Fix AudioTrack offloaded timestamp handling.
getTimestamp for offloaded tracks now returns WOULD_BLOCK for
situations where the timestamp is unavailable due to the
previous track still flushing or the timestamp is stale.
It is fixed for normal playback conditions.
Bug: 14659809
Bug: 17428188
Change-Id: Ic9ec07ccabc604236979769db5c4ea2dec252660
diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h
index 72e51f9..b5256f0 100644
--- a/include/media/AudioTrack.h
+++ b/include/media/AudioTrack.h
@@ -580,7 +580,14 @@
* Caution: calling this method too often may be inefficient;
* if you need a high resolution mapping between frame position and presentation time,
* consider implementing that at application level, based on the low resolution timestamps.
- * Returns NO_ERROR if timestamp is valid.
+ * Returns NO_ERROR if timestamp is valid.
+ * WOULD_BLOCK if called in STOPPED or FLUSHED state, or if called immediately after
+ * start/ACTIVE, when the number of frames consumed is less than the
+ * overall hardware latency to physical output. In WOULD_BLOCK cases,
+ * one might poll again, or use getPosition(), or use 0 position and
+ * current time for the timestamp.
+ * INVALID_OPERATION if called on a FastTrack, wrong state, or some other error.
+ *
* The timestamp parameter is undefined on return, if status is not NO_ERROR.
*/
status_t getTimestamp(AudioTimestamp& timestamp);
@@ -747,6 +754,8 @@
// reset by stop() but continues monotonically
// after new IAudioTrack to restore mPosition,
// and could be easily widened to uint64_t
+ int64_t mStartUs; // the start time after flush or stop.
+ // only used for offloaded and direct tracks.
audio_output_flags_t mFlags;
// const after set(), except for bits AUDIO_OUTPUT_FLAG_FAST and AUDIO_OUTPUT_FLAG_OFFLOAD.