winealsa: Optimize GetPosition() more in dsalsa
Maarten Lankhorst
m.b.lankhorst at gmail.com
Wed Jun 27 16:46:01 CDT 2007
Use a seperate writelead for big period sizes to decrease latency. Use
only 1 call to hw avail update and no calls to snd_pcm_hw_sync, since it
requires a context switch.
-------------- next part --------------
>From 4e64c41d452174893a6eef61a2ef413f5e09b57e Mon Sep 17 00:00:00 2001
From: Maarten Lankhorst <m.b.lankhorst at gmail.com>
Date: Wed, 27 Jun 2007 23:37:26 +0200
Subject: [PATCH] winealsa: Optimize GetPosition() further for dsalsa
Use a seperate writelead for big period sizes to decrease latency and use only 1 call to hw avail update
---
dlls/winealsa.drv/dsoutput.c | 110 +++++++++++++++++++++++++-----------------
1 files changed, 65 insertions(+), 45 deletions(-)
diff --git a/dlls/winealsa.drv/dsoutput.c b/dlls/winealsa.drv/dsoutput.c
index 2d14a2c..2879d2e 100644
--- a/dlls/winealsa.drv/dsoutput.c
+++ b/dlls/winealsa.drv/dsoutput.c
@@ -88,42 +88,46 @@ struct IDsDriverBufferImpl
snd_pcm_t *pcm;
snd_pcm_hw_params_t *hw_params;
snd_pcm_sw_params_t *sw_params;
- snd_pcm_uframes_t mmap_buflen_frames, mmap_pos, mmap_writeahead;
+ snd_pcm_uframes_t mmap_buflen_frames, mmap_pos, mmap_commitahead, mmap_writeahead;
};
/** Fill buffers, for starting and stopping
* Alsa won't start playing until everything is filled up
* This also updates mmap_pos
+ *
+ * Returns: Amount of periods in use so snd_pcm_avail_update
+ * doesn't have to be called up to 4x in GetPosition()
*/
-static void CommitAll(IDsDriverBufferImpl *This)
+static snd_pcm_uframes_t CommitAll(IDsDriverBufferImpl *This)
{
const snd_pcm_channel_area_t *areas;
snd_pcm_uframes_t used;
- const snd_pcm_uframes_t writeahead = This->mmap_writeahead;
+ const snd_pcm_uframes_t commitahead = This->mmap_commitahead;
- TRACE("%p want to %ld\n", This, writeahead);
used = This->mmap_buflen_frames - snd_pcm_avail_update(This->pcm);
- if (used < writeahead)
+ TRACE("%p needs to commit to %lu, used: %lu\n", This, commitahead, used);
+ if (used < commitahead)
{
- snd_pcm_uframes_t putin = writeahead - used;
+ snd_pcm_uframes_t done, putin = commitahead - used;
snd_pcm_mmap_begin(This->pcm, &areas, &This->mmap_pos, &putin);
- This->mmap_pos += snd_pcm_mmap_commit(This->pcm, This->mmap_pos, putin);
+ done = snd_pcm_mmap_commit(This->pcm, This->mmap_pos, putin);
+ This->mmap_pos += done;
+ used += done;
+ putin = commitahead - used;
- used = This->mmap_buflen_frames - snd_pcm_avail_update(This->pcm);
- if (This->mmap_pos == This->mmap_buflen_frames)
+ if (This->mmap_pos == This->mmap_buflen_frames && (snd_pcm_sframes_t)putin > 0)
{
- putin = writeahead;
- used = This->mmap_buflen_frames - snd_pcm_avail_update(This->pcm);
- putin -= used;
-
- if ((snd_pcm_sframes_t)putin > 0)
- {
- snd_pcm_mmap_begin(This->pcm, &areas, &This->mmap_pos, &putin);
- This->mmap_pos += snd_pcm_mmap_commit(This->pcm, This->mmap_pos, putin);
- }
+ snd_pcm_mmap_begin(This->pcm, &areas, &This->mmap_pos, &putin);
+ done = snd_pcm_mmap_commit(This->pcm, This->mmap_pos, putin);
+ This->mmap_pos += done;
+ used += done;
}
-
}
+
+ if (This->mmap_pos == This->mmap_buflen_frames)
+ This->mmap_pos = 0;
+
+ return used;
}
static void CheckXRUN(IDsDriverBufferImpl* This)
@@ -175,9 +179,11 @@ static int DSDB_CreateMMAP(IDsDriverBufferImpl* pdbi)
mmap_mode = snd_pcm_type(pcm);
if (mmap_mode == SND_PCM_TYPE_HW)
- TRACE("mmap'd buffer is a hardware buffer.\n");
+ TRACE("mmap'd buffer is a direct hardware buffer.\n");
+ else if (mmap_mode == SND_PCM_TYPE_DMIX)
+ TRACE("mmap'd buffer is an ALSA dmix buffer\n");
else
