SDL  2.0
SDL_audio.c File Reference
#include "../SDL_internal.h"
#include "SDL.h"
#include "SDL_audio.h"
#include "SDL_audio_c.h"
#include "SDL_sysaudio.h"
#include "../thread/SDL_systhread.h"
+ Include dependency graph for SDL_audio.c:

Go to the source code of this file.

Macros

#define _THIS   SDL_AudioDevice *_this
 
#define FILL_STUB(x)
 
#define CHECK_FMT_STRING(x)   if (SDL_strcmp(string, #x) == 0) return AUDIO_##x
 
#define NUM_FORMATS   10
 

Functions

static SDL_AudioDeviceget_audio_device (SDL_AudioDeviceID id)
 
static void SDL_AudioDetectDevices_Default (void)
 
static void SDL_AudioThreadInit_Default (_THIS)
 
static void SDL_AudioThreadDeinit_Default (_THIS)
 
static void SDL_AudioBeginLoopIteration_Default (_THIS)
 
static void SDL_AudioWaitDevice_Default (_THIS)
 
static void SDL_AudioPlayDevice_Default (_THIS)
 
static Uint8SDL_AudioGetDeviceBuf_Default (_THIS)
 
static int SDL_AudioCaptureFromDevice_Default (_THIS, void *buffer, int buflen)
 
static void SDL_AudioFlushCapture_Default (_THIS)
 
static void SDL_AudioPrepareToClose_Default (_THIS)
 
static void SDL_AudioCloseDevice_Default (_THIS)
 
static void SDL_AudioDeinitialize_Default (void)
 
static void SDL_AudioFreeDeviceHandle_Default (void *handle)
 
static int SDL_AudioOpenDevice_Default (_THIS, void *handle, const char *devname, int iscapture)
 
static SDL_INLINE SDL_bool is_in_audio_device_thread (SDL_AudioDevice *device)
 
static void SDL_AudioLockDevice_Default (SDL_AudioDevice *device)
 
static void SDL_AudioUnlockDevice_Default (SDL_AudioDevice *device)
 
static void SDL_AudioLockOrUnlockDeviceWithNoMixerLock (SDL_AudioDevice *device)
 
static void finish_audio_entry_points_init (void)
 
static int add_audio_device (const char *name, void *handle, SDL_AudioDeviceItem **devices, int *devCount)
 
static SDL_INLINE int add_capture_device (const char *name, void *handle)
 
static SDL_INLINE int add_output_device (const char *name, void *handle)
 
static void free_device_list (SDL_AudioDeviceItem **devices, int *devCount)
 
void SDL_AddAudioDevice (const int iscapture, const char *name, void *handle)
 
void SDL_OpenedAudioDeviceDisconnected (SDL_AudioDevice *device)
 
static void mark_device_removed (void *handle, SDL_AudioDeviceItem *devices, SDL_bool *removedFlag)
 
void SDL_RemoveAudioDevice (const int iscapture, void *handle)
 
static void SDL_BufferQueueDrainCallback (void *userdata, Uint8 *stream, int len)
 
static void SDL_BufferQueueFillCallback (void *userdata, Uint8 *stream, int len)
 
int SDL_QueueAudio (SDL_AudioDeviceID devid, const void *data, Uint32 len)
 
Uint32 SDL_DequeueAudio (SDL_AudioDeviceID devid, void *data, Uint32 len)
 
Uint32 SDL_GetQueuedAudioSize (SDL_AudioDeviceID devid)
 
void SDL_ClearQueuedAudio (SDL_AudioDeviceID devid)
 
static int SDL_RunAudio (void *devicep)
 
static int SDL_CaptureAudio (void *devicep)
 
static SDL_AudioFormat SDL_ParseAudioFormat (const char *string)
 
int SDL_GetNumAudioDrivers (void)
 
const char * SDL_GetAudioDriver (int index)
 
int SDL_AudioInit (const char *driver_name)
 
const char * SDL_GetCurrentAudioDriver ()
 
static void clean_out_device_list (SDL_AudioDeviceItem **devices, int *devCount, SDL_bool *removedFlag)
 
int SDL_GetNumAudioDevices (int iscapture)
 
const char * SDL_GetAudioDeviceName (int index, int iscapture)
 
static void close_audio_device (SDL_AudioDevice *device)
 
static int prepare_audiospec (const SDL_AudioSpec *orig, SDL_AudioSpec *prepared)
 
static SDL_AudioDeviceID open_audio_device (const char *devname, int iscapture, const SDL_AudioSpec *desired, SDL_AudioSpec *obtained, int allowed_changes, int min_id)
 
int SDL_OpenAudio (SDL_AudioSpec *desired, SDL_AudioSpec *obtained)
 
SDL_AudioDeviceID SDL_OpenAudioDevice (const char *device, int iscapture, const SDL_AudioSpec *desired, SDL_AudioSpec *obtained, int allowed_changes)
 
SDL_AudioStatus SDL_GetAudioDeviceStatus (SDL_AudioDeviceID devid)
 
SDL_AudioStatus SDL_GetAudioStatus (void)
 
void SDL_PauseAudioDevice (SDL_AudioDeviceID devid, int pause_on)
 
void SDL_PauseAudio (int pause_on)
 
void SDL_LockAudioDevice (SDL_AudioDeviceID devid)
 
void SDL_LockAudio (void)
 
void SDL_UnlockAudioDevice (SDL_AudioDeviceID devid)
 
void SDL_UnlockAudio (void)
 
void SDL_CloseAudioDevice (SDL_AudioDeviceID devid)
 
void SDL_CloseAudio (void)
 
void SDL_AudioQuit (void)
 
SDL_AudioFormat SDL_FirstAudioFormat (SDL_AudioFormat format)
 
SDL_AudioFormat SDL_NextAudioFormat (void)
 
void SDL_CalculateAudioSpec (SDL_AudioSpec *spec)
 
void SDL_MixAudio (Uint8 *dst, const Uint8 *src, Uint32 len, int volume)
 

Variables

static SDL_AudioDriver current_audio
 
static SDL_AudioDeviceopen_devices [16]
 
static const AudioBootStrap *const bootstrap []
 
static int format_idx
 
static int format_idx_sub
 
static SDL_AudioFormat format_list [NUM_FORMATS][NUM_FORMATS]
 

Macro Definition Documentation

◆ _THIS

#define _THIS   SDL_AudioDevice *_this

Definition at line 31 of file SDL_audio.c.

◆ CHECK_FMT_STRING

#define CHECK_FMT_STRING (   x)    if (SDL_strcmp(string, #x) == 0) return AUDIO_##x

◆ FILL_STUB

#define FILL_STUB (   x)
Value:
if (current_audio.impl.x == NULL) { \
current_audio.impl.x = SDL_Audio##x##_Default; \
}

◆ NUM_FORMATS

#define NUM_FORMATS   10

Definition at line 1620 of file SDL_audio.c.

Function Documentation

◆ add_audio_device()

static int add_audio_device ( const char *  name,
void handle,
SDL_AudioDeviceItem **  devices,
int *  devCount 
)
static

Definition at line 374 of file SDL_audio.c.

375 {
376  int retval = -1;
377  SDL_AudioDeviceItem *item;
378  const SDL_AudioDeviceItem *i;
379  int dupenum = 0;
380 
381  SDL_assert(handle != NULL); /* we reserve NULL, audio backends can't use it. */
382  SDL_assert(name != NULL);
383 
385  if (!item) {
386  return SDL_OutOfMemory();
387  }
388 
389  item->original_name = SDL_strdup(name);
390  if (!item->original_name) {
391  SDL_free(item);
392  return SDL_OutOfMemory();
393  }
394 
395  item->dupenum = 0;
396  item->name = item->original_name;
397  item->handle = handle;
398 
400 
401  for (i = *devices; i != NULL; i = i->next) {
402  if (SDL_strcmp(name, i->original_name) == 0) {
403  dupenum = i->dupenum + 1;
404  break; /* stop at the highest-numbered dupe. */
405  }
406  }
407 
408  if (dupenum) {
409  const size_t len = SDL_strlen(name) + 16;
410  char *replacement = (char *) SDL_malloc(len);
411  if (!replacement) {
413  SDL_free(item->original_name);
414  SDL_free(item);
415  SDL_OutOfMemory();
416  return -1;
417  }
418 
419  SDL_snprintf(replacement, len, "%s (%d)", name, dupenum + 1);
420  item->dupenum = dupenum;
421  item->name = replacement;
422  }
423 
424  item->next = *devices;
425  *devices = item;
426  retval = (*devCount)++; /* !!! FIXME: this should be an atomic increment */
427 
429 
430  return retval;
431 }

References current_audio, SDL_AudioDriver::detectionLock, SDL_AudioDeviceItem::dupenum, SDL_AudioDeviceItem::handle, i, SDL_AudioDeviceItem::name, SDL_AudioDeviceItem::next, NULL, SDL_AudioDeviceItem::original_name, retval, SDL_assert, SDL_free, SDL_LockMutex, SDL_malloc, SDL_OutOfMemory, SDL_snprintf, SDL_strcmp, SDL_strdup, SDL_strlen, and SDL_UnlockMutex.

Referenced by add_capture_device(), and add_output_device().

◆ add_capture_device()

◆ add_output_device()

static SDL_INLINE int add_output_device ( const char *  name,
void handle 
)
static

◆ clean_out_device_list()

static void clean_out_device_list ( SDL_AudioDeviceItem **  devices,
int *  devCount,
SDL_bool removedFlag 
)
static

Definition at line 1012 of file SDL_audio.c.

1013 {
1014  SDL_AudioDeviceItem *item = *devices;
1015  SDL_AudioDeviceItem *prev = NULL;
1016  int total = 0;
1017 
1018  while (item) {
1019  SDL_AudioDeviceItem *next = item->next;
1020  if (item->handle != NULL) {
1021  total++;
1022  prev = item;
1023  } else {
1024  if (prev) {
1025  prev->next = next;
1026  } else {
1027  *devices = next;
1028  }
1029  /* these two pointers are the same if not a duplicate devname */
1030  if (item->name != item->original_name) {
1031  SDL_free(item->name);
1032  }
1033  SDL_free(item->original_name);
1034  SDL_free(item);
1035  }
1036  item = next;
1037  }
1038 
1039  *devCount = total;
1040  *removedFlag = SDL_FALSE;
1041 }

References SDL_AudioDeviceItem::handle, SDL_AudioDeviceItem::name, SDL_AudioDeviceItem::next, NULL, SDL_AudioDeviceItem::original_name, SDL_FALSE, and SDL_free.

