qemu/audio/dsoundaudio.c
Kővágó, Zoltán 6dd35fd81e dsoundaudio: remove primary buffer
Enabling this option just creates a playback buffer with the specified settings,
and then ignores it. It's probably some outdated hack to set audio formats on
windows. (The first created stream dictates all other streams settings, at least
on some Windows versions). Setting DAC_FIXED_SETTINGS should have the same
effect as setting (the now removed) primary buffer.

Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-06-15 12:42:48 +02:00

905 lines
22 KiB
C

/*
* QEMU DirectSound audio driver
*
* Copyright (c) 2005 Vassili Karpov (malc)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/*
* SEAL 1.07 by Carlos 'pel' Hasan was used as documentation
*/
#include "qemu-common.h"
#include "audio.h"
#define AUDIO_CAP "dsound"
#include "audio_int.h"
#include <windows.h>
#include <mmsystem.h>
#include <objbase.h>
#include <dsound.h>
#include "audio_win_int.h"
/* #define DEBUG_DSOUND */
typedef struct {
int bufsize_in;
int bufsize_out;
int latency_millis;
} DSoundConf;
typedef struct {
LPDIRECTSOUND dsound;
LPDIRECTSOUNDCAPTURE dsound_capture;
struct audsettings settings;
DSoundConf conf;
} dsound;
typedef struct {
HWVoiceOut hw;
LPDIRECTSOUNDBUFFER dsound_buffer;
DWORD old_pos;
int first_time;
dsound *s;
#ifdef DEBUG_DSOUND
DWORD old_ppos;
DWORD played;
DWORD mixed;
#endif
} DSoundVoiceOut;
typedef struct {
HWVoiceIn hw;
int first_time;
LPDIRECTSOUNDCAPTUREBUFFER dsound_capture_buffer;
dsound *s;
} DSoundVoiceIn;
static void dsound_log_hresult (HRESULT hr)
{
const char *str = "BUG";
switch (hr) {
case DS_OK:
str = "The method succeeded";
break;
#ifdef DS_NO_VIRTUALIZATION
case DS_NO_VIRTUALIZATION:
str = "The buffer was created, but another 3D algorithm was substituted";
break;
#endif
#ifdef DS_INCOMPLETE
case DS_INCOMPLETE:
str = "The method succeeded, but not all the optional effects were obtained";
break;
#endif
#ifdef DSERR_ACCESSDENIED
case DSERR_ACCESSDENIED:
str = "The request failed because access was denied";
break;
#endif
#ifdef DSERR_ALLOCATED
case DSERR_ALLOCATED:
str = "The request failed because resources, such as a priority level, were already in use by another caller";
break;
#endif
#ifdef DSERR_ALREADYINITIALIZED
case DSERR_ALREADYINITIALIZED:
str = "The object is already initialized";
break;
#endif
#ifdef DSERR_BADFORMAT
case DSERR_BADFORMAT:
str = "The specified wave format is not supported";
break;
#endif
#ifdef DSERR_BADSENDBUFFERGUID
case DSERR_BADSENDBUFFERGUID:
str = "The GUID specified in an audiopath file does not match a valid mix-in buffer";
break;
#endif
#ifdef DSERR_BUFFERLOST
case DSERR_BUFFERLOST:
str = "The buffer memory has been lost and must be restored";
break;
#endif
#ifdef DSERR_BUFFERTOOSMALL
case DSERR_BUFFERTOOSMALL:
str = "The buffer size is not great enough to enable effects processing";
break;
#endif
#ifdef DSERR_CONTROLUNAVAIL
