[MP4] MP4 plugin has a test case with audio and video but the HLS playlist only lists video.

[jerzywilczek]

https://github.com/membraneframework/membrane_mp4_plugin/blob/8b55570faaecfa79b1eeffb4b8077b18624f1f25/test/fixtures/cmaf/muxed_audio_video/index.m3u8#L4C44-L4C48

Other than the issue mentioned in the topic, some values in the mp4 seem to be strange, e.g. the second sidx box in the first segment has earliest_presentation_time = 18446744073709537000, which does not seem right...

[mat-hek]

https://github.com/membraneframework/membrane_mp4_plugin/blob/8b55570faaecfa79b1eeffb4b8077b18624f1f25/test/fixtures/cmaf/muxed_audio_video/index.m3u8#L4C44-L4C48

It's more like an HLS issue, @Karolk99 why don't we put the audio codec in there as well?

the second sidx box in the first segment has earliest_presentation_time = 18446744073709537000

Indeed, @Qizot any idea why is that?

some values in the mp4 seem to be strange

@jerzywilczek any others that feel strange?

[Qizot]

@mat-hek earliest_presentation_time in the schema is represented by :uint64 where I believe it should be :int64?

If you change the given time to a signed integer you get -14616.

[jerzywilczek]

@mat-hek I think other timestamps may be wrong too, don't remember anymore

[mat-hek]

@Qizot it should be unsigned according to the spec. It seems we pass a negative value there and we shouldn't.

[Qizot]

@mat-hek This fragment takes DTS instead of the PTS value so here is the bug.

[mat-hek]

@Qizot it fixes the problem, but unfortunately it's also somehow used for calculating durations. Changing it makes the following tests fail:

  3) test video with partial segments should create as many partial segments as possible until reaching a key frame (Membrane.MP4.Muxer.CMAF.IntegrationTest)
     test/membrane_mp4/muxer/cmaf/integration_test.exs:215
     Assertion with <= failed
     code:  assert buffer.metadata.duration <= Membrane.Time.milliseconds(550)
     left:  1000000000
     right: 550000000
     stacktrace:
       test/membrane_mp4/muxer/cmaf/integration_test.exs:227: (test)

  6) test video partial segments (Membrane.MP4.Muxer.CMAF.IntegrationTest)
     test/membrane_mp4/muxer/cmaf/integration_test.exs:170
     Assertion with < failed
     code:  assert buffer.metadata.duration < Membrane.Time.milliseconds(550)
     left:  1000000000
     right: 550000000
     stacktrace:
       test/membrane_mp4/muxer/cmaf/integration_test.exs:182: anonymous fn/3 in Membrane.MP4.Muxer.CMAF.IntegrationTest."test video partial segments"/1
       (elixir 1.15.4) lib/enum.ex:4379: Enum.reduce/3
       test/membrane_mp4/muxer/cmaf/integration_test.exs:179: (test)

[Karolk99]

@mat-hek, the link you referred to for the master manifest in the mp4_plugin is a hardcoded fixture from three years ago. If you look at the fixtures in the HTTP Adaptive Stream Plugin (for example, master manifest), you'll see that they include the audio codec.

[mat-hek]

Ok, so we just don't compare manifests as we focus on the m4s files, thus the outdated fixtures. I'm removing them in membraneframework/membrane_mp4_plugin#103. @jerzywilczek have a look at the HTTP adaptive stream plugin for manifest-related stuff.

[mat-hek]

Closing as membraneframework/membrane_mp4_plugin#103. and membraneframework/membrane_mp4_plugin#104 are merged, @jerzywilczek feel free to report more weird values :D