Layer based HRD buffer management for scalable HEVC
The buffer management methods simplify the complexity of STD buffer management for HEVC and make is easy to implement HEVC in deployed AVC/MPEG-2 networks (as legacy re-multiplexers are able to be used for re-purposing HEVC content). The buffers for base and enhancement layers are also be managed independently before re-assembly and this simplifies the STD model. Re-assembly is still implemented before decoding an enhanced HEVC video stream.
1. A method, comprising:
in a decoder system:
accessing a video bitstream that includes a base layer bitstream and a combined base and enhancement layer bitstream,
wherein the base layer bitstream and the combined base and enhancement layer bitstream include hypothetical reference decoder parameters for each layer, and
wherein the hypothetical reference decoder parameters comprise at least one of a bit rate or a Coded Picture Buffer (CPB) size;
decoding the video bitstream,
wherein a first buffer for the base layer bitstream and a second buffer for the combined base and enhancement layer bitstream are managed independently based on respective hypothetical reference decoder parameters;
utilizing a same picture timing supplemental enhancement information message for each of the base layer bitstream and the combined base and enhancement layer bitstream, for synchronization of removal times such that a number of bits that is present in the video bitstream are counted to decode a particular set of bits of the video bitstream; and
utilizing a first buffering period supplemental enhancement information message for the base layer bitstream.
2. The method of claim 1 , wherein the base layer bitstream utilizes a different profile than the combined base and enhancement layer bitstream.
3. The method of claim 1 , wherein the video bitstream indicates at least one of the bit rate or the coded picture buffer size allocated for each of the base layer bitstream and the combined base and enhancement layer bitstream.
4. The method of claim 1 , further comprising associating the first buffering period supplemental enhancement information message and the same picture timing supplemental enhancement information message with each of the base layer bitstream and the combined base and enhancement layer bitstream.
5. The method of claim 1 , further comprising:
utilizing a second buffering period supplemental enhancement information message for the combined base and enhancement layer bitstream,
wherein the first buffering period supplemental enhancement information message is different from the second buffering period supplemental enhancement information message.
6. A decoder system, comprising:
at least one processor configured to:
access a video bitstream that includes a base layer bitstream and a combined base and enhancement layer bitstream,
wherein the base layer bitstream and the combined base and enhancement layer bitstream include hypothetical reference decoder parameters for each layer, and
wherein the hypothetical reference decoder parameters comprise at least one of a bit rate or a Coded Picture Buffer (CPB) size;
a decoder configured to decode the video bitstream,
wherein a first buffer for the base layer bitstream and a second buffer for the combined base and enhancement layer bitstream are managed independently based on respective hypothetical reference decoder parameters;
utilize a same picture timing supplemental enhancement information message for each of the base layer bitstream and the combined base and enhancement layer bitstream, for synchronization of removal times such that a number of bits that is present in the video bitstream are counted to decode a particular set of bits of the video bitstream; and
utilize a first buffering period supplemental enhancement information message for the base layer bitstream.
7. The decoder system of claim 6 , wherein the base layer bitstream utilizes a different profile than the combined base and enhancement layer bitstream.
8. The decoder system of claim 6 , wherein video bitstream indicates at least one of the bit rate or the coded picture buffer size allocated for each of the base layer bitstream and the combined base and enhancement layer bitstream.
9. The decoder system of claim 6 ,
wherein the first buffering period supplemental enhancement information message and the same picture timing supplemental enhancement information message are associated with each of the base layer bitstream and the combined base and enhancement layer bitstream.
10. The decoder system of claim 6 ,
wherein a second buffering period supplemental enhancement information message is utilized for the combined base and enhancement layer bitstream, and
wherein the first buffering period supplemental enhancement information message is different from the second buffering period supplemental enhancement information message.
11. The decoder system of claim 6 , wherein the decoder comprises a bitstream demultiplexer, at least two Bitstream Partition Buffers (BPB), at least two instantaneous decoders, a Decoding Picture Buffer (DPB), and output cropping circuitry.
12. The decoder system of claim 6 , wherein the hypothetical reference decoder parameters of the base layer bitstream are different from the hypothetical reference decoder parameters of the combined base and enhancement layer bitstream.