Referenced by SDL_GetNumAudioDevices().

◆ close_audio_device()

static void close_audio_device ( SDL_AudioDevice device)
static

Definition at line 1110 of file SDL_audio.c.

1111 {
1112  if (!device) {
1113  return;
1114  }
1115 
1116  /* make sure the device is paused before we do anything else, so the
1117  audio callback definitely won't fire again. */
1119  SDL_AtomicSet(&device->paused, 1);
1120  SDL_AtomicSet(&device->shutdown, 1);
1121  SDL_AtomicSet(&device->enabled, 0);
1123 
1124  if (device->thread != NULL) {
1125  SDL_WaitThread(device->thread, NULL);
1126  }
1127  if (device->mixer_lock != NULL) {
1128  SDL_DestroyMutex(device->mixer_lock);
1129  }
1130 
1131  SDL_free(device->work_buffer);
1132  SDL_FreeAudioStream(device->stream);
1133 
1134  if (device->id > 0) {
1135  SDL_AudioDevice *opendev = open_devices[device->id - 1];
1136  SDL_assert((opendev == device) || (opendev == NULL));
1137  if (opendev == device) {
1138  open_devices[device->id - 1] = NULL;
1139  }
1140  }
1141 
1142  if (device->hidden != NULL) {
1144  }
1145 
1146  SDL_FreeDataQueue(device->buffer_queue);
1147 
1148  SDL_free(device);
1149 }

References SDL_AudioDriverImpl::CloseDevice, current_audio, device, SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, NULL, open_devices, SDL_assert, SDL_AtomicSet, SDL_DestroyMutex, SDL_free, SDL_FreeAudioStream, SDL_FreeDataQueue(), SDL_WaitThread, and SDL_AudioDriverImpl::UnlockDevice.

Referenced by open_audio_device(), SDL_AudioQuit(), and SDL_CloseAudioDevice().

◆ finish_audio_entry_points_init()

static void finish_audio_entry_points_init ( void  )
static

Definition at line 331 of file SDL_audio.c.

332 {
333  /*
334  * Fill in stub functions for unused driver entry points. This lets us
335  * blindly call them without having to check for validity first.
336  */
337 
341  }
344  }
345  }
346 
347 #define FILL_STUB(x) \
348  if (current_audio.impl.x == NULL) { \
349  current_audio.impl.x = SDL_Audio##x##_Default; \
350  }
351  FILL_STUB(DetectDevices);
352  FILL_STUB(OpenDevice);
353  FILL_STUB(ThreadInit);
354  FILL_STUB(ThreadDeinit);
355  FILL_STUB(BeginLoopIteration);
356  FILL_STUB(WaitDevice);
357  FILL_STUB(PlayDevice);
358  FILL_STUB(GetDeviceBuf);
359  FILL_STUB(CaptureFromDevice);
360  FILL_STUB(FlushCapture);
361  FILL_STUB(PrepareToClose);
362  FILL_STUB(CloseDevice);
363  FILL_STUB(LockDevice);
364  FILL_STUB(UnlockDevice);
365  FILL_STUB(FreeDeviceHandle);
366  FILL_STUB(Deinitialize);
367 #undef FILL_STUB
368 }

References current_audio, FILL_STUB, SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, NULL, SDL_AudioLockOrUnlockDeviceWithNoMixerLock(), SDL_AudioDriverImpl::SkipMixerLock, and SDL_AudioDriverImpl::UnlockDevice.

Referenced by SDL_AudioInit().

◆ free_device_list()

static void free_device_list ( SDL_AudioDeviceItem **  devices,
int *  devCount 
)
static

Definition at line 447 of file SDL_audio.c.

448 {
449  SDL_AudioDeviceItem *item, *next;
450  for (item = *devices; item != NULL; item = next) {
451  next = item->next;
452  if (item->handle != NULL) {
454  }
455  /* these two pointers are the same if not a duplicate devname */
456  if (item->name != item->original_name) {
457  SDL_free(item->name);
458  }
459  SDL_free(item->original_name);
460  SDL_free(item);
461  }
462  *devices = NULL;
463  *devCount = 0;
464 }

References current_audio, SDL_AudioDriverImpl::FreeDeviceHandle, SDL_AudioDeviceItem::handle, SDL_AudioDriver::impl, SDL_AudioDeviceItem::name, SDL_AudioDeviceItem::next, NULL, SDL_AudioDeviceItem::original_name, and SDL_free.

Referenced by SDL_AudioQuit().

◆ get_audio_device()

static SDL_AudioDevice* get_audio_device ( SDL_AudioDeviceID  id)
static

◆ is_in_audio_device_thread()

static SDL_INLINE SDL_bool is_in_audio_device_thread ( SDL_AudioDevice device)
static

Definition at line 296 of file SDL_audio.c.

297 {
298  /* The device thread locks the same mutex, but not through the public API.
299  This check is in case the application, in the audio callback,
300  tries to lock the thread that we've already locked from the
301  device thread...just in case we only have non-recursive mutexes. */
302  if (device->thread && (SDL_ThreadID() == device->threadid)) {
303  return SDL_TRUE;
304  }
305 
306  return SDL_FALSE;
307 }

References device, SDL_FALSE, SDL_ThreadID, and SDL_TRUE.

Referenced by SDL_AudioLockDevice_Default(), and SDL_AudioUnlockDevice_Default().

◆ mark_device_removed()

static void mark_device_removed ( void handle,
SDL_AudioDeviceItem devices,
SDL_bool removedFlag 
)
static

Definition at line 516 of file SDL_audio.c.

517 {
518  SDL_AudioDeviceItem *item;
519  SDL_assert(handle != NULL);
520  for (item = devices; item != NULL; item = item->next) {
521  if (item->handle == handle) {
522  item->handle = NULL;
523  *removedFlag = SDL_TRUE;
524  return;
525  }
526  }
527 }

References SDL_AudioDeviceItem::handle, SDL_AudioDeviceItem::next, NULL, SDL_assert, and SDL_TRUE.

Referenced by SDL_RemoveAudioDevice().

◆ open_audio_device()

static SDL_AudioDeviceID open_audio_device ( const char *  devname,
int  iscapture,
const SDL_AudioSpec desired,
SDL_AudioSpec obtained,
int  allowed_changes,
int  min_id 
)
static

Definition at line 1216 of file SDL_audio.c.

