As the speculations have gone far enough by now (mystery coders and people reading the specs ), and with the release of the HE AAC Nero plugin coming soon, it is about time to announce that FAAD2 2.0 will include the Ahead SBR decoder source code.

It was already decided a while ago (need for players to play HE AAC files), but we decided to keep it a bit low profile.

FAAD2 2.0 is planned for release around the same time as Nero 6.0.

So, just a few weeks of even more anxious waiting ahead


Greetings,

Menno

(w00t) (w00t) (w00t)

Nice, I was just 9 hours ago earlier talking privately with Dibrom and said this would be in the best interest also for Ahead, that your sbr code was in FAAD2..
And now when I get back..

After listening to SBR stuff, I'm so excited!

Make no doubt that HE-AAC is absolutely stunning at 16-80 kbps.

I just hope the code or functionality makes it to a streamable form quickly.

Ruairi

I think that this is a very good strategy...

SBR decoder is very good, completely compatible with the standard, and what's more important - it will be publically available months before the official reference software

Wow, this is good news.

Another Excellent news!
I will remember this Week all my life!

I wonder if CoreAAC will just need a recomplile with the new FAAD...

/me stop encoding WMAv9 22kbps and wait for FACC+


No doubt tat it will kick WMA @ 22kbps

For a sec I misunderstood it's the SBR encoder that will be given away. That would have been real good

Since it uses the MP4 AudioSpecificConfig, it seems that there is no problem with initialisation of the SBR AAC file. Although the output of 1024 samples per frame seems to be hardcoded, which is not good.

Menno

The encoder (FAAC) will not have the SBR code. Only the decoder. Encoding should be done with the Nero codec.

And it's AAC not ACC

Menno

well, I don't get some things.

if the aac + (with SBR) encoder is completely compliant to the AAC specs, why do AAC-spec compliant decoders like FAAD have to be modified to play the SBR part?

or is the plus (+) in aac just an addition to the specs like it was the pro in mp3?

will there be a sbr in other encoders (quicktime, sorensen) as well?

and will faad be able to play those at well?

Is there a way to know the maximum number of sample allowed per frame ?

Regards
Toff

AAC+/AAC-HE is compliant with the MPEG4 specs. Yes, the SBR part was added to the MPEG4-AAC specs..

Only Apple and Sorensen know when they will possibly add AAC-HE support. They haven't announced anything yet. So it seems that Ahead is starting the AAC-HE game first.
My guess is, that since Apple is interested in QT streaming and AAC-HE is very useful at lower bitrates, it will be added sooner or later.

As far as I understand, SBR was an addition to the spec, so SBR is decoded with new specs-decoders and just ignored by the old. It works the same like in mp3pro, just that SBR never become standard. Maybe it´s similar like MPEG-2 multichannel, the files look like normal MPEG-1 and only special decoders can output multichannel, all other decoders play stereo.

If there are other SBR-standard encoders FAAD2 should be able to decode them, too, like in DRM (Digital Radio Mondale).
If it works identicall in AAC+ and mp3pro, could it be possible to add SBR decoding to MAD, so that there would be an open-source mp3pro decoder?

No. The AAC SBR specification is different from the one used in MP3.Since there are no specifications on MP3pro, the only solution would be reverse-engineering.

Hello Toff,

The absolute maximum is 2048.
You can know the actual number of samples in a decoded frame from the frameInfo structure returned after decoding a frame (samples member).

Menno

OK thanks, I will correct this in CoreAAC
I can't wait to listen to AAC-HE (w00t)

just found an interesting (not to technical paper) that deals basicaly with AVC and mentiones AAC + sbr as transparent at 60 kb/s.

http://www.harmonicinc.com/view_csd_folder....cfm?FolderID=2
(scroll to bottom)
the pdf is named:
'AVC+AAC The Next Generation of Compression - Technical Version' (page 10)

any news if the sbr source will be included into faad2? are the license issues resolved?

or will there be some sort of faad3 released under a new license?

(Sorry to be OT) @Menno: How would you find the number of samples without faad/decoding the frame? Could you do it from the ADTS header?

-Nic

is the nero/faad2 implementation of aac-he 100% compatible with AacPlus of CodingTechnologies (http://www.codingtechnologies.com/products/aacPlus.htm)?

and how fun that would be :-)
but illegal i guess?

Nero/faad2 implementation is 100% compatible with the ISO/MPEG-4 High Efficiency AAC specification. Latest versions of the aacPlus encoders are also compatible with the same specs, so I would say that we are compatible

Now serious, we did a lot of interop tests with the CT decoder, and everything works well.

so no news according to sbr in faad2 to your knowledge, ivan?

Well, faad2 with SBR will be released soon, I don't know the exact timing details as Menno is on holiday

great to hear that this idea wasnt abandoned by ahead (after all these license discussions) do you know which license will be used - gpl?

hell, call menno back home, we need him here

AVC = SBR?

No, black box reverse engineering is legal.

But you would still have to license their technology.

AVC = Advanced Video Coder. Also known as H.264 and H.26L