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coreaudio: Make sure device handles are unique.
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AudioDeviceID is not unique (hardware that can do both capture and output
will expose both interfaces off the same AudioDeviceID!).
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@icculus @slouken
icculus authored and slouken committed Mar 29, 2024
1 parent 87235e0 commit 2fd9447
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Showing 2 changed files with 49 additions and 18 deletions.
3 changes: 3 additions & 0 deletions src/audio/SDL_audio.c
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Expand Up @@ -594,6 +594,9 @@ static SDL_AudioDevice *CreateAudioOutputDevice(const char *name, const SDL_Audi
// The audio backends call this when a new device is plugged in.
SDL_AudioDevice *SDL_AddAudioDevice(const SDL_bool iscapture, const char *name, const SDL_AudioSpec *inspec, void *handle)
{
// device handles MUST be unique! If the target reuses the same handle for hardware with both input and output interfaces, wrap it in a pointer you SDL_malloc'd!
SDL_assert(SDL_FindPhysicalAudioDeviceByHandle(handle) == NULL);

const SDL_AudioFormat default_format = iscapture ? DEFAULT_AUDIO_CAPTURE_FORMAT : DEFAULT_AUDIO_OUTPUT_FORMAT;
const int default_channels = iscapture ? DEFAULT_AUDIO_CAPTURE_CHANNELS : DEFAULT_AUDIO_OUTPUT_CHANNELS;
const int default_freq = iscapture ? DEFAULT_AUDIO_CAPTURE_FREQUENCY : DEFAULT_AUDIO_OUTPUT_FREQUENCY;
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64 changes: 46 additions & 18 deletions src/audio/coreaudio/SDL_coreaudio.m
View file
Expand Up @@ -42,6 +42,28 @@
#endif

#ifdef MACOSX_COREAUDIO
// Apparently AudioDeviceID values might not be unique, so we wrap it in an SDL_malloc()'d pointer
// to make it so. Use FindCoreAudioDeviceByHandle to deal with this redirection, if you need to
// map from an AudioDeviceID to a SDL handle.
typedef struct SDLCoreAudioHandle
{
AudioDeviceID devid;
SDL_bool iscapture;
} SDLCoreAudioHandle;

static SDL_bool TestCoreAudioDeviceHandleCallback(SDL_AudioDevice *device, void *handle)
{
const SDLCoreAudioHandle *a = (const SDLCoreAudioHandle *) device->handle;
const SDLCoreAudioHandle *b = (const SDLCoreAudioHandle *) handle;
return (a->devid == b->devid) && (!!a->iscapture == !!b->iscapture);
}

static SDL_AudioDevice *FindCoreAudioDeviceByHandle(const AudioDeviceID devid, const SDL_bool iscapture)
{
SDLCoreAudioHandle handle = { devid, iscapture };
return SDL_FindPhysicalAudioDeviceByCallback(TestCoreAudioDeviceHandleCallback, &handle);
}

static const AudioObjectPropertyAddress devlist_address = {
kAudioHardwarePropertyDevices,
kAudioObjectPropertyScopeGlobal,
Expand Down Expand Up @@ -70,7 +92,7 @@
static OSStatus DeviceAliveNotification(AudioObjectID devid, UInt32 num_addr, const AudioObjectPropertyAddress *addrs, void *data)
{
SDL_AudioDevice *device = (SDL_AudioDevice *)data;
SDL_assert(((AudioObjectID)(size_t)device->handle) == devid);
SDL_assert(((const SDLCoreAudioHandle *) device->handle)->devid == devid);

UInt32 alive = 1;
UInt32 size = sizeof(alive);
Expand All @@ -95,8 +117,9 @@ static OSStatus DeviceAliveNotification(AudioObjectID devid, UInt32 num_addr, co

static void COREAUDIO_FreeDeviceHandle(SDL_AudioDevice *device)
{
const AudioDeviceID devid = (AudioDeviceID)(size_t)device->handle;
AudioObjectRemovePropertyListener(devid, &alive_address, DeviceAliveNotification, device);
SDLCoreAudioHandle *handle = (SDLCoreAudioHandle *) device->handle;
AudioObjectRemovePropertyListener(handle->devid, &alive_address, DeviceAliveNotification, device);
SDL_free(handle);
}

// This only _adds_ new devices. Removal is handled by devices triggering kAudioDevicePropertyDeviceIsAlive property changes.
Expand All @@ -117,8 +140,7 @@ static void RefreshPhysicalDevices(void)

const UInt32 total_devices = (UInt32) (size / sizeof(AudioDeviceID));
for (UInt32 i = 0; i < total_devices; i++) {
SDL_AudioDevice *device = SDL_FindPhysicalAudioDeviceByHandle((void *)((size_t)devs[i]));
if (device) {
if (FindCoreAudioDeviceByHandle(devs[i], SDL_TRUE) || FindCoreAudioDeviceByHandle(devs[i], SDL_FALSE)) {
devs[i] = 0; // The system and SDL both agree it's already here, don't check it again.
}
}
Expand Down Expand Up @@ -206,10 +228,16 @@ static void RefreshPhysicalDevices(void)
((iscapture) ? "capture" : "output"),
(int)i, name, (int)dev);
#endif

