Re: [hatari-devel] Cracks in the sound (YM+DMA)

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

On 03/03/2013 15:23, Nicolas Pomarède wrote:
> On 03/03/2013 05:41, David Savinkoff wrote:
> > Hi Nicolas,
> >
> > This patch has sound clipping for LMC1992 saturation distortion
> > (same code as before for expedience, change it to your liking).
> > See hunk at line 642 (dmaSnd.c).
> >
> > This patch also fixes the sound overflow when DMA samples and
> > YM2149 are summed on the STe.
> > See all other hunks.
> >
> > The sound overflow fix incurs no performance penalty because
> > the YM2149 volume table is scaled by 1/2 in sound.c for the
> > STe; and the LMC1992 gain is doubled in dmaSnd.c to compensate
> > afterwards. DMA sound samples are scaled and summed
> > with 1/2 attenuated YM2149 to avoid overflow. DC filtering
> > removes the large dc offset before the gain is scaled up by 2.
> >
> > David
>
> Hi
>
> that's great, thanks for the patch ; I will check it later to head the
> difference.
>
> Nicolas

Hello

I applied the patch ; sound seems ok, but despite the comments you added 
in the source about doubling gain to compensate for halving dma, volume 
is much lower than before.

For example, try the demo Music Dream II by Phenomena 
http://pouet.net/prod.php?which=3418 ; it's dma sound only and volume is 
lower with your latest patch (try to restore a memory snapshot of music 
dream II with 2 versions of Hatari with/without patch to quickly hear 
the difference)

Is this expected ?

Nicolas