Open Source Fraunhofer AAC Encoder (fdk-aac) Options

[D404]

Android 4.1 has included an AAC encoding library by Fraunhofer, and Libav/FFmpeg support for this library is in the works (that is, in a day or two, it will be official.)

From the release announcement:

As part of the Android Jelly Bean source code released recently, a new AAC
library was released as well, developed by Fraunhofer:
https://android.googlesource.com/platform/external/aac

To ease using this library on platforms other than Android, I have added
an autotools based build system and done a minor portability fix, and
released this code as fdk-aac 0.1.0 today.

This project is hosted at sourceforge, under the opencore-amr project,
acting as an umbrella project for these codecs that are repackaged from
Android as standalone libraries, just as opencore-amr, vo-amrwbenc and
vo-aacenc before this one.

The release file is available at
http://sourceforge.net/projects/opencore-amr/files/fdk-aac/
and the code is available in git at
git://opencore-amr.git.sourceforge.net/gitroot/opencore-amr/fdk-aac.

This library is licensed under a custom copyleft style license:
http://opencore-amr.git.sourceforge.net/gi...a=blob;f=NOTICE

I in general intend to limit this project to minor tweaks and portability
fixes - for anything larger than that, I'd prefer if it first is
contributed upstream, to keep the difference between the upstream code and
this library as small as possible.

Edit: Obvious patent violation removed.

It can be used as such:

Bitrate Mode

CODE

avconv -i <input> -c:a libfdk_aac -b:a <bitrate> -afterburner 1 <output>

VBR Mode

CODE

aconv -i <input> -c:a libfdk_aac -flags +qscale -global_quality [1-5] -afterburner 1 <output>

VBR modes 1-5 correspond to roughly:

1. about 32 kbps/channel
2. about 40 kbps/channel
3. about 48-56 kbps/channel
4. about 64 kbps/channel
5. about 80-96 kbps/channel

-afterburner 1 enabkes "improved quality" mode.

Cheers.

Edit: This should be moved to the Tech forum.

This post has been edited by Garf: Jul 11 2012, 19:30

[m45t3r]

Overall, all pv or vo codecs that google bought from packetvideo or visual on are clear ripoffs from 3gpp code and they aren't even well done. Looks like some graduates from china worked on the 3gpp code.

from china

Does this actually have any relevance, or is it just a daft stereotype with potential to be very offensive?

I'm no sound expert, but why don't you guys start pushing OPUS all over the place?

I’m sure that plenty of people are and that even more people will be once it’s seen a stable release. You should realise, though, that AAC’s popularity is due in no small part to its adoption and consequent aggressive promotion by Apple, Nero, et al.. You’ll excuse me if I’m pessimistic and suspect that all the open initiatives in the world and all of their enthusiastic supporters at the grassroots can’t eclipse corporate power. Vorbis is an illustrative example of this for numerous reasons.

I guess that ties into your fourth paragraph, at least as far as I’m capable of decoding it.

Well, Opus do have some big corporations behind it (Broadcom, Skype a.k.a. Microsoft, Google...). Vorbis didn't have this momentum on release (it did have some support of Google after WebM but it only appeared on 2010 and Vorbis already was a old codec by this time), so maybe Opus will have a better chance to succeed. Anyway, even if Opus didn't succeed on general music applications it will probably survive on it's niche (it's way better than any other low-delay codec for Super-Wideband and Fullband applications, and it's very competitive on Wideband and Narrowband). Remembering that Opus is a MTI (mandatory-to-implement) codec on WebRTC, so it already have some uses.

This is really off-topic, but I don't think AAC is very succeful too. It have too many different profiles, many of them just eclipse one or another (just see this page here, that describes the entire MPEG-4 Audio; you have two codec for speech, three for general audio and three codecs for lossless). The majority of devices only supports the AAC-LC, many of them didn't support even the AAC Main Profile. The standard is so complex that some codecs never seem a working implementation (like ALS)-

AAC have it's niche too, but it didn't really eclipsed MP3 as the new standard for general music files, and I think no other lossy codec will ever have this achievement. Vorbis is very succesful on its own niche too (just look how many games use Vorbis as the codec to store music files).