Hard Coding Subtitles

[mephistopheles93]

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?

[davexnet]

Use Handbrake/Vidcoder and if you really want to set a specific size use 2-pass encode

[jagabo]

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.

[daigo99]

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.

[mephistopheles93]

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.

[mephistopheles93]

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?

[jagabo]

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.

[mephistopheles93]

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?.

[jagabo]

Is there tables online which give a rough estimate of bitrate to file size?.

size = bitrate * time

for example, a 2 hour movie at 5 kbps:

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.

[mephistopheles93]

Is there tables online which give a rough estimate of bitrate to file size?.

size = bitrate * time

for example, a 2 hour movie at 5 kbps:

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!

[mephistopheles93]

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.

[davexnet]

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)

[sneaker]

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:

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

[mephistopheles93]

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.

[sneaker]

HandBrake is based on ffmpeg. Getting the same speed/file size from both is only a matter of choosing the same settings.