI specification (ITU-T H.274 | ISO / IEC 23002-7), the payloadType values are aligned with similar SEI messages specified in AVC (Rec. ITU-T H.264 | ISO / IEC 14496-10) and HEVC (Rec. ITU-T H.265 | ISO / IEC 23008-2).

[0157] Note the SEI reserved payload extension data at the end of the syntax structure.

[0158] The VVC SEI message syntax introduces considerable overhead for large SEI message payloads through the necessary signalling of many OxFF bytes. The TUC SEI message design alleviates this problem by introducing a larger two byte syntax element for the size. However, the TUC design cannot accommodate SEI messages that have a size larger than the maximum range of lsei_payload_size_16bits, i.e. 16 Bits are available to indicate a payload size of 64KB. Second, transport of small SEI messages such as Constrained RASL encoding indication SEI message (0 bytes lengths) or are burdened by indicating two useless payload size bytes with a value of 0x00 and same goes for other small SEI messages with sizes unequal to 0.

[0159] In the following, particular embodiments addressing these two outlined problems are provided:

[0160] In particular, the two outlined problems are overcome by introducing additional signalling to indicate that the following constraints are active:

[0161] • The (SEI message) NAL unit hosts one and only one SEI message payload.

[0162] • The SEI message payload is equal to the NAL unit payload size minus SEI message header.

[0163] In one embodiment, the payload size is indicated as value plus 1, e.g. lsei_payload_size_16bits_plus_l or payload size byte plus l and a signalled value of 0 indicates the above listed constraints. The following shows integration into the TUC design.

[0164] FH251023PCT-2025353027.DOCX

[0165] Isei payload size 16bits plus 1 minus 1 is the payload size in bits of a large SEI message. When Isei payload size 16bits plusl is greater than 0, payloadSize = lsei_payload_size_16bits_plusl - 1, otherwise. payloadSize is equal to NAL unit payload size minus 4 and the (SEI message) NAL unit contains a single SEI message payload. It should be noted that the value of 4 in 4 bytes stems from the respective size of the lsei_message( ) structure and may be adjusted to whatever size the respecitve strucutre assumes in a given technical standard.

[0166] The following shows integration into the VVC design. payload size byte plusl minus 1 is a byte of the payload size of an SEI message. When the value of the first occurance of payload sizes plusl is equal 0, the SEI message NAL unit contains a single SEI message payload.

[0167] In another embodiment, an additional flag lsei_payload_size_present_flag indicates the above listed constraints. The following shows an integration into the TUC design.

[0168] FH251023PCT-2025353027.DOCX

[0169] Isei payload size present flag equal to 1 indicates that Isei payload size 16bits is present in the Isei message sytnax structure. Isei payload size present flag equal to 0 indicates that Isei payload size 16bits is not present in the Isei message sytnax structure. lsei_payload_size_16bits is the payload size in bits of a large SEI message. When Isei payload size present flag equal to 1, payloadSize = Isei payload size 16bits. otherwise (Isei payload size present flag equal to 0), payloadSize is equal to NAL unit payload size minus 4 and the SEI message NAL unit contains a single SEI message payload. As mentioned above, the number of 4 may be adjusted to the length of the respective syntax structure in a given technical standard.

[0170] The following shows integration into the VVC design.

[0171] FH251023PCT-2025353027.DOCX payload_size_byte is a byte of the payload size of an SEI message. When Isei payload size present flag equal to 1, the SEI message NAL unit contains a single SEI message payload. Note that all syntax examples correspond to each of the SEI messages in an SEI NAL unit, i.e. the following SEI RBSP syntax.

[0172] Currently such an SEI message, only encapsulates several sei_message() structures. As an alternative to what it has been described above, some of the syntax that is discussed above could be included in this structure and apply to all sei_message() structures included inside. E.g., payload_size_present_flag or even something like sei_payload_size_length_in_bytes that is used within sei_message() (the later shown in the following example with the payload size indicated as plus 1 just as an example).

[0173] FH251023PCT-2025353027.DOCX

[0174] Alternatively, the seijayload_size_length_in_bytes syntax element could be sei jayload_size_length_in_bytes jlusl, the zero indicating that there is no payload size indicated in the sei_message() structure and therefore only one is present and extend until the end of the sei bps() structure, i.e. until the last byte of the payload of the SEI NAL unit.

[0175] Similarly, in a further embodiment, as done for sei_payload_size_length_in_bytes a generalized signalling mechanism is added to sei_rbsp to indicate properties of the encapsulated sei_message() structures. Such a mechanism could indicate properties of all the SEI messages within the NAL unit or some of them of a particular type. The integration for such an structure is shown in the following.

