Merge "Default to minimum buffer size for AudioRecord.Builder"

1 files changed, 28 insertions, 3 deletions

diff --git a/media/java/android/media/AudioRecord.java b/media/java/android/media/AudioRecord.java
index fc0189c..9e1e055 100644
--- a/media/java/android/media/AudioRecord.java
+++ b/media/java/android/media/AudioRecord.java
@@ -398,8 +398,8 @@ public class AudioRecord
      * default output sample rate of the device (see
      * {@link AudioManager#PROPERTY_OUTPUT_SAMPLE_RATE}), its channel configuration will be
      * {@link AudioFormat#CHANNEL_IN_DEFAULT}.
-     * <br>Failing to set an adequate buffer size with {@link #setBufferSizeInBytes(int)} will
-     * prevent the successful creation of an <code>AudioRecord</code> instance.
+     * <br>If the buffer size is not specified with {@link #setBufferSizeInBytes(int)},
+     * the minimum buffer size for the source is used.
      */
     public static class Builder {
         private AudioAttributes mAttributes;
@@ -473,7 +473,9 @@ public class AudioRecord
          * during the recording. New audio data can be read from this buffer in smaller chunks
          * than this size. See {@link #getMinBufferSize(int, int, int)} to determine the minimum
          * required buffer size for the successful creation of an AudioRecord instance.
-         * Using values smaller than getMinBufferSize() will result in an initialization failure.
+         * Since bufferSizeInBytes may be internally increased to accommodate the source
+         * requirements, use {@link #getNativeFrameCount()} to determine the actual buffer size
+         * in frames.
          * @param bufferSizeInBytes a value strictly greater than 0
          * @return the same Builder instance.
          * @throws IllegalArgumentException
@@ -520,6 +522,13 @@ public class AudioRecord
                         .build();
             }
             try {
+                // If the buffer size is not specified,
+                // use a single frame for the buffer size and let the
+                // native code figure out the minimum buffer size.
+                if (mBufferSizeInBytes == 0) {
+                    mBufferSizeInBytes = mFormat.getChannelCount()
+                            * mFormat.getBytesPerSample(mFormat.getEncoding());
+                }
                 return new AudioRecord(mAttributes, mFormat, mBufferSizeInBytes, mSessionId);
             } catch (IllegalArgumentException e) {
                 throw new UnsupportedOperationException(e.getMessage());
@@ -711,6 +720,20 @@ public class AudioRecord
     }
 
     /**
+     *  Returns the "native frame count" of the <code>AudioRecord</code> buffer.
+     *  This is greater than or equal to the bufferSizeInBytes converted to frame units
+     *  specified in the <code>AudioRecord</code> constructor or Builder.
+     *  The native frame count may be enlarged to accommodate the requirements of the
+     *  source on creation or if the <code>AudioRecord</code>
+     *  is subsequently rerouted.
+     *  @return current size in frames of the <code>AudioRecord</code> buffer.
+     *  @throws IllegalStateException
+     */
+    public int getNativeFrameCount() throws IllegalStateException {
+        return native_get_native_frame_count();
+    }
+
+    /**
      * Returns the notification marker position expressed in frames.
      */
     public int getNotificationMarkerPosition() {
@@ -1173,6 +1196,8 @@ public class AudioRecord
 
     private native final int native_read_in_direct_buffer(Object jBuffer, int sizeInBytes);
 
+    private native final int native_get_native_frame_count();
+
     private native final int native_set_marker_pos(int marker);
     private native final int native_get_marker_pos();