PSPAtari: Atari 800/130/5200 Emulator for PSP v1.0.2

**cyphre** · July 9th, 2006, 19:13

...though it is still not perfect

In some games (International Karate, Ball Blazer etc.) at specific musc parts you can hear that the final sound volume is getting too high which resulted into distorted 'scratches'. Unfortunately I was not able to found out what part of code is causing this problem. There must be some problem either with SDL mixing(although the SDL volume is set to 1/4 of MAX) or with the Pokey emulation part.

**cyphre** · July 9th, 2006, 19:16

Maybe it would be worth to try save the RAW sound output from Pokey emulator to file on MemoryCard at runtime and see if the distortion is present even there?

**zx-81** · July 9th, 2006, 19:46

Originally Posted by cyphre

Well, I got some little time to play with the sources even today... Te problem was that you 'desired' from SDL to initialize sound as 8bit unsigned sample but you 'obtained' 16bit signed setting from the system. So I changed the defaults:

in atari_sdl.c file:
static int sound_flags = SND_BIT16;
static int sound_bits = 16;

and enabled

in pokeysnd.h file:

#define SIGNED_SAMPLES

and voila, it sounds much better!

Excellent, thanks, i will try it now

**zx-81** · July 9th, 2006, 19:59

Originally Posted by cyphre

...though it is still not perfect

In some games (International Karate, Ball Blazer etc.) at specific musc parts you can hear that the final sound volume is getting too high which resulted into distorted 'scratches'. Unfortunately I was not able to found out what part of code is causing this problem. There must be some problem either with SDL mixing(although the SDL volume is set to 1/4 of MAX) or with the Pokey emulation part.

I've tested it, and it works great now (may be not on all games, but it's better than before

). I was working on it this afternoon to add some new features (such as battery stuff), and thanks to you i will do a relase the evenning with the sound part modified according to your search results

.

I've put the volume to 3/4 instead of 1/4 it's better. Anyway many thanks for your hard work