[0176] Example of the properties shown above could be as follows: sei payload size length in bytes indicates the length in bytes of the syntax element that indicates the size of the payload for each of the all sei_messages encapsulated in the same NAL unit. sei affects displayed samples flag indicates whether processing / executing the SEI messages (all or at least one within the NAL unit) affects the decoded samples or display output (e.g., frame jacking, region_wise jacking, some kind of composition information, post fdters).

[0177] FH251023PCT-2025353027.DOCX sei same scope flag indicates whether all SEI messages have the same scope (apply to the same amount of pictures / AUs). sei applies all ols indicates whether the SEI messages apply only to the current output layer set or all output layer sets (still applies when dropping a couple of layers). sei essentiality flag indicates whether a receiver is expected to cease decoding or suppress picture output in case it cannot interpret all of the contained SEI messages.

[0178] Further examples for properties could include the following: sei_preceding_vlc_nal_flag indicates whether all contained SEI messages apply to the following VCL NAL units or to the preceding VCL NAL units sei_post_encoding_flag indicates whether all contained SEI messages have been generated or inserted into the video data stream by a video encoder or by another device after encoding has been carried out (e.g., at a network device) sei_repetition_flag indicates whether all contained SEI messages contain repeated SEI messages or whether the SEI messages are not a repetition (e.g., first time within the picture or access unit)

[0179] Such properties could have a fixed length, e.g. 8 bits or 16 bits, or could be adaptive and a size would be indicated.

[0180] It should be pointed out that in the last examples there is a length indicated in the sei_rbsp() structure (the structure encapsulating one or more sei messages) that indicates the length of the field present in each of the sei_message() that indicates the size of the payload in each of the sei_message() structures. Combining this aspect, which indicates the length of the size indication in each sei_message() structure, with the first aspect indicating a predetermined value that means that an SEI message extends until the end of the sei_rbsp() / NAL unit, a value equal to 0 could be indicated for the length field (sei_payload_size_length_in_bytes), which would mean that there is no size field present within sei_message(), which would imply that there is only one message and that it expands to the end of the NAL unit, saving thus the bytes to indicate at the sei_message() level the predetermined value.

[0181] Although some aspects have been described in the context of an apparatus, it is clear that these aspects also represent a description of the corresponding method, where a block or device corresponds to a method step or a feature of a method step. Analogously, aspects described in the

[0182] FH251023PCT-2025353027.DOCX context of a method step also represent a description of a corresponding block or item or feature of a corresponding apparatus. Some or all of the method steps may be executed by (or using) a hardware apparatus, like for example, a microprocessor, a programmable computer or an electronic circuit. In some embodiments, one or more of the most important method steps may be executed by such an apparatus.

[0183] Depending on certain implementation requirements, embodiments of the invention can be implemented in hardware or in software or at least partially in hardware or at least partially in software. The implementation can be performed using a digital storage medium, for example a floppy disk, a DVD, a Blu-Ray, a CD, a ROM, a PROM, an EPROM, an EEPROM or a FLASH memory, having electronically readable control signals stored thereon, which cooperate (or are capable of cooperating) with a programmable computer system such that the respective method is performed. Therefore, the digital storage medium may be computer readable.

[0184] Some embodiments according to the invention comprise a data carrier having electronically readable control signals, which are capable of cooperating with a programmable computer system, such that one of the methods described herein is performed.

[0185] Generally, embodiments of the present invention can be implemented as a computer program product with a program code, the program code being operative for performing one of the methods when the computer program product runs on a computer. The program code may for example be stored on a machine readable carrier.

[0186] Other embodiments comprise the computer program for performing one of the methods described herein, stored on a machine readable carrier.

[0187] In other words, an embodiment of the inventive method is, therefore, a computer program having a program code for performing one of the methods described herein, when the computer program runs on a computer.

[0188] A further embodiment of the inventive methods is, therefore, a data carrier (or a digital storage medium, or a computer-readable medium) comprising, recorded thereon, the computer program for performing one of the methods described herein. The data carrier, the digital storage medium or the recorded medium are typically tangible and / or non-transitory.

[0189] A further embodiment of the inventive method is, therefore, a data stream or a sequence of signals representing the computer program for performing one of the methods described herein. The data

[0190] FH251023PCT-2025353027.DOCX stream or the sequence of signals may for example be configured to be transferred via a data communication connection, for example via the Internet.

