Allow get sample rate in conf.lua, read back with lovr.audio.getSampleRate()

src/api/l_audio.c

@@ -202,6 +202,11 @@ static int l_lovrAudioGetSpatializer(lua_State *L) {
   return 1;
 }
 
+static int l_lovrAudioGetSampleRate(lua_State *L) {
+  lua_pushnumber(L, lovrAudioGetSampleRate());
+  return 1;
+}
+
 static int l_lovrAudioGetAbsorption(lua_State* L) {
   float absorption[3];
   lovrAudioGetAbsorption(absorption);
@@ -290,6 +295,7 @@ static const luaL_Reg lovrAudio[] = {
   { "setPose", l_lovrAudioSetPose },
   { "setGeometry", l_lovrAudioSetGeometry },
   { "getSpatializer", l_lovrAudioGetSpatializer },
+  { "getSampleRate", l_lovrAudioGetSampleRate },
   { "getAbsorption", l_lovrAudioGetAbsorption },
   { "setAbsorption", l_lovrAudioSetAbsorption },
   { "newSource", l_lovrAudioNewSource },
@@ -305,6 +311,7 @@ int luaopen_lovr_audio(lua_State* L) {
 
   bool start = true;
   const char *spatializer = NULL;
+  int sampleRate = DEFAULT_SAMPLE_RATE;
   luax_pushconf(L);
   lua_getfield(L, -1, "audio");
   if (lua_istable(L, -1)) {
@@ -312,13 +319,19 @@ int luaopen_lovr_audio(lua_State* L) {
     spatializer = lua_tostring(L, -1);
     lua_pop(L, 1);
 
+    lua_getfield(L, -1, "sampleRate");
+    int userSampleRate = luaL_optnumber(L, -1, 0);
+    if (userSampleRate > 0)
+      sampleRate = userSampleRate;
+    lua_pop(L, 1);
+
     lua_getfield(L, -1, "start");
     start = lua_isnil(L, -1) || lua_toboolean(L, -1);
     lua_pop(L, 1);
   }
   lua_pop(L, 2);
 
-  if (lovrAudioInit(spatializer)) {
+  if (lovrAudioInit(spatializer, sampleRate)) {
     luax_atexit(L, lovrAudioDestroy);
     if (start) {
       lovrAudioSetDevice(AUDIO_PLAYBACK, NULL, 0, NULL, AUDIO_SHARED);

src/modules/audio/audio.c

@@ -52,6 +52,7 @@ static struct {
   float leftovers[BUFFER_SIZE * 2];
   float absorption[3];
   ma_data_converter playbackConverter;
+  int sampleRate;
 } state;
 
 static const ma_format miniaudioFormats[] = {
@@ -226,9 +227,11 @@ static Spatializer* spatializers[] = {
 
 // Entry
 
-bool lovrAudioInit(const char* spatializer) {
+bool lovrAudioInit(const char* spatializer, int sampleRate) {
   if (state.initialized) return false;
 
+  state.sampleRate = sampleRate;
+
   ma_result result = ma_context_init(NULL, 0, NULL, &state.context);
   lovrAssert(result == MA_SUCCESS, "Failed to initialize miniaudio");
 
@@ -295,7 +298,7 @@ bool lovrAudioSetDevice(AudioType type, void* id, size_t size, Sound* sink, Audi
 
   // If no sink is provided for a capture device, one is created internally
   if (type == AUDIO_CAPTURE && !sink) {
-    sink = lovrSoundCreateStream(SAMPLE_RATE * 1., SAMPLE_F32, CHANNEL_MONO, SAMPLE_RATE);
+    sink = lovrSoundCreateStream(state.sampleRate * 1., SAMPLE_F32, CHANNEL_MONO, state.sampleRate);
   } else {
     lovrRetain(sink);
   }
@@ -327,7 +330,7 @@ bool lovrAudioSetDevice(AudioType type, void* id, size_t size, Sound* sink, Audi
     config.playback.shareMode = shareModes[shareMode];
     config.playback.format = ma_format_f32;
     config.playback.channels = OUTPUT_CHANNELS;
-    config.sampleRate = SAMPLE_RATE;
+    config.sampleRate = state.sampleRate;
     if (sink) {
       ma_data_converter_config converterConfig = ma_data_converter_config_init_default();
       converterConfig.formatIn = config.playback.format;
@@ -403,6 +406,10 @@ const char* lovrAudioGetSpatializer() {
   return state.spatializer->name;
 }
 
