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Status: Available
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OS: All
Pri: 3
Type: Bug

Blocking:
issue 707649



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Experiment with adding web platform tests for codecs using MediaRecorder.

Project Member Reported by dalecur...@chromium.org, Aug 8 2017

Issue description

Specifically we could add web platform codec decoding tests for <audio>, <video>, and WebAudio by using the MediaRecorder framework.

Similar to how we have unittests for this today we could record and hash the lossless result. See media/test/pipeline_integration_test and media/base/audio_hash.h for examples of how we could use a hash with some room for library changes that occur with lossy test clips.

Video may be slightly harder to get bit-perfect tests for because unlike with audio MediaRecorder may miss some frames if they are dropped due to load. Our existing unittests specifically disable frame dropping when running.

 
Components: Blink>WebAudio

Comment 2 by rtoy@chromium.org, Aug 8 2017

WebAudio has some codec tests that compares the output with a 16-bit reference output.  These must match exactly.  I think we do this because we want to know when decoding changes even slightly (well, with 16-bit outputs).  That forces us to make a conscious decision on whether the change is acceptable or not.  If an FFMPEG roll caused this, we usually just update our reference.

Comment 3 by rbyers@chromium.org, Aug 10 2017

Cc: rbyers@chromium.org foolip@chromium.org
Thanks for digging into this!  Let foolip@/ecosystem-infra@chromium.org know if you need any help/advice on web-platform-test infrastructure or automation for this.

Comment 4 by foolip@chromium.org, Aug 10 2017

Blocking: 707649
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Comment 5 by sheriffbot@chromium.org, Aug 10

Labels: Hotlist-Recharge-Cold
Status: Untriaged (was: Available)
This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot
Status: Available (was: Untriaged)

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