Still confused about all kinds of AAC..

[puntloos]

What does and what doesnt the ipod accept AAC-wise?

Does it accept:

.mp4 files?
.aac files?
.m4p files?
.m4a files?

Frankly I don't know the differences between the above, I think MP4 and AAC are 'raw' streams while m4p and m4a are some DRM container thing but don't quote me on that.

Secondly does the ipod accept

AAC LC (I think it does.. Low complexity easy to decode)
AAC Main (No idea.. Main system, harder to encode, probably better quality)
AAC HE (I dont think so but just asking.. High Efficiency has some tricks (SBR) to make the most of low bitrates but I hear that over 96kbps SBR is not a good choice anyway..)

Thirdly:

does it like VBR aac? Im not even sure if there is such a thing since the distinctions between ABR, VBR and CBR seem to be a bit murky with AAC ..although I get some noises here and there that quicktime 'only encodes CBR aac', and that in the future..

-sigh- so confused so confused.

And finally any informed opinions what the best encoder is to use right now?

[ech3]

Regarding the first part of your question, the iPod is looking for either .m4a or .m4p. Or at least those are the only ones Ephpod will allow me to use. I'm still not sure of the differences between all the AAC file extensions, but I think .m4p has a DRM wrapper and .m4a does not.

When I encode .wav files with Quicktime 6.3, it creates .mp4 files which I rename to .m4a and add them with Ephpod.

I haven't used anything yet that creates .aac files.

About your second and third questions...I don't really know what the iPod will support but when I encode with Quicktime it specifically says the resulting file will be AAC Low Complexity. There are no options for any other type and no options for VBR. Maybe a future firmware release will support those features.

When I looked into AAC I did a bunch of net searching and it appeared that Apple's own Quicktime was rated very highly for its AAC encoding. I've also read that they used Quicktime for encoding the songs in their iTunes Music Store. So I bought Quicktime Pro for $30. The free download doesn't encode.

My main complaint with it is that it has no way of batch encoding. You have to encode one song at a time. If you have a Mac, you can use Applescript but not on Windows.

Because I have such a large CD collection, I decided (after some listening tests) that 128K AAC is good enough for me. The sound quality is much better than mp3 at that bitrate and the small compression will allow me to store 450 - 500 hours on my 30G iPod.

[puntloos]

Indeed, on the hydrogenaudio forums basically it sid that with its test settings (I think it was somehow CBR only because 1/ this gives fair results, every coder has the same amount of bits per block but also 2/ because apple quicktime and perhaps others didnt support anything better.

And even though I have 20Gb which is just fine I think I will recode all music I have to say 128kbit.. saves 40% space..

Eek but thats a daunting task so I NEED NEED NEED batch processing. Anyone reccomend anything that does both batch processing and doesnt rate too low? Or any way to use quicktime in 'batch mode'?

[BigIzz]

I just posted this in another thread yesterday, maybe it will help. I've been using Nero to encode 128 AAC, I'm pretty happy with it.

I've encoded 150 or so of my CDs in AAC and I have had excellent results so far. This is what I've been doing:

1) ripping CDs to .wav files with EAC
2) after ripping about 20 or 30, I encode to AAC with Nero 5.5whatever and the AAC plug in. This is very time consuming (I think it is my 3 year old P3 700), so at night I just load them all up and encode while I am asleep.
3) The next morning, I wake up and using a cheap shareware thing, rename the .mp4 to .m4a en masse.
4) I load the songs onto my iPod and name them all manually, which isn't too bad (group name the Album, Artist and Genere, then just delete every part of the file name except the titile and enter the track number.)

I haven't found a way to tag them yet, and unfortunatley EphPod dosen't recgonize the tags if I delete them, so I'm going to need to figure out a tagging solution one of these days. I make sure all the file names are in the same format though. The only downside is it is very time consuming for me, but thankfully I am currently unemployed so I can do it all day.

If anyone figured out a tagging solution, please post it. I hear foobar masstagger worked but it dosen't for me.

[puntloos]

Originally posted by BigIzz
I just posted this in another thread yesterday, maybe it will help. I've been using Nero to encode 128 AAC, I'm pretty happy with it.

