Re: [hatari-devel] STe DMA sound

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 14/04/2018 à 17:51, Christian Zietz a écrit :
> Vincent Rivière schrieb:
>
> > On real hardware, there is no such stair-like steps (should be measured),
>
> Indeed, one a real STE there are no such artifacts, since of course no
> upsampling is done. Compare the measurement real-ste.png and Hatari's
> output hatari-distorted.png produced by the same program playing a
> sawtooth waveform via DMA sound. Again, the LMC1992 was set to maximum
> treble boost.

Hi

this is the idea I was thinking in another email I sent at the same time 
as you did :)

If you have a set of dma samples (square, triangle, ...) you can combine 
with some diferrent LMC settings, and you can record the real STE output 
the same way, we could use this as a reference wav file to compare with 
Hatari.

Another interesting test could be to record YM playing voice A at volume 
15 and dma sound playing also a square vaw at max amplitude (ie -127 to 
128) with a different freq. This way, we can compare the relative output 
of YM and DMA sound, as they're known to be of different max level and 
it's possible this level is not right yet under Hatari.

Nicolas