case DSERR_CONTROLUNAVAIL:
str = "The buffer control (volume, pan, and so on) requested by the caller is not available. Controls must be specified when the buffer is created, using the dwFlags member of DSBUFFERDESC";
break;
#endif
#ifdef DSERR_DS8_REQUIRED
case DSERR_DS8_REQUIRED:
str = "A DirectSound object of class CLSID_DirectSound8 or later is required for the requested functionality. For more information, see IDirectSound8 Interface";
break;
#endif
#ifdef DSERR_FXUNAVAILABLE
case DSERR_FXUNAVAILABLE:
str = "The effects requested could not be found on the system, or they are in the wrong order or in the wrong location; for example, an effect expected in hardware was found in software";
break;
#endif
#ifdef DSERR_GENERIC
case DSERR_GENERIC :
str = "An undetermined error occurred inside the DirectSound subsystem";
break;
#endif
#ifdef DSERR_INVALIDCALL
case DSERR_INVALIDCALL:
str = "This function is not valid for the current state of this object";
break;
#endif
#ifdef DSERR_INVALIDPARAM
case DSERR_INVALIDPARAM:
str = "An invalid parameter was passed to the returning function";
break;
#endif
#ifdef DSERR_NOAGGREGATION
case DSERR_NOAGGREGATION:
str = "The object does not support aggregation";
break;
#endif
#ifdef DSERR_NODRIVER
case DSERR_NODRIVER:
str = "No sound driver is available for use, or the given GUID is not a valid DirectSound device ID";
break;
#endif
#ifdef DSERR_NOINTERFACE
case DSERR_NOINTERFACE:
str = "The requested COM interface is not available";
break;
#endif
#ifdef DSERR_OBJECTNOTFOUND
case DSERR_OBJECTNOTFOUND:
str = "The requested object was not found";
break;
#endif
#ifdef DSERR_OTHERAPPHASPRIO
case DSERR_OTHERAPPHASPRIO:
str = "Another application has a higher priority level, preventing this call from succeeding";
break;
#endif
#ifdef DSERR_OUTOFMEMORY
case DSERR_OUTOFMEMORY:
str = "The DirectSound subsystem could not allocate sufficient memory to complete the caller's request";
break;
#endif
#ifdef DSERR_PRIOLEVELNEEDED
case DSERR_PRIOLEVELNEEDED:
str = "A cooperative level of DSSCL_PRIORITY or higher is required";
break;
#endif
#ifdef DSERR_SENDLOOP
case DSERR_SENDLOOP:
str = "A circular loop of send effects was detected";
break;
#endif
#ifdef DSERR_UNINITIALIZED
case DSERR_UNINITIALIZED:
str = "The Initialize method has not been called or has not been called successfully before other methods were called";
break;
#endif
#ifdef DSERR_UNSUPPORTED
case DSERR_UNSUPPORTED:
str = "The function called is not supported at this time";
break;
#endif
default:
AUD_log (AUDIO_CAP, "Reason: Unknown (HRESULT %#lx)\n", hr);
return;
}
AUD_log (AUDIO_CAP, "Reason: %s\n", str);
}
static void GCC_FMT_ATTR (2, 3) dsound_logerr (
HRESULT hr,
const char *fmt,
...
)
{
va_list ap;
va_start (ap, fmt);
AUD_vlog (AUDIO_CAP, fmt, ap);
va_end (ap);
dsound_log_hresult (hr);
}
static void GCC_FMT_ATTR (3, 4) dsound_logerr2 (
HRESULT hr,
const char *typ,
const char *fmt,
...