SDL_AudioDevice *device = SDL_AddAudioDevice(iscapture ? SDL_TRUE : SDL_FALSE, name, &spec, (void *)((size_t)dev));
if (device) {
AudioObjectAddPropertyListener(dev, &alive_address, DeviceAliveNotification, device);
SDLCoreAudioHandle *newhandle = (SDLCoreAudioHandle *) SDL_calloc(1, sizeof (*newhandle));
if (newhandle) {
newhandle->devid = dev;
newhandle->iscapture = iscapture ? SDL_TRUE : SDL_FALSE;
SDL_AudioDevice *device = SDL_AddAudioDevice(newhandle->iscapture, name, &spec, newhandle);
if (device) {
AudioObjectAddPropertyListener(dev, &alive_address, DeviceAliveNotification, device);
} else {
SDL_free(newhandle);
}
}
}
SDL_free(name); // SDL_AddAudioDevice() would have copied the string.
Expand All @@ -226,12 +254,12 @@ static OSStatus DeviceListChangedNotification(AudioObjectID systemObj, UInt32 nu
return noErr;
}

static OSStatus DefaultAudioDeviceChangedNotification(AudioObjectID inObjectID, const AudioObjectPropertyAddress *addr)
static OSStatus DefaultAudioDeviceChangedNotification(const SDL_bool iscapture, AudioObjectID inObjectID, const AudioObjectPropertyAddress *addr)
{
AudioDeviceID devid;
UInt32 size = sizeof(devid);
if (AudioObjectGetPropertyData(inObjectID, addr, 0, NULL, &size, &devid) == noErr) {
SDL_DefaultAudioDeviceChanged(SDL_FindPhysicalAudioDeviceByHandle((void *)((size_t)devid)));
SDL_DefaultAudioDeviceChanged(FindCoreAudioDeviceByHandle(devid, iscapture));
}
return noErr;
}
Expand All @@ -242,7 +270,7 @@ static OSStatus DefaultOutputDeviceChangedNotification(AudioObjectID inObjectID,
SDL_Log("COREAUDIO: default output device changed!");
#endif
SDL_assert(inNumberAddresses == 1);
return DefaultAudioDeviceChangedNotification(inObjectID, inAddresses);
return DefaultAudioDeviceChangedNotification(SDL_FALSE, inObjectID, inAddresses);
}

static OSStatus DefaultInputDeviceChangedNotification(AudioObjectID inObjectID, UInt32 inNumberAddresses, const AudioObjectPropertyAddress *inAddresses, void *inUserData)
Expand All @@ -251,7 +279,7 @@ static OSStatus DefaultInputDeviceChangedNotification(AudioObjectID inObjectID,
SDL_Log("COREAUDIO: default input device changed!");
#endif
SDL_assert(inNumberAddresses == 1);
return DefaultAudioDeviceChangedNotification(inObjectID, inAddresses);
return DefaultAudioDeviceChangedNotification(SDL_TRUE, inObjectID, inAddresses);
}

static void COREAUDIO_DetectDevices(SDL_AudioDevice **default_output, SDL_AudioDevice **default_capture)
Expand All @@ -266,7 +294,7 @@ static void COREAUDIO_DetectDevices(SDL_AudioDevice **default_output, SDL_AudioD

size = sizeof(AudioDeviceID);
if (AudioObjectGetPropertyData(kAudioObjectSystemObject, &default_output_device_address, 0, NULL, &size, &devid) == noErr) {
SDL_AudioDevice *device = SDL_FindPhysicalAudioDeviceByHandle((void *)((size_t)devid));
SDL_AudioDevice *device = FindCoreAudioDeviceByHandle(devid, SDL_FALSE);
if (device) {
*default_output = device;
}
Expand All @@ -275,7 +303,7 @@ static void COREAUDIO_DetectDevices(SDL_AudioDevice **default_output, SDL_AudioD

size = sizeof(AudioDeviceID);
if (AudioObjectGetPropertyData(kAudioObjectSystemObject, &default_input_device_address, 0, NULL, &size, &devid) == noErr) {
SDL_AudioDevice *device = SDL_FindPhysicalAudioDeviceByHandle((void *)((size_t)devid));
SDL_AudioDevice *device = FindCoreAudioDeviceByHandle(devid, SDL_TRUE);
if (device) {
*default_capture = device;
}
Expand Down Expand Up @@ -631,10 +659,10 @@ static void COREAUDIO_CloseDevice(SDL_AudioDevice *device)
#ifdef MACOSX_COREAUDIO
static int PrepareDevice(SDL_AudioDevice *device)
{
void *handle = device->handle;
SDL_assert(handle != NULL); // this meant "system default" in SDL2, but doesn't anymore
SDL_assert(device->handle != NULL); // this meant "system default" in SDL2, but doesn't anymore

const AudioDeviceID devid = (AudioDeviceID)((size_t)handle);
const SDLCoreAudioHandle *handle = (const SDLCoreAudioHandle *) device->handle;
const AudioDeviceID devid = handle->devid;
OSStatus result = noErr;
UInt32 size = 0;

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