Use display refresh rates rather than input rate directly.

config.def.h

@@ -159,6 +159,16 @@ static const bool post_filter_record = false;
 // OSD-messages
 static const bool font_enable = true;
 
+// The accurate refresh rate of your monitor (Hz).
+// This is used to calculate audio input rate with the formula:
+// audio_input_rate = game_input_rate * display_refresh_rate / game_refresh_rate.
+// If the implementation does not report any values,
+// SNES NTSC defaults will be assumed for compatibility.
+// This value should stay close to 60Hz to avoid large pitch changes.
+// If your monitor does not run at 60Hz, or something close to it, disable VSync,
+// and leave this at its default.
+static const float refresh_rate = 59.95; 
+
 ////////////////
 // Audio
 ////////////////
@@ -169,10 +179,6 @@ static const bool audio_enable = true;
 // Output samplerate
 static const unsigned out_rate = 48000; 
 
-// Input samplerate from libSNES. 
-// Lower this (slightly) if you are experiencing frequent audio dropouts while vsync is enabled.
-static const float in_rate = 31980.0; 
-
 // When changing input rate on-the-fly
 static const float audio_rate_step = 0.25;
 

driver.c

@@ -222,6 +222,27 @@ static void deinit_dsp_plugin(void)
    }
 }
 
+static void adjust_audio_input_rate(void)
+{
+   static bool first = true;
+   if (!first)
+      return;
+
+   if (g_extern.system.timing_set)
+   {
+      g_settings.audio.in_rate = g_extern.system.timing.sample_rate *
+         (g_settings.video.refresh_rate / g_extern.system.timing.fps);
+   }
+   else
+   {
+      g_settings.audio.in_rate = 32040.5 *
+         (g_settings.video.refresh_rate / (21477272.0 / 357366.0)); // SNES metrics.
+   }
+
+   SSNES_LOG("Adjusted audio input rate to: %.2f Hz.\n", g_settings.audio.in_rate);
+   first = false;
+}
+
 #define AUDIO_CHUNK_SIZE_BLOCKING 64
 #define AUDIO_CHUNK_SIZE_NONBLOCKING 2048 // So we don't get complete line-noise when fast-forwarding audio.
 #define AUDIO_MAX_RATIO 16
@@ -233,6 +254,7 @@ void init_audio(void)
       return;
    }
 
+   adjust_audio_input_rate();
    find_audio_driver();
 
    g_extern.audio_data.block_chunk_size = AUDIO_CHUNK_SIZE_BLOCKING;

general.h

@@ -86,6 +86,7 @@ struct settings
       char bsnes_shader_path[MAXPATHLEN];
       char filter_path[MAXPATHLEN];
       enum ssnes_shader_type shader_type;
+      float refresh_rate;
 
       bool render_to_texture;
       double fbo_scale_x;

settings.c

@@ -150,12 +150,12 @@ static void set_defaults(void)
    g_settings.video.second_pass_smooth = second_pass_smooth;
 #endif
 
+   g_settings.video.refresh_rate = refresh_rate;
    g_settings.video.hires_record = hires_record;
    g_settings.video.post_filter_record = post_filter_record;
 
    g_settings.audio.enable = audio_enable;
    g_settings.audio.out_rate = out_rate;
-   g_settings.audio.in_rate = in_rate;
    g_settings.audio.rate_step = audio_rate_step;
    if (audio_device)
       strlcpy(g_settings.audio.device, audio_device, sizeof(g_settings.audio.device));
@@ -317,6 +317,7 @@ static void parse_config_file(void)
    CONFIG_GET_BOOL(video.force_aspect, "video_force_aspect");
    CONFIG_GET_BOOL(video.crop_overscan, "video_crop_overscan");
    CONFIG_GET_DOUBLE(video.aspect_ratio, "video_aspect_ratio");
+   CONFIG_GET_DOUBLE(video.refresh_rate, "video_refresh_rate");
 
    CONFIG_GET_STRING(video.cg_shader_path, "video_cg_shader");
    CONFIG_GET_STRING(video.bsnes_shader_path, "video_bsnes_shader");
@@ -380,7 +381,6 @@ static void parse_config_file(void)
    // Audio settings.
    CONFIG_GET_BOOL(audio.enable, "audio_enable");
    CONFIG_GET_INT(audio.out_rate, "audio_out_rate");
-   CONFIG_GET_DOUBLE(audio.in_rate, "audio_in_rate");
    CONFIG_GET_DOUBLE(audio.rate_step, "audio_rate_step");
    CONFIG_GET_STRING(audio.device, "audio_device");
    CONFIG_GET_INT(audio.latency, "audio_latency");

ssnes.cfg

@@ -101,6 +101,10 @@
 # It is a regular RGB hex number, i.e. red is "ff0000".
 # video_message_color = ffffff
 
+# Video refresh rate of your monitor.
+# Used to calculate a suitable audio input rate.
+# video_refresh_rate = 59.95
+
 #### Audio
 
 # Enable audio.
@@ -109,12 +113,6 @@
 # Audio output samplerate.
 # audio_out_rate = 48000
 
-# Audio input samplerate from libsnes.
-# Lower this (slightly) if you are experiencing frequent audio dropouts while vsync is enabled.
-# Conversely, increase this slightly if you are experiencing good audio, 
-# but lots of dropped frames. Reasonable values for this is 32000 +/- 100 Hz.
-# audio_in_rate = 31980
-
 # When altering audio_in_rate on-the-fly, define by how much each time.
 # audio_rate_step = 0.25