Quiero convertir yuv a rgb en opengl es sombreado con sólo un sampler que contiene yuv datos. Mi código es el siguiente:

1) puedo enviar yuv datos de textura:

GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_LUMINANCE,
            mData.w, mData.h * 3 /2, 0, GLES20.GL_LUMINANCE,
            GLES20.GL_UNSIGNED_BYTE, ByteBuffer.wrap(mData.yuv));

2) Mi vertex shader:

attribute vec4 position;
attribute vec2 inputTextureCoordinate;
attribute mediump float width;

varying vec2 v_texCoord;
varying mediump vec2 v_vuTexCoord;
varying mediump float x_coord;

void main()
{
    gl_Position = position;
    v_texCoord = vec2(inputTextureCoordinate.x, inputTextureCoordinate.y * 0.6666667);
    v_vuTexCoord = vec2(inputTextureCoordinate.x, inputTextureCoordinate.y * 0.333333 + 0.6666667);
    x_coord = floor(inputTextureCoordinate.x * width);
}

3) Mi fragment shader:

uniform sampler2D inputImageTexture;  
varying mediump vec2 v_texCoord;
varying mediump vec2 v_vuTexCoord;
varying mediump float x_coord;
uniform mediump float u_one_over_tex_size;

void main()
{
    mediump vec3 yuv;
    mediump vec3 rgb;
    mediump float valx = mod(x_coord , 2.0);
    if(valx < 1.0) 
    {
        yuv.y = texture2D(inputImageTexture, v_vuTexCoord + vec2(u_one_over_tex_size, 0)).r - 0.5;
        yuv.z = texture2D(inputImageTexture, v_vuTexCoord).r - 0.5;
    } 
    else {
        yuv.y = texture2D(inputImageTexture, v_vuTexCoord).r - 0.5;
        yuv.z = texture2D(inputImageTexture, v_vuTexCoord + vec2(u_one_over_tex_size, 0)).r - 0.5;
    }
    yuv.x = texture2D(inputImageTexture, v_texCoord).r;
    rgb = mat3(    1,       1,     1,
                   0, -.34413, 1.772,
               1.402, -.71414,     0) * yuv;
    gl_FragColor = vec4(rgb, 1);
}

Pero el resultado no es como yo pensaba. Si divido yuv datos a y uv samplers y cambio de vertex y fragment shader, y no puedo tener el resultado correcto. Pero, ¿cómo podría yo sólo enviar un sampler sólo

como el de arriba?

He encontrado algo de información interesante en este sitio web code.google.com/p/o3d/source/browse/trunk/samples_webgl/shaders/…

OriginalEl autor The Lord Of Ring | 2013-06-14

2 Comentarios

  1. 4

    Tener una mirada en el código aquí: http://www.fourcc.org/source/YUV420P-OpenGL-GLSLang.c

    /*
     * Very simple example of how to perform YUV->RGB (YCrCb->RGB)
     * conversion with an OpenGL fragmen shader. The data (not included)
     * is presumed to be three files with Y, U and V samples for a 720x576
     * pixels large image.
     *
     * Note! The example uses NVidia extensions for rectangular textures
     * to make it simpler to read (non-normalised coordinates).
     * Rewriting it without the extensions is quite simple, but left as an
     * exercise to the reader. (The trick is that the shader must know the
     * image dimensions instead)
     *
     * The program also does not check to see if the shader extensions are
     * available - this is after all just a simple example.
     *
     * This code is released under a BSD style license. Do what you want, but
     * do not blame me.
     *
     * Peter Bengtsson, Dec 2004.
     */
    
    #include <stdio.h>
    #include <stdlib.h>
    #include <unistd.h>
    #include <GL/gl.h>
    #include <GL/glext.h>
    #include <SDL/SDL.h>
    
    int Quit=0;
    
    static int B_WIDTH=640;
    static int B_HEIGHT=480;
    
    int main(int cnt,char *arg[])
    {
    SDL_Surface *Win=NULL;
    GLubyte *Ytex,*Utex,*Vtex;
    SDL_Event evt;
    int i;
    GLhandleARB FSHandle,PHandle;
    char *s;
    FILE *fp;
    
    char *FProgram=
      "uniform sampler2DRect Ytex;\n"
      "uniform sampler2DRect Utex,Vtex;\n"
      "void main(void) {\n"
      "  float nx,ny,r,g,b,y,u,v;\n"
      "  vec4 txl,ux,vx;"
      "  nx=gl_TexCoord[0].x;\n"
      "  ny=576.0-gl_TexCoord[0].y;\n"
      "  y=texture2DRect(Ytex,vec2(nx,ny)).r;\n"
      "  u=texture2DRect(Utex,vec2(nx/2.0,ny/2.0)).r;\n"
      "  v=texture2DRect(Vtex,vec2(nx/2.0,ny/2.0)).r;\n"
    
