Re: [hatari-devel] Falcon tests -> sound issues

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On 17.6.2022 17.52, Nicolas Pomarède wrote:
> good news, the sound problem in Falcon mode was finally fixed.
>
> This was quite hard to debug because the whole crossbar code requires to 
> mix several input source at different freq and to output sound at 
> another freq too (44.1 kHz for example), all that with possible rounding 
> errors that must be compensated to keep a constant flow of bytes.
>
> After much tracing, the problem was in fact that this code used a wrong 
> value for the Falcon's cpu freq since several years :-( This was not 
> noticable before because sound mixing was done in a different (less 
> accurate) way, but now with cycle accurate YM2149 we require all the 
> clocks (cpu, dma, ym) to be as accurate as possible.
>
> Anyway, sound quality should be as good as before ; only remaining 
> rounding error can cause a small drift that will mess sound again after 
> 2 hours of playing sound :(
>
> So not perfect yet, but it will be good enough for Hatari 2.4 and should 
> be fixed later.
>
> I tested with 4musiK, the falcsmp example program from Ander and 030 
> demo by DML. Please check the demos that didn't sound good recently.

All the non-DSP demos that I had tested to have bad sound, are now OK 
from start to end. I.e. the issue seems to have been fixed for good now.

I'll test some Falcon apps too, and update compatibility doc after that.

I'll do full TOS tester run again during weekend, or very early next week.


	- Eero