yt-dlc: merge video and audio. and convert video to mp4 ERROR

and how to Automatically delete mp4 if the Conversion failed?

I don’t know, but why don’t you use:

-f worstvideo[ext=mp4]+worstaudio[ext=m4a]/worst[ext=mp4]

Then it will never fail.

[Edit] I’m trying to help you and all you come up with is a thumbs down? Please explain.

@nicolaasjan Write your own postprocessing. Something like youtube-dlc --exec "ffmpeg -i {} -preset fast -c:a copy {}.mp4" URL

@nicolaasjan Write your own postprocessing. Something like youtube-dlc --exec "ffmpeg -i {} -preset fast -c:a copy {}.mp4" URL

Thanks, I forgot about that one. Must be my age…

This worked: youtube-dl -v --ignore-config -f "worstvideo+worstaudio" --exec "ffmpeg -i {} -preset fast -c:a copy {}.mp4" https://youtu.be/FbNEvuaUabY

Besides this, I believe this whole issue here is not really a youtube-dlc one, but more related to ffmpeg itself…

but why the file size increased to 32,8 MB from 20,4 MB?

That’s because of the compression values ffmpeg uses by default. See: https://trac.ffmpeg.org/wiki/Encode/H.264

For example it used a Constant Rate Factor (crf) of 23 in this case. If you want a smaller file size, you’ll have to try other options.

I downloaded the .mkv and managed to get a 21.5 MB .mp4 with this command: (renamed to 1.mkv for convenience)

ffmpeg -i 1.mkv -preset fast -c:a copy 1.mp4

@pukkandan, Can such ffmpeg options be somehow incorporated in the youtube-dlc command?