# US 9,438,900 B2 · Encoding and decoding video sequences comprising reference picture sets > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,900 B2 - Document ID: US9438900B2 - Status: Granted - Kind: B2 - Application number: 14/000,506 - Filed: 2013-07-01 - Published: 2014-03-20 - Granted: 2016-09-06 - Earliest claimed: 2012-06-29 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget L M Ericsson (publ) - Inventors: Jacob Ström; Jonatan Samuelsson; Rickard Sjöberg - Web page: https://patentgrep.com/patent/US9438900B2 ## CPC - H04N 19/58: Motion compensation with long-term prediction, i.e. the reference frame for a current frame not being the temporally closest one (H04N19/23 takes precedence) - H04N 19/105: Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction - H04N 19/136: Incoming video signal characteristics or properties - H04N 19/139: Analysis of motion vectors, e.g. their magnitude, direction, variance or reliability - H04N 19/174: the region being a slice, e.g. a line of blocks or a group of blocks - H04N 19/176: the region being a block, e.g. a macroblock - H04N 19/463: by compressing encoding parameters before transmission - H04N 19/70: characterised by syntax aspects related to video coding, e.g. related to compression standards - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method of encoding a video sequence comprising Reference Picture Sets (RPSs) is provided. The method comprises arranging the RPSs in transmission order in a data structure, such as a Sequence Parameter Set (SPS), determining whether explicit RPS transmission is used for an RPS of a current picture of the video sequence, and encoding information indicating an RPS comprised in the data structure to be used for predicting the RPS of the current picture, such as delta_idx_minus1, only if explicit RPS transmission is used. By transmitting delta_idx_minus1 only if explicit RPS transmission is used, and interpreting delta_idx_minus1 to be equal to zero otherwise, a reduced bitrate is achieved. Further, a method of decoding a video sequence comprising RPSs, corresponding computer programs and computer program products, as well as corresponding encoders and decoders are provided. ## Claims ### Claim 1 A method of encoding a video sequence comprising Reference Picture Sets, RPSs, the method comprising: arranging the RPSs in a decoding order in a Sequence Parameter Set, SPS, wherein at least one RPS of the RPSs arranged in the SPS is inter-predicted from an RPS which is directly preceding the at least one RPS in the decoding order; determining whether explicit RPS transmission is used for an RPS of a current picture of the video sequence; and encoding information indicating an RPS comprised in the SPS to be used for RPS inter-prediction in response to the determining that the explicit RPS transmission is used for the RPS of the current picture. ### Claim 2 (depends on 1) The method according to claim 1, further comprising: determining whether inter-prediction is used for the RPS of the current picture, wherein the information indicating an RPS comprised in the SPS to be used for RPS inter-prediction is only encoded if explicit RPS transmission and inter-prediction are determined to be used. ### Claim 3 (depends on 1) The method according to claim 1, further comprising assigning an index to each RPS comprised in the SPS, and wherein the information indicating an RPS to be used for RPS inter-prediction specifies the difference between an index of the RPS of the current picture and an index of the RPS used for inter-prediction. ### Claim 4 (depends on 1) The method according to claim 1, wherein the determining whether explicit RPS transmission is used comprises determining whether an index of the RPS of the current picture is equal to a number of RPSs comprised in the SPS. ### Claim 5 (depends on 1) The method according to claim 1, wherein the determining whether explicit RPS transmission is used comprises determining whether the RPS of the current picture is encoded in a slice header of the current picture. ### Claim 6 (depends on 1) A computer program comprising computer program code embodied on a non-transitory computer readable storage medium, the computer program code being adapted, when executed on a processor, to implement the method according to claim 1. ### Claim 7 (depends on 6) A computer program product comprising the non-transitory computer readable storage medium, the computer readable storage medium having the computer program embodied therein, according to claim 6. ### Claim 8 A method of decoding a video sequence comprising Reference Picture Sets, RPSs, the method comprising: receiving a Sequence Parameter Set, SPS comprising the RPSs arranged in a decoding order, inter-predicting at least one RPS from a directly preceding RPS in the decoding order, determining whether explicit RPS transmission is used for an RPS of a current picture of the video sequence, and receiving information indicating an RPS comprised in the SPS to be used for RPS inter-prediction only if explicit RPS transmission is determined to be used. ### Claim 9 (depends on 8) The method according to claim 8, further comprising determining whether inter-prediction is used for the RPS of the current picture, and wherein the information indicating an RPS comprised in the SPS to be used for RPS inter-prediction is only received if explicit RPS transmission and inter-prediction are determined to be used. ### Claim 10 (depends on 8) The method according to claim 8, wherein an index is assigned to each RPS comprised in the SPS, and wherein the information indicating an RPS to be used for RPS inter-prediction specifies the difference between an index of the RPS of the current picture and an index of the RPS used for inter-prediction. ### Claim 11 (depends on 8) The method according to claim 8, wherein the determining whether explicit RPS transmission is used comprises determining whether an index of the RPS of the current picture is equal to a number of RPSs comprised in the SPS. ### Claim 12 (depends on 8) The method according to claim 8, wherein the determining whether explicit RPS transmission is used comprises determining whether the RPS of the current picture is encoded in a slice header of the current picture. ### Claim 13 (depends on 8) A computer program comprising computer program code embodied on a non-transitory computer readable storage medium, the computer program code being adapted, when executed on a processor, to implement the method according to claim 8. ### Claim 14 (depends on 13) A computer program product comprising the non-transitory computer readable storage medium, the computer readable storage medium having the computer program embodied therein, according to claim 13. ### Claim 15 An encoder for encoding a video sequence comprising Reference Picture Sets, RPSs, the encoder comprising a processor and a memory comprising instructions executable by the processor, whereby the encoder is operative to