Difference between .aac encoders

[LonelyPixel]

After upgrading to the latest version I see there are two encoders for .aac files. Fraunhofer FDK and Fraunhofer IIS [Pro]. These names don't make much sense because the codec was developed (like MP3) by the Fraunhofer IIS institute (just a few km from here). But what is FDK and what is [Pro]? Which should I use?

[yamasakiross]

After upgrading to the latest version I see there are two encoders for .aac files. Fraunhofer FDK and Fraunhofer IIS [Pro]. These names don't make much sense because the codec was developed (like MP3) by the Fraunhofer IIS institute (just a few km from here). But what is FDK and what is [Pro]? Which should I use?

I also found it confusing. But from what little I know, it seems that the FDK was developed with Android in mind and is open source. IIS Pro is a company proprietary project. In my tests both are good, but AAC IIS PRO is superior. I even noticed the spectrogram of the files:

AAC FDK, 288 Kbps, 44.1 Khz, CBR


AAC IIS PRO, 288 Kbps, 44.1 Khz, CBR


ORIGINAL FILE, 48 Khz

The difference is small looking in the spectrogram.
I just don't understand why the AAC FDK has more bitrate options in both CBR and VBR than the AAC ISS PRO.

[iBypass]

Hello Poiko !

I was just about to create a new post with the exact same question ... I did verify the "encoder versions" page from the website but can't find any details about that ... so could you please specify what's the differences between the Fraunhofer encoders ?

Regards, iBypass

[LonelyPixel]

AAC FDK, 288 Kbps, 44.1 Khz, CBR

Well, if you flood it with bitrate, everything is good. My target is more around 64 kBit/s. I found this good enough for mobile use with Bluetooth earbuds. It's also a tradeoff to storage space.

[iBypass]

Well, if you flood it with bitrate, everything is good. My target is more around 64 kBit/s. I found this good enough for mobile use with Bluetooth earbuds. It's also a tradeoff to storage space.

That is not the question in the first place ...

We're asking Poiko to explain what's the actual differences between the Fraunhofer encoders :

"Fraunhofer FDK" and "Fraunhofer IIS [Pro]" ?

Regards, iBypass

[LonelyPixel]

I've sent them a question through their contact form. Maybe it helps. I'll let you know if I get an answer directly.

[poiko]

Fraunhofer FDK is AAC encoder developed for Android operating system and uses integer math

Fraunhofer IIS AAC encoder is the "Professional" encoder officially licensed from Fraunhofer IIS by Poikosoft. It uses floating point math, is faster than FDK, and provides better audio quality than FDK (especially with low bit rates)

Fraunhofer FDK is included for backward-compatibility and also for formats that Fraunhofer IIS encoder does not support (some multichannel formats at least)

There is also a 3rd AAC encoder EZ CD Audio Converter supports; Apple AAC encoder is available if Apple iTunes is installed in the system

It's recommended to use the Fraunhofer IIS "Pro" encoder for all AAC encoding because of the best audio quality. For even improved audio quality you can use Fraunhofer IIS xHE-AAC encoder

[LonelyPixel]

Thank you for clarification.

So was there only the FDK encoder in the past and everything I've encoded was with that encoder? In other words, would it have any effect to re-encode those files with the Pro encoder now?

[iBypass]

Many thanks Poiko for the complete story !

Regards, iBypass

[washinoboku]

Same questions about xHE-ACC codecs. Fraunhofer IIS is better in quality than Exhale? Thanks!

[thexfile]

You're not going to get full cd quality from any lossy rip.

Apple AAC encoder sounds good.
https://www.poikosoft.com/install-apple-aac-encoder

[LonelyPixel]

No thanks, I'm not interested in apples that I can't eat.

I'm still waiting for a clarification about my last question. Seems like there isn't much support here.

[CrimsonSky]

If you're re-encoding from a lossless source (i.e. CD or Flac file) then it would make sense. If you mean converting directly from the current FDK encoded files using the IIS Pro encoder, then no, this won't improve the sound quality. In fact, it is likely to make it sound even worse.