Backed out changeset ffd52bb02bcc
This was meant to migrate CoreAudio onto the same SDL_RunAudio() path that
most other audio drivers are on, but it introduced a bug because it doesn't
deal with dropped audio buffers...and fixing that properly just introduces
latency.
I might revisit this later, perhaps by reworking SDL_RunAudio to allow for
this sort of API better, or redesigning the whole subsystem or something, I
don't know. I'm not super-thrilled that this has to exist outside of the usual
codepaths, though.
Fixes Bugzilla #4481.
diff --git a/src/audio/SDL_audio.c b/src/audio/SDL_audio.c
index 83d3673..836b7b6 100644
--- a/src/audio/SDL_audio.c
+++ b/src/audio/SDL_audio.c
@@ -896,8 +896,6 @@
}
}
- current_audio.impl.PrepareToClose(device);
-
current_audio.impl.FlushCapture(device);
current_audio.impl.ThreadDeinit(device);
diff --git a/src/audio/coreaudio/SDL_coreaudio.h b/src/audio/coreaudio/SDL_coreaudio.h
index 014f283..9a9b885 100644
--- a/src/audio/coreaudio/SDL_coreaudio.h
+++ b/src/audio/coreaudio/SDL_coreaudio.h
@@ -45,14 +45,16 @@
struct SDL_PrivateAudioData
{
+ SDL_Thread *thread;
AudioQueueRef audioQueue;
- int numAudioBuffers;
AudioQueueBufferRef *audioBuffer;
void *buffer;
+ UInt32 bufferOffset;
UInt32 bufferSize;
AudioStreamBasicDescription strdesc;
- SDL_bool refill;
- SDL_AudioStream *capturestream;
+ SDL_sem *ready_semaphore;
+ char *thread_error;
+ SDL_atomic_t shutdown;
#if MACOSX_COREAUDIO
AudioDeviceID deviceID;
#else
diff --git a/src/audio/coreaudio/SDL_coreaudio.m b/src/audio/coreaudio/SDL_coreaudio.m
index 238951a..b8bb4ab 100644
--- a/src/audio/coreaudio/SDL_coreaudio.m
+++ b/src/audio/coreaudio/SDL_coreaudio.m
@@ -26,7 +26,6 @@
#include "SDL_audio.h"
#include "SDL_hints.h"
-#include "SDL_timer.h"
#include "../SDL_audio_c.h"
#include "../SDL_sysaudio.h"
#include "SDL_coreaudio.h"
@@ -410,27 +409,43 @@
outputCallback(void *inUserData, AudioQueueRef inAQ, AudioQueueBufferRef inBuffer)
{
SDL_AudioDevice *this = (SDL_AudioDevice *) inUserData;
- SDL_assert(inBuffer->mAudioDataBytesCapacity == this->hidden->bufferSize);
- SDL_memcpy(inBuffer->mAudioData, this->hidden->buffer, this->hidden->bufferSize);
- SDL_memset(this->hidden->buffer, '\0', this->hidden->bufferSize); /* zero out in case we have to fill again without new data. */
- inBuffer->mAudioDataByteSize = this->hidden->bufferSize;
- AudioQueueEnqueueBuffer(this->hidden->audioQueue, inBuffer, 0, NULL);
- this->hidden->refill = SDL_TRUE;
-}
-
-static Uint8 *
-COREAUDIO_GetDeviceBuf(_THIS)
-{
- return this->hidden->buffer;
-}
-
-static void
-COREAUDIO_WaitDevice(_THIS)
-{
- while (SDL_AtomicGet(&this->enabled) && !this->hidden->refill) {
- CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.10, 1);
+ if (SDL_AtomicGet(&this->hidden->shutdown)) {
+ return; /* don't do anything. */
}
- this->hidden->refill = SDL_FALSE;
+
+ if (!SDL_AtomicGet(&this->enabled) || SDL_AtomicGet(&this->paused)) {
+ /* Supply silence if audio is not enabled or paused */
+ SDL_memset(inBuffer->mAudioData, this->spec.silence, inBuffer->mAudioDataBytesCapacity);
+ } else {
+ UInt32 remaining = inBuffer->mAudioDataBytesCapacity;
+ Uint8 *ptr = (Uint8 *) inBuffer->mAudioData;
+
+ while (remaining > 0) {
+ UInt32 len;
+ if (this->hidden->bufferOffset >= this->hidden->bufferSize) {
+ /* Generate the data */
+ SDL_LockMutex(this->mixer_lock);
+ (*this->callbackspec.callback)(this->callbackspec.userdata,
+ this->hidden->buffer, this->hidden->bufferSize);
+ SDL_UnlockMutex(this->mixer_lock);
+ this->hidden->bufferOffset = 0;
+ }
+
+ len = this->hidden->bufferSize - this->hidden->bufferOffset;
+ if (len > remaining) {
+ len = remaining;
+ }
+ SDL_memcpy(ptr, (char *)this->hidden->buffer +
+ this->hidden->bufferOffset, len);
+ ptr = ptr + len;
+ remaining -= len;
+ this->hidden->bufferOffset += len;
+ }
+ }
+
+ AudioQueueEnqueueBuffer(this->hidden->audioQueue, inBuffer, 0, NULL);