1219 {
1220  const SDL_bool is_internal_thread = (desired->callback == NULL);
1221  SDL_AudioDeviceID id = 0;
1222  SDL_AudioSpec _obtained;
1224  SDL_bool build_stream;
1225  void *handle = NULL;
1226  int i = 0;
1227 
1228  if (!SDL_WasInit(SDL_INIT_AUDIO)) {
1229  SDL_SetError("Audio subsystem is not initialized");
1230  return 0;
1231  }
1232 
1233  if ((iscapture) && (!current_audio.impl.HasCaptureSupport)) {
1234  SDL_SetError("No capture support");
1235  return 0;
1236  }
1237 
1238  /* !!! FIXME: there is a race condition here if two devices open from two threads at once. */
1239  /* Find an available device ID... */
1240  for (id = min_id - 1; id < SDL_arraysize(open_devices); id++) {
1241  if (open_devices[id] == NULL) {
1242  break;
1243  }
1244  }
1245 
1246  if (id == SDL_arraysize(open_devices)) {
1247  SDL_SetError("Too many open audio devices");
1248  return 0;
1249  }
1250 
1251  if (!obtained) {
1252  obtained = &_obtained;
1253  }
1254  if (!prepare_audiospec(desired, obtained)) {
1255  return 0;
1256  }
1257 
1258  /* If app doesn't care about a specific device, let the user override. */
1259  if (devname == NULL) {
1260  devname = SDL_getenv("SDL_AUDIO_DEVICE_NAME");
1261  }
1262 
1263  /*
1264  * Catch device names at the high level for the simple case...
1265  * This lets us have a basic "device enumeration" for systems that
1266  * don't have multiple devices, but makes sure the device name is
1267  * always NULL when it hits the low level.
1268  *
1269  * Also make sure that the simple case prevents multiple simultaneous
1270  * opens of the default system device.
1271  */
1272 
1273  if ((iscapture) && (current_audio.impl.OnlyHasDefaultCaptureDevice)) {
1274  if ((devname) && (SDL_strcmp(devname, DEFAULT_INPUT_DEVNAME) != 0)) {
1275  SDL_SetError("No such device");
1276  return 0;
1277  }
1278  devname = NULL;
1279 
1280  for (i = 0; i < SDL_arraysize(open_devices); i++) {
1281  if ((open_devices[i]) && (open_devices[i]->iscapture)) {
1282  SDL_SetError("Audio device already open");
1283  return 0;
1284  }
1285  }
1286  } else if ((!iscapture) && (current_audio.impl.OnlyHasDefaultOutputDevice)) {
1287  if ((devname) && (SDL_strcmp(devname, DEFAULT_OUTPUT_DEVNAME) != 0)) {
1288  SDL_SetError("No such device");
1289  return 0;
1290  }
1291  devname = NULL;
1292 
1293  for (i = 0; i < SDL_arraysize(open_devices); i++) {
1294  if ((open_devices[i]) && (!open_devices[i]->iscapture)) {
1295  SDL_SetError("Audio device already open");
1296  return 0;
1297  }
1298  }
1299  } else if (devname != NULL) {
1300  /* if the app specifies an exact string, we can pass the backend
1301  an actual device handle thingey, which saves them the effort of
1302  figuring out what device this was (such as, reenumerating
1303  everything again to find the matching human-readable name).
1304  It might still need to open a device based on the string for,
1305  say, a network audio server, but this optimizes some cases. */
1306  SDL_AudioDeviceItem *item;
1308  for (item = iscapture ? current_audio.inputDevices : current_audio.outputDevices; item; item = item->next) {
1309  if ((item->handle != NULL) && (SDL_strcmp(item->name, devname) == 0)) {
1310  handle = item->handle;
1311  break;
1312  }
1313  }
1315  }
1316 
1318  /* has to be in our device list, or the default device. */
1319  if ((handle == NULL) && (devname != NULL)) {
1320  SDL_SetError("No such device.");
1321  return 0;
1322  }
1323  }
1324 
1325  device = (SDL_AudioDevice *) SDL_calloc(1, sizeof (SDL_AudioDevice));
1326  if (device == NULL) {
1327  SDL_OutOfMemory();
1328  return 0;
1329  }
1330  device->id = id + 1;
1331  device->spec = *obtained;
1332  device->iscapture = iscapture ? SDL_TRUE : SDL_FALSE;
1333  device->handle = handle;
1334 
1335  SDL_AtomicSet(&device->shutdown, 0); /* just in case. */
1336  SDL_AtomicSet(&device->paused, 1);
1337  SDL_AtomicSet(&device->enabled, 1);
1338 
1339  /* Create a mutex for locking the sound buffers */
1341  device->mixer_lock = SDL_CreateMutex();
1342  if (device->mixer_lock == NULL) {
1344  SDL_SetError("Couldn't create mixer lock");
1345  return 0;
1346  }
1347  }
1348 
1349  if (current_audio.impl.OpenDevice(device, handle, devname, iscapture) < 0) {
1351  return 0;
1352  }
1353 
1354  /* if your target really doesn't need it, set it to 0x1 or something. */
1355  /* otherwise, close_audio_device() won't call impl.CloseDevice(). */
1356  SDL_assert(device->hidden != NULL);
1357 
1358  /* See if we need to do any conversion */
1359  build_stream = SDL_FALSE;
1360  if (obtained->freq != device->spec.freq) {
1361  if (allowed_changes & SDL_AUDIO_ALLOW_FREQUENCY_CHANGE) {
1362  obtained->freq = device->spec.freq;
1363  } else {
1364  build_stream = SDL_TRUE;
1365  }
1366  }
1367  if (obtained->format != device->spec.format) {
1368  if (allowed_changes & SDL_AUDIO_ALLOW_FORMAT_CHANGE) {
1369  obtained->format = device->spec.format;
1370  } else {
1371  build_stream = SDL_TRUE;
1372  }
1373  }
1374  if (obtained->channels != device->spec.channels) {
1375  if (allowed_changes & SDL_AUDIO_ALLOW_CHANNELS_CHANGE) {
1376  obtained->channels = device->spec.channels;
1377  } else {
1378  build_stream = SDL_TRUE;
1379  }
1380  }
1381  if (device->spec.samples != obtained->samples) {
1382  if (allowed_changes & SDL_AUDIO_ALLOW_SAMPLES_CHANGE) {
1383  obtained->samples = device->spec.samples;
1384  } else {
1385  build_stream = SDL_TRUE;
1386  }
1387  }
1388 
1389  SDL_CalculateAudioSpec(obtained); /* recalc after possible changes. */
1390 
1391  device->callbackspec = *obtained;
1392 
1393  if (build_stream) {
1394  if (iscapture) {
1395  device->stream = SDL_NewAudioStream(device->spec.format,
1396  device->spec.channels, device->spec.freq,
1397  obtained->format, obtained->channels, obtained->freq);
1398  } else {
1399  device->stream = SDL_NewAudioStream(obtained->format, obtained->channels,
1400  obtained->freq, device->spec.format,
1401  device->spec.channels, device->spec.freq);
1402  }
1403 
1404  if (!device->stream) {
1406  return 0;
1407  }
1408  }
1409 
1410  if (device->spec.callback == NULL) { /* use buffer queueing? */
1411  /* pool a few packets to start. Enough for two callbacks. */
1412  device->buffer_queue = SDL_NewDataQueue(SDL_AUDIOBUFFERQUEUE_PACKETLEN, obtained->size * 2);
1413  if (!device->buffer_queue) {
1415  SDL_SetError("Couldn't create audio buffer queue");
1416  return 0;
1417  }
1418  device->callbackspec.callback = iscapture ? SDL_BufferQueueFillCallback : SDL_BufferQueueDrainCallback;
1419  device->callbackspec.userdata = device;
1420  }
1421 
1422  /* Allocate a scratch audio buffer */
1423  device->work_buffer_len = build_stream ? device->callbackspec.size : 0;
1424  if (device->spec.size > device->work_buffer_len) {
1425  device->work_buffer_len = device->spec.size;
1426  }
1427  SDL_assert(device->work_buffer_len > 0);
1428 
1429  device->work_buffer = (Uint8 *) SDL_malloc(device->work_buffer_len);
1430  if (device->work_buffer == NULL) {
1432  SDL_OutOfMemory();
1433  return 0;
1434  }
1435 
1436  open_devices[id] = device; /* add it to our list of open devices. */
1437 
1438  /* Start the audio thread if necessary */
1440  /* Start the audio thread */
1441  /* !!! FIXME: we don't force the audio thread stack size here if it calls into user code, but maybe we should? */
1442  /* buffer queueing callback only needs a few bytes, so make the stack tiny. */
1443  const size_t stacksize = is_internal_thread ? 64 * 1024 : 0;
1444  char threadname[64];
1445 
1446  SDL_snprintf(threadname, sizeof (threadname), "SDLAudio%c%d", (iscapture) ? 'C' : 'P', (int) device->id);
1447  device->thread = SDL_CreateThreadInternal(iscapture ? SDL_CaptureAudio : SDL_RunAudio, threadname, stacksize, device);
1448 
1449  if (device->thread == NULL) {
1451  SDL_SetError("Couldn't create audio thread");
1452  return 0;
1453  }
1454  }
1455 
1456  return device->id;
1457 }

References SDL_AudioDriverImpl::AllowsArbitraryDeviceNames, SDL_AudioSpec::callback, SDL_AudioSpec::channels, close_audio_device(), current_audio, DEFAULT_INPUT_DEVNAME, DEFAULT_OUTPUT_DEVNAME, SDL_AudioDriver::detectionLock, device, SDL_AudioSpec::format, SDL_AudioSpec::freq, SDL_AudioDeviceItem::handle, SDL_AudioDriverImpl::HasCaptureSupport, i, SDL_AudioDriver::impl, SDL_AudioDriver::inputDevices, SDL_AudioDevice::iscapture, SDL_AudioDeviceItem::name, SDL_AudioDeviceItem::next, NULL, SDL_AudioDriverImpl::OnlyHasDefaultCaptureDevice, SDL_AudioDriverImpl::OnlyHasDefaultOutputDevice, open_devices, SDL_AudioDriverImpl::OpenDevice, SDL_AudioDriver::outputDevices, prepare_audiospec(), SDL_AudioDriverImpl::ProvidesOwnCallbackThread, SDL_AudioSpec::samples, SDL_arraysize, SDL_assert, SDL_AtomicSet, SDL_AUDIO_ALLOW_CHANNELS_CHANGE, SDL_AUDIO_ALLOW_FORMAT_CHANGE, SDL_AUDIO_ALLOW_FREQUENCY_CHANGE, SDL_AUDIO_ALLOW_SAMPLES_CHANGE, SDL_AUDIOBUFFERQUEUE_PACKETLEN, SDL_BufferQueueDrainCallback(), SDL_BufferQueueFillCallback(), SDL_CalculateAudioSpec(), SDL_calloc, SDL_CaptureAudio(), SDL_CreateMutex, SDL_CreateThreadInternal(), SDL_FALSE, SDL_getenv, SDL_INIT_AUDIO, SDL_LockMutex, SDL_malloc, SDL_NewAudioStream, SDL_NewDataQueue(), SDL_OutOfMemory, SDL_RunAudio(), SDL_SetError, SDL_snprintf, SDL_strcmp, SDL_TRUE, SDL_UnlockMutex, SDL_WasInit, SDL_AudioSpec::size, and SDL_AudioDriverImpl::SkipMixerLock.

Referenced by SDL_OpenAudio(), and SDL_OpenAudioDevice().

◆ prepare_audiospec()

static int prepare_audiospec ( const SDL_AudioSpec orig,
SDL_AudioSpec prepared 
)
static

Definition at line 1158 of file SDL_audio.c.

1159 {
1160  SDL_memcpy(prepared, orig, sizeof(SDL_AudioSpec));
1161 
1162  if (orig->freq == 0) {
1163  const char *env = SDL_getenv("SDL_AUDIO_FREQUENCY");
1164  if ((!env) || ((prepared->freq = SDL_atoi(env)) == 0)) {
1165  prepared->freq = 22050; /* a reasonable default */
1166  }
1167  }
1168 
1169  if (orig->format == 0) {
1170  const char *env = SDL_getenv("SDL_AUDIO_FORMAT");
1171  if ((!env) || ((prepared->format = SDL_ParseAudioFormat(env)) == 0)) {
1172  prepared->format = AUDIO_S16; /* a reasonable default */
1173  }
1174  }
1175 
1176  switch (orig->channels) {
1177  case 0:{
1178  const char *env = SDL_getenv("SDL_AUDIO_CHANNELS");
1179  if ((!env) || ((prepared->channels = (Uint8) SDL_atoi(env)) == 0)) {
1180  prepared->channels = 2; /* a reasonable default */
1181  }
1182  break;
1183  }
1184  case 1: /* Mono */
1185  case 2: /* Stereo */
1186  case 4: /* Quadrophonic */
1187  case 6: /* 5.1 surround */
1188  case 8: /* 7.1 surround */
1189  break;
1190  default:
1191  SDL_SetError("Unsupported number of audio channels.");
1192  return 0;
1193  }
1194 
1195  if (orig->samples == 0) {
1196  const char *env = SDL_getenv("SDL_AUDIO_SAMPLES");
1197  if ((!env) || ((prepared->samples = (Uint16) SDL_atoi(env)) == 0)) {
1198  /* Pick a default of ~46 ms at desired frequency */
1199  /* !!! FIXME: remove this when the non-Po2 resampling is in. */
1200  const int samples = (prepared->freq / 1000) * 46;
1201  int power2 = 1;
1202  while (power2 < samples) {
1203  power2 *= 2;
1204  }
1205  prepared->samples = power2;
1206  }
1207  }
1208 
1209  /* Calculate the silence and size of the audio specification */
1210  SDL_CalculateAudioSpec(prepared);
1211 
1212  return 1;
1213 }

References AUDIO_S16, SDL_AudioSpec::channels, SDL_AudioSpec::format, SDL_AudioSpec::freq, SDL_AudioSpec::samples, SDL_atoi, SDL_CalculateAudioSpec(), SDL_getenv, SDL_memcpy, SDL_ParseAudioFormat(), and SDL_SetError.

