mirrors/SDL
1
0
Fork 0
mirror of https://github.com/libsdl-org/SDL.git synced 2025-10-26 12:27:44 +00:00
Code Issues Packages Projects Releases Wiki Activity

Revert "audio: Added SDL_SetAudioIterationCallbacks()."

Browse Source 
This reverts commit 608f706a95.

Didn't end up using this in SDL3_mixer, and it's a super-awkward API if we
don't need it.

I _might_ bite the bullet and let people lock a physical audio device, though,
as I could see that being useful but less awkward for the same reasons I
originally wanted it.
This commit is contained in:
Ryan C. Gordon
2025-07-25 01:29:13 -04:00
parent e5d57d8ad6
commit c80d6954cb
6 changed files with 1 additions and 127 deletions
Download Patch File Download Diff File Expand all files Collapse all files

79
include/SDL3/SDL_audio.h
View File

@@ -2035,85 +2035,6 @@ extern SDL_DECLSPEC void SDLCALL SDL_DestroyAudioStream(SDL_AudioStream *stream)
*/
extern SDL_DECLSPEC SDL_AudioStream * SDLCALL SDL_OpenAudioDeviceStream(SDL_AudioDeviceID devid, const SDL_AudioSpec *spec, SDL_AudioStreamCallback callback, void *userdata);
/**
* A callback that fires around an audio device's processing work.
*
* This callback fires when a logical audio device is about to start accessing
* its bound audio streams, and fires again when it has finished accessing
* them. It covers the range of one "iteration" of the audio device.
*
* It can be useful to use this callback to update state that must apply to
* all bound audio streams atomically: to make sure state changes don't happen
* while half of the streams are already processed for the latest audio
* buffer.
*
* This callback should run as quickly as possible and not block for any
* significant time, as this callback delays submission of data to the audio
* device, which can cause audio playback problems. This callback delays all
* audio processing across a single physical audio device: all its logical
* devices and all bound audio streams. Use it carefully.
*
* \param userdata a pointer provided by the app through
* SDL_SetAudioPostmixCallback, for its own use.
* \param devid the audio device this callback is running for.
* \param start true if this is the start of the iteration, false if the end.
*
* \threadsafety This will run from a background thread owned by SDL. The
* application is responsible for locking resources the callback
* touches that need to be protected.
*
* \since This datatype is available since SDL 3.4.0.
*
* \sa SDL_SetAudioIterationCallbacks
*/
typedef void (SDLCALL *SDL_AudioIterationCallback)(void *userdata, SDL_AudioDeviceID devid, bool start);
/**
* Set callbacks that fire around a new iteration of audio device processing.
*
* Two callbacks are provided here: one that runs when a device is about to
* process its bound audio streams, and another that runs when the device has
* finished processing them.
*
* These callbacks can run at any time, and from any thread; if you need to
* serialize access to your app's data, you should provide and use a mutex or
* other synchronization device.
*
* Generally these callbacks are used to apply state that applies to multiple
* bound audio streams, with a guarantee that the audio device's thread isn't
* halfway through processing them. Generally a finer-grained lock through
* SDL_LockAudioStream() is more appropriate.
*
* The callbacks are extremely time-sensitive; the callback should do the
* least amount of work possible and return as quickly as it can. The longer
* the callback runs, the higher the risk of audio dropouts or other problems.
*
* This function will block until the audio device is in between iterations,
* so any existing callback that might be running will finish before this
* function sets the new callback and returns.
*
* Physical devices do not accept these callbacks, only logical devices
* created through SDL_OpenAudioDevice() can be.
*
* Setting a NULL callback function disables any previously-set callback.
* Either callback may be NULL, and the same callback is permitted to be used
* for both.
*
* \param devid the ID of an opened audio device.
* \param start a callback function to be called at the start of an iteration.
* Can be NULL.
* \param end a callback function to be called at the end of an iteration. Can
* be NULL.
* \param userdata app-controlled pointer passed to callback. Can be NULL.
* \returns true on success or false on failure; call SDL_GetError() for more
* information.
*
* \threadsafety It is safe to call this function from any thread.
*
* \since This function is available since SDL 3.4.0.
*/
extern SDL_DECLSPEC bool SDLCALL SDL_SetAudioIterationCallbacks(SDL_AudioDeviceID devid, SDL_AudioIterationCallback start, SDL_AudioIterationCallback end, void *userdata);
/**
* A callback that fires when data is about to be fed to an audio device.
*

