[Feat]: Support for SDR rec.709 color standard

[bkekelic2]

Version

3.0.0-RC3

Environment that reproduces the issue

Samsung s25 ultra

Use case description

Hi,
I'm wondering if there is there any kind of support for SDR rec.709 color standard?
Using SRT with HEVC.

When I set VideoConfig with profile MediaCodecInfo.CodecProfileLevel.HEVCProfileMain and level MediaCodecInfo.CodecProfileLevel.HEVCHighTierLevel62 on the receiver side I got SDR rec.601 (bt470bg).

I found enums: ColorPrimaries and MatrixCoefficients which contain values BT709 and MediaFormat.COLOR_STANDARD_BT709 but cannot get to this point anyhow.
Do you have any idea how to accomplish this?

Proposed solution

No response

Alternative solutions

No response

[ThibaultBee]

Hi,

HDR is a bit experimental for now, I don't have a full knowledge of standards.
I guess the reason why is somewhere here

If you could help me understand and what is the best implementation, that would be nice.

[bkekelic2]

Hi,
this is actually color standard used in SDR, not HDR.
I'm not expert but here is the idea.
Because it has nothing to do with hdr, we can maybe extend if statement which will set format for sdr profiles.
We can maybe hardcode here some format, or even pass optional parameter in method and then use optional color standard, if set.
What do you think about this?

Or, make an extra method which will just set color standard, so it is not related to the profiles and levels. Then, the user should be careful to not use rec.601 or 709 with HDR profile. Or add some checks.

[ThibaultBee]

Could you test that your phone does support SDR rec.709?

• clone the repo
• set: format.setInteger(MediaFormat.KEY_COLOR_STANDARD, MediaFormat.COLOR_STANDARD_BT709) in getFormat

[bkekelic2]

I've added else case to previously mentioned if statement

else { format.setInteger(MediaFormat.KEY_COLOR_STANDARD, MediaFormat.COLOR_STANDARD_BT709) format.setInteger(MediaFormat.KEY_COLOR_RANGE, MediaFormat.COLOR_RANGE_LIMITED) format.setInteger(MediaFormat.KEY_COLOR_TRANSFER, MediaFormat.COLOR_TRANSFER_SDR_VIDEO) }

and it works!
Works also if you set only first line, which you mentioned.

To confirm,
on the receiver side, in ffplay I see stream info:
Stream #0:0[0x20]: Video: hevc (Main), 1 reference frame (HEVC / 0x43564548), yuv420p(tv, bt709, left), 1920x1080, 30 tbr, 90k tbn, start 76458.550533

Without this else case, default behaviour is to use rec.601:
Stream #0:0[0x20]: Video: hevc (Main), 1 reference frame (HEVC / 0x43564548), yuv420p(tv, bt470bg/bt470bg/smpte170m, left), 1920x1080, 30 tbr, 90k tbn, start 76547.168633

[ThibaultBee]

I am afraid this kind of feature won't be available on every devices. Is there an API to retrieve the supported color standard of the encoder?

[bkekelic2]

Hmm, not sure if there is such feature.
But you can check if format is supported at runtime with MediaCodecHelper. Tried, seems to be working just fine.

Maybe add some logic which will check if supports 709 and use it, otherwise use default 601.
Or, what do you think about idea with optional param? Then user has ability to use whatever he wants, and responsibility is on him?

[ThibaultBee]

I hesitate between 2 solutions:

• an optional value with require to verify when set to rec.601 or 709 that the profile is SDR. If it is not set, we shouldn't try to force a value (this stuff might crash on few devices)
• a way to set custom user field to MediaFormat. I want something like that for a long time, but it is risky (what work on a device might crash on another)

[ThibaultBee]

Could you have a look at #244?

[bkekelic2]

Tested on s25 ultra, works. Good job :)
Tried only setting 709, and it applied changes.

I've hardcoded configure param in
videoConfigFlow and put:

configure = { this.setInteger(MediaFormat.KEY_COLOR_STANDARD, MediaFormat.COLOR_STANDARD_BT709) this.setInteger(MediaFormat.KEY_COLOR_RANGE, MediaFormat.COLOR_RANGE_LIMITED) this.setInteger(MediaFormat.KEY_COLOR_TRANSFER, MediaFormat.COLOR_TRANSFER_SDR_VIDEO) }

At the output (ffmpeg) I see:

Stream #0:0[0x20]: Video: hevc (Main), 1 reference frame (HEVC / 0x43564548), yuv420p(tv, bt709, left), 1920x1080, 30 tbr, 90k tbn, start 11908.888067

which confirms that settings were applied, if we compare it with stream without changes:

Stream #0:0[0x20]: Video: hevc (Main), 1 reference frame (HEVC / 0x43564548), yuv420p(tv, bt470bg/bt470bg/smpte170m, left), 1920x1080, 30 tbr, 90k tbn, start 11315.282922

I'm really looking forward to try this and other changes in new release, 3.0.1. Do you have any idea when we could expect it?
One more time, bravo for all of the work you are putting in this :)

[ThibaultBee]

Do you really need to set MediaFormat.KEY_COLOR_RANGE and MediaFormat.KEY_COLOR_TRANSFER?

My advice would be to test on multiple devices. It might crash on few devices.
I am curious about your use case, could you contact me on linkedin?

[bkekelic2]

Actually, seems that I do not need. As I tested before with it, and now also, it works both ways.
I've tested on 3 newer devices in total, and on all devices it works only if I stream in landscape mode (eg. 1920x1080) and not if I stream in portrait mode (eg. 1080x1920).
Devices:

• s25 ultra (android 16)
• s23 (android 15)
• s21 FE (android 15)

In portrait mode cases, it simply fallback to the .601, and there was no crash.

On LinkedIn you are accessible for me only through Premium version, which I do not have, thus I cannot send you a message.

[ThibaultBee]

Devices:
s25 ultra (android 16)
s23 (android 15)
s21 FE (android 15)

In portrait mode cases, it simply fallback to the .601, and there was no crash.

Yeah but that's only Samsung devices.

On LinkedIn you are accessible for me only through Premium version, which I do not have, thus I cannot send you a message.

You can connect :) and then talked

[bkekelic2]

Yeah but that's only Samsung devices.

I will test with other devices, mid-low end in the next few days, and will let you know.

You can connect :) and then talked

I was blind, obviously... didn't see it

[ThibaultBee]

On the same PR, I push a way to set color standard.
In VideoConfig, there is a parameter called profileLevelColorBuilder to use this way:

val config = VideoConfig(profileLevelColorBuilder = {
sdrColorStandard = MediaFormat.COLOR_STANDARD_BT709
}