- TRACE("mmap'd buffer is an ALSA emulation of hardware buffer.\n");
+ TRACE("mmap'd buffer is an ALSA type %d buffer\n", mmap_mode);
err = snd_pcm_hw_params_get_period_size(hw_params, &psize, NULL);
@@ -375,16 +381,23 @@ static HRESULT SetFormat(IDsDriverBufferImpl *This, LPWAVEFORMATEX pwfx, BOOL fo
err = snd_pcm_hw_params_get_period_size(hw_params, &psize, NULL);
TRACE("Period size is: %lu\n", psize);
- if (psize > 512)
+ /* If period size is 'high', try to commit less
+ * dmix needs at least 2 buffers to work succesfully but prefers 3
+ * however it seems to work ok if I just commit 2 1/2 buffers
+ */
+ if (psize >= 512)
{
- if (++warnonce == 1)
+ if (psize > 512 && ++warnonce == 1)
FIXME("Your alsa dmix period size is excessively high, unfortunately this is alsa default, try decreasing it to 512 or 256 (but double the amount of periods) if possible\n");
- This->mmap_writeahead = 3 * psize;
+ This->mmap_commitahead = 2 * psize + psize/2;
+ This->mmap_writeahead = 2 * psize;
}
- else
+ else
{
- This->mmap_writeahead = 3 * psize;
- while (This->mmap_writeahead <= 512) This->mmap_writeahead += psize;
+ This->mmap_commitahead = 3 * psize;
+ while (This->mmap_commitahead <= 512)
+ This->mmap_commitahead += psize;
+ This->mmap_writeahead = This->mmap_commitahead;
}
if (This->pcm)
@@ -405,6 +418,11 @@ static HRESULT SetFormat(IDsDriverBufferImpl *This, LPWAVEFORMATEX pwfx, BOOL fo
if (err < 0)
WARN("Failed to apply changes: %s\n", snd_strerror(err));
+ if (!This->pcm)
+ This->pcm = pcm;
+ else
+ snd_pcm_close(pcm);
+
if (This->pcm)
snd_pcm_hw_params_current(This->pcm, This->hw_params);
@@ -468,21 +486,24 @@ static HRESULT WINAPI IDsDriverBufferImpl_GetPosition(PIDSDRIVERBUFFER iface,
}
state = snd_pcm_state(This->pcm);
- if (state == SND_PCM_STATE_RUNNING)
+
+ if (state != SND_PCM_STATE_RUNNING)
+ CheckXRUN(This);
+ else
{
- snd_pcm_uframes_t avail;
- avail = snd_pcm_avail_update(This->pcm);
- hw_pptr = This->mmap_pos + avail;
- hw_pptr %= This->mmap_buflen_frames;
- hw_wptr = hw_pptr + This->mmap_writeahead - 512;
+ snd_pcm_uframes_t used = CommitAll(This);
+
+ if (This->mmap_pos > used)
+ hw_pptr = This->mmap_pos - used;
+ else
+ hw_pptr = This->mmap_buflen_frames - used + This->mmap_pos;
+
+ hw_wptr = hw_pptr + (This->mmap_writeahead > used ? used : This->mmap_writeahead);
hw_wptr %= This->mmap_buflen_frames;
- WARN("At position: %ld (%ld) - Avail %ld\n", hw_pptr, This->mmap_pos, avail);
- assert((snd_pcm_sframes_t)hw_pptr >= 0);
- }
- else WARN("%p: State = %d\n", lpdwPlay, state);
+ hw_pptr %= This->mmap_buflen_frames;
- CheckXRUN(This);
- CommitAll(This);
+ TRACE("At position: %ld (%ld) - Used %ld\n", hw_pptr, This->mmap_pos, used);
+ }
LeaveCriticalSection(&This->pcm_crst);
@@ -738,16 +759,15 @@ DWORD wodDsCreate(UINT wDevID, PIDSDRIVER* drv)
TRACE("driver created\n");
/* the HAL isn't much better than the HEL if we can't do mmap() */
- if (!(WOutDev[wDevID].outcaps.dwSupport & WAVECAPS_DIRECTSOUND)) {
- ERR("DirectSound flag not set\n");
- MESSAGE("This sound card's driver does not support direct access\n");
- MESSAGE("The (slower) DirectSound HEL mode will be used instead.\n");
- return MMSYSERR_NOTSUPPORTED;
+ if (!(WOutDev[wDevID].outcaps.dwSupport & WAVECAPS_DIRECTSOUND))
+ {
+ WARN("MMAP not supported for this device, falling back to waveout, should be harmless\n");
+ return MMSYSERR_NOTSUPPORTED;
}
*idrv = HeapAlloc(GetProcessHeap(),0,sizeof(IDsDriverImpl));
if (!*idrv)
- return MMSYSERR_NOMEM;
+ return MMSYSERR_NOMEM;
(*idrv)->lpVtbl = &dsdvt;
(*idrv)->ref = 1;
--
1.4.4.2
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