Closed Bug 1300711 Opened 7 years ago Closed 7 years ago

Remove MediaDecoderStateMachine::mQuickBuffering

Categories

(Core :: Audio/Video: Playback, defect, P3)

defect

Tracking

()

RESOLVED FIXED
mozilla52
Tracking Status
firefox52 --- fixed

People

(Reporter: jwwang, Assigned: jwwang)

References

Details

Attachments

(1 file)

https://hg.mozilla.org/mozilla-central/file/tip/dom/media/MediaDecoderStateMachine.h#l825

I think we can remove this member now because MDSM prerolls enough audio/video before starting playback to ensure it won't enter buffering immediately after playback starts.
Assignee: nobody → jwwang
Blocks: 1295892
Flags: needinfo?(cpearce)
Priority: -- → P3
Depends on: 628665
Worth testing. You can use https://github.com/cpearce/HttpMediaServer or something similar to limit the bandwidth that video files are served over, and use that to ensure buffering happens.
Flags: needinfo?(cpearce)
Depends on: 1302040
Depends on: 1302045
After fixing bug 1302040 and bug 1302045, MDSM will not enter buffering prematurely at the beginning of playback.

Here are the test results after removing quick buffering:
1. When download is slow (ex: rate=200), it enters buffering 2 or 3 secs after playback starts.
2. When download is fast enough (ex: rate=500), no buffering happens during playback.

Without removing quick buffering:
1. When download is slow (ex: rate=200), it enters quick buffering 2 or 3 secs after playback starts, and exits quick buffering one sec later, and then enters buffering again 3 or 4 sec later.

So I conclude quick buffering doesn't buy us much. If download is slow, we will need to stop for buffering anyway some time. The point of quick buffering is to prevent entering buffering right after playback starts. Since prerolling + bug 1302040 + bug 1302045 have fix that, there is not point keeping quick buffering anymore.
Attachment #8792376 - Flags: review?(cpearce)
Comment on attachment 8792376 [details]
Bug 1300711 - Remove MediaDecoderStateMachine::mQuickBuffering.

https://reviewboard.mozilla.org/r/79448/#review78316

I always thought quick buffering was a hack. Good riddance!
Attachment #8792376 - Flags: review?(cpearce) → review+
Thanks!
Pushed by jwwang@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/9a5ccc0e7270
Remove MediaDecoderStateMachine::mQuickBuffering. r=cpearce
https://hg.mozilla.org/mozilla-central/rev/9a5ccc0e7270
Status: NEW → RESOLVED
Closed: 7 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla52
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