I'm trying to burn .ass subtitles onto a .webm, using ffmpeg -i input.webm -vf ass=subtitles.ass output.webm but it shrinks from like 150MB to 9MB. How do I add the subtitles without losing quality ?



ffmpeg -i input.webm -vf ass=subtitles.ass -b:v 0 -crf 20 output.webm

The libvpx encoders for WebM, by default, perform Constrained Quality encoding, and use the bitrate as a ceiling. Default bitrate is 200 kbps. To remove bitrate ceiling, set bitrate to 0. -crf controls the quality level.

  • Cheers! Worked perfectly. – Jon May 16 '19 at 20:32
  • 2
    @Jon, so why you don't accept this answer? Click on check mark near it. – MarianD May 16 '19 at 21:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.