I've edited together a music video using AVI video combined with an MP3 audio track. Edits are made in time to the beat of the music, making sync problems very noticeable. After completing the video, it plays correctly within kdenlive and audio is in sync. When I render it, however, the audio is out of sync by about 1 second. I've tried rendering to various output formats but it's always out of sync.

Is there any way to have the audio sync in the rendered output match the audio sync in the editor? As a work around, I'm rendering, guessing sync error, shifting audio in the editor, and re-rendering; basically doing it by trial and error until it works. But would be nice to learn the secret of audio sync'ed rendering!

Thats a common problem. I would also like to know the reason and how to fix it? I have never understood why this issue happened. In Avidemux there is a time shifting parameter to correct such shifts... Do we have some correction parameter in Kdenlive or is it a problem of wrong format settings?

Thanks.

At least editing videos with mpeg2 clips, synchronized to a mp3 audio track works perfectly with Kdenlive 0.77. Rendering to mpeg4 and transcoding to DVD (mpeg2) does not unsync video and audio. A render to PAL-DV also showed no inconsistencies.

Maybe the sync problem only shows up with avi files...

Is there any way to specify time difference similar to Avidemux? Instead of trying to understand the reason of this problem just fix it specifying the shift in miliseconds???

It depends on what kind of shift you are talking about.

If it is less than 1/framerate, e.g. less than 1/24 seconds, then the only idea I have for now is to delay the audio with audacity for example. Some audio delay effect would certainly be nice (anyone wanting to implement it? :))

If you mean delays of more than 1/framerate (which I guess), then the problem lies at the audio backend, as far as I remember (Dan once told me), and there is nothing we can do about it. However there is a workaround which I have used as well, namely to use Audio Thumbnails (kdenlive settings > Timeline). There you can see audio peaks, and these are accurate and can be used for aligning. Needs a little practice though until you get it right, but then it works fine.

Thanks. This is what I'm using. I always work with audio and video splitted and with thumbnails activated.