fix-pal-speedup: delay video track if needed

[transcoding] / fix-pal-speedup

diff --git a/fix-pal-speedup b/fix-pal-speedup
index 17e5e012fb9aab9b4771c89c1d23670bb87588b0..5b77d451163c122b638e618f181167fd0f675064 100755 (executable)
--- a/fix-pal-speedup
+++ b/fix-pal-speedup
@@ -1,4 +1,4 @@
-#!/bin/bash -e
+#!/bin/bash
 
 # Many DVDs released in Australia are sped up from 24fps to 25fps.
 # This script reverses the procedure, correcting the audio pitch.
@@ -10,7 +10,7 @@ if [ -z "$1" -o -z "$2" ]; then
     exit 1
 fi
 
-set -xe
+set -o pipefail -eux
 FORCEFPS="24"
 SLOWFILTER="-filter asetrate=46080,aresample=osr=48000:resampler=soxr"
 
@@ -19,24 +19,25 @@ function mux_replace_audio {
     local audiofile="$2"
     local outfile="$3"
 
-    local audiodelay="$(get_audio_delay "$infile")"
-    local videotrackid="$(get_video_trackid "$infile")"
+    local audiodelay="$(get_minimum_timestamp "$infile" "audio")"
+    local videodelay="$(get_minimum_timestamp "$infile" "video")"
+    local videotrackid="$(get_track_id "$infile" "video")"
 
     mkvmerge \
         -o "${outfile}" \
         --default-duration "${videotrackid}:${FORCEFPS}fps" \
+        --sync "${videotrackid}:$((videodelay / 1000000))" \
         --no-audio "$infile" \
         --sync "0:$((audiodelay / 1000000))" \
         "$audiofile"
 }
 
-function get_video_trackid {
-    mkvmerge -i "$1" | sed -n 's/Track ID \([0-9]*\): .*video.*/\1/p'
+function get_track_id {
+    mkvmerge -i -F json "$1" | jq -r ".tracks[] | select(.type == \"$2\") | .id"
 }
 
-function get_audio_delay {
-    mkvmerge -F json -i "$1" | \
-        jq -r '.tracks[] | select(.type == "audio") | .properties.minimum_timestamp'
+function get_minimum_timestamp {
+    mkvmerge -F json -i "$1" | jq -r ".tracks[] | select(.type == \"$2\") | .properties.minimum_timestamp"
 }
 
 function encode_audio {