Mp3

As part of a Hazel rule to process downloaded mp3 files, I worked out a couple different methods for extracting the ID3 title tag. Not rocket science, but it took a little time to sort out. Both rely on non-standard third-party tools, both for parsing the text and for extracting the ID3 tags.

Extracting ID3 title with ffprobe

ffprobe is part of the ffmpeg suite of tools which on macOS can be installed with Homebrew. If you don’t have the latter, go install it now; because it opens up so many tools for your use. In this case, it makes ffmpeg available via brew install ffmpeg.

I’ve written previously about extracting and processing mp3 files from web pages. The use case that I described, obtaining Russian word pronunciations for Anki cards is basically the same although I’m now obtaining many of my words from Forvo. However, Forvo doesn’t seem to apply any audio dynamic range processing or normalization to the audio files. While many of the pronunciation mp3’s are excellent as-is, some need post-processing chiefly because the amplitude is too low. However, being lazy by nature, I set out to find a way of improving the audio quality automatically before I insert the mp3 file into my new vocabulary cards.