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  1. Hi,
    I have an animated cartoon digitalized from PAL DIGIBETA tape onto the mov file with the ProRes 422HQ codec.
    It is an old cartoon called PEPA: http://www.youtube.com/watch?v=DCWHh_mZogE

    The initial video bitrate is variable bitrate @24.5 Mbps. I need to recompess the file into h264 with the bitrate of 6-8 Mbps and wrapp in a mov container. I have used iFFMpeg, with the Force Constant Bitrate option enabled and the bitrate set to 8000. The output file only reaches about 2000kbps.

    I assume that the reason for such a low bitrate output is caused by the fact that the video file is not complex so the compresor is able to work very efficiently.

    Would anyone here have a solution to this problem? How to create a forced CBR H264 video in mov container?

    All the best!
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  2. Explorer Case's Avatar
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    Most home users want a small file. So the defaults may not suit what you need. But you may tweak the settings:
    • Perhaps the Constant Quantizer wasn't set to OFF. Any setting other that OFF will disregard any bitrate settings, including CBR.
    • Perhaps the Quantizer range wasn't broad enough to get to the desired high bitrate. (Tip: slide Qmin to "1" or "2".)
    These sliders can be found in Advanced > S4.
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  3. Hi Case,
    I have checked the settings which you are referring to and they are set as follow:
    https://forum.videohelp.com/images/imgfiles/oZpV9T4.png?1
    I have also disabled b-frames.

    The output file comes out at about 2Mb/sec. When I check the output file in iMEdia HUD it says:
    https://forum.videohelp.com/images/imgfiles/9NRemjY

    The nominal bitrate is what I have set: 8Mb/sec but the bitrate value is only 1971 Kbps
    The VOD platform that I work for requires the files with a bitrate between 6-8 Mb/sec.

    HEre is the rundown of all the settings: https://forum.videohelp.com/images/imgfiles/4kB1Fno
    Do you have any idea how to fix this?

    Best!
    Andrzej
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