Transcode all archived music in a directory to MP4, preserving base directory layouts

convert_mp4.bash

#!/bin/bash

DEST_DIR="/home/iPod"
FULL_PATH="$1"
ALBUM=$(basename "$FULL_PATH")
NEW_PATH="$DEST_DIR/$ALBUM"

echo "Transcoding into $NEW_PATH"
mkdir "$NEW_PATH"

FILES=$(find "$FULL_PATH" -regextype posix-extended -iregex ".*(ogg|flac)$")
IFS="
"

for OLD_FILE in $FILES; do
  OLD_FILE_NAME=$(basename "$OLD_FILE")
  FILE_BASE="${OLD_FILE_NAME%.*}"
  TEMP_FILE="$NEW_PATH/$FILE_BASE.tmp.m4a"
  NEW_FILE="$NEW_PATH/$FILE_BASE.m4a"

  echo "Convert $OLD_FILE to $NEW_FILE"
  avconv -loglevel error -i "$OLD_FILE" -acodec aac -strict experimental "$TEMP_FILE"
  avconv -loglevel error -i "$TEMP_FILE" -i "$OLD_FILE" -map 0 -c copy -map_metadata 1:s:a "$NEW_FILE"
  rm -f "$TEMP_FILE"
done

Example of execution:
find /home/music/ -maxdepth 1 -mindepth 1 -type d -perm -u=x -exec convert_ipod.bash {} \;