This script is my answer to the common problem of wanting to put one's music library onto a device that doesn't support some of your music formats. All the solutions that I've seen to this problem have at least one of the following drawbacks:
- Assume that I want to transcode everything into a single format, even though the device supports multiple formats.
- Incorrect handling of tags
- Require a large media player
So I wrote my own script to do it. You specify your music directory and the device's music directory, as well as the file extensions that require transcoding and the format to transcode to. All your music is copied to the device, preserving the directory structure. Any files with the specified extensions are transcoded, keeping the same base name and changing the extension. All other files are copied with no modification. This includes all other files, not just other music files. So your album art and stuff gets transferred too. Transcoding happens in parallel if you have multiple cores avilable. Running the same script a second time will only update files that are newer in your music directory. The default transcoding options will transcode several lossless formats to ogg.
Put the script in your path. Install the prereqs. Then, use
$ transfercoder /home/yourname/Music /media/musicplayer/music
See the help for more options. Or ask me.
- Python
- Quod Libet - For copying audio tags
- Perl Audio Converter (yes, Perl) - For transcoding
- Audio encoders and/or decoders for the formats that you are transcoding
- Rsync (optional) - For faster copying of small changes
The prerequisites are a little odd. This Python script calls a Perl script for transcoding. Why? Because it took about five lines of code to implement it. I would rather do it via Gstreamer, but I haven't used it before and it looks like it would be a lot more than five lines of code. PAC encapsulates the logic for choosing the proper audio decoders and encoders, and Quod Libet's MusicFile class does the same for loading and saving tags. Note that you don't need to actually use Quod Libet the music player. The script simply requires one of its modules.
As indicated, rsync is an optional dependency. It is primarily be useful if you changed only file tags on files that do not require transcoding, in which case there will only be a small difference to transfer.
- You can only choose one target transcoding target format. I can't see a reason you would want more than one. You wouldn't want to transcode flac to ogg and then transcode wavpack to mp3.
- No playlist support. Playlists can get complicated. They may have relative or absolute paths, and the device may expect them in odd formats. You'll need to come up with your own solution here, or just use a media player that handles them.
- Replaygain tags are not copied. This is because in my experience, different formats of the same song need different adjustments, even though in theory they should have identical volumes. So replaygain your library on your device after syncing. If only there was a tool for that too.
This written both as a useful tool for myself, as well as a way for me to write a basic parallel python program.