text: /*
   *  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 API_VIDEO_I420_BUFFER_H_
  #define API_VIDEO_I420_BUFFER_H_
  
  #include <stdint.h>
  #include <memory>
  
  #include "api/scoped_refptr.h"
  #include "api/video/video_frame_buffer.h"
  #include "api/video/video_rotation.h"
  #include "rtc_base/memory/aligned_malloc.h"
  #include "rtc_base/system/rtc_export.h"
  
  namespace webrtc {
  
  // Plain I420 buffer in standard memory.
  class RTC_EXPORT I420Buffer : public I420BufferInterface {
   public:
    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);
  
    // Create a new buffer and copy the pixel data.
    static rtc::scoped_refptr<I420Buffer> Copy(const I420BufferInterface& buffer);
    // Deprecated.
    static rtc::scoped_refptr<I420Buffer> Copy(const VideoFrameBuffer& buffer) {
      return Copy(*buffer.GetI420());
    }
  
    static rtc::scoped_refptr<I420Buffer> Copy(int width,
                                               int height,
                                               const uint8_t* data_y,
                                               int stride_y,
                                               const uint8_t* data_u,
                                               int stride_u,
                                               const uint8_t* data_v,
                                               int stride_v);
  
    // Returns a rotated copy of |src|.
    static rtc::scoped_refptr<I420Buffer> Rotate(const I420BufferInterface& src,
                                                 VideoRotation rotation);
    // Deprecated.
    static rtc::scoped_refptr<I420Buffer> Rotate(const VideoFrameBuffer& src,
                                                 VideoRotation rotation) {
      return Rotate(*src.GetI420(), rotation);
    }
  
    // Sets the buffer to all black.
    static void SetBlack(I420Buffer* buffer);
  
    // 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): Deprecated. Should be deleted if/when those issues
    // are resolved in a better way. Or in the mean time, use SetBlack.
    void InitializeData();
  
    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;
  
    uint8_t* MutableDataY();
    uint8_t* MutableDataU();
    uint8_t* MutableDataV();
  
    // Scale the cropped area of |src| to the size of |this| buffer, and
    // write the result into |this|.
    void CropAndScaleFrom(const I420BufferInterface& 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 I420BufferInterface& src);
  
    // Scale all of |src| to the size of |this| buffer, with no cropping.
    void ScaleFrom(const I420BufferInterface& src);
  
    // Pastes whole picture to canvas at (offset_row, offset_col).
    // Offsets and picture dimensions must be even.
    void PasteFrom(const I420BufferInterface& picture,
                   int offset_col,
                   int offset_row);
  
   protected:
    I420Buffer(int width, int height);
    I420Buffer(int width, int height, int stride_y, int stride_u, int stride_v);
  
    ~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_;
  };
  
  }  // namespace webrtc
  
  #endif  // API_VIDEO_I420_BUFFER_H_
  