Re-land "Convert native handles to buffers before encoding."

webrtc/common_video/interface/video_frame_buffer.h

 /*
  *  Copyright (c) 2015 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 34 matching lines @@
   // Non-const data access is only allowed if |HasOneRef| is true.
   virtual uint8_t* data(PlaneType type) = 0;
 
   // Returns the number of bytes between successive rows for a given plane.
   virtual int stride(PlaneType type) const = 0;
 
   // Return the handle of the underlying video frame. This is used when the
   // frame is backed by a texture.
   virtual void* native_handle() const = 0;
 
+  // Returns a new memory-backed frame buffer converted from this buffer's
+  // native handle.
+  virtual rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() = 0;
+
  protected:
   virtual ~VideoFrameBuffer();
 };
 
 // Plain I420 buffer in standard memory.
 class I420Buffer : public VideoFrameBuffer {
  public:
   I420Buffer(int width, int height);
   I420Buffer(int width, int height, int stride_y, int stride_u, int stride_v);
 
   int width() const override;
   int height() const override;
   const uint8_t* data(PlaneType type) const override;
   uint8_t* data(PlaneType type) override;
   int stride(PlaneType type) const override;
   void* native_handle() const override;
+  rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() override;
 
  protected:
   ~I420Buffer() override;
 
  private:
   const int width_;
   const int height_;
   const int stride_y_;
   const int stride_u_;
   const int stride_v_;
   const rtc::scoped_ptr<uint8_t, AlignedFreeDeleter> data_;
 };
 
-// Texture buffer is a VideoFrameBuffer wrapper around a |native_handle|.
-// |native_handle| must be valid for the lifetime of an instance of this object.
-// |no_longer_used| can be used to manage the lifetime of |native_handle|.
-class TextureBuffer : public VideoFrameBuffer {
+// Base class for native-handle buffer is a wrapper around a |native_handle|.
+// This is used for convenience as most native-handle implementations can share
+// many VideoFrame implementations, but need to implement a few others (such
+// as their own destructors or conversion methods back to software I420).
+class NativeHandleBuffer : public VideoFrameBuffer {
  public:
-  TextureBuffer(void* native_handle,
-                int width,
-                int height,
-                const rtc::Callback0<void>& no_longer_used);
+  NativeHandleBuffer(void* native_handle, int width, int height);
+
   int width() const override;
   int height() const override;
   const uint8_t* data(PlaneType type) const override;
   uint8_t* data(PlaneType type) override;
   int stride(PlaneType type) const override;
   void* native_handle() const override;
 
- private:
-  friend class rtc::RefCountedObject<TextureBuffer>;
-  ~TextureBuffer() override;
-
-  // |native_handle_| is a raw pointer and not owned by TextureBuffer.
+ protected:
   void* native_handle_;
   const int width_;
   const int height_;
-  rtc::Callback0<void> no_longer_used_cb_;
 };
 
 class WrappedI420Buffer : public webrtc::VideoFrameBuffer {
  public:
   WrappedI420Buffer(int desired_width,
                     int desired_height,
                     int width,
                     int height,
                     const uint8_t* y_plane,
                     int y_stride,
                     const uint8_t* u_plane,
                     int u_stride,
                     const uint8_t* v_plane,
                     int v_stride,
                     const rtc::Callback0<void>& no_longer_used);
   int width() const override;
   int height() const override;
 
   const uint8_t* data(PlaneType type) const override;
   uint8_t* data(PlaneType type) override;
 
   int stride(PlaneType type) const override;
   void* native_handle() const override;
 
+  rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() override;
+
  private:
   friend class rtc::RefCountedObject<WrappedI420Buffer>;
   ~WrappedI420Buffer() override;
 
   int width_;
   int height_;
   const uint8_t* y_plane_;
   const uint8_t* u_plane_;
   const uint8_t* v_plane_;
   const int y_stride_;
   const int u_stride_;
   const int v_stride_;
   rtc::Callback0<void> no_longer_used_cb_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_VIDEO_FRAME_BUFFER_H_