)
{
va_list ap;
AUD_log (AUDIO_CAP, "Could not initialize %s\n", typ);
va_start (ap, fmt);
AUD_vlog (AUDIO_CAP, fmt, ap);
va_end (ap);
dsound_log_hresult (hr);
}
static DWORD millis_to_bytes (struct audio_pcm_info *info, DWORD millis)
{
return (millis * info->bytes_per_second) / 1000;
}
#ifdef DEBUG_DSOUND
static void print_wave_format (WAVEFORMATEX *wfx)
{
dolog ("tag = %d\n", wfx->wFormatTag);
dolog ("nChannels = %d\n", wfx->nChannels);
dolog ("nSamplesPerSec = %ld\n", wfx->nSamplesPerSec);
dolog ("nAvgBytesPerSec = %ld\n", wfx->nAvgBytesPerSec);
dolog ("nBlockAlign = %d\n", wfx->nBlockAlign);
dolog ("wBitsPerSample = %d\n", wfx->wBitsPerSample);
dolog ("cbSize = %d\n", wfx->cbSize);
}
#endif
static int dsound_restore_out (LPDIRECTSOUNDBUFFER dsb, dsound *s)
{
HRESULT hr;
hr = IDirectSoundBuffer_Restore (dsb);
if (hr != DS_OK) {
dsound_logerr (hr, "Could not restore playback buffer\n");
return -1;
}
return 0;
}
#include "dsound_template.h"
#define DSBTYPE_IN
#include "dsound_template.h"
#undef DSBTYPE_IN
static int dsound_get_status_out (LPDIRECTSOUNDBUFFER dsb, DWORD *statusp,
dsound *s)
{
HRESULT hr;
hr = IDirectSoundBuffer_GetStatus (dsb, statusp);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not get playback buffer status\n");
return -1;
}
if (*statusp & DSERR_BUFFERLOST) {
dsound_restore_out(dsb, s);
return -1;
}
return 0;
}
static int dsound_get_status_in (LPDIRECTSOUNDCAPTUREBUFFER dscb,
DWORD *statusp)
{
HRESULT hr;
hr = IDirectSoundCaptureBuffer_GetStatus (dscb, statusp);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not get capture buffer status\n");
return -1;
}
return 0;
}
static void dsound_write_sample (HWVoiceOut *hw, uint8_t *dst, int dst_len)
{
int src_len1 = dst_len;
int src_len2 = 0;
int pos = hw->rpos + dst_len;
struct st_sample *src1 = hw->mix_buf + hw->rpos;
struct st_sample *src2 = NULL;
if (pos > hw->samples) {
src_len1 = hw->samples - hw->rpos;
src2 = hw->mix_buf;
src_len2 = dst_len - src_len1;
pos = src_len2;
}
if (src_len1) {
hw->clip (dst, src1, src_len1);
}
if (src_len2) {
dst = advance (dst, src_len1 << hw->info.shift);
hw->clip (dst, src2, src_len2);
}
hw->rpos = pos % hw->samples;
}
static void dsound_clear_sample (HWVoiceOut *hw, LPDIRECTSOUNDBUFFER dsb,
dsound *s)
{
int err;
LPVOID p1, p2;
DWORD blen1, blen2, len1, len2;
err = dsound_lock_out (
dsb,
&hw->info,
0,
hw->samples << hw->info.shift,
&p1, &p2,
&blen1, &blen2,
1,
s
);
if (err) {
return;
}
len1 = blen1 >> hw->info.shift;
len2 = blen2 >> hw->info.shift;
#ifdef DEBUG_DSOUND
dolog ("clear %p,%ld,%ld %p,%ld,%ld\n",
p1, blen1, len1,
p2, blen2, len2);
#endif
if (p1 && len1) {
audio_pcm_info_clear_buf (&hw->info, p1, len1);
}
if (p2 && len2) {
audio_pcm_info_clear_buf (&hw->info, p2, len2);
}
dsound_unlock_out (dsb, p1, p2, blen1, blen2);
}
static int dsound_open (dsound *s)
{
HRESULT hr;
HWND hwnd;
hwnd = GetForegroundWindow ();
hr = IDirectSound_SetCooperativeLevel (
s->dsound,
hwnd,
DSSCL_PRIORITY
);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not set cooperative level for window %p\n",
hwnd);
return -1;
}
return 0;
}
static int dsound_ctl_out (HWVoiceOut *hw, int cmd, ...)
