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  1. I'm trying to compress a 14GB MKV file to at least 3GB and it only compresses to 10GB that is still too big. I'm compressing to MKV as well and I'm using Handbrake. I thought of using XMedia Recode but there's no MKV file in that software. When I try other files like M2TS, MP4 and WMV where it's compressed to 3GB the picture quality is ruined with slight pixels. When I compress MKV files from about 30GB they compress to a MKV file at 5GB at the smallest with good picture quality. Why I am I having problems with compressing the 13GB file and why is the picture quality pixelled when I compress to M2TS, MP4 and WMV?

    Thanks.
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  2. Member
    Join Date: Sep 2007
    Location: Canada
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    It depends on the content. Some videos are more compressible than others. It has nothing to do with m2ts, Mp4 which are containers

    The main reason is the way temporal compression works - only the differences are stored between frames

    Noise, motion, sharpness, content complexity all reduce compressibility. An action movie is difficult to compress, but something like a simple cartoon with repeated frames will easily compress 5-10x more . A 14GB action movie might compress to 10GB under some settings. But a 14GB cartoon might compress to 3GB with those same settings
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  3. vanished El Heggunte's Avatar
    Join Date: Jun 2009
    Location: Misplaced Childhood
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    Some sources are easier to compress than others. Sharper images are more difficult to compress. Sequences with lots of motion and scene changes also are difficult to compress. BTW:
    MKV, (M2)TS, MP4 and WMV (actually ASF) are containers, so one cannot really "compress to" MKV, MP4, TS or ASF.

    http://en.wikipedia.org/wiki/Comparison_of_container_formats
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  4. XMedia Recode but there's no MKV file
    Under Format use Custom with Matroska Video.

    Instead of HandBrake you could use Vidcoder which allows you to specify target size.
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  5. https://en.wikipedia.org/wiki/Display_resolution#mediaviewer/File:Vector_Video_Standards8.svg

    You could keep a better bitrate by dropping the resolution some, the tv/player will upscale it again for viewing.
    And a variable bitrate will compress better that constant.
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  6. Member
    Join Date: Sep 2007
    Location: Canada
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    In addition to reducing the resolution another technique to improve the "compressibility" is by using filtering, noise reduction etc... Thus at low bitrate ranges compared to content complexity - the subjective quality will increase


    And the other part of the equation is the running time of the video. You haven't mentioned anything about that in your examples
    Filesize = bitrate * running time

    A 3 hour movie will obviously be larger in filesize for the same level of "quality" than a 30 min TV episode of similar content compexity
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  7. Originally Posted by videobruger View Post
    XMedia Recode but there's no MKV file
    Under Format use Custom with Matroska Video.

    Instead of HandBrake you could use Vidcoder which allows you to specify target size.
    The target size option has been removed from Handbrake? I wonder what the logic behind that is?

    I'd advocate CRF encoding as generally being the better method myself, but sometimes you do need a particular file/size bitrate for one reason or another.
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  8. Thanks for the info everyone. Also the Blu-ray I'm trying to compress is a Region B that I believe was released in Germany. I don't know if the Germans do their Blu-ray discs different to the way they are in England.
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