webrtc/common_video/include/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.
 */

#ifndef WEBRTC_COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_H_
#define WEBRTC_COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_H_

#include <stdint.h>

#include <memory>

#include "webrtc/base/callback.h"
#include "webrtc/base/refcount.h"
#include "webrtc/base/scoped_ref_ptr.h"
#include "webrtc/common_video/rotation.h"
#include "webrtc/system_wrappers/include/aligned_malloc.h"

namespace webrtc {

enum PlaneType {
  kYPlane = 0,
  kUPlane = 1,
  kVPlane = 2,
  kNumOfPlanes = 3,
};

// Interface of a simple frame buffer containing pixel data. This interface does
// not contain any frame metadata such as rotation, timestamp, pixel_width, etc.
class VideoFrameBuffer : public rtc::RefCountInterface {
 public:
  // The resolution of the frame in pixels. For formats where some planes are
  // subsampled, this is the highest-resolution plane.
  virtual int width() const = 0;
  virtual int height() const = 0;

  // Returns pointer to the pixel data for a given plane. The memory is owned by
  // the VideoFrameBuffer object and must not be freed by the caller.
  virtual const uint8_t* DataY() const = 0;
  virtual const uint8_t* DataU() const = 0;
  virtual const uint8_t* DataV() const = 0;

  // TODO(nisse): Move MutableData methods to the I420Buffer subclass.
  // Non-const data access.
  virtual uint8_t* MutableDataY();
  virtual uint8_t* MutableDataU();
  virtual uint8_t* MutableDataV();

  // Returns the number of bytes between successive rows for a given plane.
  virtual int StrideY() const = 0;
  virtual int StrideU() const = 0;
  virtual int StrideV() 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);

  static rtc::scoped_refptr<I420Buffer> Create(int width, int height);
  static rtc::scoped_refptr<I420Buffer> Create(int width,
                                               int height,
                                               int stride_y,
                                               int stride_u,
                                               int stride_v);

  // Sets all three planes to all zeros. Used to work around for
  // quirks in memory checkers
  // (https://bugs.chromium.org/p/libyuv/issues/detail?id=377) and
  // ffmpeg (http://crbug.com/390941).
  // TODO(nisse): Should be deleted if/when those issues are resolved
  // in a better way.
  void InitializeData();

  // Sets the frame buffer to all black.
  void SetToBlack();

  int width() const override;
  int height() const override;
  const uint8_t* DataY() const override;
  const uint8_t* DataU() const override;
  const uint8_t* DataV() const override;

  uint8_t* MutableDataY() override;
  uint8_t* MutableDataU() override;
  uint8_t* MutableDataV() override;
  int StrideY() const override;
  int StrideU() const override;
  int StrideV() const override;

  void* native_handle() const override;
  rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() override;

  // Create a new buffer and copy the pixel data.
  static rtc::scoped_refptr<I420Buffer> Copy(
      const rtc::scoped_refptr<VideoFrameBuffer>& buffer);

  // Scale the cropped area of |src| to the size of |this| buffer, and
  // write the result into |this|.
  void CropAndScaleFrom(const rtc::scoped_refptr<VideoFrameBuffer>& src,
                        int offset_x,
                        int offset_y,
                        int crop_width,
                        int crop_height);

  // The common case of a center crop, when needed to adjust the
  // aspect ratio without distorting the image.
  void CropAndScaleFrom(const rtc::scoped_refptr<VideoFrameBuffer>& src);

  // Scale all of |src| to the size of |this| buffer, with no cropping.
  void ScaleFrom(const rtc::scoped_refptr<VideoFrameBuffer>& src);

  // Create a new buffer with identical strides, and copy the pixel data.
  static rtc::scoped_refptr<I420Buffer> CopyKeepStride(
      const rtc::scoped_refptr<VideoFrameBuffer>& buffer);

  // Returns a rotated versions of |src|. Native buffers are not
  // supported. The reason this function doesn't return an I420Buffer,
  // is that it returns |src| unchanged in case |rotation| is zero.
  static rtc::scoped_refptr<VideoFrameBuffer> Rotate(
      const rtc::scoped_refptr<VideoFrameBuffer>& src,
      VideoRotation rotation);

 protected:
  ~I420Buffer() override;

 private:
  const int width_;
  const int height_;
  const int stride_y_;
  const int stride_u_;
  const int stride_v_;
  const std::unique_ptr<uint8_t, AlignedFreeDeleter> data_;
};

// 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:
  NativeHandleBuffer(void* native_handle, int width, int height);

  int width() const override;
  int height() const override;
  const uint8_t* DataY() const override;
  const uint8_t* DataU() const override;
  const uint8_t* DataV() const override;
  int StrideY() const override;
  int StrideU() const override;
  int StrideV() const override;

  void* native_handle() const override;

 protected:
  void* native_handle_;
  const int width_;
  const int height_;
};

class WrappedI420Buffer : public webrtc::VideoFrameBuffer {
 public:
  WrappedI420Buffer(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* DataY() const override;
  const uint8_t* DataU() const override;
  const uint8_t* DataV() const override;
  int StrideY() const override;
  int StrideU() const override;
  int StrideV() const override;

  void* native_handle() const override;

  rtc::scoped_refptr<VideoFrameBuffer> NativeToI420Buffer() override;

 private:
  friend class rtc::RefCountedObject<WrappedI420Buffer>;
  ~WrappedI420Buffer() override;

  const int width_;
  const int height_;
  const uint8_t* const y_plane_;
  const uint8_t* const u_plane_;
  const uint8_t* const 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_COMMON_VIDEO_INCLUDE_VIDEO_FRAME_BUFFER_H_