faac m4b on 2nd gen ipod mini "No file!"

[acongdon]

I'm using r15915-071213 on a 2nd generation ipod mini.
I've created many m4b files using faac over the past couple of years
and I don't specify any coding options only tags.
Currently using faac 1.26.1 but a database update fails to find the files
and a file play results in "No file!" and the screen doesn't update after
that. Doesn't seem to be related to file size either?

Mp3s work fine.

Both work fine with the native software and any other programs
I've tried so any help would be greatly appreciated.

[Lear]

Rockbox currently need MP4 files to be streamable (meaning that metadata, such as information tags, are placed before the audio data). I tested with faac 1.24, and that didn't generate such files. You can use a program called mp4creator (using the -optimize option) to fix the files. Foobar2000 can also do it.

And I hope you're aware that there are better AAC encoders out there...

[acongdon]

Thanks for the pointers but it's not got me very far...

I've built mpeg4ip 1.5.0.1 and used mp4creator as you suggest. Now rockbox can see the tags, no more "No file!", but it still can't play the file. BTW, the test file is 15mins and 6.5MB and mp4info:

MPEG-4 AAC LTP, 844.483 secs, 61 kbps, 44100 Hz

Older faac (1.24+) has produced:

MPEG-4 AAC LC, 1344.336 secs, 62 kbps, 44100 Hz

It doesn't look like mp4creator can be used to create audio only files?

Foobar2000 looks like a windoze gui player so I didn't pursue that?

I did find aacenc which seems to run fine under wine. It produces MPEG4 m4bs which can be
played with xine, not with mplayer, not with amarok using xine, not mp4player, and not with rockbox. The files are twice the size of those produced with faac.

Please tell me more about the "better" encoders that I'm not aware of given that my interest is in mono audiobooks and podcasts where fidelity is not so important.

[Llorean]

If you're just interested in encoding audiobooks, why not simply use speex, a far more suitable format for spoken word  at those bitrates?

As it is, I'm not sure Rockbox supports LTP. I'm pretty sure it's expected that they're LC profile, but don't quote me on that.

[saratoga]

Thanks for the pointers but it's not got me very far...

I've built mpeg4ip 1.5.0.1 and used mp4creator as you suggest. Now rockbox can see the tags, no more "No file!", but it still can't play the file. BTW, the test file is 15mins and 6.5MB and mp4info:

MPEG-4 AAC LTP, 844.483 secs, 61 kbps, 44100 Hz

I'm mildly surprised you managed to make such a file.  I wasn't aware LTP encoders actually existed in the wild.  I doubt very much rockbox will play such a file though.

You should really only use AAC-LC on your player.  Other AAC profiles are either not supported, not well tested, or too slow for the limited CPU on your iPod.

Please tell me more about the "better" encoders that I'm not aware of given that my interest is in mono audiobooks and podcasts where fidelity is not so important.

FAAC is a reference encoder showing how to make a standards compliant bitstream.  Its not actually meant to be used to encode actual audio.  I don't even think FAAC has a functioning psymodel.

Any audio encoder made in the last 10 years should produce better results.  

[acongdon]

Thanks for your help on this.. all working and understood now.

Using faac <=1.25 creating LC files (most of my AAC were LC) and "mp4creator --optimize" and
the files play fine. The few LTP files can be played with the original firmware and I can dual boot to
play those.

Experimented with the Linux Nero coder and the files are much the same size and quality at the
same bitrate as the faac files and play fine too. The Nero files can be tagged with the mpeg4ip tools.

The speex experimenting was not so encouraging - the quality was noticably inferior.

[Llorean]

Are you sure you're using speex properly? Many people don't resample their audio, and for example do something silly like trying to encode speex at 44.1khz.

At equal bitrates, with spoken word content, it's rather unlikely that a music focused codec is going to encode speech better than one designed for speech, unless you're up encoding at far higher bitrates than necessary, with strange settings.