Hey guys, I am recording windowed mode of Portal which was just released for Linux. The window I am playing it in is 1200x800 at only 15FPS. I am not sure what other choices I have as far as windowed modes I can use, i guess I should check that next time I open Portal. My entire desktop is 1680x1050 and my computer is not powerful enough to play in fullscreen mode AND record the game in fullscreen mode so I do the windowed mode and just record that window using Kazam screencaster. All I've done is added the .mp4 file from kazam to kdenlive (my normal profile is 1280x720@59.97) because that's what I normally capture with an HD-PVR from my xbox 360.

When playing back the file in the preview monitor it's laggy and even my voice sounds weird. I am not sure if this is because the project settings don't match the imported video resolution. I am rendering it now to see if it comes out ok but what do you guys suggest? THanks

You can create a custom project profile to suit your source. I think MLT will attempt to 'retime' the source to suit the project profile if the two differ otherwise.

I've added 60fps overcranked source into a 25fps project to play in slow motion only to find it doesn't but instead is 'retimed' to the project framerate which I assume just decimates, deleting frames or duplicates frames as required to get the fps rather than optical flow.

Is playback lagging because of the source, are you using proxies or have you tried proxies and it still lags?

i am not using proxies, the playback is a little laggy when watching the source .mp4 file in vlc, i'm guessing because me capturing 1280x800 (16:10) at 15 FPS just wasn't enough. I think I have to make the window smaller for portal so I can capture a higher FPS so the gameplay is smoother. The smallest I can make it though is 1280x720 (16:9), i'll try to crank up kazam screencaster to see if I can capture 24 FPS as that's the lowest FPS I see.

Settings > Manage Project Profiles
http://userbase.kde.org/Kdenlive/Manual/Settings_Menu/Manage_Project_Profiles