[0191] A further embodiment comprises a processing means, for example a computer, or a programmable logic device, configured to or adapted to perform one of the methods described herein.

[0192] A further embodiment comprises a computer having installed thereon the computer program for performing one of the methods described herein.

[0193] A further embodiment according to the invention comprises an apparatus or a system configured to transfer (for example, electronically or optically) a computer program for performing one of the methods described herein to a receiver. The receiver may, for example, be a computer, a mobile device, a memory device or the like. The apparatus or system may, for example, comprise a file server for transferring the computer program to the receiver.

[0194] In some embodiments, a programmable logic device (for example a field programmable gate array) may be used to perform some or all of the functionalities of the methods described herein. In some embodiments, a field programmable gate array may cooperate with a microprocessor in order to perform one of the methods described herein. Generally, the methods are preferably performed by any hardware apparatus.

[0195] The apparatus described herein may be implemented using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

[0196] The methods described herein may be performed using a hardware apparatus, or using a computer, or using a combination of a hardware apparatus and a computer.

[0197] The above described embodiments are merely illustrative for the principles of the present invention. It is understood that modifications and variations of the arrangements and the details described herein will be apparent to others skilled in the art. It is the intent, therefore, to be limited only by the scope of the impending patent claims and not by the specific details presented by way of description and explanation of the embodiments herein.

[0198] FH251023PCT-2025353027.DOCX

Claims

Claims1. A video encoder (100), wherein the video encoder (100) is configured to encode a video comprising a plurality of pictures into a video data stream, wherein the video encoder ( 100) is configured to generate the video data stream such that the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages, wherein the video encoder ( 100) is configured to generate the video data stream such that the video data stream comprises a size indication, wherein, if the size indication is equal to a predefined value, the one or more messages are exactly one message, and the payload of the packet comprises the payload of the exactly one message.

2. A video encoder (100) according to claim 1, wherein, if the size indication is equal to the predefined value, a size of the payload of the exactly one message depends on a size of a payload of the packet and depends on a size of a header or on a size of metadata information of the exactly one message.

3. A video encoder ( 100) according to claim 2, wherein, if the size indication is equal to the predefined value, the size of the payload of the exactly one message is equal to a size of the payload of the packet minus the size of the header or minus the size of the metadata information of the exactly one message.

4. A video encoder (100) according to one of the preceding claims,FH251023PCT-2025353027.DOCXwherein the video encoder ( 100) is configured to generate the video data stream such that the packet is a NAL unit, and wherein the video encoder ( 100) is configured to generate the video data stream such that the one or more messages are one or more SEI messages.

5. A video encoder (300) according to one of the preceding claims, wherein the size indication is an integer value; or wherein the size indication is a flag.

6. A video encoder (100) according to one of the preceding claims, wherein the video encoder (100) is configured to generate the video data stream such that a header or metadata information of one of the one or more messages comprises the size indication.

7. A video encoder (100) according to one of the preceding claims, wherein, if the size indication is different from the predefined value, the size indication indicates a size of a payload of one of the one or more messages, or indicates the size of the payload of said one of the one or more messages minus a predefined value or plus a predefined value, or indicates a length in bytes of the syntax element that indicates the size of the payload of the one or more messages encapsulated in the same NAL unit.

8. A video encoder (100) according to claim 7, wherein the video encoder ( 100) is configured to generate the video data stream such that the predefined value is 0, wherein, if the size indication is equal to 0,FH251023PCT-2025353027.DOCXthe one or more messages are exactly one message, the payload of the packet comprises the payload of the exactly one message, the size of the payload of the exactly one message is equal to a size of a payload of the packet minus a size of a header or minus a size of metadata information of the exactly one message; wherein, if the size indication is different from 0, the size indication indicates a size of a payload of one of the one or more messages minus 1.

9. A video encoder (100) according to one of the preceding claims, wherein the video encoder ( 100) is configured to generate the video data stream such that the size indication applies to two or more messages being encapsulated by the packet.

10. A video encoder (100) according to one of claims 7 to 9, wherein the video encoder ( 100) is configured to generate the video data stream such that the size indication is an 8 bit information (payload_size_byte_plusl) or is a 16 bit information (lsei_payload_size_ 16bits_plus 1 ) .

