GBA Audio: Audio buffer sizes are now correct sizes for both sample rates

CHANGES

@@ -22,6 +22,7 @@ Bugfixes:
  - GBA Memory: Properly initialize 1 Mb flash, and add debug logging
  - Qt: Properly set default video recording settings
  - GBA Audio: Make larger buffer sizes than 2048 actually work properly
+ - GBA Audio: Audio buffer sizes are now correct sizes for both sample rates
 Misc:
  - Qt: Disable sync to video by default
  - GBA: Exit cleanly on FATAL if the port supports it

src/gba/gba-audio.c

@@ -861,6 +861,6 @@ void GBAAudioDeserialize(struct GBAAudio* audio, const struct GBASerializedState
 	audio->nextSample = state->audio.nextSample;
 }
 
-float GBAAudioCalculateRatio(struct GBAAudio* audio, float desiredFPS, float desiredSampleRate) {
+float GBAAudioCalculateRatio(float inputSampleRate, float desiredFPS, float desiredSampleRate) {
-	return desiredSampleRate * GBA_ARM7TDMI_FREQUENCY / (VIDEO_TOTAL_LENGTH * desiredFPS * audio->sampleRate);
+	return desiredSampleRate * GBA_ARM7TDMI_FREQUENCY / (VIDEO_TOTAL_LENGTH * desiredFPS * inputSampleRate);
 }

src/gba/gba-audio.h

@@ -263,6 +263,6 @@ struct GBASerializedState;
 void GBAAudioSerialize(const struct GBAAudio* audio, struct GBASerializedState* state);
 void GBAAudioDeserialize(struct GBAAudio* audio, const struct GBASerializedState* state);
 
-float GBAAudioCalculateRatio(struct GBAAudio* audio, float desiredFPS, float desiredSampleRatio);
+float GBAAudioCalculateRatio(float inputSampleRate, float desiredFPS, float desiredSampleRatio);
 
 #endif

src/platform/ffmpeg/ffmpeg-resample.c

@@ -10,11 +10,11 @@
 #include <libavresample/avresample.h>
 #include <libavutil/opt.h>
 
-struct AVAudioResampleContext* GBAAudioOpenLAVR(struct GBAAudio* audio, unsigned outputRate) {
+struct AVAudioResampleContext* GBAAudioOpenLAVR(unsigned inputRate, unsigned outputRate) {
 	AVAudioResampleContext *avr = avresample_alloc_context();
 	av_opt_set_int(avr, "in_channel_layout", AV_CH_LAYOUT_STEREO, 0);
 	av_opt_set_int(avr, "out_channel_layout", AV_CH_LAYOUT_STEREO, 0);
-	av_opt_set_int(avr, "in_sample_rate", audio->sampleRate, 0);
+	av_opt_set_int(avr, "in_sample_rate", inputRate, 0);
 	av_opt_set_int(avr, "out_sample_rate", outputRate, 0);
 	av_opt_set_int(avr, "in_sample_fmt", AV_SAMPLE_FMT_S16P, 0);
 	av_opt_set_int(avr, "out_sample_fmt", AV_SAMPLE_FMT_S16, 0);
@@ -25,6 +25,17 @@ struct AVAudioResampleContext* GBAAudioOpenLAVR(struct GBAAudio* audio, unsigned
 	return avr;
 }
 
+struct AVAudioResampleContext* GBAAudioReopenLAVR(struct AVAudioResampleContext* avr, unsigned inputRate, unsigned outputRate) {
+	avresample_close(avr);
+	av_opt_set_int(avr, "in_sample_rate", inputRate, 0);
+	av_opt_set_int(avr, "out_sample_rate", outputRate, 0);
+	if (avresample_open(avr)) {
+		avresample_free(&avr);
+		return 0;
+	}
+	return avr;
+}
+
 unsigned GBAAudioResampleLAVR(struct GBAAudio* audio, struct AVAudioResampleContext* avr, struct GBAStereoSample* output, unsigned nSamples) {
 	int16_t left[GBA_AUDIO_SAMPLES];
 	int16_t right[GBA_AUDIO_SAMPLES];

src/platform/ffmpeg/ffmpeg-resample.h

@@ -10,7 +10,8 @@ struct AVAudioResampleContext;
 struct GBAAudio;
 struct GBAStereoSample;
 
-struct AVAudioResampleContext* GBAAudioOpenLAVR(struct GBAAudio* audio, unsigned outputRate);
+struct AVAudioResampleContext* GBAAudioOpenLAVR(unsigned inputRate, unsigned outputRate);
+struct AVAudioResampleContext* GBAAudioReopenLAVR(struct AVAudioResampleContext* avr, unsigned inputRate, unsigned outputRate);
 unsigned GBAAudioResampleLAVR(struct GBAAudio* audio, struct AVAudioResampleContext* avr, struct GBAStereoSample* output, unsigned nSamples);
 
