Add H265 payloader and depacketizer

[kevmo314]

This change completes the H265 implementation.

[codecov]

Codecov Report

Attention: Patch coverage is 35.22727% with 114 lines in your changes missing coverage. Please review.

Project coverage is 79.86%. Comparing base (a21194e) to head (dd05d22).

Files with missing lines	Patch %	Lines
codecs/h265_packet.go	35.22%	111 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #165      +/-   ##
==========================================
- Coverage   83.95%   79.86%   -4.09%     
==========================================
  Files          24       24              
  Lines        1957     2126     +169     
==========================================
+ Hits         1643     1698      +55     
- Misses        255      366     +111     
- Partials       59       62       +3     

Flag	Coverage Δ
go	79.86% <35.22%> (-4.09%)	⬇️
wasm	79.30% <35.22%> (-4.04%)	⬇️

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[lebedyncrs]

Hi @kevmo314 are you planning to continue on this one?

[kevmo314]

Hi @kevmo314 are you planning to continue on this one?

There is no additional work necessary, however there is perhaps not a huge desire to merge it yet due to the relative rarity of H265 in WebRTC. I'll defer to @Sean-Der.

[Sean-Der]

@kevmo314 @lebedyncrs Lets get this merged today! The only issue for me is Payload has no coverage

@kevmo314 Do you have any tests you liked? Or should I just generate stuff via ffmpeg. Do you have any suggestions on flags I should use?

[kevmo314]

@kevmo314 @lebedyncrs Lets get this merged today! The only issue for me is Payload has no coverage

@kevmo314 Do you have any tests you liked? Or should I just generate stuff via ffmpeg. Do you have any suggestions on flags I should use?

ffmpeg-generated stuff works! The only gotcha I know of is the Safari H265 payloading thing: AlexxIT/Blog#5

I vaguely recall a post indicating that Safari has or intends to migrate off this custom format but I'm not sure how we want to handle that from pion since that's not truly spec-compliant. Pion to pion worked great for me when I had used this code.

[lebedyncrs]

Thanks for pushing it forward @Sean-Der . @kevmo314 I tried to prepare example of how to stream video using h265 in browser (there is Chromium build which supports h265). I am getting an error "unable to start track, codec is not supported by remote". When I look at SDP from browser there is information about h265 support but when I check go answer SDP I cannot see it.

Steps to reproduce:

• Build and run go project https://go.dev/play/p/M63vYtY0jfS
• Save https://jsfiddle.net/uns74ogx/1/ to index.html and open in browser which support h265
• Check go output to see an error

[kevmo314]

Thanks for pushing it forward @Sean-Der . @kevmo314 I tried to prepare example of how to stream video using h265 in browser (there is Chromium build which supports h265). I am getting an error "unable to start track, codec is not supported by remote". When I look at SDP from browser there is information about h265 support but when I check go answer SDP I cannot see it.

Steps to reproduce:

• Build and run go project go.dev/play/p/M63vYtY0jfS
• Save jsfiddle.net/uns74ogx/1 to index.html and open in browser which support h265
• Check go output to see an error

This PR only adds the payloader and depacketizer. You'll have to configure Pion to respond with H265 which is not on by default. It can be added in the media engine.

[aleksitto-gh]

thanks for this PR, but before you merge, what about

annexbNALUStartCode ?

it looks like a mock at the moment

[kevmo314]

thanks for this PR, but before you merge, what about

annexbNALUStartCode ?

it looks like a mock at the moment

Where do you see that it's a mock?

[aleksitto-gh]

thanks for this PR, but before you merge, what about
annexbNALUStartCode ?
it looks like a mock at the moment

Where do you see that it's a mock?

// TODO: this is not actually correct following B.2.2, not all NALUs have a 4-byte start code.
buf = append(buf, annexbNALUStartCode...)

[kevmo314]

thanks for this PR, but before you merge, what about
annexbNALUStartCode ?
it looks like a mock at the moment

Where do you see that it's a mock?

// TODO: this is not actually correct following B.2.2, not all NALUs have a 4-byte start code.
buf = append(buf, annexbNALUStartCode...)

That doesn't mean it's a mock, it only means that it's not fully correct as the comment suggests. Pion always uses a 4-byte start code which is suboptimal according to the specification but it does work and play back correctly.

[aleksitto-gh]

thanks for this PR, but before you merge, what about
annexbNALUStartCode ?
it looks like a mock at the moment

Where do you see that it's a mock?

// TODO: this is not actually correct following B.2.2, not all NALUs have a 4-byte start code.
buf = append(buf, annexbNALUStartCode...)

That doesn't mean it's a mock, it only means that it's not fully correct as the comment suggests. Pion always uses a 4-byte start code which is suboptimal according to the specification but it does work and play back correctly.

Great, thank you! The TODO comment confused me.