Recently I've encoded several hundred files using "Nero 6" HE-AAC (64 CBR), in the hopes that I could playback on an I-Pod.

I am reading some conflicting information in the threads about I-Pod supporting LC-AAC only!

I haven't yet purchased the portable music player, but have lots more encoding to do. Should I be starting the project over using LC, and is CBR appropriate or should I be using VBR - and is there a prefered bi-rate?

Help is much appreciated!

I'm not sure about HE-AAC support for the iPod, but AFAIK VBR is always perferred over CBR with Nero AAC, just as it is with almost any other audio codec out there.

The iPod doesn't support HE AAC as of yet.

Are there any sample HE-AAC files anywhere I could use for testing? Just some samples or something. There could be a way, sort of thing.

http://rarewares.hydrogenaudio.org/rja/41_30sec.mp4
http://rarewares.hydrogenaudio.org/rja/Bachpsichord.mp4

I don't think 41_30sec is a good example of 56kbps AAC-HE quality at all, or of any other codec at that bitrate. That's a killer test sample for 128kbps...
It's rather showing how AAC-HE sounds at worst.

I think that Otto42 just wanted to see if he could make it work on the iPod, so quality shouldn't be a huge issue for a test like that, at least thats how I understood him.

Yes, that's all I wanted them for. And here's a shocker: They work just fine on my iPod.

Assuming that 41_30sec.mp4 is indeed an HE-AAC file, then yes, the iPod plays HE-AAC perfectly well.

What I did:

1) Renamed the file to .m4a. Probably not required, but I did it anyway.
2) Drag/drop the file into iTunes. It added it to my library, but didn't find any tag info in there. I didn't much care anyway. I noticed right away that iTunes had no problem playing the file.
3) Synced the iPod (30 gig, 3rd gen, dock connector, running 2.1 firmware)
4) Unplugged the iPod, plugged in headphones, found the song (in my "new stuff" smart playlist), hit play, heard music.

Doesn't really get much easier than that.

Edit: Here's a weird thing though... iTunes stops playing the 30 second clip at about 16-17 seconds into it. The iPod, however, plays it all the way through. Odd, that.

Do you actually get the HE part?

HE-AAC is backwards compatible with LC-AAC, so they should play, but not at full quality.

HE AAC files should play in an iPod, albeit only the "low" encoded portion (say 22kHz instead of the normal 44.1 kHz). The "SBR" portion (high portion) is ignored, so playback quality won't be at normal HE AAC levels on an iPod. It is the same quality you get when playing through WinAmp 5.02's using its native mp4/m4a player/muxer (i.e. without Menno's MP4 plugin).

Well, I probably just don't have the ear to tell the difference actually. I plugged the iPod into the stereo and switched back and forth between the iPod's rendition of the file and Foobar's rendition on my laptop (going through the same stereo), and I can't hear any obvious differences between the two. But I may simply be missing it.

Strange you can't hear a difference between Foobar2000 and the iPod on playback of HE AAC files. That is... unless Apple started supporting HE AAC native playback support in iPod/iTunes without telling us

Heheh.. Well, I'm not saying they did, but I can't personally tell any difference. Of course, I don't have the best hearing in the world either. And it's not like I'm doing blind testing or anything here, I just set it up with a quick connection and switched back and forth for a couple minutes. Unless it's a *really* obvious difference in quality, I probably won't hear it.

You would definately be able to tell the difference, it is quite profound. Try playing the HE-AAC files back in Winamp (if you have it) with the default AAC decoder.

Edit: It is a VERY obvious difference

I think it should be really obvious. The frequency bandwidth without the SBR part is something like 9khz...

I'm pretty sure it plays at 22kHz sample rate in this case . . . . still very obvious.

Okay, I can tell the difference between Winamp and Foobar playing that same file, after switching back and forth quite a bit. The difference, however, isn't that much, IMO. The only real difference I can really find is that there's a very much "crisper" sound when playing with Foobar, after I mess with them both to get the volumes to be about the same.

Anyway, now that I know what to listen for, I tried the iPod and iTunes again. iTunes still doesn't play the thing properly, but the section that it does play sounds closer to the Winamp rendition of the file, to me. The iPod plays it fine, but yes, it's closer to the Winamp rendition.

But the difference is anything but "obvious", in my opinion. It's very minimal, at best. The cymbal crashes have a slightly different kind of ring to them, and that's really about it as far as I can hear. However, like I said, I don't have the best hearing either.

Anyway, I didn't mean to be doing quality comparisons. From the first few posts I was under the impression that these types of files wouldn't play at all on the iPod. They do play, but appearantly at a lower quality. That's all I really wanted to know.

Edit: Regarding file extensions.. If you leave it as "mp4" then iTunes loads it just fine, but strangely won't transfer it to the iPod. If you rename it to "m4a", then iTunes loads and plays it and will transfer it to the iPod. Also, iTunes will do the volume scan when it's named m4a but not when it's named mp4. The Sound Check volume equalizing adjustment then takes effect too, and the difference is easily noticable.