11. A video encoder (100) according to one of claims 7 to 10, wherein the video encoder ( 100) is configured to generate the video data stream such that the packet is a NAL unit, and wherein the video encoder ( 100) is configured to generate the video data stream such that the one or more messages are one or more SEI messages, wherein, if the size indication is equal to the predefined value, the size of the payload payloadSize of the exactly one message is equal to NAL unit payload size minus a first constant number (e.g., 4) and the NAL unit contains a single SEI message payload.FH251023PCT-2025353027.DOCX12. A video encoder (100) according to one of claims 7 to 10, wherein the video encoder (100) is configured to generate the video data stream such that the packet is a NAL unit, and wherein the video encoder ( 100) is configured to generate the video data stream such that the one or more messages are one or more SEI messages, wherein, if the size indication is equal to the predefined value, the size of the payload payloadSize of the exactly one message is equal to payloadSize = NAL unit payload size minus (a second constant number, e.g. 2, + a number of payload type byte with a value equal to a third constant number, e.g. OxFF).

13. A video encoder (100) according to one of claims 1 to 6, wherein the video encoder ( 100) is configured to generate the video data stream such that the size indication is a payload size present flag, wherein, if the payload size present flag indicates a first value being the predefined value, payload size information indicating a size of a payload of one of the one more messages is not present in a header or in metadata information of said one of the one or more messages, wherein, if the payload size present flag indicates a second value being different from the predefined value, payload size information indicating a size of a payload of one of the one more messages is present in the header or in metadata information of said one of the one or more messages and indicates the size of the payload of said one of the one more messages.

14. A video encoder (100) according to one of claims 1 to 6, wherein the video encoder ( 100) is configured to generate the video data stream such that the size indication is an 8 bit information (payload size byte) or is a 16 bit information (lsei_payload_size_l 6bits) .FH251023PCT-2025353027.DOCX15. A video encoder (100) according to claim 13 or 14, wherein the video encoder (100) is configured to generate the video data stream such that the packet is a NAL unit, and wherein the video encoder ( 100) is configured to generate the video data stream such that the one or more messages are one or more SEI messages, wherein if the payload size present flag is equal to the second value being different from the predefined value, the payload size information is a size value which indicates the size of the payload of said one of the one or more messages, wherein if the payload size present flag is equal to the predefined value, the size of the payload of said one of the one or more messages being exactly one message is equal to NAL unit payload size minus a first constant number (e.g., 4) and the NAL unit contains a single SEI message payload.

16. A video encoder (100) according to one of the preceding claims, wherein the video encoder ( 100) is configured to generate the video data stream such that the payload size present flag and / or the payload size information apply to two or more messages being encapsulated by the packet.

17. A video encoder (100) according to one of the preceding claims, wherein the video encoder ( 100) is configured to generate the video data stream such that the packet comprises properties information comprising information on the one or more messages being encapsulated by the packet.

18. A video encoder (100) according to claim 17, further depending on claim 9 or 16, wherein the video encoder ( 100) is configured to generate the video data stream such that the packet comprises the properties information comprising information on the two or more messages being encapsulated by the packet.

19. A video encoder (100) according to claim 17,FH251023PCT-2025353027.DOCXwherein, if the size indication is equal to the predefined value, the video encoder (100) is configured to generate the video data stream, such that a size of the payload of the exactly one message depends on a size of a payload of the packet and depends on a size of the properties information.

20. A video encoder (100) according to claim 17 or 19, wherein the video encoder (100) is configured to generate the video data stream, such that the size of the payload of the exactly one message is equal to a size of the payload of the packet minus the size of the properties information or minus (the size of the metadata information of the exactly one message and of the properties information) .

21. A video encoder (100), wherein the video encoder (100) is configured to encode a video comprising a plurality of pictures into a video data stream, wherein the video encoder ( 100) is configured to generate the video data stream such that the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages, wherein the video encoder (100) is configured to generate the video data stream such that the packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

22. A video encoder (100) according to claim 21, wherein the video encoder ( 100) is configured to generate the video data stream such that the packet is a NAL unit, and wherein the video encoder ( 100) is configured to generate the video data stream such that the one or more messages are one or more SEI messages.

