Add module: speaker capture

test/audio_capture/miniaudio.cpp

@@ -0,0 +1,86 @@
+/*
+Demonstrates how to implement loopback recording.
+
+This example simply captures data from your default playback device until you
+press Enter. The output is saved to the file specified on the command line.
+
+Loopback mode is when you record audio that is played from a given speaker. It
+is only supported on WASAPI, but can be used indirectly with PulseAudio by
+choosing the appropriate loopback device after enumeration.
+
+To use loopback mode you just need to set the device type to
+ma_device_type_loopback and set the capture device config properties. The output
+buffer in the callback will be null whereas the input buffer will be valid.
+*/
+#define MINIAUDIO_IMPLEMENTATION
+#include "miniaudio.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+void data_callback(ma_device* pDevice, void* pOutput, const void* pInput,
+                   ma_uint32 frameCount) {
+  ma_encoder* pEncoder = (ma_encoder*)pDevice->pUserData;
+  MA_ASSERT(pEncoder != NULL);
+
+  ma_encoder_write_pcm_frames(pEncoder, pInput, frameCount, NULL);
+
+  (void)pOutput;
+}
+
+int main(int argc, char** argv) {
+  ma_result result;
+  ma_encoder_config encoderConfig;
+  ma_encoder encoder;
+  ma_device_config deviceConfig;
+  ma_device device;
+
+  /* Loopback mode is currently only supported on WASAPI. */
+  ma_backend backends[] = {ma_backend_wasapi};
+
+  if (argc < 2) {
+    printf("No output file.\n");
+    return -1;
+  }
+
+  encoderConfig =
+      ma_encoder_config_init(ma_encoding_format_wav, ma_format_s16, 1, 48000);
+
+  if (ma_encoder_init_file(argv[1], &encoderConfig, &encoder) != MA_SUCCESS) {
+    printf("Failed to initialize output file.\n");
+    return -1;
+  }
+
+  deviceConfig = ma_device_config_init(ma_device_type_loopback);
+  deviceConfig.capture.pDeviceID =
+      NULL; /* Use default device for this example. Set this to the ID of a
+               _playback_ device if you want to capture from a specific device.
+             */
+  deviceConfig.capture.format = encoder.config.format;
+  deviceConfig.capture.channels = encoder.config.channels;
+  deviceConfig.sampleRate = encoder.config.sampleRate;
+  deviceConfig.dataCallback = data_callback;
+  deviceConfig.pUserData = &encoder;
+
+  result = ma_device_init_ex(backends, sizeof(backends) / sizeof(backends[0]),
+                             NULL, &deviceConfig, &device);
+  if (result != MA_SUCCESS) {
+    printf("Failed to initialize loopback device.\n");
+    return -2;
+  }
+
+  result = ma_device_start(&device);
+  if (result != MA_SUCCESS) {
+    ma_device_uninit(&device);
+    printf("Failed to start device.\n");
+    return -3;
+  }
+
+  printf("Press Enter to stop recording...\n");
+  getchar();
+
+  ma_device_uninit(&device);
+  ma_encoder_uninit(&encoder);
+
+  return 0;
+}