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Demos Amiga Demoscene Archive Forum / Coding / Playing 14bits sound on Amiga


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#1 - Posted: 7 Apr 2010 10:27 - Edited
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Hello guys,

sorry to be so lazy but can you explain me some trick to play 14bits sound on Amiga? I've read you cannot render more than 22khz (hardware limitation), and to achieve 14bits you have to mix 2 channels. So you can play 14bits stereo sounds with 2 channels, each one is made using the two hardware 8bits channels. Is it right or is it impossible to do some stereo ? I've never programmed something for sound rendering, always used some mod players. Can you explain me how to do ?

I've read Kalms saying it takes around 10 sl to decompress adpcm and to render it, I've already downloaded his code but it's just adpcm decruncher not player. Perhaps someone already realased one and it's stupid to try to do an other one.

After the breakpoint, I made a little check of all my never realesed codes and if I want to do a demo I need now a good 14bits sound player because it's hard to find someone doing some 8bits mod.

#2 - Posted: 7 Apr 2010 17:00
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I think you are miss calculating a couple of things.

First the Amiga has 4 hardware channels, two per left/right channel. These 2 per output can be combined, using 8 pcm bits and 6 volume bits, by combining the channels, hence, the 14bit. This will most likely save you some hissing on your audio.

Secondary, the 22khz hardware limitation. This is only true when you relate it directly to the screenmode you choose. Most demos will run at normal PAL, and then 22khz is correct (although actually I remember it being around 28khz). Setting a screenmode with a higher frequency will allow you to drive it a higher speeds. I think with 040's and 060's it was also feasible to directly drive Paula from the CPU ?
#3 - Posted: 8 Apr 2010 14:45 - Edited
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If i remember correctly, AHI's Paula sources show how to do 14 bit playback. Maybe a bit overcomplex, but it's possible to dig out the important parts anyway. But there are other 14 bit stream player sources floating around too. Even on Aminet, for example.
#4 - Posted: 12 Apr 2010 01:46
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This package includes both an ADPCM decoder and a 14bit replay routine. Not very well tested.
#5 - Posted: 12 Apr 2010 11:04
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Thank you very much for your reply, I will have a look at your code
#6 - Posted: 5 May 2010 12:09
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hi all

im' not really a coder , not really at all

but i have a 14bits hummm didn't remember
from wich team, a protracker clone for 12
or 14 bits samples ?

hoops perhaps simply surrely 12



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