1. A method of decoding video data, the method comprising:', 'decoding a bitstream that includes video data and syntax information for decoding the video data, wherein the syntax information comprises a supplemental enhancement information (SEl) message of an access unit, and wherein the SEl message indicates a plurality of sequence parameter sets (SPSs) and a video parameter set (VPS) for decoding video data of the access unit; and', 'decoding the video data of the access unit based on the plurality of SPSs and the VPS indicated in the SEl message.

2. The method of claim 1, wherein the SEl message comprises an active parameter sets SEl message.

3. The method of claim 2, wherein the active parameter sets SEl message precedes, in decoding order, a first portion of the video data of the access unit.

4. The method of claim 1, wherein the SEl message comprises a buffering period SEl message.

5. The method of claim 1, wherein the SEl message includes a first syntax element that indicates a first SPS of the plurality of SPSs, a second syntax element that specifies a number of additional SPSs indicated in the SEl message, and one or more additional syntax elements that respectively indicate the additional SPSs.

6. The method of claim 5, wherein the first syntax element comprises a', 'active seq param set id syntax element, the second syntax element comprises a num additional sps ids minusl syntax element, and the one or more additional syntax elements comprise additional_active_sps_idi syntax elements for i = 0; i <', 'num additional sps ids minusl ; i++.

7. The method of claim 1, wherein the SEl message includes a first syntax element that specifies a number of the plurality of SPSs, and one or more additional syntax elements that respectively indicate the plurality of SPSs.

8. The method of claim 7, wherein the first syntax element comprises a', 'num sps ids minusl syntax element, and the one or more additional syntax elements comprise active_sps_idi syntax elements for i = 0; i <', 'num additional sps ids minusl ; i++.

9. The method of claim 1,', 'wherein the video data comprises at least one of a plurality of layers or a plurality of views,', 'wherein each of the plurality of SPSs is associated with a respective one or more of the plurality of layers or plurality of views, and', 'wherein decoding the video data of the access unit based on the plurality of SPSs and the VPS comprises, for each of the layers or views, decoding the video data of the layer or view based on the SPS associated with the layer or view

10. The method of claim 9, further comprising:', 'determining identifiers that are respectively associated with the plurality of layers or views, wherein determining the identifiers comprises at least one of:', 'decoding at least one of the identifiers, or', 'deriving at least one of the identifiers based on a hierarchical position of the respective layer or view; and', 'determining the plurality of SPSs for respectively decoding the video data of the plurality of layers or views based on the indication in the SEI message and the determined identifiers

11. The method of claim 9, wherein each of the plurality of SPSs is associated with a respective one or more of the plurality of layers, and at least one of the plurality of SPSs comprises an active layer SPS

12. The method of claim 9, wherein the video data comprises at least one of multiview video data, three-dimensional video data, or scalable video coding video data

13. The method of claim 1, further comprising activating the plurality of SPSs and the VPS based on the indication of the plurality of SPSs and the VPS in the SEI

message, wherein decoding the video data comprises decoding the video data of the access unit based on the plurality of activated SPSs and the activated VPS

14. A method of encoding video data, the method comprising:', 'encoding a bitstream that includes video data and syntax information for encoding the video data, wherein the syntax information comprises a supplemental enhancement information (SEl) message of an access unit, and wherein the SEl message indicates a plurality of sequence parameter sets (SPSs) and a video parameter set (VPS) for decoding video data of the access unit; and', 'encoding the video data of the access unit based on the plurality of SPSs and the VPS indicated in the SEl message

15. The method of claim 14, wherein the SEl message comprises an active parameter sets SEl message

16. The method of claim 15, wherein the active parameter sets SEl message precedes, in encoding order, a first portion of the video data of the access unit

17. The method of claim 14, wherein the SEl message comprises a buffering period SEl message

18. The method of claim 14, wherein the SEl message includes a first syntax element that indicates a first SPS of the plurality of SPSs, a second syntax element that specifies a number of additional SPSs indicated in the SEl message, and one or more additional syntax elements that respectively indicate the additional SPSs

19. The method of claim 18, wherein the first syntax element comprises a active seq param set id syntax element, the second syntax element comprises a num additional sps ids minusl syntax element, and the one or more additional syntax elements comprise additional_active_sps_idi syntax elements for i = 0; i <', 'num additional sps ids minusl ; i++.

20. The method of claim 14, wherein the SEI message includes a first syntax element that specifies a number of the plurality of SPSs, and one or more additional syntax elements that respectively indicate the plurality of SPSs.