23. A video encoder (100) according to one of claims 17 to 22, wherein the properties information comprises the size indication.FH251023PCT-2025353027.DOCX24. A video encoder (100) according to one of claims 17 to 23, wherein the properties information comprises one or more of the following: information (e.g., sei_payload_size_length_in_bytes) indicating a length in bytes of the syntax element that indicates the size of the payload for each of the all sei_messages encapsulated in the same NAL unit; information (e.g., sei_affects_displayed_samples_flag) indicating whether processing / executing the SEI messages (all or at least one within the NAL unit) affects the decoded samples or display output (e.g., frame_packing, region_wise jacking, some kind of composition information, post fdters); information (e.g., sei_same_scope_flag) indicating whether all SEI messages have the same scope (apply to the same amount of pictures / AUs); information (e.g., sei_applies_all ls) indicating whether the SEI messages apply only to the current output layer set or all output layer sets (still applies when dropping a couple of layers); information (e.g., sei_essentiality_flag) indicating whether processing all contained SEI message is necessary to get a valid output or an output as intended by an encoder and / or indicating whether a receiver is expected to cease decoding or suppress picture output in case it cannot interpret all of the contained SEI messages; information (e.g., sei receding_vlc al_flag) indicating whether all contained SEI messages apply to the following VCL NAL units or to the preceding VCL NAL units; information (e.g., sei jost_encoding_flag) indicating whether all contained SEI messages have been generated or inserted into the video data stream by the video encoder (100) or by another device after encoding has been carried out (e.g., at a network device); information (e.g., sei_repetition_flag) indicating whether all contained SEI messages contain repeated SEI messages or whether the SEI messages are not a repetition (e.g., first time within the picture or access unit).FH251023PCT-2025353027.DOCX25. A video decoder (200) for decoding a video data stream having a video comprising a plurality of pictures stored therein, wherein the video decoder (200) is configured to receive the video data stream, wherein the video decoder (200) is configured to decode the video from the video data stream, wherein the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages, wherein the video data stream comprises a size indication, wherein, if the size indication is equal to a predefined value, the one or more messages are exactly one message, and the payload of the packet comprises the payload of the exactly one message.

26. A video decoder (200) according to claim 25, wherein, if the size indication is equal to the predefined value, a size of the payload of the exactly one message depends on a size of a payload of the packet and depends on a size of a header or on a size of metadata information of the exactly one message.

27. A video decoder (200) according to claim 26, wherein, if the size indication is equal to the predefined value, the size of the payload of the exactly one message is equal to a size of the payload of the packet minus the size of the header or minus the size of the metadata information of the exactly one message.

28. A video decoder (200) according to one of claims 25 to 27,FH251023PCT-2025353027.DOCXwherein the packet is a NAL unit, and wherein the one or more messages are one or more SEI messages.

29. A video decoder (200) according to one of claims 25 to 28, wherein the size indication is an integer value; or wherein the size indication is a flag.

30. A video decoder (200) according to one of claims 25 to 29, wherein a header or metadata information of one of the one or more messages comprises the size indication.

31. A video decoder (200) according to one of claims 25 to 30, wherein, if the size indication is different from the predefined value, the size indication indicates a size of a payload of one of the one or more messages, or indicates the size of the payload of said one of the one or more messages minus a predefined value or plus a predefined value, or indicates a length in bytes of the syntax element that indicates the size of the payload of the one or more messages encapsulated in the same NAL unit.

32. A video decoder (200) according to claim 31, wherein the predefined value is 0, wherein, if the size indication is equal to 0, the one or more messages are exactly one message, the payload of the packet comprises the payload of the exactly one message, the size of the payload of the exactly one message is equal to a size of a payload of the packet minus a size of a header or minus a size of metadata information of the exactly one message;FH251023PCT-2025353027.DOCXwherein, if the size indication is different from 0, the size indication indicates a size of a payload of one of the one or more messages minus 1.

33. A video decoder (200) according to one of claims 25 to 32, wherein the size indication applies to two or more messages being encapsulated by the packet.

34. A video decoder (200) according to one of claims 31 to 33, wherein the size indication is an 8 bit information (payload_size_byte_plusl) or is a 16 bit information (lsei_payload_size_l 6bits_plus 1) .

35. A video decoder (200) according to one of claims 31 to 34, wherein the packet is a NAL unit, and wherein the one or more messages are one or more SEI messages, wherein, if the size indication is equal to the predefined value, the size of the payload payloadSize of the exactly one message is equal toNAL unit payload size minus a first constant number (e.g., 4) and the NAL unit contains a single SEI message payload.

36. A video decoder (200) according to one of claims 31 to 34, wherein the packet is a NAL unit, and wherein the one or more messages are one or more SEI messages, wherein, if the size indication is equal to the predefined value,FH251023PCT-2025353027.DOCXthe size of the payload payloadSize of the exactly one message is equal to payloadSize = NAL unit payload size minus (a second constant number, e.g. 2, + a number of payload type byte with a value equal to a third constant number, e.g. OxFF).

