Audio and video out of sync from the start

Hello there,

On Ubuntu 13.04 64bits, with Kdenlive 0.9.4

I'm trying to render segments of a video file in wmv in several format (mp4 and flv) for web page embedding but I'm facing a sync issue.

To create the segments, I used the clip monitor, positioning myself at the desired timings and using the InPoint and OutPoint to set the segments' boundaries. I would then drag and drop the content of the monitor to the project timeline and ended with my segments.

I can select only the segment I want for rendering through the « guide zone » radio button. The rendering operation is performed without error. The output video corresponds to the segment I created.

I tried to render both in mp4 and in flv with following options :

Scanning auto
Bitrate : video = 12000, audio = 128
Export audio : automatic or checked
Play after render

Both rendered versions have audio out of sync of 1 up to 2 seconds from the start.

Thanks in advance !


While working on a project last week, I came across a similar problem. A/V is in sync (by 99%) when playing the preview from the very beginning of the timeline, but...

Previewing or rendering from anywhere in the timeline gives one of two reproducible results:
1. A/V is in sync (works from some small regions scattered on the timeline) or
2. A/V is and stays out of sync by about a second (for the huge rest of the timeline)

The only way to work precisely was to render the complete region with video clips repeatedly and check if all new cuts were in place, then find a reliable starting point in the timeline for previewing, place the next cuts, render the project and so on.

Fortunately my project was only 2:10 minutes long. A reliable starting point had to be in the region that has already been rendered correctly and where the preview is in sync as well. As the results 1. or 2. from above are reproducible, the final result was synced correctly.

I am running archlinux with kdenlive 0.9.6 and mlt 0.9.

Probably out of date libav or ffmpeg in your disitribution. I had this many times.

The best solution (tested - works on EVERY system without touching your system libraries) - use a bundle of newest kdnlive + mlt + ffmpeg + frei0r + etc (Build script):

3 - Build script
The build script will download and compile for you the latest versions of lame, libvpx, libx264, FFmpeg, Frei0r, MLT and Kdenlive. It will then install all of this in a user folder, without touching your system libraries. The script takes quite a while to complete, but it is a risk free way to test the latest Kdenlive version.

Thanks for the hint vylaern.

As archlinux is a rolling release distribution, all mentioned libs are at the latest version as provided on their homepages. Maybe downgrading mlt to version 0.8.8 (as stated on the release info for 0.9.6) might help for arch users - currently there are other issues on archlinux like this:

Hi al25fps,

I use Gentoo which is also a rolling release distribution - but this doesn't means you have everything up-to-date, especially in terms of video & graphics, as eg. our developers says we do not have the newest ffmpeg (its harde masked) as its broke some API/ABI (so maybe this a reason of your issue in Arch). Even your kdenlive 0.9.6 is much older in comparasion to the bundle version (eg. bug in vectorscope was fixed soon after 0.9.6 relase). And the bundle version is rolling relase like your Arch, easy to install, works out of box and do not affect your libraries.

Try it, and check if you have still your issues :)

Build kdenlive yesterday from scratch. The problem persists and in the snapshot (0.9.7) preview is even worse since it stutters at every effect or transition (using identical kdenliverc files).

No worries, I am fine with the official package right now, my next project is still in an early stage of gathering clips in and around my hometown.

No irony: Thank you for making me compile the whole thing, I wanted to do that for a long time, but for some reason I did not. It's pretty straightforward and easy.