Linux command to concatenate audio files and output them to ogg

audiocommand linelinux

What command-line tools do I need in order to concatenate several audio files and output them as one ogg (and/or mp3)?

If you can provide the complete command to concatenate and output to ogg, that would be awesome.

Edit: Input files (in my case, currently) are in wma format, but ideally it should be flexible enough to support a wide range of popular formats.

Edit2: Just to clarify, I don't want to merge all wmas in a certain directory, I just want to concatenate 2 or 3 files into one.

Thanks for the proposed solutions, but they all seem to require creating temporary files, if possible at all, I'd like to avoid that.

Best Answer

Here's my suggestion: Use mplayer and oggenc connected with a named pipe.

  • Use mplayer to decode the audio. It can play back a wide variety of audio (and video) formats, and it also can play multiple files.

  • Use oggencto encode the audio to Ogg Vorbis.

  • To eliminate the need for a temporary file, use a named pipe to transfer the data between encoder and decoder.

Putting that into a script:

#!/bin/sh
# Usage: ./combine2ogg destination.ogg source1.wma source2.wma ...
# Requires: mplayer, oggenc
destination="$1"
shift
readpipe="$destination.tmpr"
writepipe="$destination.tmpw"
mkfifo "$readpipe"
mkfifo "$writepipe"
cat "$writepipe" > "$readpipe" &
mplayer -really-quiet -slave -nolirc -vc null -vo null -ao "pcm:fast:file=$writepipe" "$@" &
oggenc --quiet -o "$destination" "$readpipe"
rm -f "$readpipe"
rm -f "$writepipe"

Explained:

  1. Take the destination file name from the first command line parameter.
  2. Remove the first command line parameter, leaving only the source file names.
  3. Create a name for a pipe for oggenc to read from.
  4. Create a name for a pipe for mplayer to write to
  5. Create the pipes.
  6. Use cat to continuously dump the writepipe to the readpipe (this helps avoid issues where mplayer may terminate, but prevents oggenc from thinking it's done when this happens)
  7. Decode the audio from the source files using mplayer. Options -really-quiet -slave -nolirc are there to disable messages and to make it not read the keyboard or the remote. Options -vc null -vo null are there to disable video encoding and output. The -ao option directs it to output the audio in WAV format to the named write pipe.
  8. While the previous command is running, simultaneously encode from the named read pipe into Ogg using oggenc.
  9. Remove the named pipes.

Stuff to left to improve: Terminating the script early if one of the commands fails (use set -e), but still properly cleaning up the fifo (trap the necessary signals).

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