The m4a problem. Peace or War?

[willow]

The issue seems simple, but don't they all at first.
The breakdown and the facts:
1. I want to play chapterized m4a files on my player (currently a Sandisk Sansa Fuze)

2. I installed the latest version (Rockbox 3.14) and tried to play a chapterized m4a file. Every time Rockbox starts playing the next file in the list, as if the m4a file was not there.

3. While I was researching this problem I came across this page on the Rockbox site listing 'Supported audio formats'. It has m4a and m4b listed.  https://download.rockbox.org/daily/manual/rockbox-ipodcolor/rockbox-buildap2.html

I am not new to Rockbox. I was dancing when I realized there was an alternative to the stupid Sandisk interface.  But I want my chapters, and that format is m4a.  Do I have to chose?  Or....oh well I will say it.  Is there alternative to Rockbox?  A replacement firmware that will read m4b?

[saratoga]

2. I installed the latest version (Rockbox 3.14) and tried to play a chapterized m4a file. Every time Rockbox starts playing the next file in the list, as if the m4a file was not there.

How did you make the file?  Normal audio mp4 files should parse ok, but more complex ones tend to run out of memory or have other problems. 

I am not new to Rockbox. I was dancing when I realized there was an alternative to the stupid Sandisk interface.  But I want my chapters, and that format is m4a.  Do I have to chose?  Or....oh well I will say it.  Is there alternative to Rockbox?  A replacement firmware that will read m4b?

I don't think there is even support for MP4 chapters in our parser.  It should just ignore them. 

[willow]

How did you make the file?  Normal audio mp4 files should parse ok, but more complex ones tend to run out of memory or have other problems.

Most of my mp4 files are from Audible AAX and AA format, converted to mp4 with most likely Epubor Audible Converter.  But some files I have downloaded from other places.  Basically, I don't know what defines 'complex', and even if I did I probably couldn't find the information.  And what is this run out of memory?  The player runs out of memory?  Rockbox runs out of memory?

I don't think there is even support for MP4 chapters in our parser.  It should just ignore them.

So, it really doesn't mater how I make the file, since this 'parser' in Rockbox doesn't support mp4 files.  And if that is so, what is this Rockbox site listing 'Supported audio formats' that has m4a and m4b listed.  https://download.rockbox.org/daily/manual/rockbox-ipodcolor/rockbox-buildap2.html
and this one https://www.rockbox.org/wiki/SoundCodecs#Current_status

[saratoga]

How did you make the file?  Normal audio mp4 files should parse ok, but more complex ones tend to run out of memory or have other problems.

Most of my mp4 files are from Audible AAX and AA format, converted to mp4 with most likely Epubor Audible Converter.  But some files I have downloaded from other places.  Basically, I don't know what defines 'complex', and even if I did I probably couldn't find the information.  And what is this run out of memory?  The player runs out of memory?  Rockbox runs out of memory?

The player runs out of memory parsing the files.  For best results, you really want to use mobile or itunes optimized AAC, which isn't necessarily what you'll get with tools that just wrap ffmpeg or some other library. 

So, it really doesn't mater how I make the file, since this 'parser' in Rockbox doesn't support mp4 files.

No, MP4 files are supported, but chapters are ignored. 

[willow]

No, MP4 files are supported, but chapters are ignored.

Well, the only reason I was interested in playing mp4 files was because they had chapter support.  So, that's it.  I suppose, referencing the title, my next steps could be called war?

Summing it up, I can't play chapterized mp4 files in Rockbox.  My Sansa Fuze without Rockbox on it won't support mp4 either.  So I have to go find me a player that can play mp4, abandoning my long faithful Fuze.  And abandon Rockbox as well.

Am I missing some clever work around, some better way?

Even if answer is no, thank you so much for all these quick answers.  When I go to a 'help me' forum like this I usually have to wait a long time for an answer, if I ever do get an answer.

[saratoga]

Am I missing some clever work around, some better way?

A typical way people implement chapters for audio files is with a .cue file (as would be used to have track markers in whole album images).  These are supported.  However, if you're used to using chapters, you may just want to buy an iPod, as I think that is the way iTunes does it. 

[willow]

A typical way people implement chapters for audio files is with a .cue file (as would be used to have track markers in whole album images).  These are supported.  However, if you're used to using chapters, you may just want to buy an iPod, as I think that is the way iTunes does it.

I dislike apple and all things with that apple on it.  I would be happy to shoot the apple, so to speak.  So no iPod.
How would this .cue file work?  How would I create it?  Do I just place it in the same folder as the mp4 file, and Rockbox will recognize the .cue and link it to the mp4 file?

[Chronon]

Here's the section about cuesheet support in the manual (also describes where to place the cuesheets):
https://download.rockbox.org/daily/manual/rockbox-sansafuze/rockbox-buildch7.html#x9-1310007.13


Here's a Wikipedia article providing more information about cuesheets:
https://en.wikipedia.org/wiki/Cue_sheet_(computing)#Audio_file_playback

Ideally, whatever software is transcoding the media to .m4a can provide a cuesheet.  Although it's a bit cumbersome, you could also create it manually using the information from the Wikipedia article.

Additionally, there are cuesheet sites where you can download cuesheets for various media, but I don't know what sort of luck you will have for your particular media.