Referenced by open_audio_device().

◆ SDL_AddAudioDevice()

void SDL_AddAudioDevice ( const int  iscapture,
const char *  name,
void handle 
)

Definition at line 469 of file SDL_audio.c.

470 {
471  const int device_index = iscapture ? add_capture_device(name, handle) : add_output_device(name, handle);
472  if (device_index != -1) {
473  /* Post the event, if desired */
476  SDL_zero(event);
477  event.adevice.type = SDL_AUDIODEVICEADDED;
478  event.adevice.which = device_index;
479  event.adevice.iscapture = iscapture;
481  }
482  }
483 }

References add_capture_device(), add_output_device(), SDL_AUDIODEVICEADDED, SDL_ENABLE, SDL_GetEventState, SDL_PushEvent, and SDL_zero.

Referenced by SDL_AudioDetectDevices_Default().

◆ SDL_AudioBeginLoopIteration_Default()

static void SDL_AudioBeginLoopIteration_Default ( _THIS  )
static

Definition at line 237 of file SDL_audio.c.

238 { /* no-op. */
239 }

◆ SDL_AudioCaptureFromDevice_Default()

static int SDL_AudioCaptureFromDevice_Default ( _THIS  ,
void buffer,
int  buflen 
)
static

Definition at line 258 of file SDL_audio.c.

259 {
260  return -1; /* just fail immediately. */
261 }

◆ SDL_AudioCloseDevice_Default()

static void SDL_AudioCloseDevice_Default ( _THIS  )
static

Definition at line 274 of file SDL_audio.c.

275 { /* no-op. */
276 }

◆ SDL_AudioDeinitialize_Default()

static void SDL_AudioDeinitialize_Default ( void  )
static

Definition at line 279 of file SDL_audio.c.

280 { /* no-op. */
281 }

◆ SDL_AudioDetectDevices_Default()

◆ SDL_AudioFlushCapture_Default()

static void SDL_AudioFlushCapture_Default ( _THIS  )
static

Definition at line 264 of file SDL_audio.c.

265 { /* no-op. */
266 }

◆ SDL_AudioFreeDeviceHandle_Default()

static void SDL_AudioFreeDeviceHandle_Default ( void handle)
static

Definition at line 284 of file SDL_audio.c.

285 { /* no-op. */
286 }

◆ SDL_AudioGetDeviceBuf_Default()

static Uint8* SDL_AudioGetDeviceBuf_Default ( _THIS  )
static

Definition at line 252 of file SDL_audio.c.

253 {
254  return NULL;
255 }

References NULL.

◆ SDL_AudioInit()

int SDL_AudioInit ( const char *  driver_name)

Definition at line 940 of file SDL_audio.c.

941 {
942  int i = 0;
943  int initialized = 0;
944  int tried_to_init = 0;
945 
947  SDL_AudioQuit(); /* shutdown driver if already running. */
948  }
949 
952 
953  /* Select the proper audio driver */
954  if (driver_name == NULL) {
955  driver_name = SDL_getenv("SDL_AUDIODRIVER");
956  }
957 
958  for (i = 0; (!initialized) && (bootstrap[i]); ++i) {
959  /* make sure we should even try this driver before doing so... */
960  const AudioBootStrap *backend = bootstrap[i];
961  if ((driver_name && (SDL_strncasecmp(backend->name, driver_name, SDL_strlen(driver_name)) != 0)) ||
962  (!driver_name && backend->demand_only)) {
963  continue;
964  }
965 
966  tried_to_init = 1;
968  current_audio.name = backend->name;
969  current_audio.desc = backend->desc;
970  initialized = backend->init(&current_audio.impl);
971  }
972 
973  if (!initialized) {
974  /* specific drivers will set the error message if they fail... */
975  if (!tried_to_init) {
976  if (driver_name) {
977  SDL_SetError("Audio target '%s' not available", driver_name);
978  } else {
979  SDL_SetError("No available audio device");
980  }
981  }
982 
984  return -1; /* No driver was available, so fail. */
985  }
986 
988 
990 
991  /* Make sure we have a list of devices available at startup. */
993 
994 #ifdef HAVE_LIBSAMPLERATE_H
995  LoadLibSampleRate();
996 #endif
997 
998  return 0;
999 }

References bootstrap, current_audio, AudioBootStrap::demand_only, SDL_AudioDriver::desc, AudioBootStrap::desc, SDL_AudioDriverImpl::DetectDevices, SDL_AudioDriver::detectionLock, finish_audio_entry_points_init(), i, SDL_AudioDriver::impl, AudioBootStrap::init, SDL_AudioDriver::name, AudioBootStrap::name, NULL, open_devices, SDL_AudioQuit(), SDL_CreateMutex, SDL_getenv, SDL_INIT_AUDIO, SDL_SetError, SDL_strlen, SDL_strncasecmp, SDL_WasInit, and SDL_zero.

◆ SDL_AudioLockDevice_Default()

static void SDL_AudioLockDevice_Default ( SDL_AudioDevice device)
static

Definition at line 310 of file SDL_audio.c.

311 {
313  SDL_LockMutex(device->mixer_lock);
314  }
315 }

References device, is_in_audio_device_thread(), and SDL_LockMutex.

◆ SDL_AudioLockOrUnlockDeviceWithNoMixerLock()

static void SDL_AudioLockOrUnlockDeviceWithNoMixerLock ( SDL_AudioDevice device)
static

Definition at line 326 of file SDL_audio.c.

327 {
328 }

Referenced by finish_audio_entry_points_init().

◆ SDL_AudioOpenDevice_Default()

static int SDL_AudioOpenDevice_Default ( _THIS  ,
void handle,
const char *  devname,
int  iscapture 
)
static

Definition at line 290 of file SDL_audio.c.

291 {
292  return SDL_Unsupported();
293 }

References SDL_Unsupported.

◆ SDL_AudioPlayDevice_Default()

static void SDL_AudioPlayDevice_Default ( _THIS  )
static

Definition at line 247 of file SDL_audio.c.

248 { /* no-op. */
249 }

◆ SDL_AudioPrepareToClose_Default()

static void SDL_AudioPrepareToClose_Default ( _THIS  )
static

Definition at line 269 of file SDL_audio.c.

270 { /* no-op. */
271 }

◆ SDL_AudioQuit()

void SDL_AudioQuit ( void  )

◆ SDL_AudioThreadDeinit_Default()

static void SDL_AudioThreadDeinit_Default ( _THIS  )
static

Definition at line 232 of file SDL_audio.c.

233 { /* no-op. */
234 }

◆ SDL_AudioThreadInit_Default()

static void SDL_AudioThreadInit_Default ( _THIS  )
static

Definition at line 227 of file SDL_audio.c.

228 { /* no-op. */
229 }

◆ SDL_AudioUnlockDevice_Default()

static void SDL_AudioUnlockDevice_Default ( SDL_AudioDevice device)
static

Definition at line 318 of file SDL_audio.c.

319 {
321  SDL_UnlockMutex(device->mixer_lock);
322  }
323 }

References device, is_in_audio_device_thread(), and SDL_UnlockMutex.

◆ SDL_AudioWaitDevice_Default()

static void SDL_AudioWaitDevice_Default ( _THIS  )
static

Definition at line 242 of file SDL_audio.c.

243 { /* no-op. */
244 }

◆ SDL_BufferQueueDrainCallback()

static void SDL_BufferQueueDrainCallback ( void userdata,
Uint8 stream,
int  len 
)
static

Definition at line 561 of file SDL_audio.c.

562 {
563  /* this function always holds the mixer lock before being called. */
564  SDL_AudioDevice *device = (SDL_AudioDevice *) userdata;
565  size_t dequeued;
566 
567  SDL_assert(device != NULL); /* this shouldn't ever happen, right?! */
568  SDL_assert(!device->iscapture); /* this shouldn't ever happen, right?! */
569  SDL_assert(len >= 0); /* this shouldn't ever happen, right?! */
570 
571  dequeued = SDL_ReadFromDataQueue(device->buffer_queue, stream, len);
572  stream += dequeued;
573  len -= (int) dequeued;
574 
575  if (len > 0) { /* fill any remaining space in the stream with silence. */
576  SDL_assert(SDL_CountDataQueue(device->buffer_queue) == 0);
577  SDL_memset(stream, device->spec.silence, len);
578  }
579 }

References device, NULL, SDL_assert, SDL_CountDataQueue(), SDL_memset, and SDL_ReadFromDataQueue().

Referenced by open_audio_device(), SDL_GetQueuedAudioSize(), and SDL_QueueAudio().

◆ SDL_BufferQueueFillCallback()

static void SDL_BufferQueueFillCallback ( void userdata,
Uint8 stream,
int  len 
)
static

Definition at line 582 of file SDL_audio.c.

583 {
584  /* this function always holds the mixer lock before being called. */
585  SDL_AudioDevice *device = (SDL_AudioDevice *) userdata;
586 
587  SDL_assert(device != NULL); /* this shouldn't ever happen, right?! */
588  SDL_assert(device->iscapture); /* this shouldn't ever happen, right?! */
589  SDL_assert(len >= 0); /* this shouldn't ever happen, right?! */
590 
591  /* note that if this needs to allocate more space and run out of memory,
592  we have no choice but to quietly drop the data and hope it works out
593  later, but you probably have bigger problems in this case anyhow. */
594  SDL_WriteToDataQueue(device->buffer_queue, stream, len);
595 }

References device, NULL, SDL_assert, and SDL_WriteToDataQueue().

Referenced by open_audio_device(), SDL_DequeueAudio(), and SDL_GetQueuedAudioSize().

◆ SDL_CalculateAudioSpec()

void SDL_CalculateAudioSpec ( SDL_AudioSpec spec)

Definition at line 1668 of file SDL_audio.c.

1669 {
1670  switch (spec->format) {
1671  case AUDIO_U8:
1672  spec->silence = 0x80;
1673  break;
1674  default:
1675  spec->silence = 0x00;
1676  break;
1677  }
1679  spec->size *= spec->channels;
1680  spec->size *= spec->samples;
1681 }

References AUDIO_U8, SDL_AudioSpec::channels, SDL_AudioSpec::format, SDL_AudioSpec::samples, SDL_AUDIO_BITSIZE, SDL_AudioSpec::silence, SDL_AudioSpec::size, and spec.

