shrinkmusic: Shrink your music for your phone, car stereo, etc.

Posted on September 12, 2018 by Mike Ledger

I love music. I have a rather large digital collection of it, hoarded over many years, and I intend to grow it indefinitely. There are a wide variety of formats, from FLAC, to Ogg Theora, to MP3, to (very poor) WMA.

Converting all the music at once, preserving the exact directory structure, is more of a challenge than it ought to be – ideally, a command should exist, like rsync, that intelligently decides what to convert and what to just copy (converting 96kbps mp3 files to a different lossy format will not do it many favours).

That’s what shrinkmusic is. It takes an input directory, an output directory, computes a plan – what to convert, what to keep, what to skip due to already existing in the output directory, and what to ignore due to a user flag – and then executes it, in parallel, using as many jobs as you’d like.

Features

Add new music without re-converting an entire library
Decides (albeit by pretty dumb heuristics) what is worth converting, and what is OK to just copy
Splits FILE.flac and FILE.cue pairs automatically
Parallel execution
Dry run mode
Can ignore specific files/directories (e.g., I don’t care to copy hoarded podcasts – readily available on the internet anyway – over)

Install

Install using Stack or Nix.

$ git pull https://github.com/mikeplus64/shrinkmusic.git
$ cd shrinkmusic
$ stack install
$ nix-env -f ./default.nix -i # alternative for Nix

Usage

Usage: shrinkmusic (-i|--input INPUT) (-o|--output OUTPUT)
                   (-b|--bitrate BITRATE) (-j|--jobs JOBS) [-z|--ignore IGNORE]
                   [-d|--dry-run]

Available options:
  -h,--help                Show this help text
  -i,--input INPUT         Input directory
  -o,--output OUTPUT       Output directory
  -b,--bitrate BITRATE     bitrate for audio
  -j,--jobs JOBS           Number of jobs to use
  -z,--ignore IGNORE       Ignore this file
  -d,--dry-run             Do nothing; just output the plan