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Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 1:37 am
by jrisreal
Is it possible? I'm thinking you could apply a dynamic expander (opposite of compression) in order to counteract the effect of mp3 compression.

Discuss.

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 1:41 am
by 3za
1. MP3 compression is a totally different form of compression to dynamic.

2. Can you turn a cooked egg, back into a raw one?

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 1:42 am
by monte-m
Don't think this would work the way you are thinking because the mp3 format is a lossy compression, meaning there is information lost from the original source after you compress it. It would be like if you zipped a file, instead of being able to unzip it and get the original file, all you would get would be (a) corrupt file(s) since some information is lost.

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 1:44 am
by jrisreal
Ahh I understand...was hoping, though haha.

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 1:54 am
by Heartless
You've gotta be fucking kidding me.

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 1:56 am
by jrisreal
Heartless wrote:You've gotta be fucking kidding me.
nope. how you doin?

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 2:08 am
by VirtualMark
3za wrote:2. Can you turn a cooked egg, back into a raw one?
Theoretically, yes. Quantum theory states that information can't be destroyed, only changed from one form to another. So if we had the necessary information we could reverse the cooking. :6:

Practically, no. :(

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 2:52 am
by wormcode
^ Need some more 1's where the 0's are! Haha.
It would be a bit like trying to get 16khz high end out of a 40hz sine wave. Can't put something back that wasn't there to begin with. That's why it's called lossy, it gets lost. (yeah I know, harmonics, distortion etc.)

It's probably possible to recreate or "reverse" if you had the original uncompressed master, and figured out how to transfer the missing fidelity over to the MP3 version, then figured out how to write the software to do it. Would take a long time with research and theory alone... but there's not much of a point with that method, because you'd already have the master, so why bother trying to reverse the MP3 except as an experiment I guess.

What would be the use of this? I suppose if you lost projects and only have low quality MP3s left. I've got a lot of stuff like that, but I just remember back to my days of trading cassette bootlegs and stuff then I feel better. A 128kbps MP3 still sounds way better than that haha.

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 3:11 am
by jrisreal
wormcode wrote:What would be the use of this? I suppose if you lost projects and only have low quality MP3s left.
You guessed correctly. Some old hiphop instrumentals that got lost on my old linux laptop...don't have the projects, but I have MP3's. It's a shame, though, because I really liked some of those tracks.

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 3:38 am
by wormcode
jrisreal wrote:
wormcode wrote:What would be the use of this? I suppose if you lost projects and only have low quality MP3s left.
You guessed correctly. Some old hiphop instrumentals that got lost on my old linux laptop...don't have the projects, but I have MP3's. It's a shame, though, because I really liked some of those tracks.
If you still have it, it's worth a shot to try data recovery. Even if it's been formatted, data on hard drives isn't deleted automatically, it's "set aside" until it's overwritten by new data. A friend of mine recovered a lot of his old projects by using http://www.recovermyfiles.com and I have used it to get a lot of stuff back as well. The more you use/fill the hard drive, the less the chance is of recovering deleted files.

Depending which linux distro it is/was, it might have utilities installed for that already. Or check out Linux Disk Recovery or these:
http://www.linux.com/news/enterprise/st ... hard-drive
http://www.linuxlinks.com/article/20100 ... overy.html

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 4:07 am
by jrisreal
haha its gona be a bit more complicated than that I'm guessing. I lost them because I was running ubuntu with XP in a virtual machine running FL Studio. and when I changed my comp's boot OS back to XP, I forgot to back it up :/

Re: Reversing the effect of MP3 compression.

Posted: Fri Aug 26, 2011 5:58 am
by nowaysj
Well something you could try is some type of harmonic excitation. This will synthesize some high frequencies based upon what is happening further down the spectrum. It may sound a bit like poo, but that is cool too. Plus, if this is hip hop we're talking about, keep it ghetto bro. Roll with that delicious mp3 compression sound. I love it. Not even kidding on that one.