1 files changed, 143 insertions, 0 deletions
diff --git a/third_party/libwebrtc/examples/androidapp/src/org/appspot/apprtc/RecordedAudioToFileController.java b/third_party/libwebrtc/examples/androidapp/src/org/appspot/apprtc/RecordedAudioToFileController.java
new file mode 100644
index 0000000000..9787852feb
--- /dev/null
+++ b/third_party/libwebrtc/examples/androidapp/src/org/appspot/apprtc/RecordedAudioToFileController.java
@@ -0,0 +1,143 @@
+/*
+ *  Copyright 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+package org.appspot.apprtc;
+
+import android.media.AudioFormat;
+import android.os.Environment;
+import android.util.Log;
+import androidx.annotation.Nullable;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.concurrent.ExecutorService;
+import org.webrtc.audio.JavaAudioDeviceModule;
+import org.webrtc.audio.JavaAudioDeviceModule.SamplesReadyCallback;
+
+/**
+ * Implements the AudioRecordSamplesReadyCallback interface and writes
+ * recorded raw audio samples to an output file.
+ */
+public class RecordedAudioToFileController implements SamplesReadyCallback {
+  private static final String TAG = "RecordedAudioToFile";
+  private static final long MAX_FILE_SIZE_IN_BYTES = 58348800L;
+
+  private final Object lock = new Object();
+  private final ExecutorService executor;
+  @Nullable private OutputStream rawAudioFileOutputStream;
+  private boolean isRunning;
+  private long fileSizeInBytes;
+
+  public RecordedAudioToFileController(ExecutorService executor) {
+    Log.d(TAG, "ctor");
+    this.executor = executor;
+  }
+
+  /**
+   * Should be called on the same executor thread as the one provided at
+   * construction.
+   */
+  public boolean start() {
+    Log.d(TAG, "start");
+    if (!isExternalStorageWritable()) {
+      Log.e(TAG, "Writing to external media is not possible");
+      return false;
+    }
+    synchronized (lock) {
+      isRunning = true;
+    }
+    return true;
+  }
+
+  /**
+   * Should be called on the same executor thread as the one provided at
+   * construction.
+   */
+  public void stop() {
+    Log.d(TAG, "stop");
+    synchronized (lock) {
+      isRunning = false;
+      if (rawAudioFileOutputStream != null) {
+        try {
+          rawAudioFileOutputStream.close();
+        } catch (IOException e) {
+          Log.e(TAG, "Failed to close file with saved input audio: " + e);
+        }
+        rawAudioFileOutputStream = null;
+      }
+      fileSizeInBytes = 0;
+    }
+  }
+
+  // Checks if external storage is available for read and write.
+  private boolean isExternalStorageWritable() {
+    String state = Environment.getExternalStorageState();
+    if (Environment.MEDIA_MOUNTED.equals(state)) {
+      return true;
+    }
+    return false;
+  }
+
+  // Utilizes audio parameters to create a file name which contains sufficient
+  // information so that the file can be played using an external file player.
+  // Example: /sdcard/recorded_audio_16bits_48000Hz_mono.pcm.
+  private void openRawAudioOutputFile(int sampleRate, int channelCount) {
+    final String fileName = Environment.getExternalStorageDirectory().getPath() + File.separator
+        + "recorded_audio_16bits_" + String.valueOf(sampleRate) + "Hz"
+        + ((channelCount == 1) ? "_mono" : "_stereo") + ".pcm";
+    final File outputFile = new File(fileName);
+    try {
+      rawAudioFileOutputStream = new FileOutputStream(outputFile);
+    } catch (FileNotFoundException e) {
+      Log.e(TAG, "Failed to open audio output file: " + e.getMessage());
+    }
+    Log.d(TAG, "Opened file for recording: " + fileName);
+  }
+
+  // Called when new audio samples are ready.
+  @Override
+  public void onWebRtcAudioRecordSamplesReady(JavaAudioDeviceModule.AudioSamples samples) {
+    // The native audio layer on Android should use 16-bit PCM format.
+    if (samples.getAudioFormat() != AudioFormat.ENCODING_PCM_16BIT) {
+      Log.e(TAG, "Invalid audio format");
+      return;
+    }
+    synchronized (lock) {
+      // Abort early if stop() has been called.
+      if (!isRunning) {
+        return;
+      }
+      // Open a new file for the first callback only since it allows us to add audio parameters to
+      // the file name.
+      if (rawAudioFileOutputStream == null) {
+        openRawAudioOutputFile(samples.getSampleRate(), samples.getChannelCount());
+        fileSizeInBytes = 0;
+      }
+    }
+    // Append the recorded 16-bit audio samples to the open output file.
+    executor.execute(() -> {
+      if (rawAudioFileOutputStream != null) {
+        try {
+          // Set a limit on max file size. 58348800 bytes corresponds to
+          // approximately 10 minutes of recording in mono at 48kHz.
+          if (fileSizeInBytes < MAX_FILE_SIZE_IN_BYTES) {
+            // Writes samples.getData().length bytes to output stream.
+            rawAudioFileOutputStream.write(samples.getData());
+            fileSizeInBytes += samples.getData().length;
+          }
+        } catch (IOException e) {
+          Log.e(TAG, "Failed to write audio to file: " + e.getMessage());
+        }
+      }
+    });
+  }
+}