I'm just starting to explore AAC, so far im convinced that it is better/will be better than mp3. But I still have many questions.

1. Are AAC files encoded from .wav files? If .wav isnt the best way to encode from, what is?
2. What is the difference between the .AAC extension, the .mp4/.m4a extensions, and HEAAC and LCAAC? Is there a difference? If they are the same thing, which one should i use?
3. What encoding program and encoder to use? What are the best settings for the encoding program?

Basically what im asking is to walk me through on how to make AAC files and the best way to do it. I've looked at "Guide to iTunes-compatible Nero-encoded AAC" but dont feel fulfilled.

You can encode to AAC from all formats, but in practise the encoder you are using will limit the possibilities. Using Nero or FAAC with foobar for example will allow you to encode all of the formats that foobar supports to AAC.



Files with an AAC extension are in raw format, meaning they can only contain the audio data. MP4 is a container format and can contain other things besides the audio. Since MP4 is acutally more efficient, i.e. giving you smaller files than .AAC, I would always recommend its usage.

mp4/m4a is just a matter of the extension used. (Actually m4a requires some header fields to be set differently but in practise everybody except for iTunes and Nero seems to get that wrong)

HE-AAC is a newer version compared to LC-AAC, which significantly improves quality at bitrates <= 64kbps. For low bitrates use HE-AAC, for high bitrates use LC-AAC.



For HE-AAC Nero is by far the best. You can use one of the VBR presets. For LC-AAC iTunes may also be interesting, though it only supports CBR/ABR.

Check out http://www.rjamorim.com/test/aac128v2/presentation.html for a comparison of the latest AAC encoders available.

If I'm not mistaken, iTunes and FAAC are both free, and you can also experiment with Nero's AAC encoder for a 30 day trial (I believe). I've used both iTunes and Nero myself and can definitely recommend them both as very strong choices. (iTunes does not support HE-AAC, however)

You can also find some useful information at www.m4a.com.

Hope that gets you started!

hi, there!



well, in the last public listening test, mp3 (lame) showed that it is still on par with mp4:



i'd suggest that you take mp3 in consideration, too.



of course you can encode any lossy format (e.g. mp3/mp4/mpc/what ever) from wav with the right encoder. if you have ripped the wav's already i'd recommend that you use foobar, a really pleasant audio-player which can be used for encoding as well. get the special installer from here

or, if you need something easier to use, you can use dbpoweramp music converter, grab it here.



that depends on what your plans are.
do you want to rip all your cds only once and want to have a lossless music archive on your computer, then you should use a lossless encoder for storage. the lossless files are exactly identical to the original wav's but only need around half of the original size. have a look in the lossless section of HA.
you can also encode on-the-fly directly from cd, if you like. use dbpoweramp or EAC for this - browse forum, therefor we have it!



the .AAC extension is for the raw data of the file, the .mp4 (apple names it m4a) extension is for the container wherein the aac data lies.
in most cases you will need an mp4/m4a file,
especially if you want to use them with an iPod or something similar.
browse AAC section on this board for more info on that.



LCAAC stands for low complexity-AAC. i do not know what this exactly means, but that profile is used most times, i guess.
HEAAC is a technology which is proposed to reach good quality with very low birates.
it works similar to mp3pro i guess. somebody might correct me!
it is not supported by any/many portable players at the moment.



it doesn't really matter which extension you use. i advice you to just use .m4a and, if you should need the raw-data, there are ways to extract that without a loss.



if you don't have nero 6 installed and don't want to pay for a AAC codec, you should use iTunes' AAC codec, which did very well in the last listening test. it is supposed to be better than ahead's one at present.
to rip your cds you could use iTunes directly which is, at least for scratched cds, not recommended.
you can first rip the wavs with EAC for example, if you want most exact results, and then use dbpoweramp to encode to mp4 via quicktime. therefor iTunes (4.2) has to be installed. use 4.2 because the newer 4.5 version has some encoding issues.
there is a guide to do the same with foobar. browse forums!
or you can use dbpoweramp for ripping, too!



as i already said, iTunes performed better in listening tests than nero's aac codec. so, use this.
for live-albums you should use nero or FAAC because of their capability of gapless playback support.

