#!/bin/bash -e
-# Many DVDs released in Australia are sped up from 23.976fps to 25fps.
+# Many DVDs released in Australia are sped up from 24fps to 25fps.
# This script reverses the procedure, correcting the audio pitch.
-# Input files are assumed to be mkv files with track 2 audio.
# The video framerate is adjusted without re-encoding. The audio is slowed and
-# normalised then re-encoded as mp3.
+# volume normalised then re-encoded as mp3.
if [ -z "$1" -o -z "$2" ]; then
- echo "Usage: $0 destdir infile"
+ echo "Usage: $0 destdir infile [infile ...]"
exit 1
fi
-# FORCEFPS = 24000 / 1001
-# SLOWDOWN = FORCEFPS / 25
-FORCEFPS="23.976023976023978"
-SLOWDOWN="0.9590409590409591"
+FORCEFPS="24"
+SLOWDOWN="0.96"
destdir="$1"
-infile="$2"
-outfile="$destdir/$(basename "$infile")"
-tmpdir="$(tempfile -p 'pal-')"
-rm "$tmpdir"
-
-if [ -f "$outfile" ]; then
- echo "Not overwriting $outfile"
- exit 0
-fi
+shift
+
+for infile in "$@"; do
+ outfile="$destdir/$(basename "$infile")"
+
+ if [ -f "$outfile" ]; then
+ echo "Not overwriting $outfile"
+ continue
+ fi
-set -x
-mkdir "$tmpdir"
-mkvextract tracks "$infile" 2:"${tmpdir}/audio"
-mplayer -ao pcm:file="${tmpdir}/audio.wav" -vo null "${tmpdir}/audio"
-sox "${tmpdir}/audio.wav" "${tmpdir}/audio-fixed.wav" speed "${SLOWDOWN}" gain -n
-lame --preset standard "${tmpdir}/audio-fixed.wav" "${tmpdir}/audio.mp3"
-mkvmerge -o "${outfile}" --default-duration "1:${FORCEFPS}fps" --no-audio "$infile" "${tmpdir}/audio.mp3"
+ set -x
+ tmpdir="$(mktemp -d "${TMPDIR:-/var/tmp}/pal-XXXXXXXX")"
+ mplayer -novideo -ao pcm:file="${tmpdir}/audio.wav" -vo null "$infile"
+ sox "${tmpdir}/audio.wav" "${tmpdir}/audio-fixed.wav" speed "${SLOWDOWN}" gain -n
+ lame --preset standard "${tmpdir}/audio-fixed.wav" "${tmpdir}/audio.mp3"
+ mkvmerge -o "${outfile}" --default-duration "1:${FORCEFPS}fps" --no-audio "$infile" "${tmpdir}/audio.mp3"
-rm -rf "$tmpdir"
+ rm -rf "$tmpdir"
+done