37. A video decoder (200) according to one of claims 25 to 30, wherein the size indication is a payload size present flag, wherein, if the payload size present flag indicates a first value being the predefined value, payload size information indicating a size of a payload of one of the one more messages is not present in a header or in metadata information of said one of the one or more messages, wherein, if the payload size present flag indicates a second value being different from the predefined value, payload size information indicating a size of a payload of one of the one more messages is present in the header or in metadata information of said one of the one or more messages and indicates the size of the payload of said one of the one more messages.

38. A video decoder (200) according to one of claims 25 to 30, wherein the size indication is an 8 bit information (payload size byte) or is a 16 bit information (lsei_payload_size_ 16bits) .

39. A video decoder (200) according to claim 37 or 38, wherein the packet is a NAL unit, and wherein the one or more messages are one or more SEI messages, wherein if the payload size present flag is equal to the second value being different from the predefined value, the payload size information is a size value which indicates the size of the payload of said one of the one or more messages, wherein if the payload size present flag is equal to the predefined value, the size of the payload of said one of the one or more messages being exactly one message is equal to NALFH251023PCT-2025353027.DOCXunit payload size minus a first constant number (e.g., 4) and the NAL unit contains a single SEI message payload.

40. A video decoder (200) according to one of claims 25 to 39, wherein the payload size present flag and / or the payload size information apply to two or more messages being encapsulated by the packet.

41. A video decoder (200) according to one of the preceding claims, wherein the packet comprises properties information comprising information on the one or more messages being encapsulated by the packet.

42. A video decoder (200) according to claim 41, further depending on claim 33 or 40, wherein the packet comprises the properties information comprising information on the two or more messages being encapsulated by the packet.

43. A video decoder (200) according to claim 41, wherein, if the size indication is equal to the predefined value, a size of the payload of the exactly one message depends on a size of a payload of the packet and depends on a size of the properties information.

44. A video decoder (200) according to claim 41 or 43, wherein the size of the payload of the exactly one message is equal to a size of the payload of the packet minus the size of the properties information or minus (the size of the metadata information of the exactly one message and of the properties information) .

45. A video decoder (200) for decoding a video data stream having a video comprising a plurality of pictures stored therein, wherein the video decoder (200) is configured to receive the video data stream,FH251023PCT-2025353027.DOCXwherein the video decoder (200) is configured to decode the video from the video data stream, wherein the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages, wherein the packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

46. A video decoder (200) according to claim 45, wherein the packet is a NAL unit, and wherein the one or more messages are one or more SEI messages.

47. A video decoder (200) according to one of claims 41 to 46, wherein the properties information comprises the size indication.

48. A video decoder (200) according to one of claims 41 to 47, wherein the properties information comprises one or more of the following: information (e.g., sei_payload_size_length_in_bytes) indicating a length in bytes of the syntax element that indicates the size of the payload for each of the all sei_messages encapsulated in the same NAL unit; information (e.g., sei_affects_displayed_samples_flag) indicating whether processing / executing the SEI messages (all or at least one within the NAL unit) affects the decoded samples or display output (e.g., frame_packing, region_wise jacking, some kind of composition information, post filters); information (e.g., sei_same_scope_flag) indicating whether all SEI messages have the same scope (apply to the same amount of pictures / AUs);FH251023PCT-2025353027.DOCXinformation (e.g., sei_applies_all_ols) indicating whether the SEI messages apply only to the current output layer set or all output layer sets (still applies when dropping a couple of layers); information (e.g., sei_essentiality_flag) indicating whether processing all contained SEI message is necessary to get a valid output or an output as intended by an encoder and / or indicating whether a receiver is expected to cease decoding or suppress picture output in case it cannot interpret all of the contained SEI messages; information (e.g., sei_preceding_vlc_nal_flag) indicating whether all contained SEI messages apply to the following VCL NAL units or to the preceding VCL NAL units; information (e.g., sei_post_encoding_flag) indicating whether all contained SEI messages have been generated or inserted into the video data stream by a video encoder or by another device after encoding has been carried out (e.g., at a network device); information (e.g., sei_repetition_flag) indicating whether all contained SEI messages contain repeated SEI messages or whether the SEI messages are not a repetition (e.g., first time within the picture or access unit).

49. A video decoder (200) according to claim 48, wherein the properties information comprises the information (e.g., sei_essentiality_flag) indicating whether processing all contained SEI message is necessary to get a valid output or an output as intended by an encoder and / or indicating whether a receiver is expected to cease decoding or suppress picture output in case it cannot interpret all of the contained SEI messages; and wherein, in response to receiving said information (e.g., sei_essentiality_flag), the video decoder (200) is configured to cease decoding or suppress picture output in case the video decoder (200) cannot interpret all of the contained SEI messages.

