talk/media/base/yuvframegenerator.h

// Generates YUV420 frames with a "landscape with striped crosshair" in the
// Y-plane, plus a horizontal gradient in the U-plane and a vertical one in the
// V-plane. This makes for a nice mix of colours that is suited for both
// catching visual errors and making sure e.g. YUV->RGB/BGR conversion looks
// the same on different platforms.
// There is also a solid box bouncing around in the Y-plane, and two differently
// coloured lines bouncing horizontally and vertically in the U and V plane.
// This helps illustrating how the frame boundary goes, and can aid as a quite
// handy visual help for noticing e.g. packet loss if the frames are encoded
// and sent over the network.

#ifndef TALK_MEDIA_BASE_YUVFRAMEGENERATOR_H_
#define TALK_MEDIA_BASE_YUVFRAMEGENERATOR_H_

#include "talk/base/basictypes.h"

namespace cricket {

class YuvFrameGenerator {
 public:
  // Constructs a frame-generator that produces frames of size |width|x|height|.
  // If |enable_barcode| is specified, barcodes can be included in the frames
  // when calling |GenerateNextFrame(uint8*, uint32)|. If |enable_barcode| is
  // |true| then |width|x|height| should be at least 160x100; otherwise this
  // constructor will abort.
  YuvFrameGenerator(int width, int height, bool enable_barcode);
  ~YuvFrameGenerator();

  int GetFrameSize() { return frame_data_size_; }

  // Generate the next frame and return it in the provided |frame_buffer|. If
  // barcode_value is not |nullptr| the value referred by it will be encoded
  // into a barcode in the frame.  The value should in the range:
  // [0..9,999,999]. If the value exceeds this range or barcodes were not
  // requested in the constructor, this function will abort.
  void GenerateNextFrame(uint8* frame_buffer, int32 barcode_value);

  int GetHeight() { return height_; }
  int GetWidth() { return width_; }

  // Fetch the bounds of the barcode from the generator. The barcode will
  // always be at this location. This function will abort if barcodes were not
  // requested in the constructor.
  void GetBarcodeBounds(int* top, int* left, int* width, int* height);

 private:
  void DrawLandscape(uint8 *p, int w, int h);
  void DrawGradientX(uint8 *p, int w, int h);
  void DrawGradientY(uint8 *p, int w, int h);
  void DrawMovingLineX(uint8 *p, int w, int h, int n);
  void DrawMovingLineY(uint8 *p, int w, int h, int n);
  void DrawBouncingCube(uint8 *p, int w, int h, int n);

  void DrawBarcode(uint32 value);
  int DrawSideGuardBars(int x, int y, int height);
  int DrawMiddleGuardBars(int x, int y, int height);
  int DrawEanEncodedDigit(int digit, int x, int y, int height, bool r_code);
  void DrawBlockRectangle(uint8* p, int x_start, int y_start,
                          int width, int height, int pitch, uint8 value);

 private:
  int width_;
  int height_;
  int frame_index_;
  int frame_data_size_;
  uint8* y_data_;
  uint8* u_data_;
  uint8* v_data_;

  int barcode_start_x_;
  int barcode_start_y_;

  DISALLOW_COPY_AND_ASSIGN(YuvFrameGenerator);
};

}  // namespace cricket

#endif  // TALK_MEDIA_BASE_YUVFRAMEGENERATOR_H_