YUV420P_Player.h

/*

  YUV420P Player
  --------------

  This class implements a simple YUV420P renderer. This means that you
  need to feed planar YUV420 data to the `setYPixels()`, `setUPixels()`
  and `setVPixels()`.

  First make sure to call setup() with the video width and height. We use
  these dimensions to allocate the Y, U and V textures. After calling setup
  you call the zset{Y,U,V}Pixels()` everytime you have a new frame that
  you want to render. With the `draw()` function you draw the current
  frame to the screen.

  If you resize your viewport, make sure to  call `resize()` so we can
  adjust the projection matrix.

 */
#ifndef ROXLU_YUV420P_PLAYER_H
#define ROXLU_YUV420P_PLAYER_H

#define GLFW_INCLUDE_GLCOREARB
#include <GLFW/glfw3.h>


#define ROXLU_USE_MATH
#define ROXLU_USE_PNG
#define ROXLU_USE_OPENGL
#include <tinylib.h>
#include <stdint.h>

static const char* YUV420P_VS = ""
  "#version 330\n"
  ""
  "uniform mat4 u_pm;"
  "uniform vec4 draw_pos;"
  ""
  "const vec2 verts[4] = vec2[] ("
  "  vec2(-0.5,  0.5), "
  "  vec2(-0.5, -0.5), "
  "  vec2( 0.5,  0.5), "
  "  vec2( 0.5, -0.5)  "
  ");"
  ""
  "const vec2 texcoords[4] = vec2[] ("
  "  vec2(0.0, 1.0), "
  "  vec2(0.0, 0.0), "
  "  vec2(1.0, 1.0), "
  "  vec2(1.0, 0.0)  "
  "); "
  ""
  "out vec2 v_coord; "
  ""
  "void main() {"
  "   vec2 vert = verts[gl_VertexID];"
  "   vec4 p = vec4((0.5 * draw_pos.z) + draw_pos.x + (vert.x * draw_pos.z), "
  "                 (0.5 * draw_pos.w) + draw_pos.y + (vert.y * draw_pos.w), "
  "                 0, 1);"
  "   gl_Position = u_pm * p;"
  "   v_coord = texcoords[gl_VertexID];"
  "}"
  "";

static const char* YUV420P_FS = ""
 "#version 330\n"
  "uniform sampler2D y_tex;"
  "uniform sampler2D u_tex;"
  "uniform sampler2D v_tex;"
  "in vec2 v_coord;"
  "layout( location = 0 ) out vec4 fragcolor;"
  ""
  "const vec3 R_cf = vec3(1.164383,  0.000000,  1.596027);"
  "const vec3 G_cf = vec3(1.164383, -0.391762, -0.812968);"
  "const vec3 B_cf = vec3(1.164383,  2.017232,  0.000000);"
  "const vec3 offset = vec3(-0.0625, -0.5, -0.5);"
  ""
  "void main() {"
  "  float y = texture(y_tex, v_coord).r;"
  "  float u = texture(u_tex, v_coord).r;"
  "  float v = texture(v_tex, v_coord).r;"
  "  vec3 yuv = vec3(y,u,v);"
  "  yuv += offset;"
  "  fragcolor = vec4(0.0, 0.0, 0.0, 1.0);"
  "  fragcolor.r = dot(yuv, R_cf);"
  "  fragcolor.g = dot(yuv, G_cf);"
  "  fragcolor.b = dot(yuv, B_cf);"
  "}"
  "";

class YUV420P_Player {

 public:
  YUV420P_Player();
  bool setup(int w, int h);
  void setYPixels(uint8_t* pixels, int stride);
  void setUPixels(uint8_t* pixels, int stride);
  void setVPixels(uint8_t* pixels, int stride);
  void draw(int x, int y, int w = 0, int h = 0);
  void resize(int winW, int winH);

 private:
  bool setupTextures();
  bool setupShader();

 public:
  int vid_w;
  int vid_h;
  int win_w;
  int win_h;
  GLuint vao;
  GLuint y_tex;
  GLuint u_tex;
  GLuint v_tex;
  GLuint vert;
  GLuint frag;
  GLuint prog;
  GLint u_pos;
  bool textures_created;
  bool shader_created;
  uint8_t* y_pixels;
  uint8_t* u_pixels;
  uint8_t* v_pixels;
  mat4 pm;
};
#endif