50. A video decoder (200) according to one of claims 25 to 49, wherein the properties information comprisesFH251023PCT-2025353027.DOCXwherein the video decoder (200) is configured to decode the video from the video data stream and / or to parse the video data stream and / or to process the video data stream depending on the size indication.

51. A video data stream, wherein the video data stream has a video comprising a plurality of pictures encoded therein, wherein the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages, wherein the video data stream comprises a size indication, wherein, if the size indication is equal to a predefined value, the one or more messages are exactly one message, and the payload of the packet comprises the payload of the exactly one message.

52. A video data stream according to claim 51, wherein, if the size indication is equal to the predefined value, a size of the payload of the exactly one message depends on a size of a payload of the packet and depends on a size of a header or on a size of metadata information of the exactly one message.

53. A video data stream according to claim 52, wherein, if the size indication is equal to the predefined value, the size of the payload of the exactly one message is equal to a size of the payload of the packet minus the size of the header or minus the size of the metadata information of the exactly one message.

54. A video data stream according to one of claims 51 to 53,FH251023PCT-2025353027.DOCXwherein the packet is a NAL unit, and wherein the one or more messages are one or more SEI messages.

55. A video data stream according to one of claims 51 to 54, wherein the size indication is an integer value; or wherein the size indication is a flag.

56. A video data stream according to one of claims 51 to 55, wherein a header or metadata information of one of the one or more messages comprises the size indication.

57. A video data stream according to one of claims 51 to 56, wherein, if the size indication is different from the predefined value, the size indication indicates a size of a payload of one of the one or more messages, or indicates the size of the payload of said one of the one or more messages minus a predefined value or plus a predefined value, or indicates a length in bytes of the syntax element that indicates the size of the payload of the one or more messages encapsulated in the same NAL unit.

58. A video data stream according to claim 57, wherein the predefined value is 0, wherein, if the size indication is equal to 0, the one or more messages are exactly one message, the payload of the packet comprises the payload of the exactly one message, the size of the payload of the exactly one message is equal to a size of a payload of the packet minus a size of a header or minus a size of metadata information of the exactly one message;FH251023PCT-2025353027.DOCXwherein, if the size indication is different from 0, the size indication indicates a size of a payload of one of the one or more messages minus 1.

59. A video data stream according to one of claims 51 to 58, wherein the size indication applies to two or more messages being encapsulated by the packet.

60. A video data stream according to one of claims 51 to 59, wherein the size indication is an 8 bit information (payload_size_byte_plusl) or is a 16 bit information (lsei_payload_size_l 6bits_plus 1) .

61. A video data stream according to one of claims 57 to 60, wherein the packet is a NAL unit, and wherein the one or more messages are one or more SEI messages, wherein, if the size indication is equal to the predefined value, the size of the payload payloadSize of the exactly one message is equal toNAL unit payload size minus a first constant number (e.g., 4) and the NAL unit contains a single SEI message payload.

62. A video data stream according to one of claims 57 to 60, wherein the packet is a NAL unit, and wherein the one or more messages are one or more SEI messages, wherein, if the size indication is equal to the predefined value,FH251023PCT-2025353027.DOCXthe size of the payload payloadSize of the exactly one message is equal to payloadSize = NAL unit payload size minus (a second constant number, e.g. 2, + a number of payload type byte with a value equal to a third constant number, e.g. OxFF).

63. A video data stream according to one of claims 51 to 56, wherein the size indication is a payload size present flag, wherein, if the payload size present flag indicates a first value being the predefined value, payload size information indicating a size of a payload of one of the one more messages is not present in a header or in metadata information of said one of the one or more messages, wherein, if the payload size present flag indicates a second value being different from the predefined value, payload size information indicating a size of a payload of one of the one more messages is present in the header or in metadata information of said one of the one or more messages and indicates the size of the payload of said one of the one more messages.

64. A video data stream according to one of claims 51 to 56, wherein the size indication is an 8 bit information (payload size byte) or is a 16 bit information (lsei_payload_size_ 16bits) .

65. A video data stream according to claim 63 or 64, wherein the packet is a NAL unit, and wherein the one or more messages are one or more SEI messages, wherein if the payload size present flag is equal to the second value being different from the predefined value, the payload size information is a size value which indicates the size of the payload of said one of the one or more messages, wherein if the payload size present flag is equal to the predefined value, the size of the payload of said one of the one or more messages being exactly one message is equal to NALFH251023PCT-2025353027.DOCXunit payload size minus a first constant number (e.g., 4) and the NAL unit contains a single SEI message payload.

