Digital Music Couldn't Exist Without the Fourier Transform

Re:Digital Music Couldn't Exist Without the Fourier Transform by ctdonath on Monday May 04, 2015 @04:02PM (#9488722)

Most people don't appreciate the transition to digitized images & audio went thru early on: as the technology went mainstream, there was an extreme insufficiency of storage space & network bandwidth that had to be overcome as a chicken-and-egg problem. In a day where multi-mile wireless >10Mbps bandwidth & >32GB storage to your pocket is cheap, we forget how painful desktop wired dialup bandwidth & ~100MB storage was, and the crazy contortions we had to go thru to transfer & store digital images & audio. FFTs and subjective image extraction solved those problems, leaving artifacts which utterly baffle today's users who can, say, store a full year's worth of HD video for $50, or 200GB wireless cloud hosting for $4/mo.

Yeah, we could have done digital audio without FFTs. Woulda been infeasible though given the circumstances.

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Re:Digital Music Couldn't Exist Without the Fourier Transform by acqq on Monday May 04, 2015 @05:27PM (#9489323)

It certainly was done without FFT and it was still good enough:

ADPCM. No FFT. Worked on my 1991 PC:

https://support.microsoft.com/en-us/kb/89879

"22 kHz mono ADPCM can be decompressed real-time (that is, while playing) on a 386SX/16 megahertz CPU"

Note: 16 MHz 386SX was effectively slower than the 286 of the same speed.

I had all the Beatles albums on one CD, all encoded with ADPCM, and the sound was not bad.

If I remember correctly, the guys at Bell Labs had also some server filled with the digital music. But I can't locate the story (maybe somebody remembers, was it Ritchie or Thompson?) and don't remember when actually.

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