+int lovrAudioGetSampleRate() {
+  return state.sampleRate;
+}
+
 void lovrAudioGetAbsorption(float absorption[3]) {
   memcpy(absorption, state.absorption, 3 * sizeof(float));
 }
@@ -434,7 +441,7 @@ Source* lovrSourceCreate(Sound* sound, uint32_t effects) {
   config.channelsIn = lovrSoundGetChannelCount(sound);
   config.channelsOut = lovrSourceUsesSpatializer(source) ? 1 : 2; // See onPlayback
   config.sampleRateIn = lovrSoundGetSampleRate(sound);
-  config.sampleRateOut = SAMPLE_RATE;
+  config.sampleRateOut = state.sampleRate;
 
   if (config.formatIn != config.formatOut || config.channelsIn != config.channelsOut || config.sampleRateIn != config.sampleRateOut) {
     source->converter = malloc(sizeof(ma_data_converter));

src/modules/audio/audio.h

@@ -4,7 +4,7 @@
 
 #pragma once
 
-#define SAMPLE_RATE 48000
+#define DEFAULT_SAMPLE_RATE 48000
 #define BUFFER_SIZE 256
 #define MAX_SOURCES 64
 
@@ -59,7 +59,7 @@ typedef enum {
 
 typedef void AudioDeviceCallback(const void* id, size_t size, const char* name, bool isDefault, void* userdata);
 
-bool lovrAudioInit(const char* spatializer);
+bool lovrAudioInit(const char* spatializer, int sampleRate);
 void lovrAudioDestroy(void);
 void lovrAudioEnumerateDevices(AudioType type, AudioDeviceCallback* callback, void* userdata);
 bool lovrAudioSetDevice(AudioType type, void* id, size_t size, struct Sound* sink, AudioShareMode shareMode);
@@ -72,6 +72,7 @@ void lovrAudioGetPose(float position[4], float orientation[4]);
 void lovrAudioSetPose(float position[4], float orientation[4]);
 bool lovrAudioSetGeometry(float* vertices, uint32_t* indices, uint32_t vertexCount, uint32_t indexCount, AudioMaterial material);
 const char* lovrAudioGetSpatializer(void);
+int lovrAudioGetSampleRate();
 void lovrAudioGetAbsorption(float absorption[3]);
 void lovrAudioSetAbsorption(float absorption[3]);
 

src/modules/audio/spatializer_oculus.c

@@ -106,7 +106,7 @@ static bool oculus_init(void) {
 
   config.acc_Size = sizeof(config);
   config.acc_MaxNumSources = MAX_SOURCES;
-  config.acc_SampleRate = SAMPLE_RATE;
+  config.acc_SampleRate = lovrAudioGetSampleRate();
   config.acc_BufferLength = BUFFER_SIZE; // Stereo
 
   if (ovrAudio_CreateContext(&state.context, &config) != ovrSuccess) {

src/modules/audio/spatializer_phonon.c

@@ -146,7 +146,7 @@ bool phonon_init() {
   status = phonon_iplCreateEnvironment(state.context, NULL, simulationSettings, NULL, NULL, &state.environment);
   if (status != IPL_STATUS_SUCCESS) return phonon_destroy(), false;
 
-  state.renderingSettings.samplingRate = SAMPLE_RATE;
+  state.renderingSettings.samplingRate = lovrAudioGetSampleRate();
   state.renderingSettings.frameSize = BUFFER_SIZE;
   state.renderingSettings.convolutionType = IPL_CONVOLUTIONTYPE_PHONON;
 

src/modules/audio/spatializer_simple.c

@@ -60,7 +60,7 @@ uint32_t simple_apply(Source* source, const float* input, float* output, uint32_
   float* gain = state.gain[index];
 
   float lerpDuration = .05f;
-  float lerpFrames = SAMPLE_RATE * lerpDuration;
+  float lerpFrames = lovrAudioGetSampleRate() * lerpDuration;
   float lerpRate = 1.f / lerpFrames;
 
   for (uint32_t c = 0; c < 2; c++) {