mp3 to wav to mp3 to wav same?
Reply #46 – 2003-08-22 14:46:15
This reply is in response to no one in particular... Be careful saying that things are "impossible". 50 years ago, there were a lot of old 78rpm discs around that people wanted to issue onto LPs. But they couldn't get the noise out of them. Or if they did, the results sounded horrible. And there's a problem: you have a valid signal, and added noise. And theory tells you that when the two are mixed together, you can no longer separate them. Where both are essentially unknown, you can't reconstruct either. It is not possible. You can't get back that nice clean audio signal from within all that noise. And then Cedar came along, followed by many others, and built products that declick and denoise old records! How? Is theory wrong? No! But it doesn't matter if the result is mathematically identical to what was originally recorded - it just matters that, after cedar processing, it sounds significantly better than the noisy version. Whether or not you can "un-decode" an mp3, I'm not sure. I'm 100% certain that you can't get from the mp3 back to the original .wav without loss. However, we often say "the information has been lost - it can't be put back". Not perfectly, no. But come 2050, when the only source of some recordings are 128kbps mp3s, I bet you some bright spark has a process which makes them sound a lot closer to the original than the surviving mp3 does. So, my advice is to try to do the impossible. (Though please, don't jump out of your upstairs window thinking you can fly!). Because some people succeed, and they usually make a lot of money out of a product that is "good enough" - much more money than the theorists who say "it is theoretically impossible to do this perfectly". Cheers, David. This is what I like about this forum. To qoute a famous US President John F Kennedy............ "Some folks dream of things as they are and say why...I dream of things that never where and say, Why Not