M4A loads but does not play

[madsic]

I'm trying to encode one large (several cds joined using audacity) audiobook wav file to aac/mp4 so that bookmarking will work on both rockbox and apple firmware (which requires aac encoding in a m4b container in order for it to work - stupid, sad & annoying but true).

I'm using the Nero AAC codec in Foobar 2000 and encoding as VBR MP4 (I've also tried ABR and CBR but with pretty much the same results). The exact file properties from foobar:

Duration : 5:06:35.602 (811246029 samples)
Sample Rate : 44100 Hz
Channels : 2
Bitrate : 48 kbps
Codec : AAC
Codec Profile : AAC LC
Encoding : lossy
Tool : Nero AAC codec / Feb 12 2007

The file loads but in a strange way. I usually have to try a few times before it finally 'gets it' - e.g. the first time it only displays filename and nothing else, second time it proclaims 'no file!', third-fourth-fifth times are repeats of this pattern and only the sixth or so time does it load and display stuff like length and so on. However, it does not play but I am able to progress the file by using FF. See screendump ('no info' is not really an error as I didn't enter any).

EDIT: Now it seems to be stuck in a different pattern where it loads like in the screen capture but immidiately returns to the file browser.

I seem to recall previously being able to use this very same method to get perfectly playable MP4s. What (is)/(am I doing) wrong?

PS: An M4B container is just an M4A container renamed so that the firmware can classify it as an audiobook.

PPS: I have tried the foobar 'optimize mp4 layout' but to no avail.

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[Llorean]

Rockbox won't play large MP4 files right now.

[madsic]

Oh. Right. Large as in Mb or large as in minutes?
EDIT: i.e. what are the limitations?

[Lear]

The exact limits aren't easy to say, because it depends on the file layout. The time is the limit though. With an optimized layout, you should be able to play somewhere between 1.5 to 2 hours long files. So five hours is way too much, unfortunately.

[madsic]

Ok thanks for the info, Lear. Another annoying aspect about apple firmware bookmarking is that - as far as i can tell anyhow - you have to select the exact file that you know/remeber/suspect that you had come to. Which is why merging seemed such a good idea. It still works on the firmware though so I guess I'll just have to have different solutions for different targets.