Use MediaRecorder for voice notes on capable devices.

Co-authored-by: Greyson Parrelli <greyson@signal.org>

app/src/main/java/org/thoughtcrime/securesms/audio/AudioCodec.java

@@ -1,13 +1,12 @@
 package org.thoughtcrime.securesms.audio;
 
-import android.annotation.TargetApi;
 import android.media.AudioFormat;
 import android.media.AudioRecord;
 import android.media.MediaCodec;
 import android.media.MediaCodecInfo;
 import android.media.MediaFormat;
 import android.media.MediaRecorder;
-import android.os.Build;
+import android.os.ParcelFileDescriptor;
 
 import org.signal.core.util.StreamUtil;
 import org.signal.core.util.logging.Log;
@@ -17,8 +16,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.nio.ByteBuffer;
 
-@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
+public class AudioCodec implements Recorder {
-public class AudioCodec {
 
   private static final String TAG = Log.tag(AudioCodec.class);
 
@@ -51,12 +49,19 @@ public class AudioCodec {
     }
   }
 
+  @Override
+  public void start(ParcelFileDescriptor fileDescriptor) {
+    Log.i(TAG, "Recording voice note using AudioCodec.");
+    start(new ParcelFileDescriptor.AutoCloseOutputStream(fileDescriptor));
+  }
+
+  @Override
   public synchronized void stop() {
     running = false;
     while (!finished) Util.wait(this, 0);
   }
 
-  public void start(final OutputStream outputStream) {
+  private void start(final OutputStream outputStream) {
     new Thread(new Runnable() {
       @Override
       public void run() {

app/src/main/java/org/thoughtcrime/securesms/audio/AudioRecorder.java

@@ -1,6 +1,5 @@
 package org.thoughtcrime.securesms.audio;
 
-import android.annotation.TargetApi;
 import android.content.Context;
 import android.net.Uri;
 import android.os.Build;
@@ -13,6 +12,7 @@ import org.signal.core.util.concurrent.SignalExecutors;
 import org.signal.core.util.logging.Log;
 import org.thoughtcrime.securesms.components.voice.VoiceNoteDraft;
 import org.thoughtcrime.securesms.providers.BlobProvider;
+import org.thoughtcrime.securesms.util.FeatureFlags;
 import org.thoughtcrime.securesms.util.MediaUtil;
 import org.thoughtcrime.securesms.util.concurrent.ListenableFuture;
 import org.thoughtcrime.securesms.util.concurrent.SettableFuture;
@@ -20,7 +20,6 @@ import org.thoughtcrime.securesms.util.concurrent.SettableFuture;
 import java.io.IOException;
 import java.util.concurrent.ExecutorService;
 
-@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
 public class AudioRecorder {
 
   private static final String TAG = Log.tag(AudioRecorder.class);
@@ -29,8 +28,8 @@ public class AudioRecorder {
 
   private final Context context;
 
-  private AudioCodec audioCodec;
+  private Recorder recorder;
-  private Uri        captureUri;
+  private Uri      captureUri;
 
   public AudioRecorder(@NonNull Context context) {
     this.context = context;
@@ -42,7 +41,7 @@ public class AudioRecorder {
     executor.execute(() -> {
       Log.i(TAG, "Running startRecording() + " + Thread.currentThread().getId());
       try {
-        if (audioCodec != null) {
+        if (recorder != null) {
           throw new AssertionError("We can only record once at a time.");
         }
 
@@ -52,9 +51,9 @@ public class AudioRecorder {
                                  .forData(new ParcelFileDescriptor.AutoCloseInputStream(fds[0]), 0)
                                  .withMimeType(MediaUtil.AUDIO_AAC)
                                  .createForDraftAttachmentAsync(context, () -> Log.i(TAG, "Write successful."), e -> Log.w(TAG, "Error during recording", e));
-        audioCodec = new AudioCodec();
 
-        audioCodec.start(new ParcelFileDescriptor.AutoCloseOutputStream(fds[1]));
+        recorder = Build.VERSION.SDK_INT >= 26 && FeatureFlags.voiceNoteRecordingV2() ? new MediaRecorderWrapper() : new AudioCodec();
+        recorder.start(fds[1]);
       } catch (IOException e) {
         Log.w(TAG, e);
       }
@@ -67,12 +66,12 @@ public class AudioRecorder {
     final SettableFuture<VoiceNoteDraft> future = new SettableFuture<>();
 
     executor.execute(() -> {
-      if (audioCodec == null) {
+      if (recorder == null) {
         sendToFuture(future, new IOException("MediaRecorder was never initialized successfully!"));
         return;
       }
 
