Commit e5d49c20331e85ad0a05999d5c6146e34c93f545
2014-07-30T11:08:31
Added a GetPendingBytes method to the audio backend. This will (eventually) make SDL_GetQueuedAudioSize() more accurate, and thus reduce latency. Right now this isn't implemented anywhere, so we assume data fed to the audio callback is consumed by the hardware and immediately played to completion.
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diff --git a/src/audio/SDL_audio.c b/src/audio/SDL_audio.c
index a788c89..804138c 100644
--- a/src/audio/SDL_audio.c
+++ b/src/audio/SDL_audio.c
@@ -178,6 +178,12 @@ SDL_AudioPlayDevice_Default(_THIS)
{ /* no-op. */
}
+static int
+SDL_AudioGetPendingBytes_Default(_THIS)
+{
+ return 0;
+}
+
static Uint8 *
SDL_AudioGetDeviceBuf_Default(_THIS)
{
@@ -253,6 +259,7 @@ finalize_audio_entry_points(void)
FILL_STUB(ThreadInit);
FILL_STUB(WaitDevice);
FILL_STUB(PlayDevice);
+ FILL_STUB(GetPendingBytes);
FILL_STUB(GetDeviceBuf);
FILL_STUB(WaitDone);
FILL_STUB(CloseDevice);
@@ -471,7 +478,7 @@ SDL_GetQueuedAudioSize(SDL_AudioDeviceID devid)
SDL_AudioDevice *device = get_audio_device(devid);
if (device) {
current_audio.impl.LockDevice(device);
- retval = device->queued_bytes;
+ retval = device->queued_bytes + current_audio.impl.GetPendingBytes(device);
current_audio.impl.UnlockDevice(device);
}
diff --git a/src/audio/SDL_sysaudio.h b/src/audio/SDL_sysaudio.h
index c1810b4..4f93320 100644
--- a/src/audio/SDL_sysaudio.h
+++ b/src/audio/SDL_sysaudio.h
@@ -60,6 +60,7 @@ typedef struct SDL_AudioDriverImpl
void (*ThreadInit) (_THIS); /* Called by audio thread at start */
void (*WaitDevice) (_THIS);
void (*PlayDevice) (_THIS);
+ int (*GetPendingBytes) (_THIS);
Uint8 *(*GetDeviceBuf) (_THIS);
void (*WaitDone) (_THIS);
void (*CloseDevice) (_THIS);