When playing a clip or a project timeline in kdenlive, the audio/video starts in sync, but drifts out of sync (over a few seconds) until the video is about 1/2 second ahead of the audio. Once it's out of sync by that amount, the problem doesn't get any worse--it just stays out of sync by about 1/2 second. Stopping and starting playback causes it to sync up again (whereupon it drifts again). Other details:
- The same thing happens using mlt directly from the command line.
- This happens with all formats which use ffmpeg, (libdv is not affected).
- Rendering works perfectly.
- Occurs with both a pro firewire audio interface connected to jack, and a built-in intel sound card using alsa.
- Downgrading mlt/kdenlive/ffmpeg a version (0.8.6/0.9.2/1.1.2 respectively, I believe), and trying the lastest from git didn't help.
- Other video players (mplayer, vlc) have no problems. Neither do other editors (cinelerra, pitivi)
Now, I rather suspect this isn't a general bug in kdenlive or mlt, as it affects almost everything and would have been noticed. Searching for solutions hasn't really turned up anything--most reported sync problems seem render-related--so I was wondering if anybody had ran into something similar or had any ideas as to what might be wrong with my system!
I'm using mlt 0.8.8, kdenlive 0.9.4, ffmpeg 1.1.3. System is a core 2 quad (Q9550), with an Nvidia 7900GS (binary blob drivers), running Arch Linux. This system previously (a year or so ago) ran kdenlive well with no problems. I was inclined to blame ffmpeg, but a nearly identical software config doesn't have a sync problem on a second machine (a old laptop which isn't fast enough to do any real editing.)
Any help would be appreciated!