"The Ghost in the MP3"... what remains after compression

[Julibee]

I thought this was really interesting... PhD student takes what was lost In both audio and video compression and presents the remains. Just sharing.

http://theghostinthemp3.com

[eusti]

Cool! Thx for sharing!

D.

[Ecopro]

It's amazing how much detail and fidelity we lose with compression codecs. What's more amazing is that tons of people don't mind listening under these conditions.

The video is kind of creepy. Interesting if we were to use that to compose something eerie. hmmm...
After watching the video for about 40 secs i got this message: 
Sorry
There was an issue with playback.

I'd stay away from mp3s. They're scary!  :t1465:

Thanks for the share Juli!

[selig]

If you've never done this yourself, you should definitely experience this on one of your own mixes so you can better understand what has been changed and how.

[Julibee]

If you've never done this yourself, you should definitely experience this on one of your own mixes so you can better understand what has been changed and how.

So. This isn't some special coding that this guy did? Meaning, there's a way for me to see?

I have always just used Sonar for mp3 encoding when I needed it done-- do other converters show what's missing? Or?

[normen]

Well its kind of silly. It seems to imply theres so much information "lost" but the point of compression is losing the irrelevant information. Its like saying "oh wow I can hear the birds outside when you turn off the vacuum! - the vacuum sucked up all that information!"

But yeah, with low bitrate compression you can definitely hear the difference. With 320kBit MP3 or 256kBit AAC I can't really distinguish the compressed vs the uncompressed audio myself anymore though.

Still an interesting soundscape and visual.. scape?

[CharlyCharlzz]

space compression !

[selig]

If you've never done this yourself, you should definitely experience this on one of your own mixes so you can better understand what has been changed and how.

So. This isn't some special coding that this guy did? Meaning, there's a way for me to see? I have always just used Sonar for mp3 encoding when I needed it done-- do other converters show what's missing? Or?

Simply convert to MP3, import both original and MP3 version into Reason, and invert the polarity of one of them! (turn off Stretch first to be safe). The result you will hear is everything NOT in the original, or rather, only what is added/changed by the MP3 process. More often we focus on what is lost by compression codecs, but here we are focusing more on what is added!

This effect will of course vary with codec algorithm and bit rate.

[kloeckno]

So. This isn't some special coding that this guy did? Meaning, there's a way for me to see? I have always just used Sonar for mp3 encoding when I needed it done-- do other converters show what's missing? Or?

Just take your original bounced file, import the compressed version, and invert the polarity of one. Voila


edit:haha Giles beat me to it!

[platzangst]

From reading the guy's statement on his website, I think he's doing a bit more than simply inverting/canceling source/compressed material, because he talks about rearranging and presenting the results according to his analysis of the original works' themes and such. So, I don't know if inverting polarity all by itself will generate quite the same haunting result as in the video. But it does seem to be an interesting way to generate strikingly odd sounds.

[reason2dance]

This product might bring the lost quality back:

http://www.factmag.com/2015/02/19/sony- ... mory-card/

[ScuzzyEye]

So, I don't know if inverting polarity all by itself will generate quite the same haunting result as in the video. But it does seem to be an interesting way to generate strikingly odd sounds.

When you invert a signal and combine it with the original, the formula looks like, this: n + (-1 * n). It's just as easy to take a negative of an image, and combine it with the original. In fact that's what a lot of people do when testing new video codecs, to get an idea what's being thrown out. I've seen such videos before, but in this case it looks like he's exaggerating the difference between video frames. Like if it is over by any amount, he clamps to full white, and if it is under he clamps to full black, and the same with color shifts, they are pushed to the extreme pure hue.

[selig]

From reading the guy's statement on his website, I think he's doing a bit more than simply inverting/canceling source/compressed material, because he talks about rearranging and presenting the results according to his analysis of the original works' themes and such. So, I don't know if inverting polarity all by itself will generate quite the same haunting result as in the video. But it does seem to be an interesting way to generate strikingly odd sounds.

I was under the impression the "ghost" sounds were just the beginning of an art project. The original work's themes etc. have nothing to do with the sounds themselves, right? Could be wrong, but this was the first thing I thought of because of the sounds I heard and my previous experience doing the same (but in my case for technical rather than creative applications). Either way, the interesting thing here IMO is what was created by the artist rather than the techniques used to derive the source material.

[platzangst]

I was under the impression the "ghost" sounds were just the beginning of an art project. The original work's themes etc. have nothing to do with the sounds themselves, right?

Well, according to the artist:

After compressing the original audio to 320kbps MP3's, I begin by analyzing the song structure, interpreting the music and text, and I then attempt to arrange the most interesting recovered material via this framework.

He goes on to describe differing techniques for a couple of the individual verses. His audio examples contain what (I think) are some of the "raw" results of his processes, and as a composition they are not quite as dramatic as the finished, longer piece.

This isn't a negative criticism, but I thought it was worth pointing out that anyone thinking they'll just compress/invert any random pop song and get a spooky masterpiece might be somewhat disappointed. There was that moment a while back where everyone and their pet aardvark was using timestretch to expand songs "800%", but this might take a bit more work to get interesting results from.