2 Replies Latest reply: May 26, 2012 7:27 PM by Jon Walker
007 James Bond Level 1 Level 1 (0 points)

I have the latest version of Mac OS X, which is Lion, ofcourse. I was doing some screen recording using Quicktime, when I noticed something weird. A 3 minutes screen recording on both medium and high quality. The weird part is the filesize for high quality was 27MB and the the filesize for medium was 720MB (Yes, 720). Is it just me? I tried several times. Same results.


MacBook Pro, Mac OS X (10.7)
  • 1. Re: Quicktime screen recording
    Joel__ Level 1 Level 1 (0 points)

    I have exactly the same problem. I want smaller files, not insanely large ones! Below is my other post - with comparison of the 2 quality settings. I can't beleive this is the default and only available behavior - surely this must be a bug, unless someone can explain to me why Apple would use that codec for the medum quality setting...

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    I'm using QT player on Lion (v10.1 I think) and I'm getting strange behavior with the different quality settings and the file sizes they produce. If I record with quality setting on HIGH I get  much smaller files than if I set quality to MEDIUM - shouldn't that be the opposite? Below are the outcomes of 2 different recordings - notice that the codecs and bit rates are WAY different.

     

    Both tests are full-rame screen recordings - my macbook pro is set to 1680 x 1050 rez. These are the default settings and the only option is to set quality at high or medum.

     

    Quality: HIGH

    Duration: 30 seconds

    File size: 2.5 MB

    Bit rate: 448

    Codec: H.264

     

    Quality: MEDIUM

    Duration: 36 seconds

    File size: 343 MB - yes really! - that would be 600 MB/sec

    Bit rate: 75,031

    Codec: Photo-Jpeg

     

    Not only is this off the scale in terms of file size but - these are the DEFAULT and ONLY options provided! I have to assume this is a bug since there's no way Apple expects people to be making like 50 GB screen recordings. It's almost like the medium quality setting is tied to single frame screen images rather than an actual video file or something? A bit rate of 75,000 seems pretty off the charts too.

     

    Can anyone tell me if this is normal behavior? Is there a way to produce smaller files for screen recrodings - even the much smaller high quality files are very large when recording for 30 mins. Lastly is there a way to reduce these files - perhaps soem transcoding to smaller versions - like on the order of less than 15 MB? I can export in QT player (used the iPad size setting) but that only cuts the size down by about half. I suppose I coudl try the iPhone size setting but that might not be legible to show what I'm doing on screen in the movie.

     

    Thanks for any insight!

  • 2. Re: Quicktime screen recording
    Jon Walker Level 6 Level 6 (17,630 points)

    I have the latest version of Mac OS X, which is Lion, ofcourse. I was doing some screen recording using Quicktime, when I noticed something weird. A 3 minutes screen recording on both medium and high quality. The weird part is the filesize for high quality was 27MB and the the filesize for medium was 720MB (Yes, 720). Is it just me? I tried several times. Same results.

    You are using two different compression codecs here with each having different characteristics. Basically, the "Medium" quality codec records faster but uses a much faster data rate making for a much larger file while the "High" quality codec is much more efficient (in terms of compression) but is much slower making for a much smaller file.

     

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