Signaling HRD parameters for bitstream partitions

1. A method of coding video data, the method comprising:

coding, by a processor, hypothetical reference decoder (HRD) parameters for each sub-layer of each bitstream partition of a video bitstream including the video data, wherein coding the HRD parameters comprises:

coding a first BIRD parameters syntax structure for a first sub-layer of a bitstream partition; and

coding a second HRD parameters syntax structure for a second sub-layer of the bitstream partition, wherein the first BIRD parameters syntax structure is different than the second BIRD parameters syntax structure, and wherein the first sub-layer is different than the second sub-layer; and

processing, by the processor, the video bitstream using the HRD parameters, wherein processing the video bitstream comprises coding one or more pictures of the first sub-layer of the bitstream partition using the HRD parameters and coding one or more pictures of the second sub-layer of the bitstream partition using the HRD parameters.

2. The method of claim 1 , wherein coding the HRD parameters comprises:

coding a number representative of a number of iterations of a loop of the HRD parameters, each of the iterations of the loop corresponding to one of the sub-layers; and

coding the HRD parameters for each of the sub-layers in a corresponding one of the loop iterations.

3. The method of claim 1 , wherein coding the HRD parameters comprises:

coding a plurality of sets of HRD parameters; and

coding indexes for each of the sub-layers such that the index for each sub-layer represents one of the sets of HRD parameters that corresponds to the sub-layer.

4. The method of claim 1 , wherein the sub-layers comprise temporal sub-layers, and wherein coding the HRD parameters comprises coding a number, equal to the number of temporal sub-layers for which the HRD parameters are coded, of syntax elements indicative of at least whether temporal distances between HRD output times of consecutive pictures in output order are constrained for a temporal sub-layer of the bitstream.

5. The method of claim 4 , wherein the syntax elements indicative of at least whether the temporal distances between HRD output times of consecutive pictures in output order are constrained comprise at least one of fixed_pic_rate_general_flag[ ] syntax elements or fixed_pic_rate_within_CVS_flag[ ] syntax elements.

6. The method of claim 1 , wherein coding the HRD parameters comprises coding syntax elements indicative of temporal distance, in clock ticks, between elemental units that specify HRD output times of consecutive pictures for the corresponding sub-layers.

7. The method of claim 1 , wherein coding the HRD parameters comprises coding syntax elements indicative of an HRD operational mode of the corresponding sub-layers.

8. The method of claim 1 , wherein coding the HRD parameters comprises one of decoding the HRD parameters or encoding the HRD parameters.

9. The method of claim 1 , the method being executable on a wireless communication device, wherein the device comprises:

a memory configured to store the HRD parameters;

the processor, the processor being configured to execute instructions to process the HRD parameters stored in the memory and the video bitstream; and

a receiver for receiving a signal including the video bitstream and the HRD parameters and for storing the HRD parameters to the memory.

10. The method of claim 9 , wherein the wireless communication device is a cellular telephone and the signal is received by the receiver and modulated according to a cellular communication standard.

11. A device for coding video data, the device comprising:

a memory configured to store video data; and

a video coder configured to:

code hypothetical reference decoder (HRD) parameters for each sub-layer of each bitstream partition of a video bitstream including the video data, wherein, to code the HRD parameters, the video coder is configured to:

code a first HRD parameters syntax structure for a first sub-layer of a bitstream partition; and

code a second HRD parameters syntax structure for a second sub-layer of the bitstream partition, wherein the first BIRD parameters syntax structure is different than the second BIRD parameters syntax structure, and wherein the first sub-layer is different than the second sub-layer; and

process the video bitstream using the BIRD parameters, wherein, to process the video bitstream, the video coder is configured to code one or more pictures of the first sub-layer of the bitstream partition using the HRD parameters and code one or more pictures of the second sub-layer of the bitstream partition using the HRD parameters.

12. The device of claim 11 , wherein to code the BIRD parameters, the video coder is configured to:

code a number representative of a number of iterations of a loop of the HRD parameters, each of the iterations of the loop corresponding to one of the sub-layers; and

code the HRD parameters for each of the sub-layers in a corresponding one of the loop iterations.

13. The device of claim 11 , wherein to code the BIRD parameters, the video coder is configured to:

code a plurality of sets of BIRD parameters; and

code indexes for each of the sub-layers such that the index for each sub-layer represents one of the sets of BIRD parameters that corresponds to the sub-layer.

14. The device of claim 11 , wherein the sub-layers comprise temporal sub-layers, and wherein to code the BIRD parameters, the video coder is configured to code a number, equal to the number of temporal sub-layers for which BIRD parameters are coded, of syntax elements indicative of at least whether temporal distances between BIRD output times of consecutive pictures in output order are constrained for a temporal sub-layer of the bitstream.

