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Video File Size?

edited September 2009 in Support
Hi, I just downloaded CS and recorded my fisrt video (with sound). I used the CS Lossless Codec 1.4. The audio & video quallity were both very good but the file size was huge at 237mb.

Video length: 2:27
Video size: 572 x 445

Any thoughts on how to dramatically reduce file size while maintaining good quality?



  • Is that figure 2h 27m or 2m 27s?
  • Oh, sorry, it's 2m 27s

    And the video settings are set at the installation defaults. The only thing I changed was the codec (to CS Lossless Codec 1.4).

  • I haven't used the CamStudio codec, but this is similar to what I get with Lagarith. Lossless codecs are designed to preserve as much of the video quality as possible at the expense of filesize. The easiest way to shrink the file size would be to use lossy codecs (x264, divx, xvid, etc) instead of lossless, although I wouldn't recommend going lossy to start with if you plan on editing the video after recording it.

    You could also try raising the keyframe distance or lowering the capture frames to something like 10 with a playback rate of 100.
  • Are you using PCM as the audio codec? If so, that means you're not compressing the audio (PCM = no compression), so try switching to MP3.

    If you intend to upload to YouTube etc. set the bit rate high-ish (96 or 128 kbps) - so when YT transcodes the video into Flash and a lower quality audio, it should still sound OK.

    If you're going to use the video file as-is, then you can increase the audio compression even more.

    If there is music or consistent audio in the background, you can drop it down to 64 kbps or possible even 56 kbps.

    If it's just one of two voices (narrating a tutorial) then I can drop mine down to 48 kbps and sometimes even 32 kbps.

    All the above applies regardless of what audio codec you're using.



    Nick :o)
  • edited September 2009
    The best compression I've been able to achieve so far has been with h.264. Go here:, and download the latest version. It will install a codec called ffdshow, which should automatically show up in the codecs drop down box in the video options dialog. ffdshow has support for many different formats, so you'll need to configure it if you want it to encode in h.264. So click the Configure button, and in the in the top left of the new dialog that pops up, there's a dropdown box that has the "Encoder" label next to it. Choose either "H.264" or "H.264 Lossless". If you choose "H.264", you might need to tweak some of the other options in dialog to get exactly what you want. It might not be perfect quality, but you'll get very good compression rates. If you choose "H.264 Lossless", most of the options are grayed out because most of the options are for tweaking the quality of the compression, and obviously if you want lossless compression, you won't need them. H.264 lossless compression has very good quality and still maintains a surprisingly high compression rate, so you'll probably be able to just go with that. It's what I'm currently using.
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