
Convert Plugin
**************

The "convert" plugin lets you convert parts of your collection to a
directory of your choice, transcoding audio and embedding album art
along the way. It can transcode to and from any format using a
configurable command line.


Installation
============

To use the "convert" plugin, first enable it in your configuration
(see *Using Plugins*). By default, the plugin depends on FFmpeg to
transcode the audio, so you might want to install it.


Usage
=====

To convert a part of your collection, run "beet convert QUERY". The
command will transcode all the files matching the query to the
destination directory given by the "-d" ("--dest") option or the
"dest" configuration. The path layout mirrors that of your library,
but it may be customized through the "paths" configuration.

The plugin uses a command-line program to transcode the audio. With
the "-f" ("--format") option you can choose the transcoding command
and customize the available commands *through the configuration*.

Unless the "-y" ("--yes") flag is set, the command will list all the
items to be converted and ask for your confirmation.

The "-a" (or "--album") option causes the command to match albums
instead of tracks.

By default, the command places converted files into the destination
directory and leaves your library pristine. To instead back up your
original files into the destination directory and keep converted files
in your library, use the "-k" (or "--keep-new") option.

To test your configuration without taking any actions, use the "--
pretend" flag. The plugin will print out the commands it will run
instead of executing them.


Configuration
=============

To configure the plugin, make a "convert:" section in your
configuration file. The available options are:

* **auto**: Import transcoded versions of your files automatically
  during imports. With this option enabled, the importer will
  transcode all (in the default configuration) non-MP3 files over the
  maximum bitrate before adding them to your library. Default: "no".

* **tmpdir**: The directory where temporary files will be stored
  during import. Default: none (system default),

* **copy_album_art**: Copy album art when copying or transcoding
  albums matched using the "-a" option. Default: "no".

* **album_art_maxwidth**: Downscale album art if it's too big. The
  resize operation reduces image width to at most "maxwidth" pixels
  while preserving the aspect ratio.

* **dest**: The directory where the files will be converted (or
  copied) to. Default: none.

* **embed**: Embed album art in converted items. Default: "yes".

* **max_bitrate**: All lossy files with a higher bitrate will be
  transcoded and those with a lower bitrate will simply be copied.
  Note that this does not guarantee that all converted files will have
  a lower bitrate---that depends on the encoder and its configuration.
  Default: none.

* **never_convert_lossy_files**: Cross-conversions between lossy
  codecs---such as mp3, ogg vorbis, etc.---makes little sense as they
  will decrease quality even further. If set to "yes", lossy files are
  always copied. Default: "no".

* **paths**: The directory structure and naming scheme for the
  converted files. Uses the same format as the top-level "paths"
  section (see *Path Format Configuration*). Default: Reuse your top-
  level path format settings.

* **quiet**: Prevent the plugin from announcing every file it
  processes. Default: "false".

* **threads**: The number of threads to use for parallel encoding. By
  default, the plugin will detect the number of processors available
  and use them all.

You can also configure the format to use for transcoding.


Configuring the transcoding command
-----------------------------------

You can customize the transcoding command through the "formats" map
and select a command with the "--format" command-line option or the
"format" configuration.

   convert:
       format: speex
       formats:
           speex:
               command: ffmpeg -i $source -y -acodec speex $dest
               extension: spx
           wav: ffmpeg -i $source -y -acodec pcm_s16le $dest

In this example "beet convert" will use the *speex* command by
default. To convert the audio to *wav*, run "beet convert -f wav".
This will also use the format key (*wav*) as the file extension.

Each entry in the "formats" map consists of a key (the name of the
format) as well as the command and optionally the file extension.
"extension" is the filename extension to be used for newly transcoded
files.  If only the command is given as a string or the extension is
not provided, the file extension defaults to the format's name.
"command" is the command to use to transcode audio. The tokens
"$source" and "$dest" in the command are replaced with the paths to
the existing and new file.

The plugin in comes with default commands for the most common audio
formats: *mp3*, *alac*, *flac*, *aac*, *opus*, *ogg*, *wmv*. For
details have a look at the output of "beet config -d".

For a one-command-fits-all solution use the "convert.command" and
"convert.extension" options. If these are set, the formats are ignored
and the given command is used for all conversions.

   convert:
       command: ffmpeg -i $source -y -vn -aq 2 $dest
       extension: mp3
