How to get near-perfect screen recording quality?

Someone suggested I direct a copy of the unmodified X display to a file and afterwards convert that file to a general purpose video file. What commands would I use to do this on a Kubuntu system? (Edit: He said something about attaching a display port to a file.) If not possible, what is my best option for an excellent quality screen recording that does not depend on fast hardware? *Background:* I tried using avconv with -f x11grab and some GUI programs. However, no matter what I try, the resulting video either has artifacts/ blurriness or is choppy (missing frames). This is probably due to CPU/ memory constraints. *Goals:* - Video quality must not be noticeably different from seeing the session directly on a screen, because the purpose is to demonstrate an animated application. - The final video must be in a common format that can be sent to Windows users and used on the web. I think H.264 MP4 should work. - The solution should not presume much prior knowledge. I am familiar with the command line and basic Linux commands, but I am still learning Linux and do not know much about video codecs. *What I already tried:* - Best command so far: ffmpeg -f x11grab -s xga -r 30 -i :0.0 -qscale 0.1 -vcodec huffyuv grab.avi, then convert to mp4 with ffmpeg -i grab.avi -sameq -vcodec mpeg4 grab.mp4. - The picture quality is great, but on my test sytem it lags the computer. On a faster target system it does not lag, but frames are obviously skipped, making the video not very *smooth*. - I am still trying to figure out how to save the grab.avi file to SHM to see if that helps. - Using Istanbul and RecordMyDesktop GUI recorders - Simple command: avconv -f x11grab -s xga -r 25 -i :0.0 simple.mpg using avconv version 0.8.3-4:0.8.3-0ubuntu0.12.04.1 - Adding -codec:copy (fails with: Requested output format 'x11grab' is not a suitable output format) - Adding -same_quant (results in great quality, but is very choppy/ missing many frames) - Adding -vpre lossless_ultrafast (fails with: Unrecognized option 'vpre', Failed to set value 'lossless_ultrafast' for option 'vpre') - Adding various values of -qscale - Adding various values of -b - Adding -vcodec h264 (outputs repeatedly: Error while decoding stream #0:0, [h264 @ 0x8300980] no frame!) - Note: h264 is listed in avconv -formats output as DE h264 raw H.264 video format