596111 - nsWebMReader::Seek assumes video is first track in the stream and fails to seek in files where this is not true

Status: RESOLVED FIXED

(Core :: Audio/Video, defect)

Description

[Matthew Gregan [:kinetik]]

Found this file via bug 593814.  Seeking to a new time fails with both remote and local files.

Comment 1

[Matthew Gregan [:kinetik]]

+ EBML head at 0
|+ Doc type: webm at 11
|+ Doc type read version: 2 at 22
+ Segment, size 17003173 at 26
|+ Seek head at 34
| + Seek entry at 86
|  + Seek ID: 0x1c 0x53 0xbb 0x6b (KaxCues) at 95
|  + Seek position: 4434 at 102
| + Muxing application: libebml2 v0.11.1 + libmatroska2 v0.11.0 at 172
| + Writing application: mkclean 0.5.6 from GStreamer plugin version 0.10.23 + OggConvert 0.3.3 at 214

Looks fine, has a Cues element.

|+ Segment tracks at 298
|  + Track number: 1 at 319
|  + Codec ID: A_VORBIS at 325
| + A track at 4402
|  + Track number: 2 at 4410
|  + Codec ID: V_VP8 at 4416

Vorbis track is first track, which is unusual.  Need to check if this is valid wrt to the WebM spec.

|+ Cues at 4468
| + Cue point at 4480
|  + Cue time: 0.000s at 4482
|  + Cue track positions at 4485
|   + Cue track: 2 at 4487
|   + Cue cluster position: 5924 at 4490

Cues are present for track 2 (VP8 track).

Comment 2

[Matthew Gregan [:kinetik]]

  int r = nestegg_track_seek(mContext, 0, aTarget * NS_PER_MS);

Oops, nsWebMReader::Seek assumes the first track is the video track.  It should be using mVideoTrack.

Comment 3

[Matthew Gregan [:kinetik]]

Attachment: patch v0

Don't assume first WebM track is video.  Use mVideoTrack (or mAudioTrack if there's no video) to seek.

Comment 4

[Matthew Gregan [:kinetik]]

http://hg.mozilla.org/mozilla-central/rev/a8cbb8e0287c