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Chapter issues with music DVD

Posted: Wed Jun 27, 2018 12:35 am
by atrocity
I posted about this earlier, probably in the wrong place. Now I've got a bit more information, so here goes:

MakeMKV: 1.12.2 for Windows.

DVD: King Crimson's "Beat" KCSP9. It's a DVD-A, but the content I'm trying to extract is in VIDEO_TS. The disc, according to both MakeMKV and DVD Decrypter, has no encryption or protection whatsoever:
NoEncryption.jpg (11.78 KiB) Viewed 4537 times
My goal is to extract the DTS stream, wrap it in FLAC and play it on a Logitech Squeezebox, something I've done many times with other discs with no issues.

The problem: When I open the disc in MakeMKV and look at the title I care about, the chapters look perfect:
BeatChapters.jpg (26.83 KiB) Viewed 4537 times
However the MKV that gets created doesn't play in VLC. It opens, just sits there for a while, then suddenly scans to the end without ever actually playing. The timeline in VLC reports a reasonable time, it just doesn't play.

If I open the MKV in AudioMuxer in order to demux the audio content and split into individual song files, the chapters that initially looked good in MakeMKV become:

Code: Select all

CHAPTER01NAME=Chapter 01
CHAPTER02NAME=Chapter 02
CHAPTER03NAME=Chapter 03
CHAPTER04NAME=Chapter 04
CHAPTER05NAME=Chapter 05
CHAPTER06NAME=Chapter 06
CHAPTER07NAME=Chapter 07
CHAPTER08NAME=Chapter 08
CHAPTER09NAME=Chapter 09
AudioMuxer winds up creating nine output files, the first eight of which are very small and silent, while the final one contains all the audio. Although VLC will not play the MKV at all, the audio as extracted by AudioMuxer from that same MKV file is good.

If I bypass MakeMKV and open the disc directly in AudioMuxer (remember, the disc is not encrypted), I get the expected results. The chapters are reasonable:

Code: Select all

And the output files are exactly what I'd expect, one file per song, properly split.

I can't figure out why MakeMKV sees the proper chapters when it opens the disc, but they don't carry over properly when creating the MKV. Or at the very least, VLC and AudioMuxer do not see them correctly.

I've seen this behavior with other discs, and while the problem discs aren't all DVD-A (that is, many do not have anything in AUDIO_TS), I think they may all be discs where the content is largely musical and the "video" is really just still images or slideshows. It's possible that I only think that's relevant because most of why I try to do involves that type of disc.

Re: Chapter issues with music DVD

Posted: Tue Mar 19, 2019 12:17 pm
by jogger
The issue is still there in the latest version. I use the following steps:

- Extract all titles with MakeMKV
- Edit chapter times with MKVToolNix (will not split correctly after editing)
- Split using ffmpeg (adjust "map 0:" to get desired track)

Tried with King Crimson.

Code: Select all

ffmpeg -i "$1" 2> tmp.txt
while read -r first _ _ start _ end; do
  if [[ $first = Chapter ]]; then
    read  # discard line with Metadata:
    read _ _ chapter
    ffmpeg -i "$1" -ss "${start%?}" -to "$end" -vn -map 0:1 "$1$chapter.flac" </dev/null
done <tmp.txt
rm tmp.txt

Re: Chapter issues with music DVD

Posted: Thu Mar 21, 2019 7:07 am
by jogger
I now discovered the root cause:

The video track is much shorter than the audio tracks. This causes MakeMkv to get chapters wrong. So it is easier to just copy the audio tracks - the resulting file splits up fine.

Chapters are copied automatically, example is for audio in tracks 1 and 2.

ffmpeg -i input.mkv -c copy -map 0:1 -map 0:2 output.mkv