-      audioCodec.stop();
+      recorder.stop();
 
       try {
         long size = MediaUtil.getMediaSize(context, captureUri);
@@ -82,7 +81,7 @@ public class AudioRecorder {
         sendToFuture(future, ioe);
       }
 
-      audioCodec = null;
+      recorder   = null;
       captureUri = null;
     });
 

app/src/main/java/org/thoughtcrime/securesms/audio/MediaRecorderWrapper.java

@@ -0,0 +1,44 @@
+package org.thoughtcrime.securesms.audio;
+
+import android.media.MediaRecorder;
+import android.os.ParcelFileDescriptor;
+
+import org.signal.core.util.logging.Log;
+
+import java.io.IOException;
+
+/**
+ * Wrap Android's {@link MediaRecorder} for use with voice notes.
+ */
+public class MediaRecorderWrapper implements Recorder {
+
+  private static final String TAG = Log.tag(MediaRecorderWrapper.class);
+
+  private static final int    SAMPLE_RATE       = 44100;
+  private static final int    CHANNELS          = 1;
+  private static final int    BIT_RATE          = 32000;
+
+  private MediaRecorder recorder = null;
+
+  @Override
+  public void start(ParcelFileDescriptor fileDescriptor) throws IOException {
+    Log.i(TAG, "Recording voice note using MediaRecorderWrapper.");
+    recorder = new MediaRecorder();
+    recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
+    recorder.setOutputFormat(MediaRecorder.OutputFormat.AAC_ADTS);
+    recorder.setOutputFile(fileDescriptor.getFileDescriptor());
+    recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
+    recorder.setAudioSamplingRate(SAMPLE_RATE);
+    recorder.setAudioEncodingBitRate(BIT_RATE);
+    recorder.setAudioChannels(CHANNELS);
+    recorder.prepare();
+    recorder.start();
+  }
+
+  @Override
+  public void stop() {
+    recorder.stop();
+    recorder.release();
+    recorder = null;
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/audio/Recorder.java

@@ -0,0 +1,13 @@
+package org.thoughtcrime.securesms.audio;
+
+import android.os.ParcelFileDescriptor;
+
+import java.io.IOException;
+
+/**
+ * Simple abstraction of the interface for the original voice note recording and the new.
+ */
+public interface Recorder {
+  void start(ParcelFileDescriptor fileDescriptor) throws IOException;
+  void stop();
+}

app/src/main/java/org/thoughtcrime/securesms/util/FeatureFlags.java

@@ -87,6 +87,7 @@ public final class FeatureFlags {
   private static final String DONOR_BADGES                      = "android.donorBadges.6";
   private static final String DONOR_BADGES_DISPLAY              = "android.donorBadges.display.4";
   private static final String CDSH                              = "android.cdsh";
+  private static final String VOICE_NOTE_RECORDING_V2           = "android.voiceNoteRecordingV2";
 
   /**
    * We will only store remote values for flags in this set. If you want a flag to be controllable
@@ -127,7 +128,8 @@ public final class FeatureFlags {
       SENDER_KEY_MAX_AGE,
       DONOR_BADGES,
       DONOR_BADGES_DISPLAY,
-      CHANGE_NUMBER_ENABLED
+      CHANGE_NUMBER_ENABLED,
+      VOICE_NOTE_RECORDING_V2
   );
 
   @VisibleForTesting
@@ -181,7 +183,8 @@ public final class FeatureFlags {
       CDSH,
       SENDER_KEY_MAX_AGE,
       DONOR_BADGES_DISPLAY,
-      DONATE_MEGAPHONE
+      DONATE_MEGAPHONE,
+      VOICE_NOTE_RECORDING_V2
   );
 
   /**
@@ -427,6 +430,11 @@ public final class FeatureFlags {
     return Environment.IS_STAGING && getBoolean(CDSH, false);
   }
 
+  /** Whether or not to use the new voice note recorder backed by MediaRecorder. */
+  public static boolean voiceNoteRecordingV2() {
+    return getBoolean(VOICE_NOTE_RECORDING_V2, true);
+  }
+
   /** Only for rendering debug info. */
   public static synchronized @NonNull Map<String, Object> getMemoryValues() {
     return new TreeMap<>(REMOTE_VALUES);