Implement timing frames.

webrtc/test/frame_generator_capturer.cc

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 142 matching lines @@
           new InsertFrameTask(this, 1000 / framerate_fps)),
       1000 / framerate_fps);
 
   return true;
 }
 
 void FrameGeneratorCapturer::InsertFrame() {
   rtc::CritScope cs(&lock_);
   if (sending_) {
     VideoFrame* frame = frame_generator_->NextFrame();
-    frame->set_timestamp_us(rtc::TimeMicros());
+    frame->set_timestamp_us(clock_->TimeInMicroseconds());

[ilnik, 2017/06/01 12:33:37]

For consistency.

[nisse-webrtc, 2017/06/02 12:04:55]

I'd rather move in the opposite direction. The frame timestamp_us should always
be in rtc::TimeMicros timescale (see comments in api/video/video_frame.h).

Not sure what's the best way to get ntp time (on the line below) without using
webrtc::Clock. timeutils.h declares a function TimeUTCMicros, which has a
compile-time constant offset to ntp time.

[ilnik, 2017/06/02 13:02:21]

I believe we should use clock_ instead of wallclock time if available. What if
we are inside some kind of test? Also, in case of realtime clock_, at least on
linux, it boils down to rtc:TimeMicros().

[sprang_webrtc, 2017/06/09 11:02:01]

Agree that we should move towards rtc::TimeMicros rather than Clock, but then we
should do so for the whole file at once, just so we're not using a fake clock
for some of the calls but not others... This CL is already very large, I think
that refactoring can "wait" for a follow-up.

     frame->set_ntp_time_ms(clock_->CurrentNtpInMilliseconds());
     frame->set_rotation(fake_rotation_);
     if (first_frame_capture_time_ == -1) {
       first_frame_capture_time_ = frame->ntp_time_ms();
     }
 
     if (sink_) {
       rtc::Optional<VideoFrame> out_frame = AdaptFrame(*frame);
       if (out_frame)
         sink_->OnFrame(*out_frame);
@@ skipping 61 matching lines @@
 
 int FrameGeneratorCapturer::GetCurrentConfiguredFramerate() {
   rtc::CritScope cs(&lock_);
   if (wanted_fps_ && *wanted_fps_ < target_fps_)
     return *wanted_fps_;
   return target_fps_;
 }
 
 }  // namespace test
 }  // namespace webrtc