Android video capture: only use reference time for outbound timestamp.

media/capture/video/android/video_capture_device_android.cc

Index: media/capture/video/android/video_capture_device_android.cc
diff --git a/media/capture/video/android/video_capture_device_android.cc b/media/capture/video/android/video_capture_device_android.cc
index b3c5d89f19f7626cdb8884c9f2dcb42224a8312b..de6dd362150632e38a454e1093198f7593d371c2 100644
--- a/media/capture/video/android/video_capture_device_android.cc
+++ b/media/capture/video/android/video_capture_device_android.cc
@@ -214,7 +214,6 @@ void VideoCaptureDeviceAndroid::OnFrameAvailable(
     if (!got_first_frame_) {
       // Set aside one frame allowance for fluctuation.
       expected_next_frame_time_ = current_time - frame_interval_;
-      first_ref_time_ = current_time;
       got_first_frame_ = true;
 
       for (const auto& request : photo_requests_queue_)
@@ -234,7 +233,7 @@ void VideoCaptureDeviceAndroid::OnFrameAvailable(
       return;
     client_->OnIncomingCapturedData(reinterpret_cast<uint8_t*>(buffer), length,
                                     capture_format_, rotation, current_time,
-                                    current_time - first_ref_time_);
+                                    base::TimeDelta());

[miu, 2016/08/31 21:09:16]

Please plumb-in timestamp here too.

[braveyao, 2016/08/31 23:01:28]

No capture timestamp available here. Maybe better to keep the previous way.

   }
 
   env->ReleaseByteArrayElements(data, buffer, JNI_ABORT);
@@ -250,12 +249,17 @@ void VideoCaptureDeviceAndroid::OnI420FrameAvailable(JNIEnv* env,
                                                      jint uv_pixel_stride,
                                                      jint width,
                                                      jint height,
-                                                     jint rotation) {
+                                                     jint rotation,
+                                                     jlong timestamp) {
   {
     base::AutoLock lock(lock_);
     if (state_ != kConfigured || !client_)
       return;
   }
+  const uint64_t absolute_micro =

[miu, 2016/08/31 21:09:16]

nit: Should be int64_t since both operands are signed integers.

[braveyao, 2016/08/31 23:01:28]

Done.

+      timestamp / base::Time::kNanosecondsPerMicrosecond;
+  const base::TimeDelta start_time =

[miu, 2016/08/31 21:09:16]

naming nit: How about |capture_time|? According to the Android API docs, the
timestamps are all relative and monotonically increasing, and determined by the
source capturer. So, basically they are exactly the media timestmaps
OnIncomingCapturedData() expects.

[braveyao, 2016/08/31 23:01:28]

Done.

+      base::TimeDelta::FromMicroseconds(absolute_micro);
 
   const base::TimeTicks current_time = base::TimeTicks::Now();
   {
@@ -263,7 +267,6 @@ void VideoCaptureDeviceAndroid::OnI420FrameAvailable(JNIEnv* env,
     if (!got_first_frame_) {
       // Set aside one frame allowance for fluctuation.
       expected_next_frame_time_ = current_time - frame_interval_;
-      first_ref_time_ = current_time;
       got_first_frame_ = true;
 
       for (const auto& request : photo_requests_queue_)
@@ -304,7 +307,7 @@ void VideoCaptureDeviceAndroid::OnI420FrameAvailable(JNIEnv* env,
       return;
     client_->OnIncomingCapturedData(buffer.get(), buffer_length,
                                     capture_format_, rotation, current_time,
-                                    current_time - first_ref_time_);
+                                    start_time);
   }
 }