66. A video data stream according to one of claims 63 to 65, wherein the payload size present flag and / or the payload size information apply to two or more messages being encapsulated by the packet.

67. A video data stream according to one of the preceding claims, wherein the packet comprises properties information comprising information on the one or more messages being encapsulated by the packet.

68. A video data stream according to claim 65, further depending on claim 59 or 66, wherein the packet comprises the properties information comprising information on the two or more messages being encapsulated by the packet.

69. A video data stream according to claim 67, wherein, if the size indication is equal to the predefined value, a size of the payload of the exactly one message depends on a size of a payload of the packet and depends on a size of the properties information.

70. A video data stream according to claim 67 or 69, wherein the size of the payload of the exactly one message is equal to a size of the payload of the packet minus the size of the properties information or minus (the size of the metadata information of the exactly one message and of the properties information) .

71. A video data stream, wherein the video data stream has a video comprising a plurality of pictures encoded therein, wherein the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages,FH251023PCT-2025353027.DOCXwherein the packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

72. A video data stream according to claim 71, wherein the packet is a NAL unit, and wherein the one or more messages are one or more SEI messages.

73. A video data stream according to one of claims 67 to 72, wherein the properties information comprises the size indication.

74. A video data stream according to one of claims 67 to 73, wherein the properties information comprises one or more of the following: information (e.g., sei_payload_size_length_in_bytes) indicating a length in bytes of the syntax element that indicates the size of the payload for each of the all sei_messages encapsulated in the same NAL unit; information (e.g., sei_affects_displayed_samples_flag) indicating whether processing / executing the SEI messages (all or at least one within the NAL unit) affects the decoded samples or display output (e.g., frame_packing, region_wise jacking, some kind of composition information, post fdters); information (e.g., sei_same_scope_flag) indicating whether all SEI messages have the same scope (apply to the same amount of pictures / AUs); information (e.g., sei_applies_all ls) indicating whether the SEI messages apply only to the current output layer set or all output layer sets (still applies when dropping a couple of layers); information (e.g., sei_essentiality_flag) indicating whether processing all contained SEI message is necessary to get a valid output or an output as intended by an encoder and / or indicating whether a receiver is expected to cease decoding or suppress picture output in case it cannot interpret all of the contained SEI messages;FH251023PCT-2025353027.DOCXinformation (e.g., sei_preceding_vlc_nal_flag) indicating whether all contained SEI messages apply to the following VCL NAL units or to the preceding VCL NAL units; information (e.g., sei_post_encoding_flag) indicating whether all contained SEI messages have been generated or inserted into the video data stream by a video encoder or by another device after encoding has been carried out (e.g., at a network device); information (e.g., sei_repetition_flag) indicating whether all contained SEI messages contain repeated SEI messages or whether the SEI messages are not a repetition (e.g., first time within the picture or access unit).

75. A system, comprising:A video encoder according to one of claims 1 to 24 for encoding a video into a video data stream, and a video decoder according to one of claims 25 to 50 for decoding the video from the video data stream being generated by the video encoder.

76. A method for encoding a video comprising a plurality of pictures into a video data stream, wherein the method comprises generating the video data stream such that the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages, wherein the method comprises generating the video data stream such that the video data stream comprises a size indication, wherein, if the size indication is equal to a predefined value, the one or more messages are exactly one message, and the payload of the packet comprises the payload of the exactly one message.

77. A method for encoding a video comprising a plurality of pictures into a video data stream,FH251023PCT-2025353027.DOCXwherein the method comprises generating the video data stream such that the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages, wherein generating the video data stream is conducted such that the packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

78. A method for decoding a video data stream having a video comprising a plurality of pictures stored therein, wherein the method comprises: receiving the video data stream, and decoding the video from the video data stream, wherein the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of one or more messages, wherein the video data stream comprises a size indication, wherein, if the size indication is equal to a predefined value, the one or more messages are exactly one message, and the payload of the packet comprises the payload of the exactly one message.

79. A method for decoding a video data stream having a video comprising a plurality of pictures stored therein, wherein the method comprises: receiving the video data stream, and decoding the video from the video data stream, wherein the video data stream comprises a packet, wherein the packet comprises a payload, wherein the payload of the packet comprises a payload of each of two or more messages,FH251023PCT-2025353027.DOCXwherein the packet comprises properties information comprising information on the two or more messages being encapsulated by the packet.

80. A computer program for implementing the method according to one of claims 76 to 79 when being executed on a computer or signal processor.FH251023PCT-2025353027.DOCX

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