21. The method of claim 20, wherein the first syntax element comprises a num sps ids minusl syntax element, and the one or more additional syntax elements comprise active_sps_idi syntax elements for i = 0; i <', 'num additional sps ids minusl ; i++.

22. The method of claim 14,', 'wherein the video data comprises at least one of a plurality of layers or a plurality of views,', 'wherein each of the plurality of SPSs is associated with a respective one or more of the plurality of layers or plurality of views, and', 'wherein encoding the video data of the access unit based on the plurality of SPSs and the VPS comprises, for each of the layers or views, encoding the video data of the layer or view based on the SPS associated with the layer or view.

23. The method of claim 22, wherein each of the plurality of SPSs is associated with a respective one or more of the plurality of layers, and at least one of the plurality of SPSs comprises an active layer SPS.

24. The method of claim 22, wherein the video data comprises at least one of multiview video data, three-dimensional video data, or scalable video coding video data.

25. The method of claim 14, wherein the plurality of SPSs and the VPS are activated by a video decoder based on the indication of the plurality of SPSs and the VPS in the SEI message.

26. A device comprising a video decoder configured to:', 'decode a bitstream that includes video data and syntax information for decoding the video data, wherein the syntax information comprises a supplemental enhancement information (SEI) message of an access unit, and wherein the SEI message indicates a

plurality of sequence parameter sets (SPSs) and a video parameter set (VPS) for decoding video data of the access unit; and', 'decode the video data of the access unit based on the plurality of SPSs and the VPS indicated in the SEI message.

27. The device of claim 26, wherein the SEI message comprises an active parameter sets SEI message.

28. The device of claim 27, wherein the active parameter sets SEI message precedes, in decoding order, a first portion of the video data of the access unit.

29. The device of claim 26, wherein the SEI message comprises a buffering period SEI message.

30. The device of claim 26, wherein the SEI message includes a first syntax element that indicates a first SPS of the plurality of SPSs, a second syntax element that specifies a number of additional SPSs indicated in the SEI message, and one or more additional syntax elements that respectively indicate the additional SPSs.

31. The device of claim 30, wherein the first syntax element comprises a', 'active seq param set id syntax element, the second syntax element comprises a num additional sps ids minusl syntax element, and the one or more additional syntax elements comprise additional_active_sps_idi syntax elements for i = 0; i <', 'num additional sps ids minusl ; i++.

32. The device of claim 26, wherein the SEI message includes a first syntax element that specifies a number of the plurality of SPSs, and one or more additional syntax elements that respectively indicate the plurality of SPSs.

33. The device of claim 32, wherein the first syntax element comprises a', 'num sps ids minusl syntax element, and the one or more additional syntax elements comprise active_sps_idi syntax elements for i = 0; i <', 'num additional sps ids minusl ; i++.

34. The device of claim 26,', 'wherein the video data comprises at least one of a plurality of layers or a plurality of views,', 'wherein each of the plurality of SPSs is associated with a respective one or more of the plurality of layers or plurality of views, and', 'wherein, for each of the layers or views, the video decoder is configured to decode the video data of the layer or view based on the SPS associated with the layer or view.

35. The device of claim 34, wherein the video decoder is further configured to: determine identifiers that are respectively associated with the plurality of layers or views, wherein determining the identifiers comprises at least one of:', 'decoding at least one of the identifiers, or', 'deriving at least one of the identifiers based on a hierarchical position of the respective layer or view; and', 'determine the plurality of SPSs for respectively decoding the video data of the plurality of layers or views based on the indication in the SEI message and the determined identifiers.

36. The device of claim 35, wherein each of the plurality of SPSs is associated with a respective one or more of the plurality of layers, and at least one of the plurality of SPSs comprises an active layer SPS.

37. The device of claim 35, wherein the video data comprises at least one of multiview video data, three-dimensional video data, or scalable video coding video data.

38. The device of claim 26, wherein the video decoder is further configured to activate the plurality of SPSs and the VPS based on the indication of the plurality of SPSs and the VPS in the SEI message, and decode the video data of the access unit based on the plurality of activated SPSs and the activated VPS.

39. The device of claim 26, wherein the device comprises at least one of:', 'an integrated circuit implementing the video decoder;', 'a microprocessor implementing the video decoder; and

a wireless communication device including the video decoder.

40. A device comprising a video encoder configured to:', 'encode a bitstream that includes video data and syntax information for encoding the video data, wherein the syntax information comprises a supplemental enhancement information (SEI) message of an access unit, and wherein the SEI message indicates a plurality of sequence parameter sets (SPSs) and a video parameter set (VPS) for decoding video data of the access unit; and', 'encode the video data of the access unit based on the plurality of SPSs and the VPS indicated in the SEI message.