 #endif

src/platform/qt/AudioDevice.cpp

@@ -26,7 +26,7 @@ void AudioDevice::setFormat(const QAudioFormat& format) {
 		return;
 	}
 	GBAThreadInterrupt(m_context);
-	m_ratio = GBAAudioCalculateRatio(&m_context->gba->audio, m_context->fpsTarget, format.sampleRate());
+	m_ratio = GBAAudioCalculateRatio(m_context->gba->audio.sampleRate, m_context->fpsTarget, format.sampleRate());
 	GBAThreadContinue(m_context);
 }
 

src/platform/qt/GameController.cpp

@@ -278,11 +278,13 @@ void GameController::keyReleased(int key) {
 void GameController::setAudioBufferSamples(int samples) {
 	if (m_gameOpen) {
 		threadInterrupt();
-		m_threadContext.audioBuffers = samples;
+		float ratio = GBAAudioCalculateRatio(m_threadContext.gba->audio.sampleRate, m_threadContext.fpsTarget, 44100);
-		GBAAudioResizeBuffer(&m_threadContext.gba->audio, samples);
+		m_threadContext.audioBuffers = samples / ratio;
+		GBAAudioResizeBuffer(&m_threadContext.gba->audio, samples / ratio);
 		threadContinue();
 	} else {
-		m_threadContext.audioBuffers = samples;
+		float ratio = GBAAudioCalculateRatio(0x8000, m_threadContext.fpsTarget, 44100);
+		m_threadContext.audioBuffers = samples / ratio;
 
 	}
 	QMetaObject::invokeMethod(m_audioProcessor, "setBufferSamples", Q_ARG(int, samples));

src/platform/sdl/sdl-audio.c

@@ -38,6 +38,8 @@ bool GBASDLInitAudio(struct GBASDLAudio* context, struct GBAThread* threadContex
 	}
 	context->thread = threadContext;
 	context->samples = context->obtainedSpec.samples;
+	float ratio = GBAAudioCalculateRatio(0x8000, threadContext->fpsTarget, 44100);
+	threadContext->audioBuffers = context->samples / ratio;
 	if (context->samples > threadContext->audioBuffers) {
 		threadContext->audioBuffers = context->samples * 2;
 	}
@@ -77,7 +79,7 @@ static void _GBASDLAudioCallback(void* context, Uint8* data, int len) {
 		return;
 	}
 #ifndef USE_FFMPEG
-	audioContext->ratio = GBAAudioCalculateRatio(&audioContext->thread->gba->audio, audioContext->thread->fpsTarget, audioContext->obtainedSpec.freq);
+	audioContext->ratio = GBAAudioCalculateRatio(audioContext->thread->gba->audio.sampleRate, audioContext->thread->fpsTarget, audioContext->obtainedSpec.freq);
 	if (audioContext->ratio == INFINITY) {
 		memset(data, 0, len);
 		return;
@@ -88,12 +90,17 @@ static void _GBASDLAudioCallback(void* context, Uint8* data, int len) {
 		GBAAudioResampleNN(&audioContext->thread->gba->audio, audioContext->ratio, &audioContext->drift, ssamples, len);
 	}
 #else
+	float ratio = GBAAudioCalculateRatio(audioContext->thread->gba->audio.sampleRate, audioContext->thread->fpsTarget, audioContext->thread->gba->audio.sampleRate);
 	if (!audioContext->avr) {
 		if (!audioContext->thread->gba->audio.sampleRate) {
 			memset(data, 0, len);
 			return;
 		}
-		audioContext->avr = GBAAudioOpenLAVR(&audioContext->thread->gba->audio, audioContext->obtainedSpec.freq);
+		audioContext->ratio = ratio;
+		audioContext->avr = GBAAudioOpenLAVR(audioContext->thread->gba->audio.sampleRate / ratio, audioContext->obtainedSpec.freq);
+	} else if (ratio != audioContext->ratio) {
+		audioContext->ratio = ratio;
+		audioContext->avr = GBAAudioReopenLAVR(audioContext->avr, audioContext->thread->gba->audio.sampleRate / ratio, audioContext->obtainedSpec.freq);
 	}
 	struct GBAStereoSample* ssamples = (struct GBAStereoSample*) data;
 	len /= 2 * audioContext->obtainedSpec.channels;

src/platform/sdl/sdl-audio.h

@@ -17,9 +17,9 @@ struct GBASDLAudio {
 	// State
 	SDL_AudioSpec desiredSpec;
 	SDL_AudioSpec obtainedSpec;
+	float ratio;
 #ifndef USE_FFMPEG
 	float drift;
-	float ratio;
 #else
 	struct AVAudioResampleContext* avr;
 #endif