Partitioning schemes in multi-layer video coding
A video decoder is configured to decode a bitstream that comprises an encoded representation of video data. As part of decoding the bitstream, the video decoder obtains, from the bitstream, one or more syntax elements indicating one or more partitioning schemes. For each respective partitioning scheme of the one or more partitioning schemes, the respective partitioning scheme specifies a respective set of disjoint partitions whose union forms an output layer set. Each respective partition of the respective set of disjoint partitions contains one or more of the layers. The video decoder is further configured to decode each of the partitions of a particular partitioning scheme using different processing cores in a plurality of hardware cores, the particular partitioning scheme being one of the one or more partitioning schemes.
1. A device for encoding video data, the device comprising:
one or more computer-readable storage media configured to store video data; and
one or more processors configured to:
generate a bitstream that comprises an encoded representation of the video data, the bitstream comprising a plurality of layers, wherein:
Network Access Layer (NAL) units of the bitstream having different layer identifiers belong to different layers of the plurality of layers, and
the one or more processors are configured such that, as part of generating the bitstream, the one or more processors include, in the bitstream, a syntax element indicating a number of different partitioning schemes of an output layer set, wherein the number of different partitioning schemes for the output layer set is greater than 1 and, for each respective partitioning scheme of the partitioning schemes for the output layer set, the respective partitioning scheme is a respective set of disjoint partitions whose union forms the output layer set, each respective partition of the respective set of disjoint partitions containing one or more layers of the plurality of layers; and
output the bitstream.
2. The device of claim 1 , wherein the one or more processors are configured such that, as part of generating the bitstream, the one or more processors, for each respective partition of each respective partitioning scheme of the partitioning schemes for the output layer set, include, in the bitstream, a respective syntax element indicating a profile, a tier, and a level for the respective partition.
3. The device of claim 1 , wherein the bitstream conforms to a video coding standard specifying all level limits and restrictions for profiles, tiers and level, except for limits and restrictions on picture width, picture height, and sub-decoded picture buffer (DPB) size, to be partition specific.
4. The device of claim 1 , wherein the output layer set is one of a plurality of output layer sets and the one or more processors are configured such that, as part of generating the bitstream, the one or more processors, for each respective output layer set of the plurality of output layer sets, signal one or more partitioning schemes of layers into partitions of the respective output layer set.
5. The device of claim 1 , wherein the device comprises at least one of:
an integrated circuit;
a microprocessor; or
a wireless communication device.
6. The device of claim 1 , further comprising a camera configured to capture the video data.
7. A method for encoding video data, the method comprising:
generating a bitstream that comprises an encoded representation of the video data, the bitstream comprising a plurality of layers, wherein:
Network Access Layer (NAL) units of the bitstream having different layer identifiers belong to different layers of the plurality of layers, and
generating the bitstream comprises including, in the bitstream, a syntax element indicating a number of different partitioning schemes for an output layer set, wherein the number of different partitioning schemes for the output layer set is greater than 1 and, for each respective partitioning scheme of the partitioning schemes for the output layer set, the respective partitioning scheme is a respective set of disjoint partitions whose union forms the output layer set, each respective partition of the respective set of disjoint partitions containing one or more layers of the plurality of layers; and
outputting the bitstream.
8. The method of claim 7 , wherein generating the bitstream comprises:
for each respective partition of each respective partitioning scheme of the plurality of partitioning schemes for the output layer set, including, in the bitstream, a respective syntax element indicating a profile, a tier, and a level for the respective partition.
9. The method of claim 7 , wherein the bitstream conforms to a video coding standard specifying all level limits and restrictions for profiles, tiers and level, except for limits and restrictions on picture width, picture height, and sub-decoded picture buffer (DPB) size, to be partition specific.
10. The method of claim 7 , wherein the output layer set is one of a plurality of output layer sets and generating the bitstream comprises, for each respective output layer set of the plurality of output layer sets, signaling one or more partitioning schemes of layers into partitions the respective output layer set.
11. A device for encoding video data, the device comprising:
means for generating a bitstream that comprises an encoded representation of the video data, the bitstream comprising a plurality of layers, wherein:
Network Access Layer (NAL) units of the bitstream having different layer identifiers belong to different layers of the plurality of layers, and
the means for generating the bitstream comprises means for including, in the bitstream, a syntax element indicating a number of different partitioning schemes for an output layer set, wherein the number of different partitioning schemes for the output layer set is greater than 1 and, for each respective partitioning scheme of the plurality of partitioning schemes for the output layer set, the respective partitioning scheme is a respective set of disjoint partitions whose union forms the output layer set, each respective partition of the respective set of disjoint partitions containing one or more layers; and
means for outputting the bitstream.
12. A computer-readable storage medium having instructions stored thereon that, when executed, cause one or more processors of a device for encoding video data to:
generate a bitstream that comprises an encoded representation of the video data, the bitstream comprising a plurality of layers, wherein:
Network Access Layer (NAL) units of the bitstream having different layer identifiers belong to different layers of the plurality of layers, and
as part of causing the one or more processors to generate the bitstream, the instructions, when executed, cause the one or more processors to include, in the bitstream, a syntax element indicating a number of different partitioning schemes for an output layer set, wherein the number of different partitioning schemes for the output layer set is greater than 1 and, for each respective partitioning scheme of the plurality of partitioning schemes for the output layer set, the respective partitioning scheme is a respective set of disjoint partitions whose union forms the output layer set, each respective partition of the respective set of disjoint partitions containing one or more layers; and
output the bitstream.