Bug 133459 – REGRESSION(169440): Repro crash when playing a video with captions

• Component: Media
• Status: RESOLVED FIXED

[Brent Fulgham]

My recent change <http://trac.webkit.org/changeset/169440> introduced a crash when viewing video with paint-on captions. The problems were related to two issues:

1. WebKit was properly identifying new cues that extended existing cues, but was not updating the bookkeeping so that the extended cue would be updated to reflect the proper end time of the cue. This resulted in some of these cues sticking around for the remaining duration of the video.
2. The crash was being caused by the logic that updates the cue time. It removes and then re-adds the cue during the time modification, but was not updating the reference count on the cue. This caused the cue to be cleaned up during the update operation, causing the crash.

This change corrects both of these problems.

[Brent Fulgham]

<rdar://problem/17079081>

[Brent Fulgham]

Created attachment 232398 [details]
Patch

[Brent Fulgham]

Created attachment 232595 [details]
Patch

[Eric Carlson]

Comment on attachment 232595 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=232595&action=review

> Source/WebCore/platform/graphics/avfoundation/InbandTextTrackPrivateAVF.cpp:405
> +                    LOG(Media, "InbandTextTrackPrivateAVF::processCue(%p) - found an extension cue for time = %.2f, position =  %.2f, line =  %.2f", this, arrivingCue->startTime(), arrivingCue->position(), arrivingCue->line());

Won't this log about every cue regardless of whether or not it extends a cue?

[Build Bot]

Comment on attachment 232595 [details]
Patch

Attachment 232595 [details] did not pass mac-wk2-ews (mac-wk2):
Output: http://webkit-queues.appspot.com/results/6501615309684736

New failing tests:
media/W3C/audio/canPlayType/canPlayType_application_octet_stream_with_codecs_1.html

[Build Bot]

Created attachment 232604 [details]
Archive of layout-test-results from webkit-ews-09 for mac-mountainlion-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: webkit-ews-09  Port: mac-mountainlion-wk2  Platform: Mac OS X 10.8.5

[Brent Fulgham]

Comment on attachment 232595 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=232595&action=review

>> Source/WebCore/platform/graphics/avfoundation/InbandTextTrackPrivateAVF.cpp:405
>> +                    LOG(Media, "InbandTextTrackPrivateAVF::processCue(%p) - found an extension cue for time = %.2f, position =  %.2f, line =  %.2f", this, arrivingCue->startTime(), arrivingCue->position(), arrivingCue->line());
> 
> Won't this log about every cue regardless of whether or not it extends a cue?

Whoops! Yes, I'll fix that.

[Brent Fulgham]

Committed r169647: <http://trac.webkit.org/changeset/169647>