diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h
index 8baad6b..3de0774 100644
--- a/include/media/AudioTrack.h
+++ b/include/media/AudioTrack.h
@@ -495,6 +495,13 @@
      * After filling these slots with data, the caller should release them with releaseBuffer().
      * If the track buffer is not full, obtainBuffer() returns as many contiguous
      * [empty slots for] frames as are available immediately.
+     *
+     * If nonContig is non-NULL, it is an output parameter that will be set to the number of
+     * additional non-contiguous frames that are predicted to be available immediately,
+     * if the client were to release the first frames and then call obtainBuffer() again.
+     * This value is only a prediction, and needs to be confirmed.
+     * It will be set to zero for an error return.
+     *
      * If the track buffer is full and track is stopped, obtainBuffer() returns WOULD_BLOCK
      * regardless of the value of waitCount.
      * If the track buffer is full and track is not stopped, obtainBuffer() blocks with a
@@ -526,14 +533,17 @@
      *  size        actual number of bytes available
      *  raw         pointer to the buffer
      */
-
     /* FIXME Deprecated public API for TRANSFER_OBTAIN mode */
-            status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount)
+            status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount,
+                                size_t *nonContig = NULL)
                                 __attribute__((__deprecated__));
 
 private:
     /* If nonContig is non-NULL, it is an output parameter that will be set to the number of
-     * additional non-contiguous frames that are available immediately.
+     * additional non-contiguous frames that are predicted to be available immediately,
+     * if the client were to release the first frames and then call obtainBuffer() again.
+     * This value is only a prediction, and needs to be confirmed.
+     * It will be set to zero for an error return.
      * FIXME We could pass an array of Buffers instead of only one Buffer to obtainBuffer(),
      * in case the requested amount of frames is in two or more non-contiguous regions.
      * FIXME requested and elapsed are both relative times.  Consider changing to absolute time.