I have used qt-recordmydesktop tool for recording a specific window (final result should be tutorial). The output file was in OGV format and in very high quality. I wanted to edit the file using Kdenlive and to change it to more common format (AVI, for example). The result was that the quality of the recording was much worse. Does anyone know how to edit the file and change file format, but also preserve the high quality which was in the original recording in OGV format. Thanks in advance.

I have the same problem.

After capturing I got high quality OGV file (this is the sample), but if I converted them to AVI (Xvid) or MP4 (H.264)  (other formats I did not try), the quality of this video is worse (look at this sample).

Then, I tried convert them with ffmpeg to the same formats as with kdenlive (Xvid and H.264) and the quality is the same as the original OGV video (sample is here).

The exactly same parameters are used to conversion in kdenlive and FFmpeg, but quality range is so big. Why?

I think that is the MLT's problem, because MLT is rendering engine in Kdenlive.

I was using this conversion paramteres:

FFmpeg:

-r 29.97 -vcodec libx264  -aspect 4:3 -b 1250k -acodec libfaac -ab 112k -ar 48000 -ac 2

Kdenlive's renderer:

r=29.97 vcodec=libx264  aspect=4:3 b=1250k acodec=libfaac ab=112k ar=48000 ac=2

SOLVED!

For the best render quality you must correctly design a MLT profile. The resolution, frame rate and aspect ratios must be the same like in used video file!

Else it will not be correctly rendered!

Examlple:

Your video file specs are:

resolution:1280x720

ratio: 16:9

frame rate: 25FPS

you must use MLT profile HDV 720 25p (if  no profile with the parameters as video file has exist, than create your own with correct parameters)

There is a desktop capture tutorial here:

http://www.kdenlive.org/contribution-manual/how-make-video-tutorial