1409272 - Silence being inserted when data is appended slowly

Status: RESOLVED FIXED

(Core :: Audio/Video: Playback, enhancement)

Description

[Jean-Yves Avenard [:jya]]

In bug 1400674, we fixed A/V sync when silence were being inserted in the stream.

However, we should make sure no silence are needed in the first place.

As data is being fed slowly, the decoding engine hits the end of the buffered range often. The MFT then enters WAITING_FOR_DATA condition which causes a drain + seek.

When using vorbis, the decoder always drops the first compressed packet, causing gaps in the data being played. We need to either seek before the target or not drain+seek the decoder.

Draining the audio decoder shouldn't be required, however this has unwanted side effect with the windows AAC decoder that requires Drain to be called in order to fix timestamps.

Comment 1

[Jean-Yves Avenard [:jya]]

I don't see a way to get what we want without explicitly calling Drain on the WMF audio decoder.

So will instead implement a pre-roll like we have for opus.

Comment 2

[Jean-Yves Avenard [:jya]]

Attachment: Bug 1409272 - P1: Remove unnecessary and/or unused variables.

Review commit: https://reviewboard.mozilla.org/r/190184/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/190184/

Comment 3

[Jean-Yves Avenard [:jya]]

Attachment: Bug 1409272 - P2. Pre-roll vorbis by 80ms when seeking.

The value by which we pre-roll is inconsequential, so long as we seek to the previous packet than the one we want. So 80ms will do.

Review commit: https://reviewboard.mozilla.org/r/190186/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/190186/

Comment 4

[Gerald Squelart (he/him) (not at Mozilla since 2022-09-15)]

Comment on attachment 8919306 [details]
Bug 1409272 - P2. Pre-roll vorbis by 80ms when seeking.

https://reviewboard.mozilla.org/r/190186/#review195574

Comment 5

[JW Wang [:jwwang] [:jw_wang]]

Comment on attachment 8919305 [details]
Bug 1409272 - P1: Remove unnecessary and/or unused variables.

https://reviewboard.mozilla.org/r/190184/#review195694

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c5f66cb5525a
P1: Remove unnecessary and/or unused variables. r=jwwang
https://hg.mozilla.org/integration/autoland/rev/7dc6e7b5d909
P2. Pre-roll vorbis by 80ms when seeking. r=gerald

Comment 7

[Stefan Hindli [:stefan_hindli]]

https://hg.mozilla.org/mozilla-central/rev/c5f66cb5525a
https://hg.mozilla.org/mozilla-central/rev/7dc6e7b5d909