+
+ inBuffer->mAudioDataByteSize = inBuffer->mAudioDataBytesCapacity;
}
static void
@@ -439,46 +454,36 @@
const AudioStreamPacketDescription *inPacketDescs )
{
SDL_AudioDevice *this = (SDL_AudioDevice *) inUserData;
- if (SDL_AtomicGet(&this->enabled)) {
- SDL_AudioStream *stream = this->hidden->capturestream;
- if (SDL_AudioStreamPut(stream, inBuffer->mAudioData, inBuffer->mAudioDataByteSize) == -1) {
- /* yikes, out of memory or something. I guess drop the buffer. Our WASAPI target kills the device in this case, though */
- }
- AudioQueueEnqueueBuffer(this->hidden->audioQueue, inBuffer, 0, NULL);
- this->hidden->refill = SDL_TRUE;
- }
-}
-static int
-COREAUDIO_CaptureFromDevice(_THIS, void *buffer, int buflen)
-{
- SDL_AudioStream *stream = this->hidden->capturestream;
- while (SDL_AtomicGet(&this->enabled)) {
- const int avail = SDL_AudioStreamAvailable(stream);
- if (avail > 0) {
- const int cpy = SDL_min(buflen, avail);
- SDL_AudioStreamGet(stream, buffer, cpy);
- return cpy;
- }
-
- /* wait for more data, try again. */
- while (SDL_AtomicGet(&this->enabled) && !this->hidden->refill) {
- CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.10, 1);
- }
- this->hidden->refill = SDL_FALSE;
+ if (SDL_AtomicGet(&this->shutdown)) {
+ return; /* don't do anything. */
}
- return 0; /* not enabled, giving up. */
-}
+ /* ignore unless we're active. */
+ if (!SDL_AtomicGet(&this->paused) && SDL_AtomicGet(&this->enabled) && !SDL_AtomicGet(&this->paused)) {
+ const Uint8 *ptr = (const Uint8 *) inBuffer->mAudioData;
+ UInt32 remaining = inBuffer->mAudioDataByteSize;
+ while (remaining > 0) {
+ UInt32 len = this->hidden->bufferSize - this->hidden->bufferOffset;
+ if (len > remaining) {
+ len = remaining;
+ }
-static void
-COREAUDIO_FlushCapture(_THIS)
-{
- while (CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0, 1) == kCFRunLoopRunHandledSource) {
- /* spin. */
+ SDL_memcpy((char *)this->hidden->buffer + this->hidden->bufferOffset, ptr, len);
+ ptr += len;
+ remaining -= len;
+ this->hidden->bufferOffset += len;
+
+ if (this->hidden->bufferOffset >= this->hidden->bufferSize) {
+ SDL_LockMutex(this->mixer_lock);
+ (*this->callbackspec.callback)(this->callbackspec.userdata, this->hidden->buffer, this->hidden->bufferSize);
+ SDL_UnlockMutex(this->mixer_lock);
+ this->hidden->bufferOffset = 0;
+ }
+ }
}
- this->hidden->refill = SDL_FALSE;
- SDL_AudioStreamClear(this->hidden->capturestream);
+
+ AudioQueueEnqueueBuffer(this->hidden->audioQueue, inBuffer, 0, NULL);
}
@@ -536,16 +541,25 @@
update_audio_session(this, SDL_FALSE);
#endif
+ /* if callback fires again, feed silence; don't call into the app. */
+ SDL_AtomicSet(&this->paused, 1);
+
if (this->hidden->audioQueue) {
AudioQueueDispose(this->hidden->audioQueue, 1);
}
- if (this->hidden->capturestream) {
- SDL_FreeAudioStream(this->hidden->capturestream);
+ if (this->hidden->thread) {
+ SDL_AtomicSet(&this->hidden->shutdown, 1);
+ SDL_WaitThread(this->hidden->thread, NULL);
+ }
+
+ if (this->hidden->ready_semaphore) {
+ SDL_DestroySemaphore(this->hidden->ready_semaphore);
}
/* AudioQueueDispose() frees the actual buffer objects. */
SDL_free(this->hidden->audioBuffer);
+ SDL_free(this->hidden->thread_error);
SDL_free(this->hidden->buffer);
SDL_free(this->hidden);
@@ -611,8 +625,6 @@
}
#endif
-
-/* this all happens in the audio thread, since it needs a separate runloop. */
static int
prepare_audioqueue(_THIS)
{
@@ -652,6 +664,19 @@
}
#endif
+ /* Calculate the final parameters for this audio specification */
+ SDL_CalculateAudioSpec(&this->spec);
+
+ /* Allocate a sample buffer */
+ this->hidden->bufferSize = this->spec.size;
+ this->hidden->bufferOffset = iscapture ? 0 : this->hidden->bufferSize;
+
+ this->hidden->buffer = SDL_malloc(this->hidden->bufferSize);
+ if (this->hidden->buffer == NULL) {
+ SDL_OutOfMemory();
+ return 0;
+ }
+
