Add TODO comments on deprecated VideoFrame methods.

webrtc/media/engine/webrtcvideoframe.h

 /*
  *  Copyright (c) 2011 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.
  */
 
 #ifndef WEBRTC_MEDIA_ENGINE_WEBRTCVIDEOFRAME_H_
 #define WEBRTC_MEDIA_ENGINE_WEBRTCVIDEOFRAME_H_
 
 #include <memory>
 
 #include "webrtc/base/buffer.h"
 #include "webrtc/base/refcount.h"
 #include "webrtc/base/scoped_ref_ptr.h"
 #include "webrtc/common_types.h"
 #include "webrtc/common_video/include/video_frame_buffer.h"
 #include "webrtc/media/base/videoframe.h"
 
 namespace cricket {
 
 struct CapturedFrame;
 
+// TODO(nisse): This class will be deleted when the cricket::VideoFrame and
+// webrtc::VideoFrame classes are merged. See
+// https://bugs.chromium.org/p/webrtc/issues/detail?id=5682. Try to use only the
+// preferred constructor, and the non-deprecated methods of the VideoFrame base
+// class.
 class WebRtcVideoFrame : public VideoFrame {
  public:
+  // TODO(nisse): Deprecated. Using the default constructor violates the
+  // reasonable assumption that video_frame_buffer() returns a valid buffer.
   WebRtcVideoFrame();
 
-  // Preferred construction, with microsecond timestamp.
+  // Preferred constructor.
   WebRtcVideoFrame(const rtc::scoped_refptr<webrtc::VideoFrameBuffer>& buffer,
                    webrtc::VideoRotation rotation,
                    int64_t timestamp_us);
 
-  // TODO(nisse): Deprecate/delete.
+  // TODO(nisse): Deprecated, delete as soon as all callers have switched to the
+  // above constructor with microsecond timestamp.
   WebRtcVideoFrame(const rtc::scoped_refptr<webrtc::VideoFrameBuffer>& buffer,
                    int64_t time_stamp_ns,
                    webrtc::VideoRotation rotation);
 
   ~WebRtcVideoFrame();
 
   // Creates a frame from a raw sample with FourCC "format" and size "w" x "h".
   // "h" can be negative indicating a vertically flipped image.
   // "dh" is destination height if cropping is desired and is always positive.
   // Returns "true" if successful.
   bool Init(uint32_t format,
             int w,
             int h,
             int dw,
             int dh,
             uint8_t* sample,
             size_t sample_size,
             int64_t time_stamp_ns,
             webrtc::VideoRotation rotation);
 
-  // The timestamp of the captured frame is expected to use the same
-  // timescale and epoch as rtc::Time.
-  // TODO(nisse): Consider adding a warning message, or even an RTC_DCHECK, if
-  // the time is too far off.
+  // TODO(nisse): We're moving to have all timestamps use the same
+  // time scale as rtc::TimeMicros. However, this method is used by
+  // WebRtcVideoFrameFactory::CreateAliasedFrame this code path
+  // currently does not conform to the new timestamp conventions and
+  // may use the camera's own clock instead. It's unclear if this
+  // should be fixed, or if instead all of the VideoFrameFactory
+  // abstraction should be eliminated.
   bool Init(const CapturedFrame* frame, int dw, int dh, bool apply_rotation);
 
   void InitToEmptyBuffer(int w, int h);
   void InitToEmptyBuffer(int w, int h, int64_t time_stamp_ns);
 
   int width() const override;
   int height() const override;
 
   const rtc::scoped_refptr<webrtc::VideoFrameBuffer>& video_frame_buffer()
       const override;
@@ skipping 43 matching lines @@
   webrtc::VideoRotation rotation_;
 
   // This is mutable as the calculation is expensive but once calculated, it
   // remains const.
   mutable std::unique_ptr<VideoFrame> rotated_frame_;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_ENGINE_WEBRTCVIDEOFRAME_H_