mdat atom getting parsed before chap

[Wombarly]

Is there an existing issue for this?

• I have searched the existing issues

music-metadata version

11.9.0

Current Behavior

I'm trying to parse an audiobook, which I converted to an m4a (m4b?). I'm unsure which software I used to originally convert it when I downloaded it. But its chapter data isn't getting parsed, I can see it in VLC and other tools.

I used the debugger in my browser to figure out what was going on. I noticed that it is parsing the mdat atom before it gets to the trak atom (or rather the chap in parseTrackBox, which is setting the chapterList).

Because the mdat parser is processing the chapter data, which requires chapterList to be set, it skips it it.

I tried to truncate it to get a sample, but when I do that it wont parse at all.

Expected Behavior

No response

Attached audio sample?

• I have provided sufficient information to reproduce the issue

[Borewit]

Any difference if you set includeChapters as an option? Looks like I forgot to document that one.

[Wombarly]

Sorry, forgot to mention that includeChapters is set to true

[Borewit]

Can you get that file to borewit@xs4all.nl somehow, I will keep it for myself.

[Wombarly]

Send from my handle at gmail, I used a pw zip to because it is going over GDrive.

[Borewit]

Your analysis is correct, this due to the fact the chap box, as part of the moov box appears after the mdat box. The chap box is required to extract the chapter information from the mdat atom.

Certainly not a trivial fix.