AAC+ playback on Rockbox

[Wrzlbrnft]

Hi there

I keep using Rockbox now for about five years. There are up-to-date builds on my iRiver H300 and on my Cowon D2 DAB. I've always been glad being able to play formats like MP2, FLAC, AAC, NSF and SPC through Rockbox.

But until today I never found out if there is a possibility for AAC+/HE-AAC playback. As I often record internet radio stations from Romania and the Netherlands which come in AAC+ it would be great if I don't had to convert it to a RB-compatible format all the time. So is there a way to get AAC+ played on my rockboxed Cowon D2? (I don't think it will work on the H300 due to it's age)

[saratoga]

But until today I never found out if there is a possibility for AAC+/HE-AAC playback.

Yes, AAC+ support was added in 2005.  You're right though that your H300 isn't fast enough to play it.  AAC+ is CPU intensive, and poorly optimized on coldfire players like the H300.  Should work on basically all newer devices though like your D2.

[Wrzlbrnft]

Sounds good!
Are there any restrictions like min/maximum bitrate, CBR-only or something? And how do I have to rename my files? The .aac extension doesn't seem to work, neither .m4a ...

[saratoga]

Are there any restrictions like min/maximum bitrate, CBR-only or something?

No.  All AAC-LC or AAC-HE files should work.

And how do I have to rename my files? The .aac extension doesn't seem to work, neither .m4a ...

Confusingly .aac is actually a somewhat different audio format then regular AAC(+), and is unsupported in rockbox.  The usual file extension for AAC(+) files is mp4 or m4a.  If your files have a different extension you should probably confirm that they're actually AAC. 

[Wrzlbrnft]

I just tried it once more. The result was the same as always. Rockbox refused to play the file. I don't know if the stream rip is a proper AAC+ file, but it's playable in Winamp or VLC as long as it carries the .aac file extension. I just uploaded the short stream rip here, maybe somebody has an idea.  (Kiss FM Romania, 32 kbps, about 1 minute)

[saratoga]

I don't know if the stream rip is a proper AAC+ file

Its not.  Thats a raw AAC transport stream, not a conventional AAC file.  AAC is supposed to be wrapped in an MP4 container.  You can probably fix it by muxing it into an MP4 container with mp4box or maybe ffmpeg.  Probably worth digging around on google for a while to find out.

[Wrzlbrnft]

Its not.  Thats a raw AAC transport stream, not a conventional AAC file.  AAC is supposed to be wrapped in an MP4 container.  You can probably fix it by muxing it into an MP4 container with mp4box or maybe ffmpeg.  Probably worth digging around on google for a while to find out.

Thank you so much!!! THAT's a very useful hint! With YAMB I really made some AAC+ files work with my Cowon D2 so far.
Some others are still not playing. For example this one from a German station works, this one from another Romanian station doesn't. Any further suggestions?

[saratoga]

I looked into that file but don't really understand why it fails.   I posted a bug report for it here:

http://www.rockbox.org/tracker/task/11916

[Buschel]

Issues (playback in general, handling runtime/bitrate, seek/resume) fixed. Might need some review before submit though.

Patch available in http://www.rockbox.org/tracker/task/11916.

[Wrzlbrnft]

Sounds good. Now I hope that this patch will be included in the daily Rockbox builds.

[Buschel]

It is (since r29186 + optimization with r29188).