Extract HDR metadata from DASH manifests

[joeyparrish]

Have you read the FAQ and checked for duplicate open issues?
Yes

Is your feature request related to a problem? Please describe.

In our isTypeSupported polyfill for Cast, we use the HEVC profile ("hevc1.2") as an indication of the HDR transfer function, but it seems that this is not always accurate. This profile of HEVC is 10-bit color, but could be non-HDR 10-bit color, according to an internal issue report.

Describe the solution you'd like

The polyfill should stop assuming that 10-bit color HEVC means HDR, and remove the extra eotf="smpte2084" parameter. Instead, the manifest parser should extract HDR profile information from the DASH manifest and pass that info along through the Stream object.

Describe alternatives you've considered

Not aware of any off-hand.

Additional context

DASH-IF docs state that conformant HDR streams for which we should use eotf="smpte2084" would be in an <AdaptationSet> with the profiles parameter set to "http://dashif.org/guidelines/dash-if-uhd#hevc-hdr-pq10".

See DASH IOP v4.3, section 10.3 "DASH-IF IOP HEVC HDR PQ10" and section 10.3.3, "Mapping to DASH".

[avelad]

I have created the PR for HLS #3116, but the implementation of DASH is not very clear to me.

@joeyparrish , according to the documentation, the profile is global, but it only applies to certain codecs ("hvc1.2.4.L153.B0" or "hev1.2.4.L153.B0"), but I don't think this is entirely correct, since VP9 profile 2 supports HDR, and AV1 also supports HDR. Do you have any idea how this should be implemented?

[dsparacio]

We are interested in this enhancements as well. Second the work on this

according to the documentation, the profile is global, but it only applies to certain codecs ("hvc1.2.4.L153.B0" or "hev1.2.4.L153.B0"), but I don't think this is entirely correct, since VP9 profile 2 supports HDR, and AV1 also supports HDR. Do you have any idea how this should be implemented?

@avelad have you asked the community on slack to help clarify this by chance? I can look into it or bring it up at the next IF meeting I attend?

[avelad]

If you can ask, I appreciate it. As soon as I know what to implement, I will send a PR. Can you send me a link to the Slack community channel? Is it the official channel of the ShakaPlayer team?

[dsparacio]

@avelad my bad I read that as you were confused on something from DASH spec, but you are saying Shaka Documentation. So no this is the best place to ask the Shaka team.

[joeyparrish]

@joeyparrish , according to the documentation, the profile is global, but it only applies to certain codecs ("hvc1.2.4.L153.B0" or "hev1.2.4.L153.B0"), but I don't think this is entirely correct, since VP9 profile 2 supports HDR, and AV1 also supports HDR.

What documentation are you referring to? DASH documentation, or codec string specs, or our docs?

Do you have any idea how this should be implemented?

No, I don't, offhand. Maybe I've misunderstood the issue, or maybe it's just outside of my area of experience. Can you explain the problem again or differently?

[avelad]

@joeyparrish , according to the documentation, the profile is global, but it only applies to certain codecs ("hvc1.2.4.L153.B0" or "hev1.2.4.L153.B0"), but I don't think this is entirely correct, since VP9 profile 2 supports HDR, and AV1 also supports HDR.

What documentation are you referring to? DASH documentation, or codec string specs, or our docs?

https://dashif.org/docs/DASH-IF-IOP-v4.3.pdf --> 10.3. DASH-IF IOP HEVC HDR PQ10 and 11.3.3. DASH-IF VP9-HDR

Do you have any idea how this should be implemented?

No, I don't, offhand. Maybe I've misunderstood the issue, or maybe it's just outside of my area of experience. Can you explain the problem again or differently?

In HLS in each video track it is identified if it is HDR or not, but in DASH it seems that it is at the manifest level, so I want to be sure of this and that I have understood the same as you.