41. The device of claim 40, wherein the SEI message comprises an active parameter sets SEI message.

42. The device of claim 41, wherein the active parameter sets SEI message precedes, in encoding order, a first portion of the video data of the access unit.

43. The device of claim 40, wherein the SEI message comprises a buffering period SEI message.

44. The device of claim 40, wherein the SEI message includes a first syntax element that indicates a first SPS of the plurality of SPSs, a second syntax element that specifies a number of additional SPSs indicated in the SEI message, and one or more additional syntax elements that respectively indicate the additional SPSs.

45. The device of claim 44, wherein the first syntax element comprises a', 'active seq param set id syntax element, the second syntax element comprises a num additional sps ids minusl syntax element, and the one or more additional syntax elements comprise additional_active_sps_idi syntax elements for i = 0; i <', 'num additional sps ids minusl ; i++.

46. The device of claim 40, wherein the SEI message includes a first syntax element that specifies a number of the plurality of SPSs, and one or more additional syntax elements that respectively indicate the plurality of SPSs.

47. The device of claim 46, wherein the first syntax element comprises a', 'num sps ids minusl syntax element, and the one or more additional syntax elements comprise active_sps_idi syntax elements for i = 0; i <', 'num additional sps ids minusl ; i++.

48. The device of claim 40,', 'wherein the video data comprises at least one of a plurality of layers or a plurality of views,', 'wherein each of the plurality of SPSs is associated with a respective one or more of the plurality of layers or plurality of views, and', 'wherein, for each of the layers or views, the video encoder is configured to encode the video data of the layer or view based on the SPS associated with the layer or view.

49. The device of claim 48, wherein each of the plurality of SPSs is associated with a respective one or more of the plurality of layers, and at least one of the plurality of SPSs comprises an active layer SPS.

50. The device of claim 48, wherein the video data comprises at least one of multiview video data, three-dimensional video data, or scalable video coding video data.

51. The device of claim 40, wherein the plurality of SPSs and the VPS are activated by a video decoder based on the indication of the plurality of SPSs and the VPS in the SEI message.

52. The device of claim 40, wherein the device comprises at least one of:', 'an integrated circuit implementing the video encoder;', 'a microprocessor implementing the video encoder; and', 'a wireless communication device including the video encoder.

53. A device comprising :', 'means for coding a bitstream that includes video data and syntax information for coding the video data, wherein the syntax information comprises a supplemental

enhancement information (SEl) message of an access unit, and wherein the SEl message indicates a plurality of sequence parameter sets (SPSs) and a video parameter set (VPS) for coding video data of the access unit; and', 'means for coding the video data of the access unit based on the plurality of SPSs and the VPS indicated in the SEl message.

54. The device of claim 53, wherein the SEl message comprises an active parameter sets SEl message.

55. The device of claim 53,', 'wherein the video data comprises at least one of a plurality of layers or a plurality of views,', 'wherein each of the plurality of SPSs is associated with a respective one or more of the plurality of layers or plurality of views, and', 'wherein the means for coding the video data of the access unit based on the plurality of SPSs and the VPS comprises means for, for each of the layers or views, coding the video data of the layer or view based on the SPS associated with the layer or view.

56. The device of claim 55, wherein the video data comprises at least one of multiview video data, three-dimensional video data, or scalable video coding video data.

57. A computer-readable storage medium having instructions stored thereon that, when executed by one or more processors of a video coder, cause the video coder to: code a bitstream that includes video data and syntax information for coding the video data, wherein the syntax information comprises a supplemental enhancement information (SEl) message of an access unit, and wherein the SEl message indicates a plurality of sequence parameter sets (SPSs) and a video parameter set (VPS) for coding video data of the access unit; and', 'code the video data of the access unit based on the plurality of SPSs and the VPS indicated in the SEl message.

58. The computer-readable storage medium of claim 57, wherein the SEl message comprises an active parameter sets SEl message.

59. The computer-readable storage medium of claim 57,', 'wherein the video data comprises at least one of a plurality of layers or a plurality of views,', 'wherein each of the plurality of SPSs is associated with a respective one or more of the plurality of layers or plurality of views, and', 'wherein the instructions that cause the one or more processors to code the video data of the access unit based on the plurality of SPSs and the VPS comprises instructions that cause the one or more processors to, for each of the layers or views, code the video data of the layer or view based on the SPS associated with the layer or view.

60. The computer-readable storage medium of claim 59, wherein the video data comprises at least one of multiview video data, three-dimensional video data, or scalable video coding video data.']