BatchAudioConvert

The goal of this gem is to batch transform audio files from one format to another.

It basically takes the assumption that the audio library is already correctly organized in the standard two levels directory structure that could be:

• artist/album
• various/compil

Nevertheless the files or directories specified could be located anywhere. Only the structure is assumed.

It actually replicates the original structure and copies all the tags (handled by taglib) to the generated audio files.

It currently supports:

• FLAC to OGG transformation
• FLAC to MP3 transformation

This gem has some system dependencies.

 sudo apt-get install libtag1-dev vorbis-tools flac lame

Both vorbis-tools and lame can be optional depending on the encoding you want (ogg or mp3)

It could probably work under Windows/Cygwin with some tweaking, but never tried... It is based on the easy_app_helper Gem(sources), but it will installed automatically by the gem/bundle mechanism.

Add this line to your application's Gemfile:

gem 'batch_audio_convert'

And then execute:

$ bundle

Or install it yourself as:

$ gem install batch_audio_convert

This is done through a YAML config file thanks to EasyAppHelper::Config module of the EasyAppHelper gem.

You should name your configuration file batch_audio_convert.conf

See the constants defined in EasyAppHelper::Config::Instanciator module to know which extensions could be used and where to place you config files. Of course as this script is based on EasyAppHelper, you still have the possiblity to directly pass a config file from the command line using the --config-file command line option.

To be clear, the easiest place to create your config should be:

~/.config/batch_audio_convert.conf

# Minimum configuration for batch_audio_convert

# Hash defining possible transformations.
extensions:
  flac: ogg
  flac: mp3

# [Optional] Quality of the generated ogg files. Default to 6
ogg-quality: 6

# [Optional] Bitrate of the generated mp3 files. Default to 256
mp3-quality: 256

# An array of sources to process. Non valid entries are skipped.
source:
  - list of files or directories
  - etc ...

# Where the transformed files will be created.
destination: the root directory of where you want the transformed files to go (do not need to exist, only the parent dir).

The inline help is provided by EasyAppHelper gem mechanism:

$ batch_audio_convert --help
Batch Audio Converter Version: 0.1.0

This application batch-transforms audio files from your central media library from one
format to another. It basically takes the assumption that the audio library is already
correctly organized in two levels directory structure that could be:
- artist/album
- various/compil
Nevertheless the files or directories specified could be located anywhere. Only the
structure is assumed.

It actually replicates the original structure and copies all the tags (handled by taglib)
to the generated audio files.

Currently only manages FLAC to OGG and FLAC to MP3, all other files are copied untouched.

-- Generic options -------------------------------------------
       	--auto              Auto mode. Bypasses questions to user.
		--simulate          Do not perform the actual underlying actions.
    -v, --verbose           Enable verbose mode.
    -h, --help              Displays this help.
    
-- Debug and logging options ---------------------------------
        --debug             Run in debug mode.
    	--debug-on-err      Run in debug mode with output to stderr.
     	--log-level         Log level from 0 to 5, default 2.
        --log-file          File to log to.
	
-- Configuration options -------------------------------------
       	--config-file       Specify a config file.
	
-- Script specific options------------------------------------
    -b, --mp3-quality       Defines encoding bitrate for MP3 files.
    -q, --ogg-quality       Defines encoding quality for OGG files.
    -f, --force             Forces files override.

As you see could then override the ogg quality (defined in the config file) from the command line.

By default batch_audio_convert won't regenerate a file already present in the destination tree, but you can force this behaviour using the --force command line option.

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Currently there is only flac to ogg and flac to mp3 conversion, but the program is ready to handle other potential transformations. Do not hesitate, you just have to implement one method named <origin>_to_<dest> in the audio_utils.rb file and add one supported extension in the config "extensions" hash.

Currently only the flac_to_ogg and flac_to_mp3 method exists and this is why the "extensions" hash in the config file contains:

extensions:
  flac: ogg
  flac: mp3