Re: [hatari-devel] Re: Hatari YM conversion

[Douglas Little <doug694@xxxxxxxxxxxxxx>]

That's all really useful info. Thanks.

I might need to work with periods which are not really multiples of a VBL but I should be able to work that out when I look at the code. I expect it has to cope with 50 and 60hz periods already...

D.

On 26 October 2013 18:24, Nicolas Pomarède <npomarede@xxxxxxxxxxxx> wrote:

On 26/10/2013 18:56, Eero Tamminen wrote:

For standalone YM conversion, it might be better to use some of the projects
from which Hatari's code originates from, though.  According to sound..c:
-----------
   The new version of the sound core uses some code/ideas from the following
GPL projects :
     - tone and noise steps computations are from StSound 1.2 by Arnaud Carré
(Leonard/Oxygene)
     - 5 bits volume table and 16*16*16 combinations of all volume are from
Sc68 by Benjamin Gerard
     - 4 bits to 5 bits volume interpolation from 16*16*16 to 32*32*32 from
YM blep synthesis by Antti Lankila

Hi,

I updated this part of the comments, because it was outdated, StSound's code has been replaced since 2008.

As for using stsound or sc68 to generate wav data, maybe stsound would be easier, because you just need to give it the content of the 14 sound registers on every VBL and it will generate sound data.

sc68 is more complex to use because it really include a complete (but not always accurate) atari emulator (cpu, mfp, sound, interrupts, ...), so lot of code not directly related to emulating the YM2149 only.

You could also have a look at Sound_Update_VBL() in Hatari to see how the sound data are generated every VBL and remove all the emulation specific code to keep only the data generation.

Nicolas