I've been encoding large parts of my music collection to AAC -q 0.2 (~48kb/s) using Nero's free encoding with foobar.

When I played the files back in foobar2000, I was very impressed with how good they sound! I couldn't believe my ears. I happily encoded a few hundred CDs to this codec, but now I've discovered that foobar is the only player that seems to play them back properly. Winamp and iTunes both identify the files as LC-AAC which they are not.

I know that winamp for sure should support it, but what's the issue here? Why would only foobar and nero work properly with nero's aac files? Is there something that can be done to make these new AAC files work, or at least encode them in such a way that they will have greater compatibility?

In other players that don't properly support the files, sometimes you get a consistent clicking, or weird noise that shouldn't be there as well. Not very nice sounding.


This may be another issue altogether, but I also have discovered that very low bitrate aac encodes (like ~42kb/s) seem to have major issues playing back (big glitches, skips, pops, etc) in foobar2000 0.9.2. It sounds fine in other players, generally... I dunno. This happens when I encoded flacs to AAC using q 0.17 or so in foobar 0.9.2. Not sure what the problem is... my 48kb/s files sound okay in foobar2000.

Some HE-AAC encoders will identify the MP4 as AAC LC even though it is not, as some players (particularly the iPod) will outright refuse to play HE-AAC (even though it is backwards compatible).

Do the files sound the same in Winamp? The decoder should figure out that it's HE-AAC after a frame or two (implicit signalling).

No, they absolutely sound like crap.
Here's a sample:
http://www.fullspec.ca/music/gettogether.mp4

edit: I just noticed that you're a winamp developer! heh...
Why won't Winamp identify this as HE-AAC? Foobar does it correctly.
Is there some kind of header that Winamp requires, or else it defaults to LC?

Winamp plays it just fine

Huh? That's weird... there's definitely a difference in sound quality on my computers between winamp and foobar.

Do you have a special 3rd party decoder installed in winamp or something?

edit: Aw... I dunno what I was thinking. I had another listen, and I think it's the same in Winamp. I think what it was is that some songs, when I don't listen too closely, sounded pretty good to me, but if I listen really closely, I could hear artefacts. I guess I didn't bother to ever listen closely with foobar, but I did with the other players. The weird clicking and artefacts in iTunes were definitely not in my head though.

edit2: I'm playing it with virtualDJ now, and it definitely sounds worse in VirtualDJ. I wish there was an easier way to abx it. For AAC playback, virtualDJ uses the General Quicktime Audio Decoder. iTunes most likely uses the same, so I'm wondering if I can use CoreCodec, the General Windows Media audio decoder or something like that instead.

Maybe I'll play around a bit.

No I just downloaded the latest version, installed it, plays fine. Didn't listen to more than 5 seconds though.

I checked the output, winamp definately decodes the SBR part.

Hrm... I can play it in Windows media player, but there's a soft click every second... kinda sounds like a record with a scratch in it.

I'm pretty sure that WMP doesn't do SBR either... there are no high frequencies, it sounds like being played through a phone. BTW Menno, how do you actually check that?

Set output to diskwriter and open the file in a wave editor

WMP doesen't have an MPEG-4 decoder AFAIK. You need to install a DirectShow system decoder. I would suggest you to try FFDShow. It definately plays AAC-HE/PS.

Well, it must have some kind of encoder, but it's likely that I installed it myself. I'll try installing FFDShow, or k-lite or something like that. Maybe if I do that, I can use the WMP General Decoder and it'll actually work properly.

Alright, I played around with virtualDJ a bit, and I uninstalled a bunch of crap, and installed several codec packs and stuff.

I tried installing the AAC core codec, but it doesn't seem to work, unfortunately. When I installed 3ivx, it sounded beautiful in Virtual DJ using the General Windows Media Player decoder. CrApple's Quicktime decoder sounds pretty bad... I can sync two songs up in virtual DJ, the same file decoded with the different decoders, and the difference is night and day.

I dunno if I wanna pay for 3ivx though. I guess it's only $7 for the decoder, but if something free works just as good, might as well use that. It's probably less bloated.

edit: Ah, all I had to do was change the extension to aac and it works with the CoreAAC codec. (I also installed a different version from free-codecs.com).

I don't really wanna do that though. For one thing, foobar2000 doesn't want to load it anymore, and for another, Virtual DJ doesn't read the tags at all now. I'm surprised that it did in the first place, actually.

Why not check it in WMP by using the Orban plugin?

I tested your sample with ffdshow (both realaac and faad2 decoders) and SBR part is there. No problem also with CoreAAC for playback and SBR decoding part.


edit: rename a mp4/m4a file to raw aac doesn"t make sense.

Okay, I think I'm just gonna use 3ivx, because it just works. I really don't know if I need to pay for it or what... only $7 maybe, for the decoders.

It's odd that I can play back the file when I have CoreAAC installed.. but yes, it doesn't make sense to rename MP4 to AAC, but why is that the only way that it will work for me (in Virtual DJ, which I have set to use the General WMP Decoder)? I now kind of understand why Virtual DJ doesn't read the tags if I rename it to AAc though... there's no container read, and thus no tags. Also, I think foobar won't play back an aac because it naturally assumes there's no container, and something breaks.

Is there something else I need to install to get WMP working with the MP4 container, maybe?

mp4 parser

<snip>

Try Haali's Media Splitter, by installing it, you'll also get support for OGM, Matroska, MPEG TS and uncomplete AVIs. Then connect Haali's splitter with FFDShow and everything will work fine. Basically these two programs are all you need to playback 99,9% of standard media files (I don't consider ASF/WMV, QT/MOV and RM a standard formats).

You don't have to pay anything, both programs are opensource (GNU/GPL). And you won't get anything better then this.

At first the in_mp4.dll that came with winamp would refuse to allow decoding of sbr, this has since been fixed in the newer versions.

You can also use the CT mp4/aac decoder for winamp instead http://www.rarewares.org/aac.html

*I do not recommend 3ivx

Any particular reason you recommend against 3ivx, game playa?

I'll try the Haali's Media Splitter thing in a bit... for now I've got things working and sounding great wit h3ivx, but I want something opensource or whatever, because I'll probably have to encourage a lot of people to adopt this setup, and anything that is too complex or costs money will be a big turnoff.

Thanks a lot for the tip Vlada. It works great. No commercial 3ivx now, and it sounds wonderful and works with the MP4 container properly. I'm a happy guy with little tiny music files