I've encoded 150 or so of my CDs in AAC and I have had excellent results so far. This is what I've been doing:

1) ripping CDs to .wav files with EAC
2) after ripping about 20 or 30, I encode to AAC with Nero 5.5whatever and the AAC plug in. This is very time consuming (I think it is my 3 year old P3 700), so at night I just load them all up and encode while I am asleep.
3) The next morning, I wake up and using a cheap shareware thing, rename the .mp4 to .m4a en masse.

Ah good.. that means that the ipod also accepts .mp4 (at least: what is IN there, i.e. doesnt choke on the actual data... renaming is easy yea)

4) I load the songs onto my iPod and name them all manually, which isn't too bad (group name the Album, Artist and Genere, then just delete every part of the file name except the titile and enter the track number.)

I haven't found a way to tag them yet, and unfortunatley EphPod dosen't recgonize the tags if I delete them, so I'm going to need to figure out a tagging solution one of these days. I make sure all the file names are in the same format though. The only downside is it is very time consuming for me, but thankfully I am currently unemployed so I can do it all day.



lol, can I send you my CDs so you do my work too? :)
Anyway hmm yeah I can see that AAC taggers are quite sparse still, and it wouldnt surprise me too much if ephpod simply doesnt have perfect AAC support either.


If anyone figured out a tagging solution, please post it. I hear foobar masstagger worked but it dosen't for me.

One last question: what settings (if any) are you using for nero? Do you have choices other than 'bitrate'? Are you encoding using the LC, Main or HE models? Does the ipod accept all? Any idea?

thanks for the reply!

[BigIzz]

Well I tried ripping directly from CD but the quality was very poor, so that is why I rip to *.wavs first. It also allows you to load up a group of a few hundred wav's so the computer can encode all night. Again, it does take a very long time, at least on my acient machine. I did about 35 CDs last night, started them at about 3:30 am and they didn't finish until about 11 am. I imagine on a fast machine it would be a lot better, although I wouldn't know.

Nero gives you a lot of options. You can encode at constant bitrates of 16-448 kbs, 7 quality options of vbr, a fit to size option where you tell nero how big you want the file to be, encoder quality, AAC profile and a few other options im not sure what they are.

In terms of quality, I rember reading a comparison on Hydrogen forums that Nero wasn't the best but it wasnt the worst encoder either. I was very impressed at the quality (128kbs) when I first heard it, although now I'm a little less impressed, it may be simply because I'm nuerotic and looking for problems and would hear them even if i encoded at 448kbs.


Overall, I'm happy with this method, although I'm sure there are better ways to do it (who knows how much better though). It took me the week before I got my iPod to figure this method out so I spent enough time trying to figure it out.

You may want to check out Nero6, which just came out. I've heard it is better and supports tagging better. You may be able to find the AAC plug in for 5.5x at places beyond the Nero website, if you get what I mean.

[puntloos]

I will definately take a closer look at nero then. one question unanswered :) - I hear nero supports HE encoding, does the ipod play this or is that one bridge too far?

[BigIzz]

I don't know, maybe someone else does?

[ech3]

If you're looking for a way of automating Quicktime AAC encoding in Windows, I read a forum on Hydrogenaudio where some people are trying to put together some Windows scripts to accomplish it. It sounds like they have it (mostly) working from within EAC. It extracts the .wav file then encodes it.

That's pretty cool within the context of one CD, but I'm hoping for a way of encoding a whole bunch of .wav files and letting it run overnight.

[puntloos]

Originally posted by ech3
If you're looking for a way of automating Quicktime AAC encoding in Windows, I read a forum on Hydrogenaudio where some people are trying to put together some Windows scripts to accomplish it. It sounds like they have it (mostly) working from within EAC. It extracts the .wav file then encodes it.

That's pretty cool within the context of one CD, but I'm hoping for a way of encoding a whole bunch of .wav files and letting it run overnight.

Hmm indeed, do you perhaps have an URL for me?

If it can be done with scripts perhaps one can also fool razorlame to think that the script is the lame binary.. razorlame as you prolly know is a GUI for lame which does allow you to explicitly specify the commandline for each wav or mp3 file you put in there... that'd work...

[BigIzz]

Originally posted by ech3

That's pretty cool within the context of one CD, but I'm hoping for a way of encoding a whole bunch of .wav files and letting it run overnight.

You can do that with Nero. Just go to File Econding under Extras (or something to that effect), load up all the files you want to encode and click go. You do have to get the AAC plugin (or plugin of whatever file type you want to encode).

[puntloos]

Yes but quicktime supposedly is the better codec :)