Referenced by open_audio_device(), and prepare_audiospec().

◆ SDL_CaptureAudio()

static int SDL_CaptureAudio ( void devicep)
static

Definition at line 785 of file SDL_audio.c.

786 {
787  SDL_AudioDevice *device = (SDL_AudioDevice *) devicep;
788  const int silence = (int) device->spec.silence;
789  const Uint32 delay = ((device->spec.samples * 1000) / device->spec.freq);
790  const int data_len = device->spec.size;
791  Uint8 *data;
792  void *udata = device->callbackspec.userdata;
793  SDL_AudioCallback callback = device->callbackspec.callback;
794 
795  SDL_assert(device->iscapture);
796 
797 #if SDL_AUDIO_DRIVER_ANDROID
798  {
799  /* Set thread priority to THREAD_PRIORITY_AUDIO */
800  extern void Android_JNI_AudioSetThreadPriority(int, int);
802  }
803 #else
804  /* The audio mixing is always a high priority thread */
806 #endif
807 
808  /* Perform any thread setup */
809  device->threadid = SDL_ThreadID();
811 
812  /* Loop, filling the audio buffers */
813  while (!SDL_AtomicGet(&device->shutdown)) {
814  int still_need;
815  Uint8 *ptr;
816 
818 
819  if (SDL_AtomicGet(&device->paused)) {
820  SDL_Delay(delay); /* just so we don't cook the CPU. */
821  if (device->stream) {
822  SDL_AudioStreamClear(device->stream);
823  }
824  current_audio.impl.FlushCapture(device); /* dump anything pending. */
825  continue;
826  }
827 
828  /* Fill the current buffer with sound */
829  still_need = data_len;
830 
831  /* Use the work_buffer to hold data read from the device. */
832  data = device->work_buffer;
833  SDL_assert(data != NULL);
834 
835  ptr = data;
836 
837  /* We still read from the device when "paused" to keep the state sane,
838  and block when there isn't data so this thread isn't eating CPU.
839  But we don't process it further or call the app's callback. */
840 
841  if (!SDL_AtomicGet(&device->enabled)) {
842  SDL_Delay(delay); /* try to keep callback firing at normal pace. */
843  } else {
844  while (still_need > 0) {
845  const int rc = current_audio.impl.CaptureFromDevice(device, ptr, still_need);
846  SDL_assert(rc <= still_need); /* device should not overflow buffer. :) */
847  if (rc > 0) {
848  still_need -= rc;
849  ptr += rc;
850  } else { /* uhoh, device failed for some reason! */
852  break;
853  }
854  }
855  }
856 
857  if (still_need > 0) {
858  /* Keep any data we already read, silence the rest. */
859  SDL_memset(ptr, silence, still_need);
860  }
861 
862  if (device->stream) {
863  /* if this fails...oh well. */
864  SDL_AudioStreamPut(device->stream, data, data_len);
865 
866  while (SDL_AudioStreamAvailable(device->stream) >= ((int) device->callbackspec.size)) {
867  const int got = SDL_AudioStreamGet(device->stream, device->work_buffer, device->callbackspec.size);
868  SDL_assert((got < 0) || (got == device->callbackspec.size));
869  if (got != device->callbackspec.size) {
870  SDL_memset(device->work_buffer, device->spec.silence, device->callbackspec.size);
871  }
872 
873  /* !!! FIXME: this should be LockDevice. */
874  SDL_LockMutex(device->mixer_lock);
875  if (!SDL_AtomicGet(&device->paused)) {
876  callback(udata, device->work_buffer, device->callbackspec.size);
877  }
878  SDL_UnlockMutex(device->mixer_lock);
879  }
880  } else { /* feeding user callback directly without streaming. */
881  /* !!! FIXME: this should be LockDevice. */
882  SDL_LockMutex(device->mixer_lock);
883  if (!SDL_AtomicGet(&device->paused)) {
884  callback(udata, data, device->callbackspec.size);
885  }
886  SDL_UnlockMutex(device->mixer_lock);
887  }
888  }
889 
891 
893 
894  return 0;
895 }

References Android_JNI_AudioSetThreadPriority(), SDL_AudioDriverImpl::BeginLoopIteration, callback(), SDL_AudioDriverImpl::CaptureFromDevice, current_audio, device, SDL_AudioDriverImpl::FlushCapture, SDL_AudioDriver::impl, NULL, SDL_assert, SDL_AtomicGet, SDL_AudioStreamAvailable, SDL_AudioStreamClear, SDL_AudioStreamGet, SDL_AudioStreamPut, SDL_Delay, SDL_LockMutex, SDL_memset, SDL_OpenedAudioDeviceDisconnected(), SDL_SetThreadPriority, SDL_THREAD_PRIORITY_HIGH, SDL_ThreadID, SDL_UnlockMutex, SDL_AudioDriverImpl::ThreadDeinit, and SDL_AudioDriverImpl::ThreadInit.

Referenced by open_audio_device().

◆ SDL_ClearQueuedAudio()

void SDL_ClearQueuedAudio ( SDL_AudioDeviceID  dev)

Drop any queued audio data. For playback devices, this is any queued data still waiting to be submitted to the hardware. For capture devices, this is any data that was queued by the device that hasn't yet been dequeued by the application.

Immediately after this call, SDL_GetQueuedAudioSize() will return 0. For playback devices, the hardware will start playing silence if more audio isn't queued. Unpaused capture devices will start filling the queue again as soon as they have more data available (which, depending on the state of the hardware and the thread, could be before this function call returns!).

This will not prevent playback of queued audio that's already been sent to the hardware, as we can not undo that, so expect there to be some fraction of a second of audio that might still be heard. This can be useful if you want to, say, drop any pending music during a level change in your game.

You may not queue audio on a device that is using an application-supplied callback; calling this function on such a device is always a no-op. You have to queue audio with SDL_QueueAudio()/SDL_DequeueAudio(), or use the audio callback, but not both.

You should not call SDL_LockAudio() on the device before clearing the queue; SDL handles locking internally for this function.

This function always succeeds and thus returns void.

Parameters
devThe device ID of which to clear the audio queue.
See also
SDL_QueueAudio
SDL_GetQueuedAudioSize

Definition at line 662 of file SDL_audio.c.

663 {
665 
666  if (!device) {
667  return; /* nothing to do. */
668  }
669 
670  /* Blank out the device and release the mutex. Free it afterwards. */
672 
673  /* Keep up to two packets in the pool to reduce future malloc pressure. */
675 
677 }

References current_audio, device, get_audio_device(), SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, SDL_AUDIOBUFFERQUEUE_PACKETLEN, SDL_ClearDataQueue(), and SDL_AudioDriverImpl::UnlockDevice.

◆ SDL_CloseAudio()

void SDL_CloseAudio ( void  )

This function shuts down audio processing and closes the audio device.

Definition at line 1584 of file SDL_audio.c.

1585 {
1587 }

References SDL_CloseAudioDevice().

◆ SDL_CloseAudioDevice()

void SDL_CloseAudioDevice ( SDL_AudioDeviceID  devid)

Definition at line 1578 of file SDL_audio.c.

1579 {
1581 }

References close_audio_device(), and get_audio_device().

Referenced by SDL_CloseAudio().

◆ SDL_DequeueAudio()

Uint32 SDL_DequeueAudio ( SDL_AudioDeviceID  dev,
void data,
Uint32  len 
)

Dequeue more audio on non-callback devices.

(If you are looking to queue audio for output on a non-callback playback device, you want SDL_QueueAudio() instead. This will always return 0 if you use it with playback devices.)

SDL offers two ways to retrieve audio from a capture device: you can either supply a callback that SDL triggers with some frequency as the device records more audio data, (push method), or you can supply no callback, and then SDL will expect you to retrieve data at regular intervals (pull method) with this function.

There are no limits on the amount of data you can queue, short of exhaustion of address space. Data from the device will keep queuing as necessary without further intervention from you. This means you will eventually run out of memory if you aren't routinely dequeueing data.

Capture devices will not queue data when paused; if you are expecting to not need captured audio for some length of time, use SDL_PauseAudioDevice() to stop the capture device from queueing more data. This can be useful during, say, level loading times. When unpaused, capture devices will start queueing data from that point, having flushed any capturable data available while paused.

This function is thread-safe, but dequeueing from the same device from two threads at once does not promise which thread will dequeued data first.

You may not dequeue audio from a device that is using an application-supplied callback; doing so returns an error. You have to use the audio callback, or dequeue audio with this function, but not both.

You should not call SDL_LockAudio() on the device before queueing; SDL handles locking internally for this function.

Parameters
devThe device ID from which we will dequeue audio.
dataA pointer into where audio data should be copied.
lenThe number of bytes (not samples!) to which (data) points.
Returns
number of bytes dequeued, which could be less than requested.
See also
SDL_GetQueuedAudioSize
SDL_ClearQueuedAudio

Definition at line 621 of file SDL_audio.c.

622 {
624  Uint32 rc;
625 
626  if ( (len == 0) || /* nothing to do? */
627  (!device) || /* called with bogus device id */
628  (!device->iscapture) || /* playback devices can't dequeue */
629  (device->callbackspec.callback != SDL_BufferQueueFillCallback) ) { /* not set for queueing */
630  return 0; /* just report zero bytes dequeued. */
631  }
632 
634  rc = (Uint32) SDL_ReadFromDataQueue(device->buffer_queue, data, len);
636  return rc;
637 }

References current_audio, device, get_audio_device(), SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, SDL_BufferQueueFillCallback(), SDL_ReadFromDataQueue(), and SDL_AudioDriverImpl::UnlockDevice.

◆ SDL_FirstAudioFormat()

SDL_AudioFormat SDL_FirstAudioFormat ( SDL_AudioFormat  format)

Definition at line 1647 of file SDL_audio.c.

1648 {
1649  for (format_idx = 0; format_idx < NUM_FORMATS; ++format_idx) {
1650  if (format_list[format_idx][0] == format) {
1651  break;
1652  }
1653  }
1654  format_idx_sub = 0;
1655  return SDL_NextAudioFormat();
1656 }

References format_idx, format_idx_sub, format_list, NUM_FORMATS, and SDL_NextAudioFormat().

