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Video captured from computer screens can be compressed very well by codecs that are optimised for screen video. Generally, this means taking into account that large areas of the screen don't change between frames, and that when areas change they are often changing back to a previously seen state.

The only one that I know of is Adobe's Flash Screen Video, specified as part of the SWF format: http://www.adobe.com/devnet/swf.html. It's slightly baroque, but usable.

I'm making an experimental HTML5/JS screencast viewer, and need a base format. At the moment, the only options I can see are implementing a FlashSV decoder in JavaScript, or rolling my own format.

Does anyone know of any other screen video codecs out there?

Edit: accepting the first answer, because the link at the bottom provided a codec very much like what I'm looking for: http://wiki.multimedia.cx/index.php?title=DosBox_Capture_Codec

Bernie Sumption
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3 Answers3

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Today I discover capability of VLC (VideoLAN media player, http://www.videolan.org/vlc/) record screen. It is opensource and free for downloading/use for all desktop OSes.

After googling I found that many people recommend use H.264 codec for screencast (and x264 as free implementation http://en.wikipedia.org/wiki/X264). It is really good!

Under Windows I cd to VLC dir and run:

$ vlc screen:// --screen-fps=12 --screen-mouse-image=e:/home/.icon/cursor.png \
  --no-sout-audio --sout \
  "#transcode{venc=x264,quality:100,scale=1,fps=12}:duplicate{dst=std{access=file,mux=mp4,dst=desktop.avi}}}"

or less quality with free codes/container (theora/ ogg):

$ vlc screen:// --screen-mouse-image cursor.png --screen-fps=12 \
  --screen-width=1680 --screen-height=1050 --no-sout-audio --sout \
  "#transcode{venc=theora,quality:10,scale=0.75,fps=12}:duplicate{dst=std{access=file,mux=ogg,dst=desktop.ogg}}}"

PS. You can also check http://en.wikipedia.org/wiki/List_of_codecs#Lossless_data_compression

gavenkoa
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    PS: Lossless is a bad idea for streaming video on the net – Karoly Horvath Jul 23 '11 at 11:30
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    When you produce screeencast it is essential get high quality video (for example to preserve text readability)... – gavenkoa Sep 19 '11 at 22:15
  • Woo! I brought a 1.25 GB (compressed) avi adobe premiere shat out to 10MB with very little loss in quality! I used the Media -> Convert/Save tool in the vlc gui app on windows tho. – B T Jan 09 '16 at 09:09
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This site What Video File Format is Best for Screencast.com Viewers? recommends use of H.264. But see also another alternatives.

gavenkoa
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The Apple Quicktime Animation codec was selected as the winner of this Screencast Codec Showdown. You should check that review.

cha0site
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Mohammad Alhashash
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    he is comparing only apple made codecs. of course their bait-and-switch quicktime codec would be better/had more work invest. This is worthless. plus he "don't have QuickTime Pro, so this is H.264 Low Profile" and then he complain about artifacts (while probably generating a file 1/100th of the size of quicktime animation)... his/her work is dedicated, but i'd look for a better source. – gcb Feb 28 '14 at 01:02