perform operations comprising: arranging the RPSs in a decoding order in a Sequence Parameter Set, SPS, wherein at least one RPS of the RPSs arranged in the SPS is inter-predicted from an RPS which is directly preceding the at least one RPS in the decoding order, determining whether explicit RPS transmission is used for an RPS of a current picture of the video sequence, and encoding information indicating an RPS comprised in the SPS to be used for RPS inter-prediction only if explicit RPS transmission is determined to be used for the RPS of the current picture. ### Claim 16 (depends on 15) The encoder according to claim 15, being further operative to perform operations comprising: determining whether inter-prediction is used for the RPS of the current picture, and encoding the information indicating an RPS comprised in the SPS to be used for RPS inter-prediction only if explicit RPS transmission and inter-prediction are determined to be used. ### Claim 17 (depends on 15) The encoder according to claim 15, being further operative to perform operations comprising: assigning an index to each RPS comprised in the SPS, wherein the information indicating an RPS to be used for RPS inter-prediction specifies the difference between an index of the RPS of the current picture and an index of the RPS used for inter-prediction. ### Claim 18 (depends on 15) The encoder according to claim 15, being further operative to perform operations comprising: determining whether explicit RPS transmission is used by determining whether an index of the RPS of the current picture is equal to a number of RPSs comprised in the SPS. ### Claim 19 (depends on 15) The encoder according to claim 15, being further operative to perform operations comprising: determining whether explicit RPS transmission is used by determining whether the RPS of the current picture is encoded in a slice header of the current picture. ### Claim 20 A decoder for decoding a video sequence comprising Reference Picture Sets, RPSs, the decoder comprising a processor and a memory comprising instructions executable by the processor, whereby the decoder is operative to perform operations comprising: receiving a Sequence Parameter Set, SPS comprising the RPSs arranged in a decoding order, inter-predicting at least one RPS from a directly preceding RPS in the decoding order, determining whether explicit RPS transmission is used for an RPS of a current picture of the video sequence, and receiving information indicating an RPS comprised in the SPS to be used for RPS inter-prediction only if explicit RPS transmission is determined to be used for the RPS of the current picture. ### Claim 21 (depends on 20) The decoder according to claim 20, being further operative to perform operations comprising: determining whether inter-prediction is used for the RPS of the current picture, and receiving the information indicating an RPS comprised in the SPS to be used for RPS inter-prediction only if explicit RPS transmission and inter-prediction are determined to be used. ### Claim 22 (depends on 20) The decoder according to claim 20, wherein an index is assigned to each RPS comprised in the SPS, and wherein the information indicating an RPS to be used for RPS inter-prediction specifies the difference between an index of the RPS of the current picture and an index of the RPS used for inter-prediction. ### Claim 23 (depends on 20) The decoder according to claim 20, being further operative to perform operations comprising: determining whether explicit RPS transmission is used by determining whether an index of the RPS of the current picture is equal to a number of RPSs comprised in the SPS. ### Claim 24 (depends on 20) The decoder according to claim 20, being further operative to perform operations comprising: determining whether explicit RPS transmission is used by determining whether the RPS of the current picture is encoded in a slice header of the current picture. ### Claim 25 (depends on 4) The method according to claim 4, further comprising: assigning an index to each RPS comprised in the SPS, the index ranging from 0 to the number of RPSs comprised in the SPS minus one. ### Claim 26 (depends on 11) The method according to claim 11, wherein an index is assigned to each RPS comprised in the SPS, the index ranging from 0 to the number of RPSs comprised in the SPS minus one. ### Claim 27 (depends on 18) The encoder according to claim 18, being further operative to perform operations comprising: assigning an index to each RPS comprised in the SPS, the index ranging from 0 to the number of RPSs comprised in the SPS minus one. ### Claim 28 (depends on 23) The decoder according to claim 23, wherein an index is assigned to each RPS comprised in the SPS, the index ranging from 0 to the number of RPSs comprised in the SPS minus one. ### Claim 29 A method of decoding a video sequence comprising Reference Picture Sets, RPSs, the method comprising: receiving a Sequence Parameter Set, SPS comprising the RPSs arranged in a decoding order; inter-predicting at least one RPS from a directly preceding RPS in the decoding order; determining whether inter-prediction is used for an RPS of a current picture of the video sequence; determining whether explicit RPS transmission is used for the RPS of the current picture; and receiving information indicating an RPS comprised in the SPS to be used for RPS inter-prediction if inter-prediction is used and if explicit RPS transmission is used for the RPS of the current picture. ### Claim 30 (depends on 1) The method according to claim 1, further comprising: if inter-prediction is used for a current RPS of the RPSs comprised in the SPS, inferring that the current RPS is inter-predicted from an RPS directly preceding the current RPS in the decoding order. ### Claim 31 (depends on 8) The method according to claim 8, further comprising: if inter-prediction is used for a current RPS of the RPSs comprised in the SPS, inferring that the current RPS is inter-predicted from an RPS directly preceding the current RPS in the decoding order. ### Claim 32 (depends on 15) The encoder according to claim 15, being further operative to perform operations comprising: if inter-prediction is used for a current RPS of the RPSs comprised in the SPS, inferring that the current RPS is inter-predicted from an RPS directly preceding the current RPS in the decoding order. ### Claim 33 (depends on 20) The decoder according to claim 20, being further operative to perform operations comprising: if inter-prediction is used for a current RPS of the RPSs comprised in the SPS, inferring that the current RPS is inter-predicted from an RPS directly preceding the current RPS in the decoding order. ### Claim 34 (depends on 29) The method according to claim 29, further comprising: if inter-prediction is used for a current RPS of the RPSs comprised in the SPS, inferring that the current RPS is inter-predicted from an RPS directly preceding the current RPS in the decoding order.