[Webkit-unassigned] [Bug 251771] New: Overlapping Timing VTTCues in InbandTextTrack does not handle correctly

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=251771

            Bug ID: 251771
           Summary: Overlapping Timing VTTCues in InbandTextTrack does not
                    handle correctly
           Product: WebKit
           Version: Safari 15
          Hardware: All
                OS: All
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: Media
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: taichiro.ishikawa at play.jp

Created attachment 464857

  --> https://bugs.webkit.org/attachment.cgi?id=464857&action=review

Sample Stream for Multiple Cue

Background:
LegibleOutput sends multiple vttc atom (VTTCue in isobmff) in one nativeSample. (nativeSamples length = 1, but multiple vttc in the nativeSample)
But, InbandTextTrackPrivateAVF::processNativeSamples handles only first vttc each callback and rest vttc still in buffer.
So, rest cues are not handles in same callback and process in next callback and use next timing information, that wrongly.

Issue:
Overlapping Timing VTTCues in InbandTextTrack does not handle correctly

Reproduction steps:
Play m3u8 in attachmend zipfile.

Actual behavior:
VTTCue[0]: startTime=0, endTIme=2
VTTCue[1]: startTime=0.5786666666666667, endTime=0.5786666666666667

Expected behavior:
VTTCue[0]: startTime=0, endTIme=2
VTTCue[1]: startTime=0, endTime=2

Impact:
Video Streaming Service not capable of using vertical splitted (top and bottom) cues.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20230206/6368edb2/attachment.htm>