dsound: Use smaller buffers for wavein capture.

dlls/dsound/dsound_private.h

@@ -253,7 +253,6 @@ struct DirectSoundCaptureDevice
     /* more stuff */
     LPBYTE                             buffer;
     DWORD                              buflen;
-    DWORD                              read_position;
 
     PWAVEFORMATEX                      pwfx;
 
@@ -420,6 +419,7 @@ HRESULT DSOUND_Create8(REFIID riid, LPDIRECTSOUND8 *ppDS);
 
 /* primary.c */
 
+DWORD DSOUND_fraglen(DWORD nSamplesPerSec, DWORD nBlockAlign);
 HRESULT DSOUND_PrimaryCreate(DirectSoundDevice *device);
 HRESULT DSOUND_PrimaryDestroy(DirectSoundDevice *device);
 HRESULT DSOUND_PrimaryPlay(DirectSoundDevice *device);

dlls/dsound/primary.c

@@ -36,36 +36,44 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(dsound);
 
-static void DSOUND_RecalcPrimary(DirectSoundDevice *device)
+/** Calculate how long a fragment length of about 10 ms should be in frames
+ *
+ * nSamplesPerSec: Frequency rate in samples per second
+ * nBlockAlign: Size of a single blockalign
+ *
+ * Returns:
+ * Size in bytes of a single fragment
+ */
+DWORD DSOUND_fraglen(DWORD nSamplesPerSec, DWORD nBlockAlign)
 {
-	DWORD nBlockAlign;
-	DWORD fraglen;
-	TRACE("(%p)\n", device);
-
-	nBlockAlign = device->pwfx->nBlockAlign;
-	/* Alsa doesn't have continuous buffers, instead it has buffers with power of 2,
-	 * If DS_TIME_DEL is about 10 ms, 512 * nBlockAlign is roughly correct */
-	fraglen = 512 * nBlockAlign;
+    DWORD fraglen = 512 * nBlockAlign;
 
     /* Compensate for only being roughly accurate */
-	if (device->pwfx->nSamplesPerSec <= 26000)
+    if (nSamplesPerSec <= 26000)
         fraglen /= 2;
 
-	if (device->pwfx->nSamplesPerSec <= 12000)
+    if (nSamplesPerSec <= 12000)
         fraglen /= 2;
 
-	if (device->pwfx->nSamplesPerSec >= 80000)
+    if (nSamplesPerSec >= 80000)
         fraglen *= 2;
 
-	device->fraglen = fraglen;
-	device->helfrags = device->buflen / fraglen;
+    return fraglen;
+}
+
+static void DSOUND_RecalcPrimary(DirectSoundDevice *device)
+{
+    TRACE("(%p)\n", device);
+
+    device->fraglen = DSOUND_fraglen(device->pwfx->nSamplesPerSec, device->pwfx->nBlockAlign);
+    device->helfrags = device->buflen / device->fraglen;
     TRACE("fraglen=%d helfrags=%d\n", device->fraglen, device->helfrags);
 
     if (device->hwbuf && device->drvdesc.dwFlags & DSDDESC_DONTNEEDWRITELEAD)
         device->writelead = 0;
     else
         /* calculate the 10ms write lead */
-		device->writelead = (device->pwfx->nSamplesPerSec / 100) * nBlockAlign;
+        device->writelead = (device->pwfx->nSamplesPerSec / 100) * device->pwfx->nBlockAlign;
 }
 
 HRESULT DSOUND_ReopenDevice(DirectSoundDevice *device, BOOL forcewave)