the setting depends on your needs.
if you want the best filesize/quality ratio i'd use iTunes at 128kbps, which is already transparent for many, for use with your iPod for example.
it really depends on your needs. do you want to listen on a portable in noisy environment, or at your pc / stereo? how important is filesize for you? can you distinguish a 128kbps file from the original at all? there are few things to consider, you see.
if you use nero, try "streaming"-preset. that's all i use with my iPod.

edit:
well, somebody was faster......

wow I've never gotten so many posts in such little time. I appreciate it . well this was very helpful. The way i want the filesizes are the best quality, nothing else but i want to encode them to 192kb/s. I plan on listening to them on my pc. Now that i know more this leads me to another question: Can you encode straight to .m4a (from .wav) ? Is this the best way to encode or is there a better way?

if you just want to listen to them on the pc and you have enough space, you can try a lossless codec like flac.

but you want to go with m4a, right? okay.
there are different possibilities:
a) just rip with iTunes and let iTunes encode.
b) rip with EAC and let Quicktime encode the WAVs via dbpoweramp or foobar as mentioned in my last post.
c) rip directly with dbpoweramp and encode on-the-fly.

comments on:
a) that's okay for me. but with scratched CD's you might get problems.
b) good but circuitous, but if you use foobar or dbpoweramp you are able to choose between FAAC, Nero, or Quicktime (BTW iTunes uses Quicktime's encoder)
c) best method if you like to chose another codec or want to have better accuracy/error detection as with iTunes.

if you just want to use iTunes-codec and don't care about quality of the rip (i.e. accuracy) and don't need gapless-playback of the resulting files - use iTunes!
i use iTunes personally to rip new (unscratched) CD's when i don't need gapless-playback. i havn't had any problems with the ripping-quality yet.
if i need gapless-playback, i rip with dbpoweramp and let it encode the CD into Nero-mp4.
with scratched CD's i use EAC and encode the WAV's with the encoder of choice.

My personal preference is to rip to a lossless codec (e.g. FLAC, MA's, etc.) with EAC. I can then transcode these lossless files to whatever format I want (Vorbis, MPC, AAC, etc.) and, if a codec is ever significantly improved down the line (which is very likely with any of the major lossy codecs these days) you can just pull out your lossless backups, and transcode your library again without having to re-rip anything.

I think ripping to lossless and transcoding is a great solution. It's easier for you, and your optical drive!

Hear, hear.

I too rip to a lossless codes (FLAC).

The world in which we are living is changing too fast for me to re-rip my entire CD collection everytime a major encoder improvement comes along.

BTW now that iTunes does scripting on Windows I can automatically convert tracks from my FLAC library into iTunes AAC from a perl script I have written.

exactly! that's what i would do, also.

but if he doesn't need lossy formats for portable devices and also doesn't want to fill up his HDD, he's on the rigth way, i guess..


edit:


how does such a pearl-script work? could you upload it for testing? that would be really nice!


2ne edit:


oh, you don't have to upgrade! i think most codecs are nearly transpatent @ 192 kbps. there will be not much improvement for the common listener..

That's certainly true. Ultimately, I think it depends on how much of an audiophile you are. The situation I had in mind when I wrote this was the recent development with auTuV b2 replacing the standard xiph.org enconder at quality levels below 5. To most end users this probably isn't that big a deal, but for those of us who are bent on getting the biggest bang for your buck (most of HA's members I would gather ) it's definitely worthwhile to re-encode.

This discussion is actually somewhat relevant to the original post, because I believe that Nero's AAC encoder has undergone significant development since its last release, and many people are holding off from encoding their libraries to AAC until this newest version is released.

Just something to bear in mind.

you are absolutely right! i am tracking this current discussion about ouTuV as well, but that's more like a foible.. i mean, i don't have those "golden ears". it just makes a lot of fun! for me, nearly every recent codec is transparent @ 192 kbps. the only thing that's interesting for me is transparency at the lowest bitrate possible.
but surely it depends on your taste, your equipment, your foible, your ears or what ever.

edit: typo

Here is a Perl iTunes example. It adds Brain Damage to iTunes, using whatever preference is set. (soundcheck / copy file to music folder according to your settings).




Perl is a programming language available for Unix, Mac, Windows, Linux etc.

