Bug 159230 – Cannot clear a MediaSource SourceBuffer in Safari 9 and WebKit nightly

• Component: Media
• Status: RESOLVED FIXED

[Joey Parrish]

Shaka Player (https://github.com/google/shaka-player) discovered that Safari does not completely remove buffered ranges.

In our test, we append 30 seconds of data (from 0 to about 30s), then remove from 0 to 60.  Even though this removal encompasses all data in buffer, Safari leaves behind a tiny buffered range (less than 1 trillionth of a second).  This causes confusion in MSE apps like ours which make decisions based on where the end of the buffer is.

To reproduce:

1. Visit http://storage.googleapis.com/shaka-demo-assets/_bugs/safari-mse-clear/index.html in Safari
2. Open the JavaScript console
3. Observe information about the steps that were taken

In Chrome, Firefox, Opera, Edge, and IE 11, the result is that nothing is buffered after removing the range from 0-60.

In Safari 9, the result is that there is still a buffered range.  You will see a failed assertion in the console after loading our test page.

OS X El Capitan, Safari 9.0.3 (11601.4.4) and in WebKit nightly r202569.

[Radar WebKit Bug Importer]

<rdar://problem/27082033>

[Jer Noble]

Created attachment 282354 [details]
Patch

[Build Bot]

Comment on attachment 282354 [details]
Patch

Attachment 282354 [details] did not pass mac-ews (mac):
Output: http://webkit-queues.webkit.org/results/1595307

New failing tests:
media/media-source/media-source-remove.html

[Build Bot]

Created attachment 282357 [details]
Archive of layout-test-results from ews103 for mac-yosemite

The attached test failures were seen while running run-webkit-tests on the mac-ews.
Bot: ews103  Port: mac-yosemite  Platform: Mac OS X 10.10.5

[Jer Noble]

Created attachment 282358 [details]
Patch for landing

[Build Bot]

Comment on attachment 282354 [details]
Patch

Attachment 282354 [details] did not pass mac-debug-ews (mac):
Output: http://webkit-queues.webkit.org/results/1595342

New failing tests:
media/media-source/media-source-remove.html

[Build Bot]

Created attachment 282359 [details]
Archive of layout-test-results from ews113 for mac-yosemite

The attached test failures were seen while running run-webkit-tests on the mac-debug-ews.
Bot: ews113  Port: mac-yosemite  Platform: Mac OS X 10.10.5

[Brent Fulgham]

Comment on attachment 282358 [details]
Patch for landing

Looks good! r=me.

[WebKit Commit Bot]

Comment on attachment 282358 [details]
Patch for landing

Clearing flags on attachment: 282358

Committed r202641: <http://trac.webkit.org/changeset/202641>

[Build Bot]

Comment on attachment 282354 [details]
Patch

Attachment 282354 [details] did not pass mac-wk2-ews (mac-wk2):
Output: http://webkit-queues.webkit.org/results/1595944

New failing tests:
media/media-source/media-source-remove.html

[Build Bot]

Created attachment 282364 [details]
Archive of layout-test-results from ews107 for mac-yosemite-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews107  Port: mac-yosemite-wk2  Platform: Mac OS X 10.10.5

[Lucas Cheon]

I'm experience exact same problem as Joey is having with Shaka Player on Safari 10 Beta.

I see that Jer has been working on making fixes here. When can we expect the fixes to be applied?

[Jer Noble]

(In reply to comment #12)
> I'm experience exact same problem as Joey is having with Shaka Player on
> Safari 10 Beta.
> 
> I see that Jer has been working on making fixes here. When can we expect the
> fixes to be applied?

Lucas, we've made a lot of changes since this patch landed. Can you file a new Bugzilla if you're still seeing issues with Shaka Player?