X-Git-Url: https://code.delx.au/transcoding/blobdiff_plain/48a35c1d3b975e17d4fd002145855c561cbddd46..698521ee62495859c3dab544eac316a308d983c1:/fix-pal-speedup

diff --git a/fix-pal-speedup b/fix-pal-speedup
index af1d30d..39c4ba4 100755
--- a/fix-pal-speedup
+++ b/fix-pal-speedup
@@ -1,37 +1,80 @@
 #!/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.
+# The video framerate is adjusted without re-encoding. The audio is
+# slowed, volume normalised, down-mixed to stereo and encoded as mp3.
 
 if [ -z "$1" -o -z "$2" ]; then
-	echo "Usage: $0 destdir infile"
-	exit 1
+    echo "Usage: $0 destdir infile [infile ...]"
+    exit 1
 fi
 
+set -xe
 FORCEFPS="24"
 SLOWDOWN="0.96"
 
+function mux_replace_audio {
+    infile="$1"
+    audiofile="$2"
+    outfile="$3"
+
+    trackid="$(mkvmerge -i "$infile" | grep video | sed 's/^Track ID \(.\):.*$/\1/')"
+    mkvmerge -o "${outfile}" --default-duration "${trackid}:${FORCEFPS}fps" --no-audio "$infile" "$audiofile"
+}
+
+function extract_audio {
+    infile="$1"
+
+    exec mpv \
+        --no-terminal \
+        --no-video \
+        --ao pcm:waveheader:file=/dev/stdout \
+        "$infile"
+}
+
+function slow_audio {
+    exec sox \
+        --temp "$tmpdir" \
+        - \
+        -t wav - \
+        speed "${SLOWDOWN}" \
+        gain -n \
+        channels 2
+}
+
+function encode_audio {
+    outfile="$1"
+    exec lame \
+        --preset standard \
+        - \
+        "${outfile}"
+}
+
+function convert_file {
+    infile="$1"
+    outfile="$2"
+    tmpdir="$(mktemp -d "${TMPDIR:-/var/tmp}/pal-XXXXXXXX")"
+    audiofile="${tmpdir}/audio.mp3"
+
+    extract_audio "${infile}" | slow_audio | encode_audio "${audiofile}"
+    mux_replace_audio "${infile}" "${audiofile}" "${outfile}"
+
+    rm -rf "$tmpdir"
+}
+
+
 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")"
 
-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"
+    if [ -f "$outfile" ]; then
+        echo "Not overwriting $outfile"
+        continue
+    fi
 
-rm -rf "$tmpdir"
+    convert_file "$infile" "$outfile"
+done