{
HRESULT hr;
DWORD status;
DSoundVoiceOut *ds = (DSoundVoiceOut *) hw;
LPDIRECTSOUNDBUFFER dsb = ds->dsound_buffer;
dsound *s = ds->s;
if (!dsb) {
dolog ("Attempt to control voice without a buffer\n");
return 0;
}
switch (cmd) {
case VOICE_ENABLE:
if (dsound_get_status_out (dsb, &status, s)) {
return -1;
}
if (status & DSBSTATUS_PLAYING) {
dolog ("warning: Voice is already playing\n");
return 0;
}
dsound_clear_sample (hw, dsb, s);
hr = IDirectSoundBuffer_Play (dsb, 0, 0, DSBPLAY_LOOPING);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not start playing buffer\n");
return -1;
}
break;
case VOICE_DISABLE:
if (dsound_get_status_out (dsb, &status, s)) {
return -1;
}
if (status & DSBSTATUS_PLAYING) {
hr = IDirectSoundBuffer_Stop (dsb);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not stop playing buffer\n");
return -1;
}
}
else {
dolog ("warning: Voice is not playing\n");
}
break;
}
return 0;
}
static int dsound_write (SWVoiceOut *sw, void *buf, int len)
{
return audio_pcm_sw_write (sw, buf, len);
}
static int dsound_run_out (HWVoiceOut *hw, int live)
{
int err;
HRESULT hr;
DSoundVoiceOut *ds = (DSoundVoiceOut *) hw;
LPDIRECTSOUNDBUFFER dsb = ds->dsound_buffer;
int len, hwshift;
DWORD blen1, blen2;
DWORD len1, len2;
DWORD decr;
DWORD wpos, ppos, old_pos;
LPVOID p1, p2;
int bufsize;
dsound *s = ds->s;
DSoundConf *conf = &s->conf;
if (!dsb) {
dolog ("Attempt to run empty with playback buffer\n");
return 0;
}
hwshift = hw->info.shift;
bufsize = hw->samples << hwshift;
hr = IDirectSoundBuffer_GetCurrentPosition (
dsb,
&ppos,
ds->first_time ? &wpos : NULL
);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not get playback buffer position\n");
return 0;
}
len = live << hwshift;
if (ds->first_time) {
if (conf->latency_millis) {
DWORD cur_blat;
cur_blat = audio_ring_dist (wpos, ppos, bufsize);
ds->first_time = 0;
old_pos = wpos;
old_pos +=
millis_to_bytes (&hw->info, conf->latency_millis) - cur_blat;
old_pos %= bufsize;
old_pos &= ~hw->info.align;
}
else {
old_pos = wpos;
}
#ifdef DEBUG_DSOUND
ds->played = 0;
ds->mixed = 0;
#endif
}
else {
if (ds->old_pos == ppos) {
#ifdef DEBUG_DSOUND
dolog ("old_pos == ppos\n");
#endif
return 0;
}
#ifdef DEBUG_DSOUND
ds->played += audio_ring_dist (ds->old_pos, ppos, hw->bufsize);
#endif
old_pos = ds->old_pos;
}
if ((old_pos < ppos) && ((old_pos + len) > ppos)) {
len = ppos - old_pos;
}
else {
if ((old_pos > ppos) && ((old_pos + len) > (ppos + bufsize))) {
len = bufsize - old_pos + ppos;
}
}
if (audio_bug (AUDIO_FUNC, len < 0 || len > bufsize)) {
dolog ("len=%d bufsize=%d old_pos=%ld ppos=%ld\n",
len, bufsize, old_pos, ppos);
return 0;
}
len &= ~hw->info.align;
if (!len) {
return 0;
}
#ifdef DEBUG_DSOUND
ds->old_ppos = ppos;
#endif
err = dsound_lock_out (
dsb,
&hw->info,
old_pos,
len,
&p1, &p2,
&blen1, &blen2,
0,
s
);
if (err) {
return 0;
}
len1 = blen1 >> hwshift;
len2 = blen2 >> hwshift;
decr = len1 + len2;
if (p1 && len1) {
dsound_write_sample (hw, p1, len1);
}
if (p2 && len2) {
dsound_write_sample (hw, p2, len2);
}
dsound_unlock_out (dsb, p1, p2, blen1, blen2);
ds->old_pos = (old_pos + (decr << hwshift)) % bufsize;
#ifdef DEBUG_DSOUND
ds->mixed += decr << hwshift;
dolog ("played %lu mixed %lu diff %ld sec %f\n",
ds->played,
ds->mixed,
ds->mixed - ds->played,
abs (ds->mixed - ds->played) / (double) hw->info.bytes_per_second);
#endif
return decr;
}
static int dsound_ctl_in (HWVoiceIn *hw, int cmd, ...)
