#!/bin/bash

# WAV to MP3 converter script.
#
# Original idea and design: Remco van Rijn
# Additional tuning: Maarten de Boer
# Thanks to: Pieter Suurmond
# Last edited on march 13, 2009.

# Put this bash script in the rootdir of a WAV-tree before running it.
# It will produce an MP3-tree next to the WAV-tree.
# It assumes all directory-names at the root of the WAV-tree are 
# composer-names, so this name can be used as an MP3-tag.

# Name of the MP3-tree:
DST=../MP3_from_WAV

# First collect all WAV-filenames in a temporary textfile
# (note that we can only run one script at a time!):
find . -iname "*.wav" > /tmp/wav_files.txt

# Then iterate over all names:
cat /tmp/wav_files.txt | while read NAAM; do
# Trim the first 2 characters (which are "./") from the name:
NAAM="${NAAM:2}"

# Construct new filename for the MP3 (substituting the .wav-suffix 
# by an .mp3-suffix):
MP3_FILE="$DST"/`echo "$NAAM" | sed 's/.\{3\}$/mp3/'`

# The first part of the path (up to first slash) is the composers name:
# (${string%%substring} = Strip longest match of $substring from back of $string)
COMPOSER="${NAAM%%/*}"

# The last part of the path is the title (without the trailing ".wav"):
# (${string##substring} = Strip longest match of $substring from front of $string)
TITLE="${NAAM##*/}"
# (${string%substring} = Strip shortest match of $substring from back of $string)
TITLE="${TITLE%.wav}"

# Name of the parent directory is the album name (could be same as composer).
ALBUM="${NAAM%/*}"
ALBUM="${ALBUM##*/}"

# Create new subdirs in the MP3-tree, if necessary:
DIR=`dirname "$MP3_FILE"`
mkdir -p "$DIR"

# Create MP3-file with variable bitrate. Quality/filesize is determined
# by "V n", with n=9 for lowest quality, and n=0 for highest quality.
lame --nohist --ta "$COMPOSER" --tl "$ALBUM" --tt "$TITLE" -h -V 1 "$NAAM" "$MP3_FILE"
done