[theora] Ogg/theora a/v sync issue with liboggplay

[Marc-André Lureau]

Hi,

The following url is being played with incorrect a/v sync in Firefox:

http://195.10.10.216/flumotion/videodemo/med.ogg?token=c965dab73e5ed982821e01174e87925a4bb3134e4bb9aaec
(it is time limited, but should work a few days, I could provide)

Tested with 3.6.3pre on Linux (with and without PulseAudio) and
Firefox 3.6 on Windows XP.

Looking at firefox source code, I found the library that is supposed
to do a/v sync for ogg is liboggplay.
glut-player, compiled from git master (3901c1c38), shows the same a/v
sync issue.

I ran oggplay-info and noticed that the theora overrun histogram is
quite important.

Theora: Track 0
       Worst overrun: 271 frames
       Average overrun: 263.202 frames
       Histogram bucket size: 13.550
       Histogram: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 42 2022
       SD of overrun: 3.162278

Vorbis: Track 1
       Worst overrun: 23552 frames
       Average overrun: 10787.287 frames
       Histogram bucket size: 1177.600
       Histogram: 94 109 109 116 107 108 156 118 107 115 109 119 117 128 118
107 96 77 39 13 2
       SD of overrun: 6028.785367

Is the stream bad, or is liboggplay doing incorrect a/v sync?

It looks to me like liboggplay should do correct sync, given the output of:

$ oggplay-info demosite.ogg
Reading 2 tracks ...
       Theora: Track 0 ... ok ...
       Vorbis: Track 1 ... ok ...
track 0 required 1 times [1892128590] track 1 required 2 times
[1892128593, 1892128614]

thanks for your help

-- 
Marc-André Lureau