I use Perl 5.8 available from activestate:
ActiveState Perl

Furthermore the Apple iTunes OLE interface is built-in to iTunes 4.5 and the documentation can be found here:
Apple iTunes scripting SDK

Another example script I made is itunes-rating-from-musicmatch that scan through all tracks in iTunes, read their Music Match rating from the MP3 tags in the file and if applicable, set the iTunes rating accordingly.

thank you for that!
it's a pitty that i don't have much of a clue regarding those stuff...
that script is for mp3? did i gather this right?
what does Brain Damage mean? is this a new "preset" within iTunes?
too bad, that it only works for iTunes 4.5 (i'm using 4.2 at the moment because of the better AAC codec).

Is there gapless playback if you rip with EAC to .wav and then encode the file with Foobar?

yes, but is doesn't matter which program you choose AFAIK. gapless-playback support is a matter of the codec that you choose, namely Nero-AAC or FAAC.

I'm real confused on how to set foobar up, i trust foobar the most so i want to use it. How would i encode the .wav in foobar with the Nero codec?

I wish the Itunes codec had gapless playback . It's the best quality as shown here:

Please don't forget the previous post. Just making sure no one skips it . I also need to know how i can write tags to the .m4a files which will also be able to be read by Itunes.

you need nero 6 installed to use their AAC codec and for iTunes it is the same, you need it on your system.
for iTunes AAC encoding via foobar just read on here
for using ahead's AAC codec you need foo_nero. get it here..
to set it up, go to foobar preferences, then go to diskwriter sub-menu.
on the right side choose under the output presets the nero codec over the pull-down menu. that's it for now.
on the left side you can also see the nero diskwriter component. when you click on it, the configuration menu opens on the right side. choose your desired profile.
to start encoding, just load all WAV's into the foobar playlist, highlight them - right cklick - convert... here are the options "run conversion". you can choose this and foobar will start converting or you can choose "settings" to set up another encoder or another encoder profile etc..



just load your m4a's, highlight them and choose "properties". now you can alter tags for multible files. for altering a single tag, just choose only one file, highlight aso.
the tags, that will be applied are iTunes compatible.
BTW if you load the WAV's into a playlist and get the tags via freedb, the (hopefully) correct tags will be applied. in fact not to the WAV's because WAV files cannot be tagged correctly but the tags will be written into the foobar database and will be kept during encoding, that means the encoded m4a's will have the same tag-infos as the input WAV-files.

for a foobar guide read on here.
and here

Does Itunes allow gapless playback?

No gapless with iTunes....

K thanx . I guess i should've already known that but I'm making sure.

Can someone explain what the options in the Nero encoder are and what they are for? They are: "Create Hint track (for streaming server)", "Mix audio into existing video .mp4 files", "Export ISO 13818-7 AAC Track", and "Downmix to mono". Also is there a way to encode to mono for cds which are in mono instead of stereo?

Also please explain all of the options to mess with in the diskwriter submenu in foobar.

the only thing you have to tick is "mix audio into video .mp4 files".
that's what I only use at least.
I cannot give any comment on the rest but I know that if you tick "use PNS..." the files won't play correctly on the iPod... out of experience.



please do some research on your own.
I gave you some links to foobar How-To's and documentation. there is also a foobar-sektion on this board. try there, do a search!

edit: typo

okay, here you are:

output directory:

here you choose the output directory

output filename formatting:

here you can choose, how the files should be named. in addition you can specify to create sub-directories for the artist for example.
i use this "%ARTIST%\$num(%tracknumber%,2) - %title%"

output presets:

here you choose, which encoder diskwriter shall use.
in your case u'd choose "Legacy 0.7 Output support: AAC (Nero)" [or similar].

output bit depth:

here you choose the resolution of the created files. you should leave the preferred bit depth @ 16 in most cases.

Dither: hmm, that's difficult. try a search on thios, or perhaps someone else can explain. - i don't use it anyway.


processing:

just tick "use replaygain" to keep all your encoded files on a comparable loudness. this only works if you have replaygain applied to the source files.

use DSP:
everything you have defined under the DSP-Manager sub-menu will be applied to the encoded files.

cannot give you any comments on the rest, because i don't have a clue.


edit:

for an explanation of dither take a look here (taken from the FAQ)

K. Well thanx. I REALLY appreciated you guys help. I have figured some out on my own so i'm fine now i believe . Take care