I have the O2 digital music player (also known as the Siemens DRM Music player) which supports AAC+ (and AAC). The problem I have is that when I save a track in Nero 6.3.0.2, and tick the export to ISO 13818-7 AAC track it generates 2 files (*.aac & *.mp4) of the same size. The .aac file plays on the player and in realplayer10, but the quality is awful - real10 shows it as 3 kbps quality. It does this no matter what quality I select

What gives? How can I get the .aac file to encode/play at the quality I select

Thanks in advance

Does this device come with some authoring/encoding tool? I'd like to get some files encoded with it because I don't know what format and signalling this device requires.

Thanks for the quick reply. Sorry, there's no software with the player - it just appears as a removable drive in windows and you drag the music files on.

In the situation I described, the player (and Real10) will play the .aac file (poor quality), but neither of them will play the .mp4 file.

I should say that this whole scenario applies to LC-AAC files generated in nero as well as HE-AAC

Sorry I can't be more helpful

he-aac .aac files contain no info that the file contains he-aac afaik
so imho its really a bad idea to use he-aac not in .mp4 (as .mp4 contains such a he-aac flag)

i wonder that this player doesnt support .mp4? isnt .mp4 included in drm?

It doesn't appear to support .mp4 even if I take the .mp4 file and change the extension to .aac

I have tried mp4creator and have tried converting some itunes .m4a files to aac, but they won't play. The .aac file generated by nero is the only one that will play (on the player), but the quality is rubbish.

As for .mp4 support in the DRM, I guess this player has it's own different DRM

foobar contains some tools to do AAC<->MP4 conversion, not sure if that'll help you.

thanks for the tip, but no luck. Although both foobar and faad both produce .aac files from .m4a, they are not compatible with my player.

Real10 displays "aac 47kbps", so where the other 80 kbps (encoded itunes 128k)has gone I have no idea - the .aac file generated is the same size as the original .m4a file. The problem still remains:

Nero generates a sound file of the correct format (.aac) and size, but when played the sound skips, the reported song length constantly changes, and the quality is poor (2-3 kbps). Any chance of the Nero guys looking into this - I know you must have lots to do but if you could stick it on your list of things to look at, I'd be extremely grateful

Are there any other apps that will generate an iso stream from .mp4 / .m4a files?

I'd guess that Real has probably faulty sbr decoder implementation which doesn't cope correctly with implicit sbr files (.aac files with no specific sbr signalling (identification)). I don't have Real10 installed so can't test. But if Foobar plays the files correctly, then there's a problem in Real and you should bug them. Notice that foobar can also show different bitrate than what it actually is..