dsound: Support downmixing quadraphonic to stereo.

Signed-off-by: Andrew Eikum <aeikum@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
This commit is contained in:
Andrew Eikum 2016-05-19 09:11:16 -05:00 committed by Alexandre Julliard
parent 88dd3b4f6e
commit 1def346bab
3 changed files with 34 additions and 0 deletions

View file

@ -252,6 +252,33 @@ void put_surround512stereo(const IDirectSoundBufferImpl *dsb, DWORD pos, DWORD c
}
}
void put_quad2stereo(const IDirectSoundBufferImpl *dsb, DWORD pos, DWORD channel, float value)
{
/* based on pulseaudio's downmix algorithm */
switch(channel){
case 2: /* back left */
value *= 0.1f; /* (1/9) / (sum of left volumes) */
dsb->put_aux(dsb, pos, 0, value);
break;
case 0: /* front left */
value *= 0.9f; /* 1 / (sum of left volumes) */
dsb->put_aux(dsb, pos, 0, value);
break;
case 3: /* back right */
value *= 0.1f; /* (1/9) / (sum of right volumes) */
dsb->put_aux(dsb, pos, 1, value);
break;
case 1: /* front right */
value *= 0.9f; /* 1 / (sum of right volumes) */
dsb->put_aux(dsb, pos, 1, value);
break;
}
}
void mixieee32(float *src, float *dst, unsigned samples)
{
TRACE("%p - %p %d\n", src, dst, samples);

View file

@ -179,6 +179,7 @@ void put_stereo2quad(const IDirectSoundBufferImpl *dsb, DWORD pos, DWORD channel
void put_mono2surround51(const IDirectSoundBufferImpl *dsb, DWORD pos, DWORD channel, float value) DECLSPEC_HIDDEN;
void put_stereo2surround51(const IDirectSoundBufferImpl *dsb, DWORD pos, DWORD channel, float value) DECLSPEC_HIDDEN;
void put_surround512stereo(const IDirectSoundBufferImpl *dsb, DWORD pos, DWORD channel, float value) DECLSPEC_HIDDEN;
void put_quad2stereo(const IDirectSoundBufferImpl *dsb, DWORD pos, DWORD channel, float value) DECLSPEC_HIDDEN;
HRESULT secondarybuffer_create(DirectSoundDevice *device, const DSBUFFERDESC *dsbd,
IDirectSoundBuffer **buffer) DECLSPEC_HIDDEN;

View file

@ -179,6 +179,12 @@ void DSOUND_RecalcFormat(IDirectSoundBufferImpl *dsb)
dsb->put = put_surround512stereo;
dsb->put_aux = putieee32_sum;
}
else if (ichannels == 4 && ochannels == 2)
{
dsb->mix_channels = 4;
dsb->put = put_quad2stereo;
dsb->put_aux = putieee32_sum;
}
else
{
if (ichannels > 2)