High layer syntax for temporal scalability

A decoding device configured to decode media encoded using scalable coding with temporal scalability at a pre-determined maximum temporal level, comprising:

• a decoder adapted to decode a single bit flag temporal_nesting_flag in a sequence parameter set that is indicative of a temporally nested structure of layers and pertains to all frames of a coded video sequence, and
• decode a coded first picture of the coded video sequence with a first layer_id;
• wherein, in response to the decoded temporal_nesting_flag equal to 1, the decoder is adapted to remove at least one second picture of the coded video sequence from a reference picture list maintained by the decoder, the at least one second picture in the reference picture list having a second layer_id, wherein a value of the second layer_id is higher than a value of the first layer_id and wherein the second picture is not used for a prediction of the first picture or any pictures following the first picture in decoding order;
• wherein the decoder is configured so that at least one second picture of the coded video sequence would be included in the reference picture list if the decoded temporal_nesting_flag were equal to 0 and wherein the temporal_nesting_flag set to one indicates for any three frames picA, picB, picC included in the coded video sequence, that picB is not used for reference of picA:
• under a first condition that picB is of a temporal level lower or equal than the temporal level of picA, and
• under a second condition that the temporal level of picC is lower than the temporal level of picB, and
• under a third condition that picC follows picB in decoding order, and
• under a fourth condition that picC precedes picA in decoding order;
• and
• wherein picB is not included in a reference picture list of picA.

A computer system comprising a processor and a memory storing instructions, that when executed by the processor, cause the computer system to:

• decode media encoded using scalable coding with temporal scalability at a pre-determined maximum temporal level, wherein decoding media comprises:
• decoding a single bit flag temporal_nesting_flag in a sequence parameter set that is indicative of a temporally nested structure of layers and pertains to all frames of a coded video sequence;
• decoding a coded first picture of the coded video sequence with a first layer_id;
• in response to the decoded temporal_nesting_flag equal to 1, removing at least one second picture of the coded video sequence from a reference picture list maintained by the decoder, the at least one second picture in the reference picture list having a second layer_id, wherein a value of the second layer_id is higher than a value of the first layer_id and wherein the second picture is not used for a prediction of the first picture or any pictures following the first picture in decoding order;
• wherein the at least one second picture of the coded video sequence would be included in the reference picture list if the decoded temporal_nesting_flag were equal to 0;
• wherein the temporal_nesting_flag set to one indicates for any three frames picA, picB, picC included in the coded video sequence, that picB is not used for reference of picA:
• under a first condition that picB is of a temporal level lower or equal than the temporal level of picA, and
• under a second condition that the temporal level of picC is lower than the temporal level of picB, and
• under a third condition that picC follows picB in decoding order, and
• under a fourth condition that picC precedes picA in decoding order;
• and
• wherein picB is not included in a reference picture list of picA.

A non-transitory computer readable medium storing instructions that, when executed by a processor, cause a computer system to decode media encoded using scalable coding with temporal scalability at a pre-determined maximum temporal level, by performing the steps of:

• decoding a single bit flag temporal_nesting_flag in a sequence parameter set that is indicative of a temporally nested structure of layers and pertains to all frames of a coded video sequence;
• decoding a coded first picture of the coded video sequence with a first layer_id;
• in response to the decoded temporal_nesting_flag equal to 1, removing at least one second picture of the coded video sequence from a reference picture list maintained by the decoder, the at least one second picture in the reference picture list having a second layer_id, wherein a value of the second layer_id is higher than a value of the first layer_id and wherein the second picture is not used for a prediction of the first picture or any pictures following the first picture in decoding order;
• wherein the at least one second picture of the coded video sequence would be included in the reference picture list if the decoded temporal_nesting_flag were equal to 0;
• wherein the temporal_nesting_flag set to one indicates for any three frames picA, picB, picC included in the coded video sequence, that picB is not used for reference of picA:
• under a first condition that picB is of a temporal level lower or equal than the temporal level of picA, and
• under a second condition that the temporal level of picC is lower than the temporal level of picB, and
• under a third condition that picC follows picB in decoding order, and
• under a fourth condition that picC precedes picA in decoding order;
• and
• wherein picB is not included in a reference picture list of picA.