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  1. Hello, all:

    I am using MKVToolNix 22.0 in Win 7 64-bit.

    There is a problem when MKVToolNix make .mkv file.

    For example, I have a xxx.h264 file, it is 1000 bytes. I use MKVToolNix to generate the xxx.mkv.

    And then extract the video track from xxx.mkv as xxx_track1.h264. It become 1038 bytes.

    Do it again, I use MKVToolNix to generate the xxx_track1.mkv

    and then extract the video from xxx_track1.mkv as xxx_track1_track1.h264. Now, it become 1076 bytes.

    Every time when using MKVToolNix to generate mkv file, the MKVToolNix will add 38 bytes in video track.

    This is very strange. Does anyone has same problem like me or any idea ?

    Thanks in advance.
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  2. Dinosaur Supervisor KarMa's Avatar
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    Maybe look at the two .h264 files in a hex editor (like Hexplorer or HxD) to see what has changed. It's probably just added header information. If the video plays back the same then I'm not sure why you started this thread. It's certainly not encoding the video again.
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  3. Originally Posted by KarMa View Post
    It's probably just added header information.
    Yes, most likely. When muxing mkvmerge reads header information (SPS/PPS) from stream and writes into Matroska "CodecPrivate" element but doesn't delete them from the bitstream data. On demuxing mkvextract writes the CodecPrivate content in front of the stream again. So each time you mux->demux the SPS/PPS is duplicated. It is not a problem per se but can be avoided by some demuxers if you absolutely want to (e.g. eac3to).
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  4. Originally Posted by sneaker View Post
    Originally Posted by KarMa View Post
    It's probably just added header information.
    Yes, most likely. When muxing mkvmerge reads header information (SPS/PPS) from stream and writes into Matroska "CodecPrivate" element but doesn't delete them from the bitstream data. On demuxing mkvextract writes the CodecPrivate content in front of the stream again. So each time you mux->demux the SPS/PPS is duplicated. It is not a problem per se but can be avoided by some demuxers if you absolutely want to (e.g. eac3to).
    Thanks.
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