tag editing

[Grant Shoshin Shangreaux]

Hello all,

working on getting my FSF assignment finished and looking forward to
contributing to the project soon.

I bumped into an issue when trying to edit tags for opus files, it
looked like it all worked fine, saved the metadata to the cache-db, but
there was no actual function defined to handle the opus format. so it
was a surprise to me to find that the files i tagged no longer had the
metadata the when i opened them in another program.

i'd like to fix that silent failure, but i also started digging around
for a solution for writing tags to all formats. unfortunately, there
isn't a simple tag writer included with the opus-tools package. you must
re-encode the audio to add tags. so far, i've found 3 candidates

  1. add a shim for TagLib to write to files (beyond me at the moment)
  2. opuscomment[1] tool (must be built from source)
  3. audiotools package's tracktag program[2]

I wrote a simple wrapper for tracktag that hooks into the tag-editor
code and have been testing that out. I'd be happy to share a patch, but
I can wait until the FSF assignment is done if that is better.

Another option might be to hook into the emms-info-native code and add
tag writing capabilities as well. I would be happy to collaborate on
that, but my time is somewhat limited. I do want to point out that
native tag writing capality would be really fantastic for my use of
EMMS. I record a lot of audio and have been hoping for a nice way to
author metadata using Emacs. I even gave a talk at emacs-conf demoing
how nice it was to use EMMS[3], not knowing my opus tags weren't even
being written xD.

Anyhow, please let me know if there's interest in the tracktag code, and
if there's any good way to help out otherwise.

best,
Grant Shangreaux


[1] https://github.com/hcmiya/opuscomment
[2] http://audiotools.sourceforge.net/tracktag.html
[3] https://emacsconf.org/2020/talks/05/