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  1. Hello all.
    I use HandBrake to convert MKV files to MP4.
    When those MKV files have subtitles within HandBrake I select the option to burn them in and it does that beautifully. Very simple and very reliable....usually.
    However I'm trying to follow that with a couple of files and I'm getting the message 'No valid source or titles found', not sure why.
    I used to use FormatFactory but never worked out how to do the same thing with subtitles.
    Does anyone know how to do that with FF?
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  2. What format are they? Maybe try converting the subs to .srt format using something like SubtitleEdit?
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  3. Member
    Join Date
    Apr 2007
    Search Comp PM
    This is my batch file. Maybe you can adapt it to suit.
    :: Subtitles - vtt to srt
    for %%a in (*.vtt) do  ffmpeg.exe -i "%%a" -y ""
    ::mp4 + srt to new mp4
    set crf=23
    echo crf is: %crf% (Press Enter to accept.)
    set /p crf=Enter new crf:
    for %%a in ("*.srt") do if exist "%%~na.mp4" ffmpeg.exe -i "%%~na.mp4" -vf subtitles="%%a" -c:v libx264 -preset slow -crf %crf% -c:a copy -y "%%~na+subs.mp4"
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  4. You can also use Avisynth and TextSub(), that way you can easily preview the output and see if it looks right (if there are no overlong subtitles for example), then encode the script directly with ffmpeg.
    A "CRF" value of 23 (which was chosen as default in the script above) seems quite high (meaning that it reduces the quality quite a lot) to re-compress already compressed footage ; if there are no specific size constraints I would advise to set it to 20 or less, so as to preserve the original quality as much as possible. If you have a powerful CPU and/or are not in a hurry, you can use a slower preset ( -preset slower or -preset veryslow ), which should yield a better compression for the same subjective quality, or a better quality for the same compression.
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