{
HRESULT hr;
DWORD status;
DSoundVoiceIn *ds = (DSoundVoiceIn *) hw;
LPDIRECTSOUNDCAPTUREBUFFER dscb = ds->dsound_capture_buffer;
if (!dscb) {
dolog ("Attempt to control capture voice without a buffer\n");
return -1;
}
switch (cmd) {
case VOICE_ENABLE:
if (dsound_get_status_in (dscb, &status)) {
return -1;
}
if (status & DSCBSTATUS_CAPTURING) {
dolog ("warning: Voice is already capturing\n");
return 0;
}
/* clear ?? */
hr = IDirectSoundCaptureBuffer_Start (dscb, DSCBSTART_LOOPING);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not start capturing\n");
return -1;
}
break;
case VOICE_DISABLE:
if (dsound_get_status_in (dscb, &status)) {
return -1;
}
if (status & DSCBSTATUS_CAPTURING) {
hr = IDirectSoundCaptureBuffer_Stop (dscb);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not stop capturing\n");
return -1;
}
}
else {
dolog ("warning: Voice is not capturing\n");
}
break;
}
return 0;
}
static int dsound_read (SWVoiceIn *sw, void *buf, int len)
{
return audio_pcm_sw_read (sw, buf, len);
}
static int dsound_run_in (HWVoiceIn *hw)
{
int err;
HRESULT hr;
DSoundVoiceIn *ds = (DSoundVoiceIn *) hw;
LPDIRECTSOUNDCAPTUREBUFFER dscb = ds->dsound_capture_buffer;
int live, len, dead;
DWORD blen1, blen2;
DWORD len1, len2;
DWORD decr;
DWORD cpos, rpos;
LPVOID p1, p2;
int hwshift;
dsound *s = ds->s;
if (!dscb) {
dolog ("Attempt to run without capture buffer\n");
return 0;
}
hwshift = hw->info.shift;
live = audio_pcm_hw_get_live_in (hw);
dead = hw->samples - live;
if (!dead) {
return 0;
}
hr = IDirectSoundCaptureBuffer_GetCurrentPosition (
dscb,
&cpos,
ds->first_time ? &rpos : NULL
);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not get capture buffer position\n");
return 0;
}
if (ds->first_time) {
ds->first_time = 0;
if (rpos & hw->info.align) {
ldebug ("warning: Misaligned capture read position %ld(%d)\n",
rpos, hw->info.align);
}
hw->wpos = rpos >> hwshift;
}
if (cpos & hw->info.align) {
ldebug ("warning: Misaligned capture position %ld(%d)\n",
cpos, hw->info.align);
}
cpos >>= hwshift;
len = audio_ring_dist (cpos, hw->wpos, hw->samples);
if (!len) {
return 0;
}
len = audio_MIN (len, dead);
err = dsound_lock_in (
dscb,
&hw->info,
hw->wpos << hwshift,
len << hwshift,
&p1,
&p2,
&blen1,
&blen2,
0,
s
);
if (err) {
return 0;
}
len1 = blen1 >> hwshift;
len2 = blen2 >> hwshift;
decr = len1 + len2;
if (p1 && len1) {
hw->conv (hw->conv_buf + hw->wpos, p1, len1);
}
if (p2 && len2) {
hw->conv (hw->conv_buf, p2, len2);
}
dsound_unlock_in (dscb, p1, p2, blen1, blen2);
hw->wpos = (hw->wpos + decr) % hw->samples;
return decr;
}
static DSoundConf glob_conf = {
.bufsize_in = 16384,
.bufsize_out = 16384,
.latency_millis = 10
};
static void dsound_audio_fini (void *opaque)
{
HRESULT hr;
dsound *s = opaque;
if (!s->dsound) {
g_free(s);
return;
}