15. The device of claim 14 , wherein the syntax elements indicative of at least whether the temporal distances between BIRD output times of consecutive pictures in output order are constrained comprise at least one of fixed_pic_rate_general_flag[ ] syntax elements or fixed_pic_rate_within_CVS_flag[ ] syntax elements.

16. The device of claim 11 , wherein to code the BIRD parameters, the video coder is configured to code syntax elements indicative of temporal distance, in clock ticks, between elemental units that specify BIRD output times of consecutive pictures for the corresponding sub-layers.

17. The device of claim 11 , wherein coding the BIRD parameters comprises coding syntax elements indicative of an BIRD operational mode of the corresponding sub-layers.

18. The device of claim 11 , wherein the video coder comprises one of a video decoder or a video encoder.

19. The device of claim 11 , wherein the device is a wireless communication device, further comprising a receiver configured to receive a signal including the video bitstream and the BIRD parameters and to store the BIRD parameters to the memory.

20. The device of claim 19 , wherein the wireless communication device is a cellular telephone and the signal is received by the receiver and modulated according to a cellular communication standard.

21. A device for coding video data, the device comprising:

means for coding hypothetical reference decoder (HRD) parameters for each sub-layer of each bitstream partition of a video bitstream including the video data, wherein the means for coding the BIRD parameters comprises:

means for coding a first HRD parameters syntax structure for a first sub-layer of a bitstream partition; and

means for coding a second HRD parameters syntax structure for a second sub-layer of the bitstream partition, wherein the first HRD parameters syntax structure is different than the second HRD parameters syntax structure, and wherein the first sub-layer is different than the second sub-layer; and

means for processing the video bitstream using the HRD parameters, wherein the means for processing the video bitstream comprises means for coding one or more pictures of the first sub-layer of the bitstream partition using the HRD parameters and means for coding one or more pictures of the second sub-layer of the bitstream partition using the HRD parameters.

22. The device of claim 21 , wherein the means for coding the HRD parameters comprises:

means for coding a number representative of a number of iterations of a loop of the HRD parameters, each of the iterations of the loop corresponding to one of the sub-layers; and

means for coding the HRD parameters for each of the sub-layers in a corresponding one of the loop iterations.

23. The device of claim 21 , wherein the means for coding the HRD parameters comprises:

means for coding a plurality of sets of HRD parameters; and

means for coding indexes for each of the sub-layers such that the index for each sub-layer represents one of the sets of BIRD parameters that corresponds to the sub-layer.

24. The device of claim 21 , wherein the sub-layers comprise temporal sub-layers, and wherein the means for coding the HRD parameters comprises means for coding a number, equal to the number of temporal sub-layers for which HRD parameters are coded, of syntax elements indicative of at least whether temporal distances between BIRD output times of consecutive pictures in output order are constrained for a temporal sub-layer of the bitstream.

25. The device of claim 21 , wherein the means for coding the HRD parameters comprises means for coding syntax elements indicative of temporal distance, in clock ticks, between elemental units that specify BIRD output times of consecutive pictures for the corresponding sub-layers.

26. The device of claim 21 , wherein the means for coding the HRD parameters comprises means for coding syntax elements indicative of an HRD operational mode of the corresponding sub-layers.

27. The device of claim 21 , wherein the means for coding the HRD parameters comprises one of means for decoding the HRD parameters or means for encoding the HRD parameters.

28. A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause a processor to:

code hypothetical reference decoder (HRD) parameters for each sub-layer of each bitstream partition of a video bitstream including the video data, wherein the instructions that cause the processor to code the BIRD parameters comprise instructions that cause the processor to:

code a first BIRD parameters syntax structure for a first sub-layer of a bitstream partition; and

code a second HRD parameters syntax structure for a second sub-layer of the bitstream partition, wherein the first BIRD parameters syntax structure is different than the second BIRD parameters syntax structure, and wherein the first sub-layer is different than the second sub-layer; and

process the video bitstream using the HRD parameters, wherein the instructions that cause the processor to process the video bitstream comprise instructions that cause the processor to code one or more pictures of the first sub-layer of the bitstream partition using the HRD parameters and code one or more pictures of the second sub-layer of the bitstream partition using the HRD parameters.

29. The non-transitory computer-readable storage medium of claim 28 , wherein the instructions that cause the processor to code the BIRD parameters comprise instructions that cause the processor to:

code a number representative of a number of iterations of a loop of the HRD parameters, each of the iterations of the loop corresponding to one of the sub-layers; and

code the HRD parameters for each of the sub-layers in a corresponding one of the loop iterations.

30. The non-transitory computer-readable storage medium of claim 28 , wherein the instructions that cause the processor to code the BIRD parameters comprise instructions that cause the processor to:

code a plurality of sets of HRD parameters; and

code indexes for each of the sub-layers such that the index for each sub-layer represents one of the sets of BIRD parameters that corresponds to the sub-layer.