shithub: zelda3

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Fix mono audio rendering

--- a/main.c

+++ b/main.c

@@ -33,7 +33,7 @@

 bool RunOneFrame(Snes *snes, int input_state, bool turbo);

 static bool LoadRom(const char *name, Snes *snes);

-static void PlayAudio(Snes *snes, SDL_AudioDeviceID device, int16 *audioBuffer);

+static void PlayAudio(Snes *snes, SDL_AudioDeviceID device, int channels, int16 *audioBuffer);

 static void RenderScreen(SDL_Window *window, SDL_Renderer *renderer, SDL_Texture *texture, bool fullscreen);

 static void HandleInput(int keyCode, int modCode, bool pressed);

 static void HandleGamepadInput(int button, bool pressed);

@@ -176,8 +176,9 @@

       g_config.audio_freq = kDefaultFreq;

   // audio_channels: As of SDL 2.0, supported values are 1 (mono), 2 (stereo), 4 (quad), and 6 (5.1).

+  // Currently, the SPC/DSP implementation only supports up to stereo.

   uint8 c = g_config.audio_channels;

-  if (c == 0 || c == 3 || c == 5 || c > 6)

+  if (c < 1 || c > 2)

       g_config.audio_channels = kDefaultChannels;

   // audio_samples: power of 2

@@ -229,7 +230,7 @@

     return 1;

   }

   g_samples_per_block = (534 * have.freq) / 32000;

-  int16_t* audioBuffer = (int16_t * )malloc(g_samples_per_block * 2 * sizeof(int16));

+  int16_t *audioBuffer = (int16_t * )malloc(g_samples_per_block * have.channels * sizeof(int16));

   SDL_PauseAudioDevice(device, 0);

   Snes *snes = snes_init(g_emulated_ram), *snes_run = NULL;

@@ -321,7 +322,7 @@

     if (is_turbo)

       continue;

-    PlayAudio(snes_run, device, audioBuffer);

+    PlayAudio(snes_run, device, have.channels, audioBuffer);

     RenderScreen(window, renderer, texture, (g_win_flags & SDL_WINDOW_FULLSCREEN_DESKTOP) != 0);

     SDL_RenderPresent(renderer); // vsyncs to 60 FPS

@@ -360,7 +361,7 @@

   return 0;

 }

-static void PlayAudio(Snes *snes, SDL_AudioDeviceID device, int16 *audioBuffer) {

+static void PlayAudio(Snes *snes, SDL_AudioDeviceID device, int channels, int16 *audioBuffer) {

   // generate enough samples

   if (snes) {

     while (snes->apu->dsp->sampleOffset < 534)

@@ -368,12 +369,11 @@

     snes->apu->dsp->sampleOffset = 0;

   }

-  dsp_getSamples(GetDspForRendering(), audioBuffer, g_samples_per_block);

-

+  dsp_getSamples(GetDspForRendering(), audioBuffer, g_samples_per_block, channels);

   for (int i = 0; i < 10; i++) {

-    if (SDL_GetQueuedAudioSize(device) <= g_samples_per_block * 4 * 6) {

+    if (SDL_GetQueuedAudioSize(device) <= g_samples_per_block * channels * sizeof(int16) * 6) {

       // don't queue audio if buffer is still filled

-      SDL_QueueAudio(device, audioBuffer, g_samples_per_block * 4);

+      SDL_QueueAudio(device, audioBuffer, g_samples_per_block * channels * sizeof(int16));

       return;

     }

     SDL_Delay(1);

--- a/snes/dsp.c

+++ b/snes/dsp.c

@@ -5,6 +5,7 @@

 #include <stdint.h>

 #include <stdbool.h>

 #include <stddef.h>

+#include <limits.h>

 #include "dsp_regs.h"

 #include "dsp.h"

@@ -633,14 +634,26 @@

   dsp->ram[adr] = val;

 }

-void dsp_getSamples(Dsp* dsp, int16_t* sampleData, int samplesPerFrame) {

+void dsp_getSamples(Dsp* dsp, int16_t* sampleData, int samplesPerFrame, int numChannels) {

   // resample from 534 samples per frame to wanted value

   float adder = 534.0 / samplesPerFrame;

   float location = 0.0;

-  for(int i = 0; i < samplesPerFrame; i++) {

-    sampleData[i * 2] = dsp->sampleBuffer[((int) location) * 2];

-    sampleData[i * 2 + 1] = dsp->sampleBuffer[((int) location) * 2 + 1];

-    location += adder;

+

+  if (numChannels == 1) {

+    for (int i = 0; i < samplesPerFrame; i++) {

+      int sampleL = dsp->sampleBuffer[((int)location) * 2];

+      int sampleR = dsp->sampleBuffer[((int)location) * 2 + 1];

+      sampleData[i] = (sampleL + sampleR) >> 1;

+      location += adder;

+    }

+  } else {

+    for (int i = 0; i < samplesPerFrame; i++) {

+      int sampleL = dsp->sampleBuffer[((int)location) * 2];

+      int sampleR = dsp->sampleBuffer[((int)location) * 2 + 1];

+      sampleData[i * 2] = sampleL;

+      sampleData[i * 2 + 1] = sampleR;

+      location += adder;

+    }

   }

   dsp->sampleOffset = 0;

 }

--- a/snes/dsp.h

+++ b/snes/dsp.h

@@ -94,7 +94,7 @@

 void dsp_cycle(Dsp* dsp);

 uint8_t dsp_read(Dsp* dsp, uint8_t adr);

 void dsp_write(Dsp* dsp, uint8_t adr, uint8_t val);

-void dsp_getSamples(Dsp* dsp, int16_t* sampleData, int samplesPerFrame);

+void dsp_getSamples(Dsp* dsp, int16_t* sampleData, int samplesPerFrame, int numChannels);

 void dsp_saveload(Dsp *dsp, SaveLoadFunc *func, void *ctx);

 #endif

--- a/spc_player.c

+++ b/spc_player.c

@@ -1368,8 +1368,8 @@

       SpcPlayer_GenerateSamples(p);

       int16_t audioBuffer[736 * 2];

-      dsp_getSamples(p->dsp, audioBuffer, 736);

-      SDL_QueueAudio(device, audioBuffer, 736 * 4);

+      dsp_getSamples(p->dsp, audioBuffer, 736, have.channels);

+      SDL_QueueAudio(device, audioBuffer, 736 * 2 * have.channels);

       while (SDL_GetQueuedAudioSize(device) >= 736 * 4 * 3/* 44100 * 4 * 300*/)

         SDL_Delay(1);

@@ -1435,8 +1435,8 @@

       if (p->dsp->sampleOffset == 534) {

         int16_t audioBuffer[736 * 2];

-        dsp_getSamples(p->dsp, audioBuffer, 736);

-        SDL_QueueAudio(device, audioBuffer, 736 * 4);

+        dsp_getSamples(p->dsp, audioBuffer, 736, have.channels);

+        SDL_QueueAudio(device, audioBuffer, 736 * 2 * have.channels);

         while (SDL_GetQueuedAudioSize(device) >= 736 * 4 * 3/* 44100 * 4 * 300*/) {

           SDL_Delay(1);

         }