Embed video thumbnails in audio files as cover art

So I found that the -f bestaudio feature downloads m4a files from youtube, which is great, but I’m missing my thumbnails. m4a files support embedding images in them, and video players such as mpv show those images as a static replacement of the video stream. Just like most of the music in video sites, but with a jpeg instead of a video with a single repeated frame.

I was considering writing a small script to get those files with youtube-dl --get-thumbnail and then embed them with AtomicParsley (a mpeg4 metadata manipulator, as this page suggests it’s not working with ffmpeg), but then realized it would be a good feature to have as part of youtube-dl, since it already has features to add metadata to the video.

Does this sound like a desirable feature? Is the dependency with AtomicParsley an issue? If it’s ok, I might go ahead and implement it, then send a PR later.

[dequis]

I tried adding thumbnails to all the m4a I downloaded before, using both add-metadata and embed-thumbnail over a list of 206 videos.

$ perl -e 'while(<*.m4a>){ print s/^.*(.{11})\.m4a$/\1\n/r; }' > id_list
$ youtube-dl -f bestaudio --embed-thumbnail --add-metadata -a id_list

It succeeded with all the m4a files, except two, which I already used --embed-thumbnail with.

[download] [...].m4a has already been downloaded
[ffmpeg] Adding metadata to '[...].m4a'
ERROR: Could not write header for output file #0 (incorrect codec parameters ?): Operation not permitted

This can be reproduced with --embed-thumbnail once, then run youtube-dl again with the same video id and either --embed-thumbnail or --add-metadata. Sounds like another thumbnail related ffmpeg bug, I’m afraid 😕

[tripulse]

@cup, is right because AtomicParsley is not only the program that is able to embed metadata into a MPEG4 file. There are several others that do the same job. One worse or better than another. But, it seems the method of using AtomicParsley is quite easy because they provide pre-built binaries on their website.