# US 12,192,528 B2 · Signaling of access unit delimiter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,192,528 B2 - Document ID: US12192528B2 - Status: Granted - Kind: B2 - Application number: 17/626,483 - Filed: 2020-07-08 - Published: 2022-09-08 - Granted: 2025-01-07 - Earliest claimed: 2019-07-12 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Martin Pettersson; Mitra Damghanian; Rickard Sjöberg - Web page: https://patentgrep.com/patent/US12192528B2 ## CPC - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N 19/188: {the unit being a video data packet, e.g. a network abstraction layer [NAL] unit} - H04N 19/46: Embedding additional information in the video signal during the compression process (H04N19/517, H04N19/68, H04N19/70 take precedence) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method performed by a decoder to decode a bitstream and a decoder is provided. One or more syntax elements are decoded from the bitstream. A first value is derived from the one or more syntax elements. The first value is compared to a predetermined set of values that comprises at least two values. Whether the first value is within a predetermined range of values in the predetermined set of values is determined. Responsive to determining the first value is within the predetermined range of values in the predetermined set of values, it is determined that a location of an access unit boundary is indicated. Analogous methods performed by an encoder and an encoder are also provided. ## Claims ### Claim 1 A method performed by a decoder, the method comprising: decoding a value from a syntax element in a parameter set, the value indicating whether there are access unit delimiter, AUD, network abstraction layer, NAL units in the access units following a current access unit in decoding order in a coded video stream, CVS; and determining whether the value indicates that there are AUD NAL units in the access units following the current access unit in decoding order in the CVS. ### Claim 2 (depends on 1) The method of claim 1, further comprising determining from a syntax element in the parameter set a number of NAL units in a first access unit. ### Claim 3 (depends on 1) The method of claim 1, further comprising determining whether there are AUD NAL units in the access units following the current access unit in decoding order in the CVS based on a specific value of NAL unit type. ### Claim 4 A decoder comprising: at least one processor; memory communicatively coupled to the at least one processor, said memory comprising instructions executable by the at least one processor, which cause the at least one processor to perform operations comprising: decoding a value from a syntax element in a parameter set, the value indicating whether there are access unit delimiter, AUD, network abstraction layer, NAL units in the access units following a current access unit in decoding order in a coded video stream, CVS; and determining whether the value indicates that there are AUD NAL units in the access units following the current access unit in decoding order in the CVS. ### Claim 5 (depends on 4) The decoder of claim 4, further comprising determining from a syntax element in the parameter set a number of NAL units in a first access unit. ### Claim 6 (depends on 4) The decoder of claim 4, further comprising determining whether there are AUD NAL units in the access units following the current access unit in decoding order in the CVS based on a specific value of NAL unit type. ### Claim 7 A method performed by an encoder, the method comprising: determining whether access unit delimiter, AUD, network abstraction layer, NAL, units are to be present in access units following a current access unit in decoding order in a coded video stream, CVS; and responsive to determining that AUD NAL units are to be present in access units following the current access unit in decoding order, encoding a value of a syntax element in a parameter set of the coded video stream, the value indicating that there are AUD NAL units in access units following the current access unit in decoding order. ### Claim 8 (depends on 7) The method of claim 7, further comprising encoding a value of a second syntax element in the parameter set, the value of the second syntax element indicating a number of NAL units in a first access unit. ### Claim 9 (depends on 7) The method of claim 7, further comprising responsive to determining that AUD NAL units are to be present in access units following the current access unit in decoding order, encoding a specific value of NAL unit type in a NAL unit header. ### Claim 10 An encoder comprising: at least one processor; memory communicatively coupled to the processor, said memory comprising instructions executable by the processor, which cause the processor to perform operations comprising: determining whether access unit delimiter, AUD, network abstraction layer, NAL, units are to be present in access units following a current access unit in decoding order in a coded video stream, CVS; and responsive to determining that AUD NAL units are to be present in access units following the current access unit in decoding order, encoding a value of a syntax element in a parameter set of the CVS, the value indicating that there are AUD NAL units in access units following the current access unit in decoding order. ### Claim 11 (depends on 10) The encoder of claim 10, wherein the memory comprises further instructions executable by the processor, which when executed, cause the processor to perform operations further comprising encoding a value of a second syntax element in the parameter set, the value of the second syntax element indicating a number of NAL units in a first access unit. ### Claim 12 (depends on 10) The encoder of claim 10, wherein the memory comprises further instructions executable by the processor, which when executed, cause the processor to perform operations further comprising responsive to determining that AUD NAL units are to be present in access units following the current access unit in decoding order, encoding a specific value of NAL unit type in a NAL unit header.