feat: Allow EssentialProperty descriptors to be used for Video Colorimetry in DASH

[gmcgarry]

Currently, video colorimetry in the dash manifest is always presented as SupplementalProperty descriptors. This means that a player may choose to ignore them.

      <EssentialProperty schemeIdUri="urn:mpeg:mpegB:cicp:MatrixCoefficients" value="9"/>
      <EssentialProperty schemeIdUri="urn:mpeg:mpegB:cicp:ColourPrimaries" value="9"/>
      <EssentialProperty schemeIdUri="urn:mpeg:mpegB:cicp:TransferCharacteristics" value="16"/>

For HDR colorimetry descriptors, using EssentialProperty descriptors will trigger the player (such as dash.js) to honour the descriptor by populating MediaCapabilities queries with information from the descriptors. It will also ensure that SDR devices will quickly filter unsupported HDR tracks. This is particularly important for HEVC since the codecs attribute does not convey the colorimetry information like av/1.

This patch introduces the --use_colorimetry_essential_property command-line flag to use EssentialProperty instead of SupplementalProperty. It is recommended by Dolby for signalling Dolby Vision Profiles 8 and 10. The semantics of this flag preserves the existing default behaviour.

[joeyparrish]

Thanks for contributing!

For my own notes: I checked source in Shaka Player and found that HDR info is taken from both EssentialProperty and SupplementalProperty, in that order.

[joeyparrish]

Looks like you have a small error in your tests:

https://github.com/shaka-project/shaka-packager/actions/runs/19561994356/job/56079257646?pr=1524

packager/app/test/packager_test.py:492:46: E0001: Parsing failed: 'invalid syntax. Perhaps you forgot a comma? (packager_test, line 492)' (syntax-error)

[joeyparrish]

If you would allow us to make edits in the future, I would be happy to correct small issues like this myself. Let us know when you've pushed a commit to fix this. Also, you might consider running the linter and test cases yourself before upload. Thanks!

[joeyparrish]

If you would allow us to make edits in the future...

Not allowed by GitHub for organization forks, rather than personal ones!

See #1523 (comment)

[joeyparrish]

https://github.com/shaka-project/shaka-packager/actions/runs/19586274341/job/56102029656?pr=1524

************* Module packager_test
packager/app/test/packager_test.py:554:7: E0602: Undefined variable 'use_colorimetry_essential_property' (undefined-variable)
packager/app/test/packager_test.py:493:16: W0613: Unused argument 'use_colorimetry_essentail_properity' (unused-argument)
packager/app/test/packager_test.py:1502:12: E1123: Unexpected keyword argument 'use_colorimetry_essential_property' in method call (unexpected-keyword-arg)
packager/app/test/packager_test.py:1521:12: E1123: Unexpected keyword argument 'use_colorimetry_essential_property' in method call (unexpected-keyword-arg)
packager/app/test/packager_test.py:1540:12: E1123: Unexpected keyword argument 'use_colorimetry_essential_property' in method call (unexpected-keyword-arg)

[gmcgarry]

https://github.com/shaka-project/shaka-packager/actions/runs/19586274341/job/56102029656?pr=1524

************* Module packager_test
packager/app/test/packager_test.py:554:7: E0602: Undefined variable 'use_colorimetry_essential_property' (undefined-variable)
packager/app/test/packager_test.py:493:16: W0613: Unused argument 'use_colorimetry_essentail_properity' (unused-argument)
packager/app/test/packager_test.py:1502:12: E1123: Unexpected keyword argument 'use_colorimetry_essential_property' in method call (unexpected-keyword-arg)
packager/app/test/packager_test.py:1521:12: E1123: Unexpected keyword argument 'use_colorimetry_essential_property' in method call (unexpected-keyword-arg)
packager/app/test/packager_test.py:1540:12: E1123: Unexpected keyword argument 'use_colorimetry_essential_property' in method call (unexpected-keyword-arg)

Oops. Fixed.

[gmcgarry]

Oops, looks like I accidentally closde the PR instead of resolving the conversation.