Cleanly switch between audio recording, playback, and both, on iOS
diff --git a/src/audio/coreaudio/SDL_coreaudio.m b/src/audio/coreaudio/SDL_coreaudio.m
index 52b40b6..b8d786d 100644
--- a/src/audio/coreaudio/SDL_coreaudio.m
+++ b/src/audio/coreaudio/SDL_coreaudio.m
@@ -280,11 +280,47 @@
#endif
-static int open_playback_devices = 0;
-static int open_capture_devices = 0;
+static int open_playback_devices;
+static int open_capture_devices;
+static int num_open_devices;
+static SDL_AudioDevice **open_devices;
#if !MACOSX_COREAUDIO
+static BOOL session_active = NO;
+
+static void pause_audio_devices()
+{
+ int i;
+
+ if (!open_devices) {
+ return;
+ }
+
+ for (i = 0; i < num_open_devices; ++i) {
+ SDL_AudioDevice *device = open_devices[i];
+ if (device->hidden->audioQueue && !device->hidden->interrupted) {
+ AudioQueuePause(device->hidden->audioQueue);
+ }
+ }
+}
+
+static void resume_audio_devices()
+{
+ int i;
+
+ if (!open_devices) {
+ return;
+ }
+
+ for (i = 0; i < num_open_devices; ++i) {
+ SDL_AudioDevice *device = open_devices[i];
+ if (device->hidden->audioQueue && !device->hidden->interrupted) {
+ AudioQueueStart(device->hidden->audioQueue, NULL);
+ }
+ }
+}
+
static void interruption_begin(_THIS)
{
if (this != NULL && this->hidden->audioQueue != NULL) {
@@ -379,9 +415,18 @@
options |= AVAudioSessionCategoryOptionAllowBluetoothA2DP |
AVAudioSessionCategoryOptionAllowAirPlay;
}
+ if (category == AVAudioSessionCategoryPlayback ||
+ category == AVAudioSessionCategoryPlayAndRecord) {
+ options |= AVAudioSessionCategoryOptionDuckOthers;
+ }
if ([session respondsToSelector:@selector(setCategory:mode:options:error:)]) {
if (![session.category isEqualToString:category] || session.categoryOptions != options) {
+ /* Stop the current session so we don't interrupt other application audio */
+ pause_audio_devices();
+ [session setActive:NO error:nil];
+ session_active = NO;
+
if (![session setCategory:category mode:mode options:options error:&err]) {
NSString *desc = err.description;
SDL_SetError("Could not set Audio Session category: %s", desc.UTF8String);
@@ -390,6 +435,11 @@
}
} else {
if (![session.category isEqualToString:category]) {
+ /* Stop the current session so we don't interrupt other application audio */
+ pause_audio_devices();
+ [session setActive:NO error:nil];
+ session_active = NO;
+
if (![session setCategory:category error:&err]) {
NSString *desc = err.description;
SDL_SetError("Could not set Audio Session category: %s", desc.UTF8String);
@@ -398,7 +448,7 @@
}
}
- if (open && (open_playback_devices + open_capture_devices) == 1) {
+ if ((open_playback_devices || open_capture_devices) && !session_active) {
if (![session setActive:YES error:&err]) {
if ([err code] == AVAudioSessionErrorCodeResourceNotAvailable &&
category == AVAudioSessionCategoryPlayAndRecord) {
@@ -409,8 +459,12 @@
SDL_SetError("Could not activate Audio Session: %s", desc.UTF8String);
return NO;
}
- } else if (!open_playback_devices && !open_capture_devices) {
+ session_active = YES;
+ resume_audio_devices();
+ } else if (!open_playback_devices && !open_capture_devices && session_active) {
+ pause_audio_devices();
[session setActive:NO error:nil];
+ session_active = NO;
}
if (open) {
