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SDL audio should use now centralized audio functions

This commit is contained in:
Jeffrey Pfau 2014-01-29 00:45:00 -08:00
parent 5fde0d8c35
commit 9d351d4a58
1 changed files with 2 additions and 44 deletions
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46
src/platform/sdl/sdl-audio.c
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@ -3,16 +3,9 @@
#include "gba.h"
#include "gba-thread.h"
#include <math.h>
#define BUFFER_SIZE (GBA_AUDIO_SAMPLES >> 2)
#define FPS_TARGET 60.f
struct StereoSample {
Sint16 left;
Sint16 right;
};
static void _GBASDLAudioCallback(void* context, Uint8* data, int len);
int GBASDLInitAudio(struct GBASDLAudio* context) {
@ -44,41 +37,6 @@ void GBASDLDeinitAudio(struct GBASDLAudio* context) {
SDL_QuitSubSystem(SDL_INIT_AUDIO);
}
static void _pulldownResample(struct GBASDLAudio* context, struct StereoSample* output, ssize_t samples) {
int32_t left[BUFFER_SIZE];
int32_t right[BUFFER_SIZE];
// toRead is in GBA samples
// TODO: Do this with fixed-point math
unsigned toRead = ceilf(samples / context->ratio);
while (samples > 0) {
unsigned currentRead = BUFFER_SIZE >> 2;
if (currentRead > toRead) {
currentRead = toRead;
}
unsigned read = GBAAudioCopy(context->audio, left, right, currentRead);
toRead -= read;
unsigned i;
for (i = 0; i < read; ++i) {
context->drift += context->ratio;
while (context->drift >= 1.f) {
output->left = left[i];
output->right = right[i];
++output;
--samples;
context->drift -= 1.f;
if (samples < 0) {
return;
}
}
}
if (read < currentRead) {
memset(output, 0, samples * sizeof(struct StereoSample));
return;
}
}
}
static void _GBASDLAudioCallback(void* context, Uint8* data, int len) {
struct GBASDLAudio* audioContext = context;
if (!context || !audioContext->audio) {
@ -87,9 +45,9 @@ static void _GBASDLAudioCallback(void* context, Uint8* data, int len) {
}
float ratio = 280896.0f * FPS_TARGET / GBA_ARM7TDMI_FREQUENCY;
audioContext->ratio = audioContext->obtainedSpec.freq / ratio / (float) audioContext->audio->sampleRate;
struct StereoSample* ssamples = (struct StereoSample*) data;
struct GBAStereoSample* ssamples = (struct GBAStereoSample*) data;
len /= 2 * audioContext->obtainedSpec.channels;
if (audioContext->obtainedSpec.channels == 2) {
_pulldownResample(audioContext, ssamples, len);
GBAAudioResampleNN(audioContext->audio, audioContext->ratio, &audioContext->drift, ssamples, len);
}
}