Wanted: HE-AAC streaming

Why? Because it sounds so much better at low bit rates! With MP3 streaming, you have to go to 128Kbps to get acceptable sound quality; with HE-AAC you can cut back to 64Kbps with very little loss.

There are free encoder and decoder libraries for HE-AAC (FAAD2 and FAAC) -- http://www.audiocoding.com/ I don't know whether the license terms allow their use in the SL client, but if it is possible, I would love to see this! Basically, it means we could supply music to twice as many listeners: always a good thing.

Background: AAC (Advanced Audio Encoding) is a relatively new codec that is used in, among other places, MPEG-4 video files. The music files from iTunes are standard, low-complexity AAC. HE-AAC (high efficiency), also sometimes known as HC (high complexity) adds more encoding tricks designed to produce high quality streams at low bit rates. See http://en.wikipedia.org/wiki/HE-AAC for more info.

As SL uses the FMOD Library for sound which doesn't appear to support ACC, how does Ogg Vorbis compare? Even though you upload sounds in WAV they are converted to Ogg for storage and playback so it seems that is the preferred LL encoding.

Just a data point.

I tried it out. Ogg compares pretty well at 64Kbps -- not quite as good sounding as HE-AAC, but certainly far better than MP3 at that bit rate. AAC can go even lower though -- it actually doesn't sound bad at 32Kbps, which is just amazing, and something that no other codec I am familiar with can manage.

Worse for me, though, is that I can't stream Ogg nearly as easily. I have access to a Shoutcast server; that protocol only handles MP3 and AAC. To stream Ogg, I would have to have an Icecast server instead, which would involve persuading somebody else to switch (I don't host that Shoutcast server at home). And it means that you can't use the most popular streaming app, the DSP plug-in for Winamp. (There is a third party replacement that also does Icecast, though.)