[PATCH 3/5] dsound: Preserve freqAccNum value in DSOUND_RecalcFormat().

[Anton Baskanov]

From: Anton Baskanov

Resetting it results in position discontinuity. With frequent
SetFrequency() calls, this produces audible crackling. The issue
affects pedestrian voices in GTA: San Andreas.
---
 dlls/dsound/mixer.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/dlls/dsound/mixer.c b/dlls/dsound/mixer.c
index dbef1bc40fa..4d0c54735cf 100644
--- a/dlls/dsound/mixer.c
+++ b/dlls/dsound/mixer.c
@@ -96,6 +96,7 @@ void DSOUND_RecalcFormat(IDirectSoundBufferImpl *dsb)
 {
    DWORD ichannels = dsb->pwfx->nChannels;
    DWORD ochannels = dsb->device->pwfx->nChannels;
+	LONG64 oldFreqAdjustDen = dsb->freqAdjustDen;
    WAVEFORMATEXTENSIBLE *pwfxe;
    BOOL ieee = FALSE;

@@ -130,7 +131,8 @@ void DSOUND_RecalcFormat(IDirectSoundBufferImpl *dsb)
    /* calculate the 10ms write lead */
    dsb->writelead = (dsb->freq / 100) * dsb->pwfx->nBlockAlign;

-	dsb->freqAccNum = 0;
+	if (oldFreqAdjustDen)
+		dsb->freqAccNum = (dsb->freqAccNum * dsb->freqAdjustDen + oldFreqAdjustDen / 2) / oldFreqAdjustDen;

dsb->get_aux = ieee ? getbpp[4] : getbpp[dsb->pwfx->wBitsPerSample/8 - 1];
    dsb->put_aux = putieee32;