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  1. I really like Asian Kung Fu movies and want to re-encode them and hard code/burn in the subs. What is the best method to do this leaving original file size and quality as close to the original file as possible? I've had some luck with AVC and Handbrake, but find the output size/quality hard to predict. Any suggestions?
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  2. Member
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    Use Handbrake/Vidcoder and if you really want to set a specific size use 2-pass encode
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  3. Use bitrate based encoding when you want a specific file size. With bitrate based encoding 2 pass encoding gives better quality than single pass encoding.
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  4. Try ffmpeg using one of these (depending on the format of the subfile)

    ffmpeg -i original.mp4 -vf subtitles=subfile.srt output.mp4
    ffmpeg -i original.mp4 -vf "ass=subfile.ssa" output.mp4

    It should just burn the subs over the existing video.
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  5. Originally Posted by daigo99 View Post
    Try ffmpeg using one of these (depending on the format of the subfile)

    ffmpeg -i original.mp4 -vf subtitles=subfile.srt output.mp4
    ffmpeg -i original.mp4 -vf "ass=subfile.ssa" output.mp4

    It should just burn the subs over the existing video.
    Thanks I will try it out.
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  6. Originally Posted by jagabo View Post
    Use bitrate based encoding when you want a specific file size. With bitrate based encoding 2 pass encoding gives better quality than single pass encoding.
    How do you calculate the proper optimal bitrate?
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  7. Originally Posted by mephistopheles93 View Post
    Originally Posted by jagabo View Post
    Use bitrate based encoding when you want a specific file size. With bitrate based encoding 2 pass encoding gives better quality than single pass encoding.
    How do you calculate the proper optimal bitrate?
    That's the problem with bitrate based encoding. There's no way to know the optimal bitrate.

    With bitrate based encoding you pick the file size but you don't know what the quality will be. With CRF based encoding you pick the quality but you don't know what the file size will be.
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  8. Originally Posted by jagabo View Post
    Originally Posted by mephistopheles93 View Post
    Originally Posted by jagabo View Post
    Use bitrate based encoding when you want a specific file size. With bitrate based encoding 2 pass encoding gives better quality than single pass encoding.
    How do you calculate the proper optimal bitrate?
    That's the problem with bitrate based encoding. There's no way to know the optimal bitrate.

    With bitrate based encoding you pick the file size but you don't know what the quality will be. With CRF based encoding you pick the quality but you don't know what the file size will be.
    I have never used the bitrate setting. Is there tables online which give a rough estimate of bitrate to file size?.
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  9. Originally Posted by mephistopheles93 View Post
    Is there tables online which give a rough estimate of bitrate to file size?.
    Code:
    size = bitrate * time
    for example, a 2 hour movie at 5 kbps:

    Code:
    size = bitrate * time
    size = 5 kbps * 2 hours
    size = 5000 bits/s * 7200 seconds
    size = 36000000 bits
    size = 4.5 MB.
    There are lots of bitrate calculators online.
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  10. Originally Posted by jagabo View Post
    Originally Posted by mephistopheles93 View Post
    Is there tables online which give a rough estimate of bitrate to file size?.
    Code:
    size = bitrate * time
    for example, a 2 hour movie at 5 kbps:

    Code:
    size = bitrate * time
    size = 5 kbps * 2 hours
    size = 5000 bits/s * 7200 seconds
    size = 36000000 bits
    size = 4.5 MB.
    There are lots of bitrate calculators online.
    Many thanks!
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  11. Originally Posted by daigo99 View Post
    Try ffmpeg using one of these (depending on the format of the subfile)

    ffmpeg -i original.mp4 -vf subtitles=subfile.srt output.mp4
    ffmpeg -i original.mp4 -vf "ass=subfile.ssa" output.mp4

    It should just burn the subs over the existing video.
    This utility is really slow.
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  12. Member
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    Originally Posted by mephistopheles93 View Post
    Originally Posted by daigo99 View Post
    Try ffmpeg using one of these (depending on the format of the subfile)

    ffmpeg -i original.mp4 -vf subtitles=subfile.srt output.mp4
    ffmpeg -i original.mp4 -vf "ass=subfile.ssa" output.mp4

    It should just burn the subs over the existing video.
    This utility is really slow.
    Of course, it's re-encoding the whole movie. You did say you wanted them "hard coded" (AKA burned in)
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  13. Originally Posted by mephistopheles93 View Post
    Originally Posted by daigo99 View Post
    Try ffmpeg using one of these (depending on the format of the subfile)

    ffmpeg -i original.mp4 -vf subtitles=subfile.srt output.mp4
    ffmpeg -i original.mp4 -vf "ass=subfile.ssa" output.mp4

    It should just burn the subs over the existing video.
    This utility is really slow.
    You can make it faster, like:
    Code:
    ffmpeg -i original.mp4 -vf subtitles=subfile.srt -preset veryfast output.mp4
    ffmpeg -i original.mp4 -vf "ass=subfile.ssa" -preset veryfast output.mp4
    https://trac.ffmpeg.org/wiki/Encode/H.264#a2.Chooseapresetandtune
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  14. Originally Posted by davexnet View Post
    Originally Posted by mephistopheles93 View Post
    Originally Posted by daigo99 View Post
    Try ffmpeg using one of these (depending on the format of the subfile)

    ffmpeg -i original.mp4 -vf subtitles=subfile.srt output.mp4
    ffmpeg -i original.mp4 -vf "ass=subfile.ssa" output.mp4

    It should just burn the subs over the existing video.
    This utility is really slow.
    Of course, it's re-encoding the whole movie. You did say you wanted them "hard coded" (AKA burned in)
    Yes but it took 6 hours and still produced a file over 50% larger than the original. I think I will stick with handbrake.
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  15. HandBrake is based on ffmpeg. Getting the same speed/file size from both is only a matter of choosing the same settings.
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