Replace Audio::MixerImpl::setOutputRate with a new 'sampleRate' param to the MixerImpl constructor

svn-id: r48238

2 files changed, 15 insertions, 26 deletions

diff --git a/backends/platform/symbian/src/SymbianOS.cpp b/backends/platform/symbian/src/SymbianOS.cpp
index 480b62849e..f8df2a5d5c 100644
--- a/backends/platform/symbian/src/SymbianOS.cpp
+++ b/backends/platform/symbian/src/SymbianOS.cpp
@@ -220,28 +220,22 @@ void OSystem_SDL_Symbian::setupMixer() {
 	SDL_AudioSpec desired;
 	SDL_AudioSpec obtained;
 
-	memset(&desired, 0, sizeof(desired));
-
+	// Determine the desired output sampling frequency.
 	uint32 samplesPerSec = 0;
-
 	if (ConfMan.hasKey("output_rate"))
 		samplesPerSec = ConfMan.getInt("output_rate");
-
 	if (samplesPerSec <= 0)
 		samplesPerSec = SAMPLES_PER_SEC;
 
-	// Originally, we always used 2048 samples. This loop will produce the
-	// same result at 22050 Hz, and should hopefully produce something
-	// sensible for other frequencies. Note that it must be a power of two.
-
-	uint32 samples = 0x8000;
-
-	for (;;) {
-		if ((1000 * samples) / samplesPerSec < 100)
-			break;
+	// Determine the sample buffer size. We want it to store enough data for
+	// at least 1/16th of a second (though at most 8192 samples). Note
+	// that it must be a power of two. So e.g. at 22050 Hz, we request a
+	// sample buffer size of 2048.
+	uint32 samples = 8192;
+	while (samples * 16 > samplesPerSec * 2)
 		samples >>= 1;
-	}
 
+	memset(&desired, 0, sizeof(desired));
 	desired.freq = samplesPerSec;
 	desired.format = AUDIO_S16SYS;
 	desired.channels = 2;
@@ -249,14 +243,11 @@ void OSystem_SDL_Symbian::setupMixer() {
 	desired.callback = symbianMixCallback;
 	desired.userdata = this;
 
-	// Create the mixer instance
 	assert(!_mixer);
-	_mixer = new Audio::MixerImpl(this);
-	assert(_mixer);
-
 	if (SDL_OpenAudio(&desired, &obtained) != 0) {
 		warning("Could not open audio device: %s", SDL_GetError());
-		samplesPerSec = 0;
+		_mixer = new Audio::MixerImpl(this, samplesPerSec);
+		assert(_mixer);
 		_mixer->setReady(false);
 	} else {
 		// Note: This should be the obtained output rate, but it seems that at
@@ -270,16 +261,16 @@ void OSystem_SDL_Symbian::setupMixer() {
 			_stereo_mix_buffer = new byte [obtained.size*2];//*2 for stereo values
 		}
 
-		// Tell the mixer that we are ready and start the sound processing
-		_mixer->setOutputRate(samplesPerSec);
+		// Create the mixer instance and start the sound processing
+		_mixer = new Audio::MixerImpl(this, samplesPerSec);
+		assert(_mixer);
 		_mixer->setReady(true);
 		SDL_PauseAudio(0);
 	}
 }
 
 /**
- * The mixer callback function, passed on to OSystem::setSoundCallback().
- * This simply calls the mix() method.
+ * The mixer callback function.
  */
 void OSystem_SDL_Symbian::symbianMixCallback(void *sys, byte *samples, int len) {
 	OSystem_SDL_Symbian *this_ = (OSystem_SDL_Symbian *)sys;
diff --git a/backends/platform/symbian/src/SymbianOS.h b/backends/platform/symbian/src/SymbianOS.h
index 5c6b7c505c..42929f8029 100644
--- a/backends/platform/symbian/src/SymbianOS.h
+++ b/backends/platform/symbian/src/SymbianOS.h
@@ -63,9 +63,7 @@ public:
 	RFs& FsSession();
 protected:
 	//
-	// The mixer callback function, passed on to OSystem::setSoundCallback().
-	// This simply calls the mix() method.
-	// and then does downmixing for symbian if needed
+	// The mixer callback function.
 	//
 	static void symbianMixCallback(void *s, byte *samples, int len);