reduce latency

Author: JoeMatt

audio/drivers_microphone/coreaudio_mic_macos.m

@@ -652,21 +652,41 @@ static void coreaudio_macos_microphone_device_list_free(const void *data, struct
    }
 
    RARCH_LOG("[CoreAudio macOS Mic]: Initializing AudioUnit %p\n", mic->audio_unit);
-   status = AudioUnitInitialize(mic->audio_unit);
-   if (status != noErr)
-   {
-      RARCH_ERR("[CoreAudio macOS Mic]: Failed to initialize AudioUnit: %d\n", (int)status);
-      AudioComponentInstanceDispose(mic->audio_unit);
-      if (mic->device_name) free(mic->device_name);
-      
-      free(mic);
-      return NULL;
-   }
+   
+   /* Set a smaller buffer frame size for lower latency */
+    UInt32 buffer_frame_size = 256; /* Small buffer for lower latency */
+    status = AudioUnitSetProperty(mic->audio_unit,
+                               kAudioDevicePropertyBufferFrameSize,
+                               kAudioUnitScope_Global,
+                               0,
+                               &buffer_frame_size,
+                               sizeof(buffer_frame_size));
+    if (status != noErr)
+    {
+        RARCH_WARN("[CoreAudio macOS Mic]: Failed to set buffer frame size to %u: %d\n", 
+                   (unsigned)buffer_frame_size, (int)status);
+        /* Non-fatal, continue with default buffer size */
+    }
+    else
+    {
+        RARCH_LOG("[CoreAudio macOS Mic]: Set buffer frame size to %u frames for lower latency\n", 
+                 (unsigned)buffer_frame_size);
+    }
+    
+    status = AudioUnitInitialize(mic->audio_unit);
+    if (status != noErr)
+    {
+        RARCH_ERR("[CoreAudio macOS Mic]: Failed to initialize AudioUnit: %d\n", (int)status);
+        AudioComponentInstanceDispose(mic->audio_unit);
+        if (mic->device_name) free(mic->device_name);
+        free(mic);
+        return NULL;
+    }
    atomic_store(&mic->is_initialized, true);
    RARCH_LOG("[CoreAudio macOS Mic]: AudioUnit successfully initialized.\n");
 
-    /* Initialize FIFO buffer - 150ms buffer size like iOS version */
-    size_t fifo_size = mic->format.mSampleRate * mic->format.mBytesPerFrame * 0.15f;
+    /* Initialize FIFO buffer - 50ms buffer size */
+    size_t fifo_size = mic->format.mSampleRate * mic->format.mBytesPerFrame * 0.05f;
     RARCH_LOG("[CoreAudio macOS Mic]: Creating FIFO buffer of size %u bytes (%.1f ms at %.0f Hz)\n", 
              (unsigned)fifo_size, 
              (float)fifo_size * 1000.0f / (mic->format.mSampleRate * mic->format.mBytesPerFrame),