Manjaro i3: PCManFM fails to display music album/cover art for mp3 and m4a files


I’m using PCManFM as my default file manager as delivered by the i3 community edition. Unfortunately, it fails to display the cover art for my music files. Instead, I get a “default” music icon, one for mp3 and m4a each.

This is particularly strange, because mp4 and webm files do have their thumbnails displayed. The cover art is saved as the front cover using MP3Tag. It is correctly recognized under windows and in VLC Media Player.
Why doesn’t PCManFM display the cover art instead of the generic icons? If a special thumbnailer is required, which is it, and why isn’t it preinstalled in i3?


pcmanfm is a file manager, not an audio file player. As such, by default it will try to find thumbnails for the specific filetype , not whatever data happens to be embedded in such file.

I am unable to find any plugins for pcmanfm that would extract the cover art as a thumbnail, so you might have to use some other software for that…


This is what surprises me severely.
There are thumbnailers preinstalled for video files, which to me means that showing the cover art would be the intended behavior. Maybe not by the PCManFM programmers, but surely by the i3 community edition maintainers. If not, why would they install thumbnailers for video files, instead of showing default icons for those as well?

The great surprise here is that there seems to be no thumbnailer for music files. I can’t believe nobody has ever programmed one, especially since I don’t think it to be such a difficult task. The image data is probably stored in a standardized way in a sector of the audio file, so I think you really just have to read it and supply it. And when in doubt, you could still just use ffmpeg -i <audio-file> cover.jpg and pipe that into whatever input PCManFM expects to display that as the thumbnail.

I guess if nobody has ever handled this task, I’ll have to read up and try to program a little thumbnailer myself?


I don’t think it displays the cover art for video files. It’s probably just a random frame it uses from within the video itself. That’s how lots of file managers do it though. :slight_smile:


Well yeah. I didn’t even consider that video files could have cover arts.

The thing is, if it shows a random video frame as a thumbnail for videos, and a downscaled version of the file as a thumbnail for images, why doesn’t it show a cover art (if available) for music files?

As far as I know, each of this is realized using thumbnailers, which are more or less external programs. I assume the file manager sends a file (video, image… music!) into the thumbnailer, and the thumbnailer returns a thumbnail for the file manager to use. As said above, I don’t think it to be very difficult to make a thumbnailer for music files if only you find which conventions and interfaces to follow.


…I am now wondering whether you could use “ffmpegthumbnailer” to do what you want? Read this:


Sounds like a good idea. Unfortunately, I couldn’t get it to work.

In fact, I couldn’t even get the pdf thumbnailer example they give there to work, even by pasting it 1 to 1 into a .thumbnailer file. Instructions unclear? Or simply obsolete information? Probably the latter, since trying to get a thumbnail by hand by running the convert command with according options failed with errors. I also find it unclear as to what the %s (the size of the image) argument will be. Will it be one number (12), multiple numbers (12 12), or a string (“12px”)? I wasn’t able to dig deep enough to capture it for a closer look.

Anyway, back to the topic. I think in theory your suggestion should work like a charm. But unfortunately, the following thumbnailer I called ffmpeg-audio-thumbnailer.thumbnailer causes no results:

[Thumbnailer Entry]
Exec=ffmpeg -i %i %o

I was just testing it for mp3 files at first. Already to no avail. Yes, I did restart the system so changes would definitely take effect.

In the end, I found a solution by taking a read here:
I simply installed totem, GNOME’s default video player. The cover art for both mp3 and m4a files is now shown as expected. Though I did have to change my default application for opening music files back to VLC media player for both files types manually (right click -> file properties).

All in all, I don’t find this to be a very clean solution and more of a workaround. Getting things to work with a lightweight thumbnailer (without installing a bloated video player) would still be preferrable to me.