From 8cfbb41e63dbb416030e3a9ad4b50691b3289901 Mon Sep 17 00:00:00 2001
From: James Bunton <jamesbunton@delx.net.au>
Date: Thu, 25 Oct 2018 08:48:48 +1100
Subject: [PATCH] fix-pal-speedup: don't try to adjust chapter-sync if there
 are zero chapters

This stops mkvmerge from exiting with an error
---
 fix-pal-speedup | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/fix-pal-speedup b/fix-pal-speedup
index 4fb9dcb..51ab6ed 100755
--- a/fix-pal-speedup
+++ b/fix-pal-speedup
@@ -59,11 +59,16 @@ function remux_file {
         suboptions+=("--sync" "${subtitletrackid}:0,${OLDFPS}/${NEWFPS}")
     done < <(get_track_id "$infile" "subtitles")
 
+    local chapteroptions=()
+    if [ "$(get_chapter_count "$infile")" -gt 0 ]; then
+        chapteroptions=("--chapter-sync" "0,${OLDFPS}/${NEWFPS}")
+    fi
+
     mkvmerge \
         -o "${outfile}" \
         --default-duration "${videotrackid}:${NEWFPS}fps" \
         --sync "${videotrackid}:$((videodelay / 1000000))" \
-        --chapter-sync "0,${OLDFPS}/${NEWFPS}" \
+        "${chapteroptions[@]}" \
         "${suboptions[@]}" \
         --no-audio "$infile" \
         --sync "0:$((audiodelay / 1000000))" \
@@ -78,4 +83,8 @@ function get_minimum_timestamp {
     mkvmerge -i -F json "$1" | jq -r ".tracks[] | select(.type == \"$2\") | .properties.minimum_timestamp"
 }
 
+function get_chapter_count {
+    mkvmerge -i -F json "$1" | jq -r ".chapters | length"
+}
+
 main "$@"
-- 
2.39.2