Hellos
We all know it. Mp3 sucks and wav/aif is teh b3st! Okie... Tests have been run, even in this very forum and we all concluded that if you are super amazing you can hear the difference.
I won't dispute the above, I agree. Especially if the bitrate of the mp3 is not at 320 kbit, but at... 128 for example.
But I've been toying with a wonderful (I think), idea, in which I need some hard info. So thought of asking here first, before starting to ask "weird" questions to Fraunhofer. ;)
It is lossy data compression! Fair enough.
So here's my question(s):
Is it possible to predict prehand, or to know before you make the conversion which bits of information will be lost?
We do know that mp3 works by "taking out" those bits of information that are not audible (up to a point of course). So would it be fair to create a track which won't lose vital information when turned into an mp3?
Could we have numeric data, or fact sheet, on what actually is lost over the conversion?
Just for the record, I'm not aiming to create a better mp3 file, but to put some audio information in the original (high quality probably, 24-bit and 96 Khz), WAv/AIF file, which I know WILL GET lost in the conversion.
Sorry I can't reply to the "whys", but this is part of my PhD and I cannot really share any further information really. You know how I like to share everything, but in this case it's just not possible. Sorry.
Thank you for your time reading this.
Nikolas
I don't know how helpful this is, but it's a fairly detailed article on how mp3 compression works. (Warning: white words upon black background.)
http://www.mp3-converter.com/mp3codec/
This page (http://www.mp3-converter.com/mp3codec/breakitdown.htm) has a bit of info about how the codec decides what info to toss. It doesn't actually say what is tossed, but I get the impression this changes according the original track, the bitrate specified and the mathematical algorithm that calculates what to toss.
The rest of the article is interesting too, though I stopped reading here because I was seeing afterimages from the white-on-black. :P
Unrelated, but your post reminded me of this article: Tom's Essay (http://measureformeasure.blogs.nytimes.com/2008/09/23/toms-essay/), or How Tom's Diner Turned Suzanne Vega Into "The Mother Of The Mp3".
edit: Here's another article (http://www.soundonsound.com/sos/may00/articles/mp3.htm) on the workings of mp3.