@@ -438,14 +492,12 @@
this->hidden->interruption_listener = CFBridgingRetain(listener);
} else {
- if (this->hidden->interruption_listener != NULL) {
- SDLInterruptionListener *listener = nil;
- listener = (SDLInterruptionListener *) CFBridgingRelease(this->hidden->interruption_listener);
- [center removeObserver:listener];
- @synchronized (listener) {
- listener.device = NULL;
- }
- }
+ SDLInterruptionListener *listener = nil;
+ listener = (SDLInterruptionListener *) CFBridgingRelease(this->hidden->interruption_listener);
+ [center removeObserver:listener];
+ @synchronized (listener) {
+ listener.device = NULL;
+ }
}
}
@@ -471,7 +523,7 @@
Uint8 *ptr = (Uint8 *) inBuffer->mAudioData;
while (remaining > 0) {
- if ( SDL_AudioStreamAvailable(this->stream) == 0 ) {
+ if (SDL_AudioStreamAvailable(this->stream) == 0) {
/* Generate the data */
SDL_LockMutex(this->mixer_lock);
(*this->callbackspec.callback)(this->callbackspec.userdata,
@@ -480,10 +532,10 @@
this->hidden->bufferOffset = 0;
SDL_AudioStreamPut(this->stream, this->hidden->buffer, this->hidden->bufferSize);
}
- if ( SDL_AudioStreamAvailable(this->stream) > 0 ) {
+ if (SDL_AudioStreamAvailable(this->stream) > 0) {
int got;
UInt32 len = SDL_AudioStreamAvailable(this->stream);
- if ( len > remaining )
+ if (len > remaining)
len = remaining;
got = SDL_AudioStreamGet(this->stream, ptr, len);
SDL_assert((got < 0) || (got == len));
@@ -529,7 +581,7 @@
static void
inputCallback(void *inUserData, AudioQueueRef inAQ, AudioQueueBufferRef inBuffer,
const AudioTimeStamp *inStartTime, UInt32 inNumberPacketDescriptions,
- const AudioStreamPacketDescription *inPacketDescs )
+ const AudioStreamPacketDescription *inPacketDescs)
{
SDL_AudioDevice *this = (SDL_AudioDevice *) inUserData;
@@ -619,6 +671,7 @@
COREAUDIO_CloseDevice(_THIS)
{
const SDL_bool iscapture = this->iscapture;
+ int i;
/* !!! FIXME: what does iOS do when a bluetooth audio device vanishes? Headphones unplugged? */
/* !!! FIXME: (we only do a "default" device on iOS right now...can we do more?) */
@@ -638,6 +691,20 @@
update_audio_session(this, SDL_FALSE, SDL_TRUE);
#endif
+ for (i = 0; i < num_open_devices; ++i) {
+ if (open_devices[i] == this) {
+ --num_open_devices;
+ if (i < num_open_devices) {
+ SDL_memmove(&open_devices[i], &open_devices[i+1], sizeof(open_devices[i])*(num_open_devices - i));
+ }
+ break;
+ }
+ }
+ if (num_open_devices == 0) {
+ SDL_free(open_devices);
+ open_devices = NULL;
+ }
+
/* if callback fires again, feed silence; don't call into the app. */
SDL_AtomicSet(&this->paused, 1);
@@ -942,6 +1009,7 @@
AudioStreamBasicDescription *strdesc;
SDL_AudioFormat test_format = SDL_FirstAudioFormat(this->spec.format);
int valid_datatype = 0;
+ SDL_AudioDevice **new_open_devices;
/* Initialize all variables that we clean on shutdown */
this->hidden = (struct SDL_PrivateAudioData *)
@@ -959,6 +1027,12 @@
open_playback_devices++;
}
+ new_open_devices = (SDL_AudioDevice **)SDL_realloc(open_devices, sizeof(open_devices[0]) * (num_open_devices + 1));
+ if (new_open_devices) {
+ open_devices = new_open_devices;
+ open_devices[num_open_devices++] = this;
+ }
+
#if !MACOSX_COREAUDIO
if (!update_audio_session(this, SDL_TRUE, SDL_TRUE)) {
return -1;