◆ SDL_GetAudioDeviceName()

const char* SDL_GetAudioDeviceName ( int  index,
int  iscapture 
)

Get the human-readable name of a specific audio device. Must be a value between 0 and (number of audio devices-1). Only valid after a successfully initializing the audio subsystem. The values returned by this function reflect the latest call to SDL_GetNumAudioDevices(); recall that function to redetect available hardware.

The string returned by this function is UTF-8 encoded, read-only, and managed internally. You are not to free it. If you need to keep the string for any length of time, you should make your own copy of it, as it will be invalid next time any of several other SDL functions is called.

Definition at line 1070 of file SDL_audio.c.

1071 {
1072  const char *retval = NULL;
1073 
1074  if (!SDL_WasInit(SDL_INIT_AUDIO)) {
1075  SDL_SetError("Audio subsystem is not initialized");
1076  return NULL;
1077  }
1078 
1079  if ((iscapture) && (!current_audio.impl.HasCaptureSupport)) {
1080  SDL_SetError("No capture support");
1081  return NULL;
1082  }
1083 
1084  if (index >= 0) {
1085  SDL_AudioDeviceItem *item;
1086  int i;
1087 
1091  if (index < i) {
1092  for (i--; i > index; i--, item = item->next) {
1093  SDL_assert(item != NULL);
1094  }
1095  SDL_assert(item != NULL);
1096  retval = item->name;
1097  }
1099  }
1100 
1101  if (retval == NULL) {
1102  SDL_SetError("No such device");
1103  }
1104 
1105  return retval;
1106 }

References current_audio, SDL_AudioDriver::detectionLock, SDL_AudioDriverImpl::HasCaptureSupport, i, SDL_AudioDriver::impl, SDL_AudioDriver::inputDeviceCount, SDL_AudioDriver::inputDevices, SDL_AudioDeviceItem::next, NULL, SDL_AudioDriver::outputDeviceCount, SDL_AudioDriver::outputDevices, retval, SDL_assert, SDL_INIT_AUDIO, SDL_LockMutex, SDL_SetError, SDL_UnlockMutex, and SDL_WasInit.

◆ SDL_GetAudioDeviceStatus()

SDL_AudioStatus SDL_GetAudioDeviceStatus ( SDL_AudioDeviceID  devid)

Definition at line 1506 of file SDL_audio.c.

1507 {
1510  if (device && SDL_AtomicGet(&device->enabled)) {
1511  if (SDL_AtomicGet(&device->paused)) {
1512  status = SDL_AUDIO_PAUSED;
1513  } else {
1514  status = SDL_AUDIO_PLAYING;
1515  }
1516  }
1517  return status;
1518 }

References device, get_audio_device(), SDL_AtomicGet, SDL_AUDIO_PAUSED, SDL_AUDIO_PLAYING, and SDL_AUDIO_STOPPED.

Referenced by SDL_GetAudioStatus().

◆ SDL_GetAudioDriver()

const char* SDL_GetAudioDriver ( int  index)

Definition at line 931 of file SDL_audio.c.

932 {
933  if (index >= 0 && index < SDL_GetNumAudioDrivers()) {
934  return bootstrap[index]->name;
935  }
936  return NULL;
937 }

References bootstrap, AudioBootStrap::name, NULL, and SDL_GetNumAudioDrivers().

◆ SDL_GetAudioStatus()

SDL_AudioStatus SDL_GetAudioStatus ( void  )

Definition at line 1522 of file SDL_audio.c.

1523 {
1524  return SDL_GetAudioDeviceStatus(1);
1525 }

References SDL_GetAudioDeviceStatus().

◆ SDL_GetCurrentAudioDriver()

const char* SDL_GetCurrentAudioDriver ( void  )

This function returns the name of the current audio driver, or NULL if no driver has been initialized.

Definition at line 1005 of file SDL_audio.c.

1006 {
1007  return current_audio.name;
1008 }

References current_audio, and SDL_AudioDriver::name.

◆ SDL_GetNumAudioDevices()

int SDL_GetNumAudioDevices ( int  iscapture)

Get the number of available devices exposed by the current driver. Only valid after a successfully initializing the audio subsystem. Returns -1 if an explicit list of devices can't be determined; this is not an error. For example, if SDL is set up to talk to a remote audio server, it can't list every one available on the Internet, but it will still allow a specific host to be specified to SDL_OpenAudioDevice().

In many common cases, when this function returns a value <= 0, it can still successfully open the default device (NULL for first argument of SDL_OpenAudioDevice()).

Definition at line 1045 of file SDL_audio.c.

References SDL_AudioDriver::captureDevicesRemoved, clean_out_device_list(), current_audio, SDL_AudioDriver::detectionLock, SDL_AudioDriver::inputDeviceCount, SDL_AudioDriver::inputDevices, SDL_AudioDriver::outputDeviceCount, SDL_AudioDriver::outputDevices, SDL_AudioDriver::outputDevicesRemoved, retval, SDL_INIT_AUDIO, SDL_LockMutex, SDL_UnlockMutex, and SDL_WasInit.

◆ SDL_GetNumAudioDrivers()

int SDL_GetNumAudioDrivers ( void  )

Definition at line 925 of file SDL_audio.c.

926 {
927  return SDL_arraysize(bootstrap) - 1;
928 }

References bootstrap, and SDL_arraysize.

Referenced by SDL_GetAudioDriver().

◆ SDL_GetQueuedAudioSize()

Uint32 SDL_GetQueuedAudioSize ( SDL_AudioDeviceID  dev)

Get the number of bytes of still-queued audio.

For playback device:

This is the number of bytes that have been queued for playback with SDL_QueueAudio(), but have not yet been sent to the hardware. This number may shrink at any time, so this only informs of pending data.

Once we've sent it to the hardware, this function can not decide the exact byte boundary of what has been played. It's possible that we just gave the hardware several kilobytes right before you called this function, but it hasn't played any of it yet, or maybe half of it, etc.

For capture devices:

This is the number of bytes that have been captured by the device and are waiting for you to dequeue. This number may grow at any time, so this only informs of the lower-bound of available data.

You may not queue audio on a device that is using an application-supplied callback; calling this function on such a device always returns 0. You have to queue audio with SDL_QueueAudio()/SDL_DequeueAudio(), or use the audio callback, but not both.

You should not call SDL_LockAudio() on the device before querying; SDL handles locking internally for this function.

Parameters
devThe device ID of which we will query queued audio size.
Returns
Number of bytes (not samples!) of queued audio.
See also
SDL_QueueAudio
SDL_ClearQueuedAudio

Definition at line 640 of file SDL_audio.c.

641 {
642  Uint32 retval = 0;
644 
645  if (!device) {
646  return 0;
647  }
648 
649  /* Nothing to do unless we're set up for queueing. */
650  if (device->callbackspec.callback == SDL_BufferQueueDrainCallback ||
651  device->callbackspec.callback == SDL_BufferQueueFillCallback)
652  {
654  retval = (Uint32) SDL_CountDataQueue(device->buffer_queue);
656  }
657 
658  return retval;
659 }

References current_audio, device, get_audio_device(), SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, retval, SDL_BufferQueueDrainCallback(), SDL_BufferQueueFillCallback(), SDL_CountDataQueue(), and SDL_AudioDriverImpl::UnlockDevice.

◆ SDL_LockAudio()

void SDL_LockAudio ( void  )

Definition at line 1556 of file SDL_audio.c.

1557 {
1559 }

References SDL_LockAudioDevice().

◆ SDL_LockAudioDevice()

void SDL_LockAudioDevice ( SDL_AudioDeviceID  devid)

Definition at line 1546 of file SDL_audio.c.

1547 {
1548  /* Obtain a lock on the mixing buffers */
1550  if (device) {
1552  }
1553 }

References current_audio, device, get_audio_device(), SDL_AudioDriver::impl, and SDL_AudioDriverImpl::LockDevice.

Referenced by SDL_LockAudio().

◆ SDL_MixAudio()

void SDL_MixAudio ( Uint8 dst,
const Uint8 src,
Uint32  len,
int  volume 
)

This takes two audio buffers of the playing audio format and mixes them, performing addition, volume adjustment, and overflow clipping. The volume ranges from 0 - 128, and should be set to SDL_MIX_MAXVOLUME for full audio volume. Note this does not change hardware volume. This is provided for convenience – you can mix your own audio data.

Definition at line 1689 of file SDL_audio.c.

1690 {
1691  /* Mix the user-level audio format */
1693  if (device != NULL) {
1694  SDL_MixAudioFormat(dst, src, device->callbackspec.format, len, volume);
1695  }
1696 }

References device, get_audio_device(), NULL, and SDL_MixAudioFormat.

◆ SDL_NextAudioFormat()

SDL_AudioFormat SDL_NextAudioFormat ( void  )

Definition at line 1659 of file SDL_audio.c.

1660 {
1661  if ((format_idx == NUM_FORMATS) || (format_idx_sub == NUM_FORMATS)) {
1662  return 0;
1663  }
1665 }

References format_idx, format_idx_sub, format_list, and NUM_FORMATS.

Referenced by SDL_FirstAudioFormat().

◆ SDL_OpenAudio()

int SDL_OpenAudio ( SDL_AudioSpec desired,
SDL_AudioSpec obtained 
)

This function opens the audio device with the desired parameters, and returns 0 if successful, placing the actual hardware parameters in the structure pointed to by obtained. If obtained is NULL, the audio data passed to the callback function will be guaranteed to be in the requested format, and will be automatically converted to the hardware audio format if necessary. This function returns -1 if it failed to open the audio device, or couldn't set up the audio thread.

When filling in the desired audio spec structure,

  • desired->freq should be the desired audio frequency in samples-per- second.
  • desired->format should be the desired audio format.
  • desired->samples is the desired size of the audio buffer, in samples. This number should be a power of two, and may be adjusted by the audio driver to a value more suitable for the hardware. Good values seem to range between 512 and 8096 inclusive, depending on the application and CPU speed. Smaller values yield faster response time, but can lead to underflow if the application is doing heavy processing and cannot fill the audio buffer in time. A stereo sample consists of both right and left channels in LR ordering. Note that the number of samples is directly related to time by the following formula:
    ms = (samples*1000)/freq
  • desired->size is the size in bytes of the audio buffer, and is calculated by SDL_OpenAudio().
  • desired->silence is the value used to set the buffer to silence, and is calculated by SDL_OpenAudio().
  • desired->callback should be set to a function that will be called when the audio device is ready for more data. It is passed a pointer to the audio buffer, and the length in bytes of the audio buffer. This function usually runs in a separate thread, and so you should protect data structures that it accesses by calling SDL_LockAudio() and SDL_UnlockAudio() in your code. Alternately, you may pass a NULL pointer here, and call SDL_QueueAudio() with some frequency, to queue more audio samples to be played (or for capture devices, call SDL_DequeueAudio() with some frequency, to obtain audio samples).
  • desired->userdata is passed as the first parameter to your callback function. If you passed a NULL callback, this value is ignored.

