Theora Video & Audio Sync

[SocketA]

Hi Everyone!

I have been testing Theora the last couple of hours, and I would really like to start using it some more, but I seem to have problems with playback.

In Windows XP, using BSplyer, WMP10 and VLC the video is lagging behind the audio, and is never in sync.
I even think that the video is playing back a little bit slower (the video file(s) is 25 fps).

In Ubuntu Linux, using Xine and Totem the video maintain sync by skipping a few frames every sec (not looking too good).

I have made sure that my video files are 100% in sync all the way.
The Theora files are made with ffmpeg2theora, and I even tried to use RealAnime 2.25 and a Linux program called 'Thoggen 0.2' and they all output in OGG format.

The only way I can playback Theora is to not have any sound in them, then it plays back perfectly, even with the right fps under Windows..

Under windows I use Illiminable filter pack, and I even tried Radlight's but still the same.

Any Ideas? Is it working for everyone else?

[bond]

if there is a constant desync, its propably already there in the source

whats your source?

[neilm]

Loss of sync under some conditions is a know problem with illiminable's
filters ie from his website.

"AVI Video files encoded with non-integral framerates (ie 29.97) may lose sync, due to rounding bug (Thanks RadicalEd)"

This bug is still open in the current version.

Have you tried Helix Producer?, encodes video and audio in one go to
theora/vorbis AND they do stay in sync<BG>, Win 32 version available
and it takes files frameserved drom AviSynth, it just needs the Xiph
plugins installing.

Or try muxing your a/v to .ogg with oggzmerge.

Neil.
[voyagevideo - Theora/Vorbis on yp.peercast.org]

[SocketA]

I seem to have found out....something strange....

I just tried a few mpeg1 files, and they seem to work after converting them with ffmpeg2theora.

So I converted the AVI files into mpeg1 files using the same formats/size/fps/audio_hz as the AVI files, and then converted them with ffmpeg2theora.....

It plays back perfect ?! :confused:

So...is there something wrong with ffmpeg2theora's AVI input?

There is really *really* nothing wrong the the AVI files, and I even tried to change video codecs and changed the audio HZ, and still the video 'lag' behind the audio after I converted them with ffmpeg2theora.

@Neil

I'm gonna take a look at oggzmerge, to see if that helps.

Isn't RealAnime using Helix Producer?

[SocketA]

Ok, just a little update..

I have encoded the AVI with VLC 0.8.1 into a perfect playing back Theora file (no sync problems at all).

So there IS something wrong with ffmpeg2theora.

Going back to lurk mode.. :)

[bond]

just stumbled over this:
http://lists.xiph.org/pipermail/theora/2005-June/000895.html