Subject: Re: [stella] interesting supercharger/mp3 challenge From: KirkIsrael@xxxxxxxxxxxxx Date: 4 Mar 2004 01:24:56 -0000 |
> > Huh...so I had this idea for using my friends "ancient" mp3 > > player (a Diamond Rio, a 'paltry' 32 megs) as a way of carrying > > around an mp3 version of the JoustPong "makewav" output. > > > > At first it was hit or miss whether it worked, but now I > > figured out how to crank up the bitrate (so the mp3 is nearly > > as big as the Wav ~250k) and it seems to be pretty reliable. > > Many (most?) MP3 players grok WAV files too. Just toss an 8KHz mono WAV > file from MakeWAV onto it and see if it will play it back. Well, I've only found one program that lets me deal w/ the Rio that runs under XP (its kind of klunky, with a printer port passthrough adapater (!)) and it only accepts mp3 files. > MP3 uses a DCT to transform the PCM input to a pseudo-frequency space. The > problem is each DCT term represents a cosine wave at a single frequency & > defined phase shift. So even if the frequency is matched, only the in phase > portion is preserved, the rest gets smeared across the entire DCT spectrum. > In between frequencies get treated even worse. And that's before the > quantization algorithm decides to reduce the resolution or chop out chunks > of the spectrum. MP3 is fine for music & speech, but horrid to anything > which requires very accurate reproduction. You know, that's EXACTLY what I was thinking before my friend convinced me to try it...well, except for the bit about the cosine wave. And the phase shift. And the DCT spectrum. And the quantization. But I DID think MP3 might be removing the bits that aren't important to our ears, like JPEG does for images, and that those bits might be important to the supercharger. So I was surprised that it work. Well, I figured it had to be a little robust, since old tape players were rather lofi but it had to work despit that. At the higher bit rate, it seems pretty reliable, but I'll burn a CD and bring a discman as back up :-) Just wont look as cool...the supercharger/mp3 combo looks pretty slick, actually. -- KirkIsrael@xxxxxxxxxxxxx http://kisrael.com "If I can't be free, at least I'll be cheap"--some guy on the net ---------------------------------------------------------------------------------------------- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
Current Thread |
---|
|
<- Previous | Index | Next -> |
---|---|---|
Re: [stella] interesting supercharg, Thomas Jentzsch | Thread | [stella] Composite Video Mod, Billy Eno |
Re: [stella] interesting supercharg, Eric Ball | Date | [stella] Composite Video Mod, Billy Eno |
Month |