[F] Problem changing tags in m4b file


#1

With certain m4b files, I can't seem to change tags in the files.

It saves the file but the changes disappear and when I try to change a tag the content is deleted entirely.

file -b Meridien\ A\ Silver\ Ships\ Novel,\ Book\ 3\ -\ 001.2.M4B
ISO Media, Apple iTunes ALAC/AAC-LC (.M4A) Audio

Here is a sample file https://drive.google.com/file/d/0B0pQAy60CI...iew?usp=sharing


#2

see e.g. here: /t/18392/1
or here: /t/18889/1


#3

Mp3tag currently doesn't support editing the chapter information of M4B files (also often referred to as Nero tags).

With Mp3tag v2.83, you can remove the chapter marks by right-clicking on the file and selecting "Strip MP4 chapters". This will remove the Nero tags from the file and will allow you to edit the normal MP4 tag as usual.

Kind regards

  • Florian

#4

Strange. but ok now that I understand the problem....

So the workflow has to be...

strip chapters

modify tags

reapply chapters?

Not the end of the world I guess.

I mean a W/A would be something like...

# save an strip chapters
mp4chaps -x %f
mp4chaps -r %f

# change tags 

# restore chapters
mp4chaps -i %f

Is there a possibility to auto execute a script/cmd pre and post save?

thanks


#5

Can you try the latest Development Build Mp3tag v2.83g and see whether this improves the situation for you?

Kind regards
– Florian


#6

Unfortunately it has no discernable effect.

I actually attached a sample file to the initial post, if you find that easier.

I have however noticed that mp3tag seems to be confusing mediainfo

Text [0/9997]
ID : 2
Format : Timed Text
Codec ID : text
Duration : 2 h 50 min
Bit rate mode : Variable
Bit rate : 0 b/s
Stream size : 116 Bytes (0%)
Language : English
Default : Yes
Forced : No
Alternate group : 3
Encoded date : UTC 1904-01-01 00:00:00
Tagged date : UTC 1904-01-01 00:00:00
Menus : 3

Menu #1
ID : 3
Codec ID : text
Duration : 2 h 24 min
Language : English
Encoded date : UTC 1904-01-01 00:00:00
Tagged date : UTC 1904-01-01 00:00:00
Bit rate mode : CBR
Menu For : 1,2
00:00:00.000 : 037
00:40:18.450 : 038
01:07:34.621 : 039
01:16:41.962 : 040
01:39:27.435 : 041
01:54:28.508 : 042
02:24:43.566 : 043

Menu #2
00:00:00.000 : M?ridien: A Silver Ships Novel, Book 3
00:40:18.450 : M?ridien: A Silver Ships Novel, Book 3
01:07:34.621 : M?ridien: A Silver Ships Novel, Book 3
01:16:41.962 : M?ridien: A Silver Ships Novel, Book 3
01:39:27.435 : M?ridien: A Silver Ships Novel, Book 3
01:54:28.508 : M?ridien: A Silver Ships Novel, Book 3
02:24:43.566 : M?ridien: A Silver Ships Novel, Book 3

When I look at the files on the binary level there is content being changed, it just doesn't to be parseable...


#7

OK, thank you.

I guess to put an end to this mess, I'll need to implement proper multi-chapter support for MP4 files in Mp3tag.

Stay tuned...
– Florian


#8

I've added support for Nero-style MP4 chapters with the latest Development Build Mp3tag v2.83h.

Would be great if you could test this new feature on some (copies) of your audiobooks.

Kind regards
– Florian


#9

Ok it seems to be better.

When I try the new version, I get what looks like 1 entry per chapter for the file in mp3tag.

It looks like the Track number is replaced by the chapter number?

If this is the intent it is a problem, as typically one uses the track number to denote the part.

i.e. books get split into 6 - hour files with chapters for each part.

e.g. track 1 may have chapter 1 - 20 and track 2 may have 20 -> 40...

Can you clarify if this is intentional?


#10

The track numbers are queried from the Nero chapter tags. I've analyzed your file and it has an additional text track which has again something that can be interpreted as track numbers (it's only numeric string data, this time with leading zeros starting at 001).

I'll focus on the Nero chapters for now, so yes – it's intentional.

Kind regards
– Florian


#11

I don't think that overloading the title, track, and pic make sense.

To be able to edit the chapter, it would make more sense to have a different view maybe?

Most(all I'm aware of) of the tools that work on these differentiate between them.

The chapter data is seen as additional meta data but doesn't prevent you working with the file level meta. As it is, although I can not edit the chapter meta, I can't seem to edit the meta that all players use who don'T support chapters.

Also I don't see how this would work with tag to filename renaming, it would rename the flle n times where n is the number of chapters.

I suppose you could add another entry for the file level tags, or have 2 modes, one that shows chapters and one that doesn't.

Also if I wanted to edit the chapter data, I'd probably also want to be able to edit the timestamps.


#12

I'm actively trying to prevent this and instead try to come up with a solution which fits into Mp3tag's lightweight UI.

Can you point me to such tools?

Mp3tag writes all data that is common to all chapters at the file level. Have you tried it?

I've also taken care of that — it only renames the file once. Have you tried it?

Yes, but this is outside the scope of this feature at the moment.

Kind regards
– Florian