/* Make sure we can feed the device a minimum amount of time */
double MINIMUM_AUDIO_BUFFER_TIME_MS = 15.0;
#if defined(__IPHONEOS__)
@@ -666,7 +691,6 @@
numAudioBuffers = ((int)SDL_ceil(MINIMUM_AUDIO_BUFFER_TIME_MS / msecs) * 2);
}
- this->hidden->numAudioBuffers = numAudioBuffers;
this->hidden->audioBuffer = SDL_calloc(1, sizeof (AudioQueueBufferRef) * numAudioBuffers);
if (this->hidden->audioBuffer == NULL) {
SDL_OutOfMemory();
@@ -693,23 +717,29 @@
return 1;
}
-static void
-COREAUDIO_ThreadInit(_THIS)
+static int
+audioqueue_thread(void *arg)
{
+ SDL_AudioDevice *this = (SDL_AudioDevice *) arg;
const int rc = prepare_audioqueue(this);
if (!rc) {
- /* !!! FIXME: do this in RunAudio, and maybe block OpenDevice until ThreadInit finishes, too, to report an opening error */
- SDL_OpenedAudioDeviceDisconnected(this); /* oh well. */
+ this->hidden->thread_error = SDL_strdup(SDL_GetError());
+ SDL_SemPost(this->hidden->ready_semaphore);
+ return 0;
}
-}
-static void
-COREAUDIO_PrepareToClose(_THIS)
-{
- /* run long enough to queue some silence, so we know our actual audio
- has been played */
- CFRunLoopRunInMode(kCFRunLoopDefaultMode, (((this->spec.samples * 1000) / this->spec.freq) * 2) / 1000.0f, 0);
- AudioQueueStop(this->hidden->audioQueue, 1);
+ /* init was successful, alert parent thread and start running... */
+ SDL_SemPost(this->hidden->ready_semaphore);
+ while (!SDL_AtomicGet(&this->hidden->shutdown)) {
+ CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.10, 1);
+ }
+
+ if (!this->iscapture) { /* Drain off any pending playback. */
+ const CFTimeInterval secs = (((this->spec.size / (SDL_AUDIO_BITSIZE(this->spec.format) / 8)) / this->spec.channels) / ((CFTimeInterval) this->spec.freq)) * 2.0;
+ CFRunLoopRunInMode(kCFRunLoopDefaultMode, secs, 0);
+ }
+
+ return 0;
}
static int
@@ -796,23 +826,28 @@
}
#endif
- /* Calculate the final parameters for this audio specification */
- SDL_CalculateAudioSpec(&this->spec);
-
- if (iscapture) {
- this->hidden->capturestream = SDL_NewAudioStream(this->spec.format, this->spec.channels, this->spec.freq, this->spec.format, this->spec.channels, this->spec.freq);
- if (!this->hidden->capturestream) {
- return -1; /* already set SDL_Error */
- }
- } else {
- this->hidden->bufferSize = this->spec.size;
- this->hidden->buffer = SDL_malloc(this->hidden->bufferSize);
- if (this->hidden->buffer == NULL) {
- return SDL_OutOfMemory();
- }
+ /* This has to init in a new thread so it can get its own CFRunLoop. :/ */
+ SDL_AtomicSet(&this->hidden->shutdown, 0);
+ this->hidden->ready_semaphore = SDL_CreateSemaphore(0);
+ if (!this->hidden->ready_semaphore) {
+ return -1; /* oh well. */
}
- return 0;
+ this->hidden->thread = SDL_CreateThreadInternal(audioqueue_thread, "AudioQueue thread", 512 * 1024, this);
+ if (!this->hidden->thread) {
+ return -1;
+ }
+
+ SDL_SemWait(this->hidden->ready_semaphore);
+ SDL_DestroySemaphore(this->hidden->ready_semaphore);
+ this->hidden->ready_semaphore = NULL;
+
+ if ((this->hidden->thread != NULL) && (this->hidden->thread_error != NULL)) {
+ SDL_SetError("%s", this->hidden->thread_error);
+ return -1;
+ }
+
+ return (this->hidden->thread != NULL) ? 0 : -1;
}
static void
@@ -832,12 +867,6 @@
impl->OpenDevice = COREAUDIO_OpenDevice;
impl->CloseDevice = COREAUDIO_CloseDevice;
impl->Deinitialize = COREAUDIO_Deinitialize;
- impl->ThreadInit = COREAUDIO_ThreadInit;
- impl->WaitDevice = COREAUDIO_WaitDevice;
- impl->GetDeviceBuf = COREAUDIO_GetDeviceBuf;
- impl->PrepareToClose = COREAUDIO_PrepareToClose;
- impl->CaptureFromDevice = COREAUDIO_CaptureFromDevice;
- impl->FlushCapture = COREAUDIO_FlushCapture;
#if MACOSX_COREAUDIO
impl->DetectDevices = COREAUDIO_DetectDevices;
@@ -847,6 +876,7 @@
impl->OnlyHasDefaultCaptureDevice = 1;
#endif
+ impl->ProvidesOwnCallbackThread = 1;
impl->HasCaptureSupport = 1;
return 1; /* this audio target is available. */