The audio device starts out playing silence when it's opened, and should be enabled for playing by calling SDL_PauseAudio(0) when you are ready for your audio callback function to be called. Since the audio driver may modify the requested size of the audio buffer, you should allocate any local mixing buffers after you open the audio device.

Definition at line 1461 of file SDL_audio.c.

1462 {
1463  SDL_AudioDeviceID id = 0;
1464 
1465  /* Start up the audio driver, if necessary. This is legacy behaviour! */
1466  if (!SDL_WasInit(SDL_INIT_AUDIO)) {
1467  if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0) {
1468  return -1;
1469  }
1470  }
1471 
1472  /* SDL_OpenAudio() is legacy and can only act on Device ID #1. */
1473  if (open_devices[0] != NULL) {
1474  SDL_SetError("Audio device is already opened");
1475  return -1;
1476  }
1477 
1478  if (obtained) {
1479  id = open_audio_device(NULL, 0, desired, obtained,
1481  } else {
1482  SDL_AudioSpec _obtained;
1483  SDL_zero(_obtained);
1484  id = open_audio_device(NULL, 0, desired, &_obtained, 0, 1);
1485  /* On successful open, copy calculated values into 'desired'. */
1486  if (id > 0) {
1487  desired->size = _obtained.size;
1488  desired->silence = _obtained.silence;
1489  }
1490  }
1491 
1492  SDL_assert((id == 0) || (id == 1));
1493  return (id == 0) ? -1 : 0;
1494 }

References NULL, open_audio_device(), open_devices, SDL_assert, SDL_AUDIO_ALLOW_ANY_CHANGE, SDL_INIT_AUDIO, SDL_InitSubSystem, SDL_SetError, SDL_WasInit, SDL_zero, SDL_AudioSpec::silence, and SDL_AudioSpec::size.

◆ SDL_OpenAudioDevice()

SDL_AudioDeviceID SDL_OpenAudioDevice ( const char *  device,
int  iscapture,
const SDL_AudioSpec desired,
SDL_AudioSpec obtained,
int  allowed_changes 
)

Open a specific audio device. Passing in a device name of NULL requests the most reasonable default (and is equivalent to calling SDL_OpenAudio()).

The device name is a UTF-8 string reported by SDL_GetAudioDeviceName(), but some drivers allow arbitrary and driver-specific strings, such as a hostname/IP address for a remote audio server, or a filename in the diskaudio driver.

Returns
0 on error, a valid device ID that is >= 2 on success.

SDL_OpenAudio(), unlike this function, always acts on device ID 1.

Definition at line 1497 of file SDL_audio.c.

1500 {
1501  return open_audio_device(device, iscapture, desired, obtained,
1502  allowed_changes, 2);
1503 }

References device, and open_audio_device().

◆ SDL_OpenedAudioDeviceDisconnected()

void SDL_OpenedAudioDeviceDisconnected ( SDL_AudioDevice device)

Definition at line 486 of file SDL_audio.c.

487 {
489 
490  if (!SDL_AtomicGet(&device->enabled)) {
491  return; /* don't report disconnects more than once. */
492  }
493 
494  if (SDL_AtomicGet(&device->shutdown)) {
495  return; /* don't report disconnect if we're trying to close device. */
496  }
497 
498  /* Ends the audio callback and mark the device as STOPPED, but the
499  app still needs to close the device to free resources. */
501  SDL_AtomicSet(&device->enabled, 0);
503 
504  /* Post the event, if desired */
507  SDL_zero(event);
508  event.adevice.type = SDL_AUDIODEVICEREMOVED;
509  event.adevice.which = device->id;
510  event.adevice.iscapture = device->iscapture ? 1 : 0;
512  }
513 }

References current_audio, device, get_audio_device(), SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, SDL_assert, SDL_AtomicGet, SDL_AtomicSet, SDL_AUDIODEVICEREMOVED, SDL_ENABLE, SDL_GetEventState, SDL_PushEvent, SDL_zero, and SDL_AudioDriverImpl::UnlockDevice.

Referenced by SDL_CaptureAudio(), and SDL_RemoveAudioDevice().

◆ SDL_ParseAudioFormat()

static SDL_AudioFormat SDL_ParseAudioFormat ( const char *  string)
static

Definition at line 899 of file SDL_audio.c.

900 {
901 #define CHECK_FMT_STRING(x) if (SDL_strcmp(string, #x) == 0) return AUDIO_##x
902  CHECK_FMT_STRING(U8);
903  CHECK_FMT_STRING(S8);
904  CHECK_FMT_STRING(U16LSB);
905  CHECK_FMT_STRING(S16LSB);
906  CHECK_FMT_STRING(U16MSB);
907  CHECK_FMT_STRING(S16MSB);
908  CHECK_FMT_STRING(U16SYS);
909  CHECK_FMT_STRING(S16SYS);
910  CHECK_FMT_STRING(U16);
911  CHECK_FMT_STRING(S16);
912  CHECK_FMT_STRING(S32LSB);
913  CHECK_FMT_STRING(S32MSB);
914  CHECK_FMT_STRING(S32SYS);
916  CHECK_FMT_STRING(F32LSB);
917  CHECK_FMT_STRING(F32MSB);
918  CHECK_FMT_STRING(F32SYS);
919  CHECK_FMT_STRING(F32);
920 #undef CHECK_FMT_STRING
921  return 0;
922 }

References CHECK_FMT_STRING, and S32.

Referenced by prepare_audiospec().

◆ SDL_PauseAudio()

void SDL_PauseAudio ( int  pause_on)

Definition at line 1539 of file SDL_audio.c.

1540 {
1541  SDL_PauseAudioDevice(1, pause_on);
1542 }

References SDL_PauseAudioDevice().

◆ SDL_PauseAudioDevice()

void SDL_PauseAudioDevice ( SDL_AudioDeviceID  devid,
int  pause_on 
)

Definition at line 1528 of file SDL_audio.c.

1529 {
1531  if (device) {
1533  SDL_AtomicSet(&device->paused, pause_on ? 1 : 0);
1535  }
1536 }

References current_audio, device, get_audio_device(), SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, SDL_AtomicSet, and SDL_AudioDriverImpl::UnlockDevice.

Referenced by SDL_PauseAudio().

◆ SDL_QueueAudio()

int SDL_QueueAudio ( SDL_AudioDeviceID  dev,
const void data,
Uint32  len 
)

Queue more audio on non-callback devices.

(If you are looking to retrieve queued audio from a non-callback capture device, you want SDL_DequeueAudio() instead. This will return -1 to signify an error if you use it with capture devices.)

SDL offers two ways to feed audio to the device: you can either supply a callback that SDL triggers with some frequency to obtain more audio (pull method), or you can supply no callback, and then SDL will expect you to supply data at regular intervals (push method) with this function.

There are no limits on the amount of data you can queue, short of exhaustion of address space. Queued data will drain to the device as necessary without further intervention from you. If the device needs audio but there is not enough queued, it will play silence to make up the difference. This means you will have skips in your audio playback if you aren't routinely queueing sufficient data.

This function copies the supplied data, so you are safe to free it when the function returns. This function is thread-safe, but queueing to the same device from two threads at once does not promise which buffer will be queued first.

You may not queue audio on a device that is using an application-supplied callback; doing so returns an error. You have to use the audio callback or queue audio with this function, but not both.

You should not call SDL_LockAudio() on the device before queueing; SDL handles locking internally for this function.

Parameters
devThe device ID to which we will queue audio.
dataThe data to queue to the device for later playback.
lenThe number of bytes (not samples!) to which (data) points.
Returns
0 on success, or -1 on error.
See also
SDL_GetQueuedAudioSize
SDL_ClearQueuedAudio

Definition at line 598 of file SDL_audio.c.

599 {
601  int rc = 0;
602 
603  if (!device) {
604  return -1; /* get_audio_device() will have set the error state */
605  } else if (device->iscapture) {
606  return SDL_SetError("This is a capture device, queueing not allowed");
607  } else if (device->callbackspec.callback != SDL_BufferQueueDrainCallback) {
608  return SDL_SetError("Audio device has a callback, queueing not allowed");
609  }
610 
611  if (len > 0) {
613  rc = SDL_WriteToDataQueue(device->buffer_queue, data, len);
615  }
616 
617  return rc;
618 }

References current_audio, device, get_audio_device(), SDL_AudioDriver::impl, SDL_AudioDriverImpl::LockDevice, SDL_BufferQueueDrainCallback(), SDL_SetError, SDL_WriteToDataQueue(), and SDL_AudioDriverImpl::UnlockDevice.

◆ SDL_RemoveAudioDevice()

◆ SDL_RunAudio()

static int SDL_RunAudio ( void devicep)
static

Definition at line 682 of file SDL_audio.c.