hr = IDirectSound_Release (s->dsound);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not release DirectSound\n");
}
s->dsound = NULL;
if (!s->dsound_capture) {
g_free(s);
return;
}
hr = IDirectSoundCapture_Release (s->dsound_capture);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not release DirectSoundCapture\n");
}
s->dsound_capture = NULL;
g_free(s);
}
static void *dsound_audio_init (void)
{
int err;
HRESULT hr;
dsound *s = g_malloc0(sizeof(dsound));
s->conf = glob_conf;
hr = CoInitialize (NULL);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not initialize COM\n");
g_free(s);
return NULL;
}
hr = CoCreateInstance (
&CLSID_DirectSound,
NULL,
CLSCTX_ALL,
&IID_IDirectSound,
(void **) &s->dsound
);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not create DirectSound instance\n");
g_free(s);
return NULL;
}
hr = IDirectSound_Initialize (s->dsound, NULL);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not initialize DirectSound\n");
hr = IDirectSound_Release (s->dsound);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not release DirectSound\n");
}
g_free(s);
return NULL;
}
hr = CoCreateInstance (
&CLSID_DirectSoundCapture,
NULL,
CLSCTX_ALL,
&IID_IDirectSoundCapture,
(void **) &s->dsound_capture
);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not create DirectSoundCapture instance\n");
}
else {
hr = IDirectSoundCapture_Initialize (s->dsound_capture, NULL);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not initialize DirectSoundCapture\n");
hr = IDirectSoundCapture_Release (s->dsound_capture);
if (FAILED (hr)) {
dsound_logerr (hr, "Could not release DirectSoundCapture\n");
}
s->dsound_capture = NULL;
}
}
err = dsound_open (s);
if (err) {
dsound_audio_fini (s);
return NULL;
}
return s;
}
static struct audio_option dsound_options[] = {
{
.name = "LATENCY_MILLIS",
.tag = AUD_OPT_INT,
.valp = &glob_conf.latency_millis,
.descr = "(undocumented)"
},
{
.name = "BUFSIZE_OUT",
.tag = AUD_OPT_INT,
.valp = &glob_conf.bufsize_out,
.descr = "(undocumented)"
},
{
.name = "BUFSIZE_IN",
.tag = AUD_OPT_INT,
.valp = &glob_conf.bufsize_in,
.descr = "(undocumented)"
},
{ /* End of list */ }
};
static struct audio_pcm_ops dsound_pcm_ops = {
.init_out = dsound_init_out,
.fini_out = dsound_fini_out,
.run_out = dsound_run_out,
.write = dsound_write,
.ctl_out = dsound_ctl_out,
.init_in = dsound_init_in,
.fini_in = dsound_fini_in,
.run_in = dsound_run_in,
.read = dsound_read,
.ctl_in = dsound_ctl_in
};
struct audio_driver dsound_audio_driver = {
.name = "dsound",
.descr = "DirectSound http://wikipedia.org/wiki/DirectSound",
.options = dsound_options,
.init = dsound_audio_init,
.fini = dsound_audio_fini,
.pcm_ops = &dsound_pcm_ops,
.can_be_default = 1,
.max_voices_out = INT_MAX,
.max_voices_in = 1,
.voice_size_out = sizeof (DSoundVoiceOut),
.voice_size_in = sizeof (DSoundVoiceIn)
};