Rendering problem with Kdenlive

Posted 7/10/2017

Rendering problem with Kdenlive

I really enjoy using the Kdenlive, a video editor for KDE on Linux. I think it’s a simple, straight forward, and yet powerful tool.

But just during the last few days, I had troubles for the first time and could not find a solution. When rendering my project, it kept failing with max_analyze_duration 5000000 reached at 5000000. I searched online, the error might be related to the size of the audio (>1h) Still, the project rendered at first, but after the final cut—with lots and lots of cuts—I started getting this error, thus, out of a sudden, I was not able to get my final video file out anymore. Was I threatened to having to do the entire work again or what??

Finally, I found a solution today! Better, a workaround.

I split up the file by adding guides—in my case three, but the number might depend on the project size—and then used the render feature “Guide zone” (at the bottom of the render dialog). So, I rendered three parts and used melt to put them together like this:

melt input*.mp4 -consumer avformat:result.mp4 acodec=aac ab=160k vcodec=libx264 vb=3000k

I’m using x.264 and AAC here – but you can also drop all those parameters and let melt figure everything out – it’s pretty capable, give it a try.

melt input*.mp4 -consumer avformat:result.mp4

If you have ffmpeg on your system, you can merge the files using the copy mode, so no quality gets lost – see details here. But even when using melt and thus re-encoding the video, you will not notice that it has been rendered in three parts and “melted” later. So I’m happy! Still a bit surprising that I could not find a solution online. So hey, hope this approach works for you too! 🙂