Hello,

First of all I'd like to congratulate the team for the latest version of kdenlive and mlt.
I've spent almost 4 days in search of a solution for choppiness in melt and kdenlive preview, then I got really disappointed with the proxy clip bug (seg fault 11 whenever they were used). But, all is well now... well almost.

I run an openSuse 12.1 and mplayer (gnome version) and melt work great, xine/kaffeine (don't really care) fails and I don't like vlc. The machine is an Acer laptop with a core i3 proc, 3 GB ram and a nVidia GT420M 1GB graphic adapter.

Note: I use a raw mts files recorded at 1080/50P.

My dilemma is related to kdenlive preview. The playback is almost good. The footage keeps it's normal pace, video and audio are in sync but it still drops a few frames. I know that in this case proxy clips would come to the rescue but I'm also very confident that kdenlive could work without them on my machine (since melt runs without any issues)

So my question would be: are there any tweaks for kdenlive to achieve a flawless playback in the previews without proxy clips? Is my HW really that outdated?

Thank you,
Mircea

Hi Mircea,
The core I3 may be a bit to slow for decoding Raw MTS files. I must say that I do not know if VDPAU handles your mts files and if it's enabled by default in Kdenlive. If so, your graphics card is already taking over much decoding work.
If it is not enabled, you could try to compile ffmpeg with VDPAU support. I don't know how to check if it's enabled though.

The easiest workaround for you is to transcode your material to DNxHD with kdenlive. It will give you no visible quality loss and kdenlive can play it smoothly even on my old core2duo laptop.

For better performance with effects you can try to set the mlt thread count up in the kdenlive settings, but this feature is not stable yet and further seems to have no effect at all to me anymore...

Hi Sunboy,

I would say that VDPAU is active. I've set mplayer to it and it is listed in ffmpeg -codecs as h264_vdpau (I hope I got it right, I'm writing from memory since I don't have the laptop here at the moment). My understanding is mlt takes ffmpeg setup as a reference hence I assume that this is working properly.

Regarding the processor, this might be true. I watched the loads on all 4 cores and oddly enough during play (can't recall if mplayer or melt) there was only one core is use and it stood somewhere at 30%. I can't say for sure if this correct since I didn't check the GPU load. I'll search the web to see if there is a good utility to monitor the GPU. During playback (clip preview) in kdenlive all 4 cores were committed up to 80%.

I will try transcoding the material to DNxHD and see what happens. Thank you for the hint.

Cheers.