Bug 159813 – [MSE] Increase the SourceBuffer "fudge factor"

• Status: RESOLVED
• Resolution: FIXED
• Component: Media

[Eric Carlson]

Some media encoding/conversion pipelines are sloppy when doing sample time/timescale math, and the error accumulation results in small gaps in the media timeline. r202641 increased the maximum allowable gap from 0.01 second to one 24fps frame, but it turns out that at least one large provider has a significant amount of content encoded with up to two 24fps frames.

[Radar WebKit Bug Importer]

<rdar://problem/27372033>

[Eric Carlson]

Created attachment 283763 [details]
Proposed patch.

[Jon Lee]

Comment on attachment 283763 [details]
Proposed patch.

View in context: https://bugs.webkit.org/attachment.cgi?id=283763&action=review

> LayoutTests/media/media-source/media-source-small-gap.html:41
> +            makeASample(7, 7, 1,                   1, SAMPLE_FLAG.NONE),

The spacing is odd here.

[Eric Carlson]

Comment on attachment 283763 [details]
Proposed patch.

View in context: https://bugs.webkit.org/attachment.cgi?id=283763&action=review

>> LayoutTests/media/media-source/media-source-small-gap.html:41
>> +            makeASample(7, 7, 1,                   1, SAMPLE_FLAG.NONE),
> 
> The spacing is odd here.

I originally used one space after each comma, but found that it was difficult to see exactly what was different in each sample.

[WebKit Commit Bot]

Comment on attachment 283763 [details]
Proposed patch.

Clearing flags on attachment: 283763

Committed r203277: <http://trac.webkit.org/changeset/203277>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Ihor Ivlev]

I think we should have different allowable gaps for Audio and Video tracks, and they should be calculated based on the current frame duration.
Otherwise AudioWithLargeGap test from http://yt-dash-mse-test.commondatastorage.googleapis.com/unit-tests/2016.html fails.

[Ihor Ivlev]

A note on my previous comment:
the test failure is reportedly not reproducible with the latest (2017) MSE test cases
http://yt-dash-mse-test.commondatastorage.googleapis.com/unit-tests/2017.html