gtk-recordMyDesktop outputs .ogv files that seem perfectly fine - they work well in Totem and VLC. However, if I try to edit them in openshot or kdenlive, the editor either crashes (kdenlive) or won't show the video properly (openshot). PiTiVi appears to work but then locks up when it tries to render the video.
Using video conversion tools, such as ffmpeg outputs a video that is a jumble of colours; although it is just about possible to make out some movement.
The only way I've managed to edit the videos is to use DeVeDe to create a DVD .iso, mount the ISO and then edit the .VOB file(s).
This is a bit of a faff; does anyone know of a better way around this?
You need to convert them first... they never worked without converting (at least for me):
Then you can edit them in your favourite video editor (I for one prefer Avidemux).
I see you had trouble with ffmpeg, but I have had a lot of good luck converting just about anything using it. If you don't specify a bitrate or quality setting in ffmpeg, it can use some really low quality settings. This may be why your conversions look so crummy. The video editors are picky about what kinds of videos they work well with, so I always convert to MP4 with MPEG4 video and FAAC audio. The command I use is:
ffmpeg -i in.ogv -vcodec mpeg4 -acodec libfaac -sameq out.mp4
The -sameq option tells ffmpeg to try to make the resulting video approximately as good looking as the original.
Once you have it in MP4, I recommend you use OpenShot to edit it.
Try lives, LiVES is a Video Editing System, it's available from the repositories.
You can try mobile media converter (.deb download)
Its a great tool to convert videos in good/high qualities then you can edit the video easily using any editor.