The Ghost in the MP3 (2014)
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The Ghost in the MP3 (2014)
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Re: The Ghost in the MP3 (2014)
#2"I am planning a series of related compositions, constructed first from the other songs involved in the listening tests, but then probing the space of MP3 compression in different ways, attempting to highlight even more explicitly the filtering effect of this codec.... Composing with these sounds and injecting them back into contemporary listening spaces is one possible act of resistance, one available mode of cultural critique."
MP3's unwitting/unintended uncovering of the possibilities of weird filtering schemes points to the hugeness of unexplored timbre space. We are so familiar with our usual collection of instrumental timbres ... we have assumed that this galaxy is the whole universe. Timbre is waiting for its Hubble.
Re: The Ghost in the MP3 (2014)
#3Compressing white noise and other "hissing" kinds of sounds is not something MP3 is good at. Compression perhaps can be split into frequency vectors and noise vectors. Frequency vectors would be plotted lines of specific frequencies and intensity.
White noise could be represented by a grid with frequency. Or perhaps use vectors with less frequency precision. That way the same mechanism can be used for both types, but with frequency re-scaled for noise to reduce data size. A given noise vector would represent an approximate frequency range rather than a specific frequency.
A frequency vector would probably need about a quarter note step in precision for a typical compression level (but adjustable). If it allows interpolation between vector nodes[1], then it can handle frequency tremolo fairly well. A vector node can have flags saying whether to interpolate frequency and/or volume, or just do a direct step jump, which ever best fits the original. (Noise vectors can also have interpolation flags.)
The noise vectors may only need a half-octave or octave range of precision. I'm guestimating only 4 to 6 bits are needed for the default precision, whereas the frequency vectors need around 11 bits.
As far as how to process the sound to produce such vectors, the encoder would have to "look" at the time/frequency plot, and divide artifacts (areas) into frequency "lines" and noise lines. I'm not an expert on such algorithms, but it probably can be refined from experimentation. Maybe make a rough guess start, and use a genetic algorithm to breed a vector set that best recreates the original, given a data size constraint.
If there's a lot of sound going on in one spot, then precision can perhaps be reduced for that spot. Human ears can't typically isolate details when the rock band is going all out, for example. Maybe give more precision to the loudest vectors, but slack on the lessor ones to save space.
[1] I'm thinking of segmented lines. Each segment node would contain a frequency value, volume value, frequency interpolation flag, and a volume interpolation flag. The range and meaning of each value would depend on the type (voice vs. noise) and precision specified for that line. "Voice" vector may be a better term than "frequency" vector.
Re: The Ghost in the MP3 (2014)
#4one interesting artifact of MP3s in pop music is that symbols are transformed from a clean Crashhhhhhhhhhh, to a sound like a dog slurping water.
However like Jpeg this is a tradeoff that we are used to. in the same way that tape has frequency inbalance, records just sound shit (sorry I know you like it, but they really don't sound better. they are great for evoking a feeling, but not for fidelity. Its lomo but for sound)
I don't like the distortion that 128k mp3 introduces, but I imagine that in years to come it'll become a fetish for certain types of audiophile
Re: The Ghost in the MP3 (2014)
#5"I am planning a series of related compositions, constructed first from the other songs involved in the listening tests, but then probing the space of MP3 compression in different ways, attempting to highlight even more explicitly the filtering effect of this codec.... Composing with these sounds and injecting them back into contemporary listening spaces is one possible act of resistance, one available mode of cultur…
> Timbre is waiting for its Hubble.
Jesus fucking Christ, man. I'm going to remember that phrase for the rest of my life. Good show, good show.
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Re: The Ghost in the MP3 (2014)
#6Wow this is really fascinating. I’ve seen a lot of support for FLAC but I’ve never been able to get an iPhone or iPod to read them. I wonder why flac and other high end lossless file formats are not supported.
Re: The Ghost in the MP3 (2014)
#7Wow this is really fascinating. I’ve seen a lot of support for FLAC but I’ve never been able to get an iPhone or iPod to read them. I wonder why flac and other high end lossless file formats are not supported.
I'd be surprised if they don't support ALAC, Apple's lossless codec. Can't say I have any iPods or iPhones to try it out myself though.
Apple generally has a very strong case of NIH.
Re: The Ghost in the MP3 (2014)
#8A few years ago I did a much more detailed comparison of lossy audio codecs: https://andrewrondeau.herokuapp.com/objectively_comparing_au...
TLDR: If you need to go lossy, use Opus. At higher bitrates, it's the only lossy codec that has a flat frequency response.
Re: The Ghost in the MP3 (2014)
#9Wow this is really fascinating. I’ve seen a lot of support for FLAC but I’ve never been able to get an iPhone or iPod to read them. I wonder why flac and other high end lossless file formats are not supported.
Maybe VLC app can read them?
Re: The Ghost in the MP3 (2014)
#10Wow this is really fascinating. I’ve seen a lot of support for FLAC but I’ve never been able to get an iPhone or iPod to read them. I wonder why flac and other high end lossless file formats are not supported.
14 years ago, when the iPod Video was popular and it had an unlocked bootloader that allowed installing third-party software, lots of tech-inclined people replaced the Apple OS with Rockbox, which had support for FLAC. Unfortunately, with the next generation of iPods, Apple locked the device down, and the only lossless format supported was Apple's own.