Use microsecond timestamp in cricket::VideoFrame.

webrtc/media/base/videoframe.h

 /*
  *  Copyright (c) 2004 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 39 matching lines @@
   // Returns the handle of the underlying video frame. This is used when the
   // frame is backed by a texture. The object should be destroyed when it is no
   // longer in use, so the underlying resource can be freed.
   virtual void* GetNativeHandle() const = 0;
 
   // Returns the underlying video frame buffer. This function is ok to call
   // multiple times, but the returned object will refer to the same memory.
   virtual rtc::scoped_refptr<webrtc::VideoFrameBuffer> GetVideoFrameBuffer()
       const = 0;
 
-  virtual int64_t GetTimeStamp() const = 0;
-  virtual void SetTimeStamp(int64_t time_stamp) = 0;
+  // System monotonic clock, same timebase as rtc::TimeMicros().
+  virtual int64_t timestamp_us() const = 0;
+  virtual void set_timestamp_us(int64_t time_us) = 0;

[perkj_webrtc, 2016/04/08 08:22:49]

no need for set_timestamp. See motivation below.

+
+  // Deprecated methods, for backwards compatibility.
+  // TODO(nisse): Delete when usage in Chrome and other applications
+  // have been replaced.
+  virtual int64_t GetTimeStamp() const {
+    return rtc::kNumNanosecsPerMicrosec * timestamp_us();
+  }
+  // Also used as a helper method for WebRtcVideoFrame methods with ns input.
+  virtual void SetTimeStamp(int64_t time_ns) {

[perkj_webrtc, 2016/04/08 08:22:49]

Can we deprecate this? Creating VideoFrames is very cheap since they just
reference a buffer. So I don't see the need why it has to be modified.

[nisse-webrtc, 2016/04/08 09:15:43]

Typical use, in videoframefactory,

    output_frame_->SetTimeStamp(cropped_input_frame->GetTimeStamp());

https://code.google.com/p/chromium/codesearch#chromium/src/third_party/webrtc...

I don't really like making new copies just to set the timestamp. If we have to
choose between either set_timestamp, or MakeCopyWithTimestamp, I'd prefer the
former. So to get rid of timestamp setters, we should add timestamp argument to
all methods that create frames.

+    set_timestamp_us(time_ns / rtc::kNumNanosecsPerMicrosec);
+  }
 
   // Indicates the rotation angle in degrees.
   virtual webrtc::VideoRotation GetVideoRotation() const  = 0;
 
   // Make a shallow copy of the frame. The frame buffer itself is not copied.
   // Both the current and new VideoFrame will share a single reference-counted
   // frame buffer.
   virtual VideoFrame *Copy() const = 0;
 
   // Since VideoFrame supports shallow copy and the internal frame buffer might
@@ skipping 59 matching lines @@
   // frame to the aspect ratio of the given dimensions before stretching.
   virtual bool CopyToPlanes(uint8_t* dst_y,
                             uint8_t* dst_u,
                             uint8_t* dst_v,
                             int32_t dst_pitch_y,
                             int32_t dst_pitch_u,
                             int32_t dst_pitch_v) const;
 
   // Creates an empty frame.
   virtual VideoFrame *CreateEmptyFrame(int w, int h,
-                                       int64_t time_stamp) const = 0;
+                                       int64_t timestamp_us) const = 0;
   virtual void SetRotation(webrtc::VideoRotation rotation) = 0;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_BASE_VIDEOFRAME_H_