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  • rohangc
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HD-AAC, Fraunhofer's new codec
Fraunhofer states that they have come up with a new codec called HD-AAC
that allegedly provides better sound quality than audio CDs.

My question is whether we need another lossless codec after all. Don't we have excellent codecs like FLAC and TAK which are both free and open-source (FLAC at least)?

Why does everyone and his grandmother keep ringing the death-knell for CDs? As far as I am concerned, I will never buy anything only in its digital form. If I can't hold it and touch it, I won't spend money on it.

That being said, I can't see any inherent advantages of this format over FLAC which is now becoming popular even commercially. This might be yet another thing that was dead even before it was conceived...

  • vlada
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HD-AAC, Fraunhofer's new codec
Reply #1
First of all, make yourself clear, what is the difference between codec and format. I know most people are confusing it, but it is very important to distinguish between the two terms.

http://en.wikipedia.org/wiki/MPEG-4_SLS

The advantage of this format is it's compatibility with AAC-LC. It is a hybrid compression like Wavpack. The format is an ISO standard. It's not just another useless proprietary thing.
  • Last Edit: 29 January, 2008, 01:05:08 AM by vlada

  • skamp
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  • Developer
HD-AAC, Fraunhofer's new codec
Reply #2
Fraunhofer states that they have come up with a new codec called HD-AAC
that allegedly provides better sound quality than audio CDs.

It isn't exactly new. HD-AAC is just Fraunhofer's name for MPEG-4 SLS. And it supports high-res audio (24-bit / 96 kHz), which is *technically* better than audio-CDs (let's not get into the practicality of it please, it's been beaten to death already).

My question is whether we need another lossless codec after all.

It's not just lossless: in short, you can generate lossy AAC from a (lossless) HD-AAC file on the fly, without transcoding.

Don't we have excellent codecs like FLAC and TAK which are both free and open-source (FLAC at least)?

Neither FLAC or TAK (or WavPack for that matter) provide the aforementionned feature. Also, companies such as Fraunhofer are in the business of patenting codecs and licensing them. Why do you think there's a HD DVD/Blu-ray war going on? Licensing. Big bucks. Free Software is of no interest to them.

Why does everyone and his grandmother keep ringing the death-knell for CDs?

Because CD sales are down, and the recording industry is always looking for new ways to make more money?

That being said, I can't see any inherent advantages of this format over FLAC which is now becoming popular even commercially. This might be yet another thing that was dead even before it was conceived...

See above. On the fly lossy scalability is a pretty nifty feature if you ask me. That said, since it will probably never be usuable under linux (with free as in beer encoder/decoder and software support), I'll probably have to stick with WavPack, as far as I'm concerned.

Edit: reading vlada's post, and seing that there's a Free as in speech (lossy) AAC codec, I guess there's a chance for MPEG-4 SLS support on my platform of choice after all. I'm not holding my breath though - it might take years.
  • Last Edit: 29 January, 2008, 01:18:44 AM by skamp
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  • spoon
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HD-AAC, Fraunhofer's new codec
Reply #3
>The advantage of this format is it's compatibility with AAC-LC.

I see it as the disavantage, put one of those files on your iPod and 80% of your storage is taken up by lossless which it cannot even play!

  • Nick.C
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HD-AAC, Fraunhofer's new codec
Reply #4
>The advantage of this format is it's compatibility with AAC-LC.

I see it as the disavantage, put one of those files on your iPod and 80% of your storage is taken up by lossless which it cannot even play!
Or, a smart transcoder can save the portion / bitrate that you want and disregard the rest when writing a smaller file to put on your iPod.
lossyWAV -q X -a 7 -A 0.586740 --feedback 5| FLAC -5 -e -p -b 512 -P=4096 -S- ~= 314kbps

  • menno
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  • Developer (Donating)
HD-AAC, Fraunhofer's new codec
Reply #5
>The advantage of this format is it's compatibility with AAC-LC.

I see it as the disavantage, put one of those files on your iPod and 80% of your storage is taken up by lossless which it cannot even play!


Not really.

When the SLS file has a LC AAC "core" (it doesn't have to, but I can't really think of a use-case where pure SLS makes any sense), this core data and lossless reconstruction data (SLS) are stored in 2 separate MPEG-4 tracks. Creating a pure LC AAC file is as easy as deleting the SLS track from the MP4 file.

So the idea is that tools (like dbPowerAmp) don't copy the whole SLS file to the iPod, but only the AAC track. You will have your lossless file on the PC and a pure LC AAC file on your iPod.

The pure lossless compression is not as good as the best out there, closer to one of the worst, but it beats everything when you count in the space required for keeping a local 128kbps (or more) LC AAC copy on your drive.

  • Garf
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HD-AAC, Fraunhofer's new codec
Reply #6
Edit: reading vlada's post, and seing that there's a Free as in speech (lossy) AAC codec, I guess there's a chance for MPEG-4 SLS support on my platform of choice after all. I'm not holding my breath though - it might take years.


Because of backwards compatibility, you will have playback support already.

  • vlada
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HD-AAC, Fraunhofer's new codec
Reply #7

Edit: reading vlada's post, and seing that there's a Free as in speech (lossy) AAC codec, I guess there's a chance for MPEG-4 SLS support on my platform of choice after all. I'm not holding my breath though - it might take years.


Because of backwards compatibility, you will have playback support already.


Yes, but probably only for the lossy part.

  • skamp
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HD-AAC, Fraunhofer's new codec
Reply #8
And it won't do me much good if I can't create the files myself (unless I download them illegally from P2P networks).
See my profile for measurements, tools and recommendations.

  • Garf
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HD-AAC, Fraunhofer's new codec
Reply #9
The idea is of course to buy them from a legal music store.

  • skamp
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HD-AAC, Fraunhofer's new codec
Reply #10
Is it? Maybe that's how Fraunhoffer wants to push it, but I'm only interested in the codec. And if the Free Software world ever gets playback support for it, surely there will be an encoder available, if only a reference encoder. Wake me up when that happens :-P
See my profile for measurements, tools and recommendations.

  • darkbyte
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HD-AAC, Fraunhofer's new codec
Reply #11
I hoped for Fraunhofer's HD-AAC encoder to show up in Winamp sooner or later but still nothing. 
I wonder why mp3HD has a reference encoder and decoder available but nothing for HD-AAC (well, this is not completly true because MPEG-4 SLS has a reference encoder and decoder). Does Apple or some other company grabbed the rights to roll out the technology first?
  • Last Edit: 23 August, 2013, 03:52:56 PM by darkbyte
WavPack -b4x4hc
Opus --cvbr --bitrate 256 --framesize 5