Add NBAIO_Sink::getTimestamp()

with a real implementation in AudioStreamOutSink
for dummy implementation initially in MonoPipe.

Use in AudioFlinger::PlaybackThread::threadLoop_write()
to keep the input to the timestamp latch up-to-date.

Change-Id: I10ef277991b63bb43d55d6f3df75116ef32246cd

6 files changed, 31 insertions, 1 deletions

diff --git a/include/media/nbaio/AudioStreamOutSink.h b/include/media/nbaio/AudioStreamOutSink.h
index 5976b18..7948d40 100644
--- a/include/media/nbaio/AudioStreamOutSink.h
+++ b/include/media/nbaio/AudioStreamOutSink.h
@@ -52,6 +52,8 @@ public:
     // implementation of GNWT (if any)
     virtual status_t getNextWriteTimestamp(int64_t *timestamp);
 
+    virtual status_t getTimestamp(AudioTimestamp& timestamp);
+
     // NBAIO_Sink end
 
 #if 0   // until necessary
diff --git a/include/media/nbaio/MonoPipe.h b/include/media/nbaio/MonoPipe.h
index 5fcfe9e..ffdcc21 100644
--- a/include/media/nbaio/MonoPipe.h
+++ b/include/media/nbaio/MonoPipe.h
@@ -88,6 +88,9 @@ public:
             // Return true if the write side of a pipe is currently shutdown.
             bool    isShutdown();
 
+            // Return NO_ERROR if there is a timestamp available
+            status_t getTimestamp(AudioTimestamp& timestamp);
+
 private:
     // A pair of methods and a helper variable which allows the reader and the
     // writer to update and observe the values of mFront and mNextRdPTS in an
diff --git a/include/media/nbaio/NBAIO.h b/include/media/nbaio/NBAIO.h
index f5d6eb5..cc5b3e6 100644
--- a/include/media/nbaio/NBAIO.h
+++ b/include/media/nbaio/NBAIO.h
@@ -28,6 +28,7 @@
 #include <stdlib.h>
 #include <utils/Errors.h>
 #include <utils/RefBase.h>
+#include <media/AudioTimestamp.h>
 
 namespace android {
 
@@ -213,6 +214,11 @@ public:
     //  <other> Something unexpected happened internally.  Check the logs and start debugging.
     virtual status_t getNextWriteTimestamp(int64_t *ts) { return INVALID_OPERATION; }
 
+    // Returns NO_ERROR if a timestamp is available.  The timestamp includes the total number
+    // of frames presented to an external observer, together with the value of CLOCK_MONOTONIC
+    // as of this presentation count.
+    virtual status_t getTimestamp(AudioTimestamp& timestamp) { return INVALID_OPERATION; }
+
 protected:
     NBAIO_Sink(NBAIO_Format format = Format_Invalid) : NBAIO_Port(format), mFramesWritten(0) { }
     virtual ~NBAIO_Sink() { }
diff --git a/media/libnbaio/AudioStreamOutSink.cpp b/media/libnbaio/AudioStreamOutSink.cpp
index 6f525e5..b2de8a2 100644
--- a/media/libnbaio/AudioStreamOutSink.cpp
+++ b/media/libnbaio/AudioStreamOutSink.cpp
@@ -79,4 +79,16 @@ status_t AudioStreamOutSink::getNextWriteTimestamp(int64_t *timestamp) {
     return mStream->get_next_write_timestamp(mStream, timestamp);
 }
 
+status_t AudioStreamOutSink::getTimestamp(AudioTimestamp& timestamp)
+{
+    // FIXME position64 won't be needed after AudioTimestamp.mPosition is changed to uint64_t
+    uint64_t position64;
+    int ok = mStream->get_presentation_position(mStream, &position64, &timestamp.mTime);
+    if (ok != 0) {
+        return INVALID_OPERATION;
+    }
+    timestamp.mPosition = position64;
+    return OK;
+}
+
 }   // namespace android
diff --git a/media/libnbaio/MonoPipe.cpp b/media/libnbaio/MonoPipe.cpp
index e8d3d9b..a74b49e 100644
--- a/media/libnbaio/MonoPipe.cpp
+++ b/media/libnbaio/MonoPipe.cpp
@@ -310,4 +310,9 @@ bool MonoPipe::isShutdown()
     return mIsShutdown;
 }
 
+status_t MonoPipe::getTimestamp(AudioTimestamp& timestamp)
+{
+    return INVALID_OPERATION;
+}
+
 }   // namespace android
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 3921b68..fda4211 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -1820,7 +1820,7 @@ ssize_t AudioFlinger::PlaybackThread::threadLoop_write()
         } else {
             bytesWritten = framesWritten;
         }
-        status_t status = INVALID_OPERATION;    // mLatchD.mTimestamp is invalid
+        status_t status = mNormalSink->getTimestamp(mLatchD.mTimestamp);
         if (status == NO_ERROR) {
             size_t totalFramesWritten = mNormalSink->framesWritten();
             if (totalFramesWritten >= mLatchD.mTimestamp.mPosition) {
@@ -1837,6 +1837,8 @@ ssize_t AudioFlinger::PlaybackThread::threadLoop_write()
             ALOG_ASSERT(mCallbackThread != 0);
             mCallbackThread->setWriteBlocked(true);
         }
+        // FIXME We should have an implementation of timestamps for direct output threads.
+        // They are used e.g for multichannel PCM playback over HDMI.
         bytesWritten = mOutput->stream->write(mOutput->stream,
                                                    mMixBuffer + offset, mBytesRemaining);
         if (mUseAsyncWrite &&