39
src/audio/SDL_audio.c
View File

@@ -1164,23 +1164,9 @@ bool SDL_PlaybackAudioThreadIterate(SDL_AudioDevice *device)
// We should have updated this elsewhere if the format changed!
SDL_assert(SDL_AudioSpecsEqual(&stream->dst_spec, &device->spec, NULL, NULL));
SDL_assert(stream->src_spec.format != SDL_AUDIO_UNKNOWN);
int br = 0;
if (!SDL_GetAtomicInt(&logdev->paused)) {
if (logdev->iteration_start) {
logdev->iteration_start(logdev->iteration_userdata, logdev->instance_id, true);
}
br = SDL_GetAudioStreamDataAdjustGain(stream, device_buffer, buffer_size, logdev->gain);
if (logdev->iteration_end) {
logdev->iteration_end(logdev->iteration_userdata, logdev->instance_id, false);
}
}
const int br = SDL_GetAtomicInt(&logdev->paused) ? 0 : SDL_GetAudioStreamDataAdjustGain(stream, device_buffer, buffer_size, logdev->gain);
if (br < 0) { // Probably OOM. Kill the audio device; the whole thing is likely dying soon anyhow.
failed = true;
SDL_memset(device_buffer, device->silence_value, buffer_size); // just supply silence to the device before we die.
@@ -1218,10 +1204,6 @@ bool SDL_PlaybackAudioThreadIterate(SDL_AudioDevice *device)
SDL_memset(mix_buffer, '\0', work_buffer_size); // start with silence.
}
if (logdev->iteration_start) {
logdev->iteration_start(logdev->iteration_userdata, logdev->instance_id, true);
}
for (SDL_AudioStream *stream = logdev->bound_streams; stream; stream = stream->next_binding) {
// We should have updated this elsewhere if the format changed!
SDL_assert(SDL_AudioSpecsEqual(&stream->dst_spec, &outspec, NULL, NULL));
@@ -1246,10 +1228,6 @@ bool SDL_PlaybackAudioThreadIterate(SDL_AudioDevice *device)
}
}
if (logdev->iteration_end) {
logdev->iteration_end(logdev->iteration_userdata, logdev->instance_id, false);
}
if (postmix) {
SDL_assert(mix_buffer == device->postmix_buffer);
postmix(logdev->postmix_userdata, &outspec, mix_buffer, work_buffer_size);
@@ -1991,21 +1969,6 @@ bool SDL_SetAudioPostmixCallback(SDL_AudioDeviceID devid, SDL_AudioPostmixCallba
return result;
}
bool SDL_SetAudioIterationCallbacks(SDL_AudioDeviceID devid, SDL_AudioIterationCallback iter_start, SDL_AudioIterationCallback iter_end, void *userdata)
{
SDL_AudioDevice *device = NULL;
SDL_LogicalAudioDevice *logdev = ObtainLogicalAudioDevice(devid, &device);
bool result = false;
if (logdev) {
logdev->iteration_start = iter_start;
logdev->iteration_end = iter_end;
logdev->iteration_userdata = userdata;
result = true;
}
ReleaseAudioDevice(device);
return result;
}
bool SDL_BindAudioStreams(SDL_AudioDeviceID devid, SDL_AudioStream * const *streams, int num_streams)
{
const bool islogical = !(devid & (1<<1));

7
src/audio/SDL_sysaudio.h
View File

@@ -264,13 +264,6 @@ struct SDL_LogicalAudioDevice
// true if device was opened with SDL_OpenAudioDeviceStream (so it forbids binding changes, etc).
bool simplified;
// If non-NULL, callback into the app that alerts it to start/end of device iteration.
SDL_AudioIterationCallback iteration_start;
SDL_AudioIterationCallback iteration_end;
// App-supplied pointer for iteration callbacks.
void *iteration_userdata;
// If non-NULL, callback into the app that lets them access the final postmix buffer.
SDL_AudioPostmixCallback postmix;

1
src/dynapi/SDL_dynapi.sym
View File

@@ -1251,7 +1251,6 @@ SDL3_0.0.0 {
SDL_GetGPUDeviceProperties;
SDL_CreateGPURenderer;
SDL_PutAudioStreamPlanarData;
SDL_SetAudioIterationCallbacks;
SDL_GetEventDescription;
SDL_PutAudioStreamDataNoCopy;
SDL_IsTraySupported;

1
src/dynapi/SDL_dynapi_overrides.h
View File

@@ -1276,7 +1276,6 @@
#define SDL_GetGPUDeviceProperties SDL_GetGPUDeviceProperties_REAL
#define SDL_CreateGPURenderer SDL_CreateGPURenderer_REAL
#define SDL_PutAudioStreamPlanarData SDL_PutAudioStreamPlanarData_REAL
#define SDL_SetAudioIterationCallbacks SDL_SetAudioIterationCallbacks_REAL
#define SDL_GetEventDescription SDL_GetEventDescription_REAL
#define SDL_PutAudioStreamDataNoCopy SDL_PutAudioStreamDataNoCopy_REAL
#define SDL_IsTraySupported SDL_IsTraySupported_REAL

1
src/dynapi/SDL_dynapi_procs.h
View File

@@ -1284,7 +1284,6 @@ SDL_DYNAPI_PROC(bool,SDL_GetRenderTextureAddressMode,(SDL_Renderer *a,SDL_Textur
SDL_DYNAPI_PROC(SDL_PropertiesID,SDL_GetGPUDeviceProperties,(SDL_GPUDevice *a),(a),return)
SDL_DYNAPI_PROC(SDL_Renderer*,SDL_CreateGPURenderer,(SDL_Window *a,SDL_GPUShaderFormat b,SDL_GPUDevice **c),(a,b,c),return)
SDL_DYNAPI_PROC(bool,SDL_PutAudioStreamPlanarData,(SDL_AudioStream *a,const void * const*b,int c,int d),(a,b,c,d),return)
SDL_DYNAPI_PROC(bool,SDL_SetAudioIterationCallbacks,(SDL_AudioDeviceID a,SDL_AudioIterationCallback b,SDL_AudioIterationCallback c,void *d),(a,b,c,d),return)
SDL_DYNAPI_PROC(int,SDL_GetEventDescription,(const SDL_Event *a,char *b,int c),(a,b,c),return)
SDL_DYNAPI_PROC(bool,SDL_PutAudioStreamDataNoCopy,(SDL_AudioStream *a,const void *b,int c,SDL_AudioStreamDataCompleteCallback d,void *e),(a,b,c,d,e),return)
SDL_DYNAPI_PROC(bool,SDL_IsTraySupported,(void),(),return)