Slashdot Mirror
MP3...in Surround Sound
A number of people sent in the latest news from the fine folks at Frauhofer that they are expecting to have surround sound working for MP3s by July. The details are pretty sketchy in the article, but supposedly it won't be much more space per MP3s, and existing players will work with it.
Fraunhofer reproduces surround sound by adding to MP3 encoding extra information that describes the spatial characteristics of the main audio track.
If they are just adding information to the main track, why put that information in the file to begin with? Just let the user have a "spatial" encoder plug-in that jacks into winamp or whatever. Doing it this way increases the file size for everybody... people with and without surround systems.
Surround information should not be "created." It should be ripped and converted from the original source.
Before long we'll have the mp3 mess that we currently have with all the video codecs.
Davak
Yes, MP3 still remains extremely popular, but it is showing its age, and it isn't doing so well in other, less high-profile areas.
One of the places Ogg Vorbis has become surprisingly popular is in soundtracks for computer games. The no licensing fees must be one useful aspect, but there's also definite technological advantages such as better compression, more channels and - very important for sound effects and looped audio - arbitrary length samples.
I was really impressed to discover that Halo for the PC uses Ogg Vorbis for all its sound, and it's published by Microsoft! It's not alone, either - if you've bought a PC game at all recently there's a good chance the audio's compressed with Ogg Vorbis.
Is Ogg Vorbis successful? I'd say it was.
It would need a new connector, because you can only get stereo stereo from the iPod as far as I can tell.
For a surround output to an audio system, you would need a new connector offering at least 4 channels (Front L/R, rear L/R), line level. They'd probably make it straight-up 5.1, though.
And how do you get surround sound from a pair of headphones with only with a left and right channel?Easily. Headphones have two channels (L/R), you have two ears (L/R). Your brain does some pretty heavy duty phase analysis to figure out where a sound is coming from. In fact, binaural recording is a technique where two microphones (L/R) are mounted on a form resembling the human head, but you need to wear headphones for the full effect.
A portable device could either use 4 channel headphones (expensive, requires 4 amplifiers to drive them, would increase battery consumption) or could use a DSP integrated circuit to decode the surround sound channels, perform the phase analysis done by the human brain, and send this synthetic binaural signal to regular headphones.
But it's still a lot of work for little payoff. Most of the use for surround sound in any form is movies. Music tends to be mixed to 2 channels from the perspective of a listener sitting in front of the stage, so I think its importance in a portable device primarily used for music is pretty limited.
Fire and Meat. Yummy.