New AudioTrack C++ API for audio timestamps
This new API is intended to replace latency(), especially for A/V sync.
The application will receive periodic timestamp notifications. The period
is unspecified, but will likely be more frequent after a pause or stop,
set position, underrun, display on/off change, route change, or when audio
framework notices drift. It will be up to the higher level application
(e.g. Stagefright) to reconstruct a clock that updates more frequently.
The current latency() method doesn't indicate when latency changes
due to screen on/off state, route changes, etc.
Includes squahsed change-Id: I2082f8752040be0c234b1a6f1be2e269abf2ce7c
Dummy implementation of AudioTrack:getTimestamp()
Rename AudioTrack::Timestamp to AudioTimestamp.
Renaming and pulling up to a higher level allows more modules to use it.
Change-Id: Ibf7f6a207c3f8d8697f25ede2cd5200697fadb86
(cherry picked from commit dd69eb893867634fd169c03204a6ad7c74b351e7)
diff --git a/include/media/AudioTimestamp.h b/include/media/AudioTimestamp.h
new file mode 100644
index 0000000..c29c7e5
--- /dev/null
+++ b/include/media/AudioTimestamp.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_AUDIO_TIMESTAMP_H
+#define ANDROID_AUDIO_TIMESTAMP_H
+
+#include <time.h>
+
+class AudioTimestamp {
+public:
+ AudioTimestamp() : mPosition(0) {
+ mTime.tv_sec = 0;
+ mTime.tv_nsec = 0;
+ }
+ // FIXME change type to match android.media.AudioTrack
+ uint32_t mPosition; // a frame position in AudioTrack::getPosition() units
+ struct timespec mTime; // corresponding CLOCK_MONOTONIC when frame is expected to present
+};
+
+#endif // ANDROID_AUDIO_TIMESTAMP_H
diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h
index ae92cdd..ebb7ef3 100644
--- a/include/media/AudioTrack.h
+++ b/include/media/AudioTrack.h
@@ -19,6 +19,7 @@
#include <cutils/sched_policy.h>
#include <media/AudioSystem.h>
+#include <media/AudioTimestamp.h>
#include <media/IAudioTrack.h>
#include <utils/threads.h>
@@ -62,6 +63,9 @@
// voluntary invalidation by mediaserver, or mediaserver crash.
EVENT_STREAM_END = 7, // Sent after all the buffers queued in AF and HW are played
// back (after stop is called)
+ EVENT_NEW_TIMESTAMP = 8, // Delivered periodically and when there's a significant change
+ // in the mapping from frame position to presentation time.
+ // See AudioTimestamp for the information included with event.
};
/* Client should declare Buffer on the stack and pass address to obtainBuffer()
@@ -107,6 +111,8 @@
* - EVENT_NEW_POS: pointer to const uint32_t containing the new position in frames.
* - EVENT_BUFFER_END: unused.
* - EVENT_NEW_IAUDIOTRACK: unused.
+ * - EVENT_STREAM_END: unused.
+ * - EVENT_NEW_TIMESTAMP: pointer to const AudioTimestamp.
*/
typedef void (*callback_t)(int event, void* user, void *info);
@@ -564,6 +570,16 @@
/* Get parameters */
String8 getParameters(const String8& keys);
+ /* Poll for a timestamp on demand.
+ * Use if EVENT_NEW_TIMESTAMP is not delivered often enough for your needs,
+ * or if you need to get the most recent timestamp outside of the event callback handler.
+ * 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.
+ */
+ status_t getTimestamp(AudioTimestamp& timestamp);
+
protected:
/* copying audio tracks is not allowed */
AudioTrack(const AudioTrack& other);
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index dd0ec73..d90e733 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -1712,6 +1712,11 @@
}
}
+status_t AudioTrack::getTimestamp(AudioTimestamp& timestamp)
+{
+ return INVALID_OPERATION;
+}
+
String8 AudioTrack::getParameters(const String8& keys)
{
if (mOutput) {