Playback Requirements for CMAF HEVC HLG10 ('clg1')

[haudiobe]

• Where is the media profile defined?
• What are Capability Discovery Options?
  • <Define how the media profile capability signaling is donediscovery of the media profile may be done, including existing practices>
• What are the Source Buffer Initialization Requirements?
  • Codec
  • max frame rate
  • etc.
• What are the Playback Requirements?
  • via reference to the above playback requirements define what the media profile playback requirement is

[haudiobe]

10.2.6 Media Profile: CMAF HEVC HLG10 ('clg1') The details for this profile will be added to an updated version of the specification after a questionnaire to the media profile proponents.

[haudiobe]

I added the HEVC Test Content Options to an updated dpctf specification here

https://standards.cta.tech/apps/org/workgroup/dpctf/download.php/34886/dpctf-s00001-v032-WAVE-DPC-v1.12.docx

In order for better tracking, I also provided the content options for each of the profiles here:

• https://github.com/cta-wave/Test-Content-Generation/blob/master/Instructions/clg1.md

Can you please review and check if you have comments. I will start to generate the content.

[sdp198]

I've got some comments / questions.

7.5.17 Track Run Box ('trun') v1 – combined with SAP type 1 (typically with P-Pictures only)

I don't understand the bit in brackets. The benefit of a v1 trun box is that it allows B-pictures to be in the stream without needing an edit list. I think maybe the text in brackets should be removed, or should mention B-pictures.

Two options for default flags default_sample_flags, sample_flags and first_sample_flags neither set in the TrackFragmentHeaderBox nor TrackRunBox default_sample_flags, sample_flags and first_sample_flags set in the TrackFragmentHeaderBox and TrackRunBox

Second, I'm not quite sure what is being said here. The CMAF spec has a shall statement in 7.7.3 requiring the latter of those two options. Was the choice here perhaps supposed to be the following?

• _default_sampleflags set in TrackFragmentHeaderBox and _first_sampleflags set in TrackRunBox. With _sampleflags not used.
• _sampleflags set in TrackRunBox for every sample. With _default_sampleflags and _first_sampleflags not used

Also, this bit about default flags is incorrectly nested under "7.5.13 Edit List Box ('elst')"

Moving on to the Test Content table, there is only one row with the hev1 sample entry. As the sample entries are something which affects track switching, it would be nice if one of the rows with multiple frame sizes used that sample entry. Perhaps hevc34 could be changed to use hev1?

One other thing, there's a typo in the table headers - "Spatial and temporal supsampling" should be "Spatial and temporal subsampling"

[haudiobe]

DPCTF 2022/02/09

• agree to remove P-Picture constraint. Leftover from AVC
• agree on the updated text - will fix @haudiobe Thanks

[haudiobe]

DPCTF

• also apply the proposed changes from #22 here

[haudiobe]

DPCTF Call on 2022/03/09:

• add a statement that you also test #22 and #23 if you do clg1

[gitwjr]

Deferred to HEVC implementation.

[haudiobe]

Implemented here in v2.08