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  1. Member Budman1's Avatar
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    the scenario is that I have 2 mp4's with different characteristics such as resolution, size, etc. When I re-encode one with as close to all attributes as I can specify to to other, certain things as GOP size, and bitrate are slightly different. They appears to join and play ok but the bitrate is now called variable.

    Now the question is is this good enough or are these minor differences going to cause a problem in some players or in some other manner?
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  2. The bitrates should be variable even within the individual videos. They'll still be variable after being joined. If there are playback problems it won't be because of VBR, since that's kind of the standard way of encoding just about anything.

    If your two videos before being joined are CBR, I might question the competence of the original encoder.
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  3. Member Budman1's Avatar
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    @Manano.. Thank you. Further experimenting confirms what you say. With even more experimenting I was able to split a closed 250 GOP into 2 consecutive videos. I re-encoded one with exactly 326k bitrate (original rate). The re-encoded one had exactly the same format as the original. I joined them and then checked frame by frame and there is no glitch between joined segment points. Both segments and the merged both say 326k bit rate, not variable now.

    This is good information since it is part of a project to make a smart cutter. So far I have a GUI that cuts and copies exactly on key frames (or anywhere else if I recode)and each segment timestamp starts at 0 for joining. I can now cut anywhere with exact frame accuracy and re-encode just that portion to be joined with the copied segment. This has only been done with the same video split into pieces. I'm sure when testing with vary dissimilar videos there are going to be more bugs.

    Your information will help me tailor the code to allow best results.

    Thank you.
    budman1
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