683 {
684  SDL_AudioDevice *device = (SDL_AudioDevice *) devicep;
685  void *udata = device->callbackspec.userdata;
686  SDL_AudioCallback callback = device->callbackspec.callback;
687  int data_len = 0;
688  Uint8 *data;
689 
690  SDL_assert(!device->iscapture);
691 
692 #if SDL_AUDIO_DRIVER_ANDROID
693  {
694  /* Set thread priority to THREAD_PRIORITY_AUDIO */
695  extern void Android_JNI_AudioSetThreadPriority(int, int);
697  }
698 #else
699  /* The audio mixing is always a high priority thread */
701 #endif
702 
703  /* Perform any thread setup */
704  device->threadid = SDL_ThreadID();
706 
707  /* Loop, filling the audio buffers */
708  while (!SDL_AtomicGet(&device->shutdown)) {
710  data_len = device->callbackspec.size;
711 
712  /* Fill the current buffer with sound */
713  if (!device->stream && SDL_AtomicGet(&device->enabled)) {
714  SDL_assert(data_len == device->spec.size);
716  } else {
717  /* if the device isn't enabled, we still write to the
718  work_buffer, so the app's callback will fire with
719  a regular frequency, in case they depend on that
720  for timing or progress. They can use hotplug
721  now to know if the device failed.
722  Streaming playback uses work_buffer, too. */
723  data = NULL;
724  }
725 
726  if (data == NULL) {
727  data = device->work_buffer;
728  }
729 
730  /* !!! FIXME: this should be LockDevice. */
731  SDL_LockMutex(device->mixer_lock);
732  if (SDL_AtomicGet(&device->paused)) {
733  SDL_memset(data, device->spec.silence, data_len);
734  } else {
735  callback(udata, data, data_len);
736  }
737  SDL_UnlockMutex(device->mixer_lock);
738 
739  if (device->stream) {
740  /* Stream available audio to device, converting/resampling. */
741  /* if this fails...oh well. We'll play silence here. */
742  SDL_AudioStreamPut(device->stream, data, data_len);
743 
744  while (SDL_AudioStreamAvailable(device->stream) >= ((int) device->spec.size)) {
745  int got;
747  got = SDL_AudioStreamGet(device->stream, data ? data : device->work_buffer, device->spec.size);
748  SDL_assert((got < 0) || (got == device->spec.size));
749 
750  if (data == NULL) { /* device is having issues... */
751  const Uint32 delay = ((device->spec.samples * 1000) / device->spec.freq);
752  SDL_Delay(delay); /* wait for as long as this buffer would have played. Maybe device recovers later? */
753  } else {
754  if (got != device->spec.size) {
755  SDL_memset(data, device->spec.silence, device->spec.size);
756  }
759  }
760  }
761  } else if (data == device->work_buffer) {
762  /* nothing to do; pause like we queued a buffer to play. */
763  const Uint32 delay = ((device->spec.samples * 1000) / device->spec.freq);
764  SDL_Delay(delay);
765  } else { /* writing directly to the device. */
766  /* queue this buffer and wait for it to finish playing. */
769  }
770  }
771 
773 
774  /* Wait for the audio to drain. */
775  SDL_Delay(((device->spec.samples * 1000) / device->spec.freq) * 2);
776 
778 
779  return 0;
780 }

References Android_JNI_AudioSetThreadPriority(), SDL_AudioDriverImpl::BeginLoopIteration, callback(), current_audio, device, SDL_AudioDriverImpl::GetDeviceBuf, SDL_AudioDriver::impl, NULL, SDL_AudioDriverImpl::PlayDevice, SDL_AudioDriverImpl::PrepareToClose, SDL_assert, SDL_AtomicGet, SDL_AudioStreamAvailable, SDL_AudioStreamGet, SDL_AudioStreamPut, SDL_Delay, SDL_LockMutex, SDL_memset, SDL_SetThreadPriority, SDL_THREAD_PRIORITY_TIME_CRITICAL, SDL_ThreadID, SDL_UnlockMutex, SDL_AudioDriverImpl::ThreadDeinit, SDL_AudioDriverImpl::ThreadInit, and SDL_AudioDriverImpl::WaitDevice.

Referenced by open_audio_device().

◆ SDL_UnlockAudio()

void SDL_UnlockAudio ( void  )

Definition at line 1572 of file SDL_audio.c.

1573 {
1575 }

References SDL_UnlockAudioDevice().

◆ SDL_UnlockAudioDevice()

void SDL_UnlockAudioDevice ( SDL_AudioDeviceID  devid)

Definition at line 1562 of file SDL_audio.c.

1563 {
1564  /* Obtain a lock on the mixing buffers */
1566  if (device) {
1568  }
1569 }

References current_audio, device, get_audio_device(), SDL_AudioDriver::impl, and SDL_AudioDriverImpl::UnlockDevice.

Referenced by SDL_UnlockAudio().

Variable Documentation

◆ bootstrap

const AudioBootStrap* const bootstrap[]
static

Definition at line 37 of file SDL_audio.c.

Referenced by SDL_AudioInit(), SDL_GetAudioDriver(), and SDL_GetNumAudioDrivers().

◆ current_audio

◆ format_idx

int format_idx
static

Definition at line 1621 of file SDL_audio.c.

Referenced by SDL_FirstAudioFormat(), and SDL_NextAudioFormat().

◆ format_idx_sub

int format_idx_sub
static

Definition at line 1622 of file SDL_audio.c.

Referenced by SDL_FirstAudioFormat(), and SDL_NextAudioFormat().

◆ format_list

SDL_AudioFormat format_list[NUM_FORMATS][NUM_FORMATS]
static

◆ open_devices

finish_audio_entry_points_init
static void finish_audio_entry_points_init(void)
Definition: SDL_audio.c:331
SDL_zero
#define SDL_zero(x)
Definition: SDL_stdinc.h:416
format_idx
static int format_idx
Definition: SDL_audio.c:1621
format
GLint GLint GLsizei GLsizei GLsizei GLint GLenum format
Definition: SDL_opengl.h:1571
SDL_NewDataQueue
SDL_DataQueue * SDL_NewDataQueue(const size_t _packetlen, const size_t initialslack)
Definition: SDL_dataqueue.c:58
SDL_SetThreadPriority
#define SDL_SetThreadPriority
Definition: SDL_dynapi_overrides.h:477
SDL_memset
#define SDL_memset
Definition: SDL_dynapi_overrides.h:386
SDL_AudioSpec::channels
Uint8 channels
Definition: SDL_audio.h:182
SDL_AudioDriverImpl::HasCaptureSupport
int HasCaptureSupport
Definition: SDL_sysaudio.h:90
SDL_CountDataQueue
size_t SDL_CountDataQueue(SDL_DataQueue *queue)
Definition: SDL_dataqueue.c:294
SDL_AudioDriverImpl::UnlockDevice
void(* UnlockDevice)(_THIS)
Definition: SDL_sysaudio.h:80
format_idx_sub
static int format_idx_sub
Definition: SDL_audio.c:1622
SDL_AudioDriverImpl::ProvidesOwnCallbackThread
int ProvidesOwnCallbackThread
Definition: SDL_sysaudio.h:88
DEFAULT_OUTPUT_DEVNAME
#define DEFAULT_OUTPUT_DEVNAME
Definition: SDL_sysaudio.h:32
AUDIO_U16LSB
#define AUDIO_U16LSB
Definition: SDL_audio.h:91
SDL_AUDIO_ALLOW_FREQUENCY_CHANGE
#define SDL_AUDIO_ALLOW_FREQUENCY_CHANGE
Definition: SDL_audio.h:140
clean_out_device_list
static void clean_out_device_list(SDL_AudioDeviceItem **devices, int *devCount, SDL_bool *removedFlag)
Definition: SDL_audio.c:1012
SDL_CaptureAudio
static int SDL_CaptureAudio(void *devicep)
Definition: SDL_audio.c:785
SDL_LockMutex
#define SDL_LockMutex
Definition: SDL_dynapi_overrides.h:260
SDL_AudioDriverImpl::FlushCapture
void(* FlushCapture)(_THIS)
Definition: SDL_sysaudio.h:76
NULL
#define NULL
Definition: begin_code.h:167
SDL_AudioStreamAvailable
#define SDL_AudioStreamAvailable
Definition: SDL_dynapi_overrides.h:647
handle
EGLImageKHR EGLint EGLint * handle
Definition: eglext.h:937
add_output_device
static SDL_INLINE int add_output_device(const char *name, void *handle)
Definition: SDL_audio.c:441
AUDIO_S32MSB
#define AUDIO_S32MSB
Definition: SDL_audio.h:104
SDL_AudioSpec::samples
Uint16 samples
Definition: SDL_audio.h:184
SDL_GetNumAudioDrivers
int SDL_GetNumAudioDrivers(void)
Definition: SDL_audio.c:925
SDL_THREAD_PRIORITY_TIME_CRITICAL
Definition: SDL_thread.h:63
samples
GLsizei samples
Definition: SDL_opengl_glext.h:1185
SDL_AudioDriver::captureDevicesRemoved
SDL_bool captureDevicesRemoved
Definition: SDL_sysaudio.h:121
SDL_FreeDataQueue
void SDL_FreeDataQueue(SDL_DataQueue *queue)
Definition: SDL_dataqueue.c:88
SDL_AudioSpec::format
SDL_AudioFormat format
Definition: SDL_audio.h:181
SDL_AudioDriverImpl::SkipMixerLock
int SkipMixerLock
Definition: SDL_sysaudio.h:89
SDL_AudioDeviceItem::dupenum
int dupenum
Definition: SDL_sysaudio.h:102
DEFAULT_INPUT_DEVNAME
#define DEFAULT_INPUT_DEVNAME
Definition: SDL_sysaudio.h:33
mark_device_removed
static void mark_device_removed(void *handle, SDL_AudioDeviceItem *devices, SDL_bool *removedFlag)
Definition: SDL_audio.c:516
SDL_MixAudioFormat
#define SDL_MixAudioFormat
Definition: SDL_dynapi_overrides.h:91
devices
EGLDeviceEXT * devices
Definition: eglext.h:621
SDL_THREAD_PRIORITY_HIGH
Definition: SDL_thread.h:62
SDL_AudioSpec::callback
SDL_AudioCallback callback
Definition: SDL_audio.h:187
SDL_AudioDeviceItem::next
struct SDL_AudioDeviceItem * next
Definition: SDL_sysaudio.h:103
stream
GLuint GLuint stream
Definition: SDL_opengl_glext.h:1776
SDL_AudioDriverImpl::OpenDevice
int(* OpenDevice)(_THIS, void *handle, const char *devname, int iscapture)
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Definition: SDL_audio.c:1578
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Definition: SDL_stdinc.h:203
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Definition: SDL_audio.h:92
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Definition: SDL_audio.h:90
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Definition: loopwave.c:37
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Definition: SDL_sysaudio.h:125
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Definition: SDL_sysaudio.h:78
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Definition: SDL_audio.h:93
i
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
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Definition: SDL_dynapi_overrides.h:475
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Definition: SDL_audio.c:469
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Definition: SDL_audio.c:1110
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Definition: SDL_audio.c:200
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Definition: SDL.h:78
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