Feel free to ask if you want to do that but don't already know how. In those cases, sometimes I'll even go ahead and lower the resolution down to 1080p or even 720p, but if it's coming from youtube, if you're going to do that, then you could just download the lower resolution version straight from them, already in mp4 format.Īlso, if you plan to do this a lot, you can set it up as an alias to speed up the typing and not have to memorize it or keep the post handy to copy/paste. I'll also sometimes go down (in quality) to 30-32 for a longer video that is mostly just informational and I don't care that much about the quality, especially if the video doesn't change much (like just someone standing there giving a speech).

Sometimes I'll go as far as 24 for a video that does seem to have higher quality compression (usually just by luck, as far as I can tell) and that I really want to preserve the quality, and that often results in a similar or larger file size compared to the webm. This also typically ends up with a moderately smaller file than the original webm. I typically use 27 for youtube videos, because they're already compressed quite a bit, and although you're re-doing the compression, I don't think there's usually enough quality you can get out of them to justify lower compression than 27.

Lower numbers are lower compression / higher quality, and h264 ranges from 0 to 51. The '-crf' is the compression/quality setting. (Obviously, replace 'original-video-file.webm' and 'new-output-file.mp4' with the file names you're using.) My guess is that you're downloading 4K from youtube and want it in a more compatible format… but my assumption is just based on the fact that that's almost the only place I've seen webm.įfmpeg -i original-video-file.webm -crf 27 -preset slow -movflags faststart -profile:v high -level 4.2 new-output-file.mp4

As someone else mentioned, it involves re-encoding, but yes.

How to use ffmpeg to trim videos