      "  y=1.1643*(y-0.0625);\n"
      "  u=u-0.5;\n"
      "  v=v-0.5;\n"
    
      "  r=y+1.5958*v;\n"
      "  g=y-0.39173*u-0.81290*v;\n"
      "  b=y+2.017*u;\n"
    
      "  gl_FragColor=vec4(r,g,b,1.0);\n"
      "}\n";
    
    
    if(!SDL_Init(SDL_INIT_VIDEO)) {
    
      SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER,1);
    
      Win=SDL_SetVideoMode(B_WIDTH,B_HEIGHT,32,SDL_HWSURFACE|SDL_ANYFORMAT|SDL_OPENGL);
    
      if(Win) {
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(0,B_WIDTH,0,B_HEIGHT,-1,1);
        glViewport(0,0,B_WIDTH,B_HEIGHT);
        glClearColor(0,0,0,0);
        glColor3f(1.0,0.84,0.0);
        glHint(GL_POLYGON_SMOOTH_HINT,GL_NICEST);
    
        /* Set up program objects. */
        PHandle=glCreateProgramObjectARB();
        FSHandle=glCreateShaderObjectARB(GL_FRAGMENT_SHADER_ARB);
    
        /* Compile the shader. */
        glShaderSourceARB(FSHandle,1,&FProgram,NULL);
        glCompileShaderARB(FSHandle);
    
        /* Print the compilation log. */
        glGetObjectParameterivARB(FSHandle,GL_OBJECT_COMPILE_STATUS_ARB,&i);
        s=malloc(32768);
        glGetInfoLogARB(FSHandle,32768,NULL,s);
        printf("Compile Log: %s\n", s);
        free(s);
    
        /* Create a complete program object. */
        glAttachObjectARB(PHandle,FSHandle);
        glLinkProgramARB(PHandle);
    
        /* And print the link log. */
        s=malloc(32768);
        glGetInfoLogARB(PHandle,32768,NULL,s);
        printf("Link Log: %s\n", s);
        free(s);
    
        /* Finally, use the program. */
        glUseProgramObjectARB(PHandle);
    
        /* Load the textures. */
        Ytex=malloc(414720);
        Utex=malloc(103680);
        Vtex=malloc(103680);
    
        fp=fopen("Image.Y","rb");
        fread(Ytex,414720,1,fp);
        fclose(fp);
        fp=fopen("Image.U","rb");
        fread(Utex,103680,1,fp);
        fclose(fp);
        fp=fopen("Image.V","rb");
        fread(Vtex,103680,1,fp);
        fclose(fp);
    
        /* This might not be required, but should not hurt. */
        glEnable(GL_TEXTURE_2D);
    
        /* Select texture unit 1 as the active unit and bind the U texture. */
        glActiveTexture(GL_TEXTURE1);
        i=glGetUniformLocationARB(PHandle,"Utex");
        glUniform1iARB(i,1);  /* Bind Utex to texture unit 1 */
        glBindTexture(GL_TEXTURE_RECTANGLE_NV,1);
    
        glTexParameteri(GL_TEXTURE_RECTANGLE_NV,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
        glTexParameteri(GL_TEXTURE_RECTANGLE_NV,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
        glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_DECAL);
        glTexImage2D(GL_TEXTURE_RECTANGLE_NV,0,GL_LUMINANCE,376,288,0,GL_LUMINANCE,GL_UNSIGNED_BYTE,Utex);
    
        /* Select texture unit 2 as the active unit and bind the V texture. */
        glActiveTexture(GL_TEXTURE2);
        i=glGetUniformLocationARB(PHandle,"Vtex");
        glBindTexture(GL_TEXTURE_RECTANGLE_NV,2);
        glUniform1iARB(i,2);  /* Bind Vtext to texture unit 2 */
    
        glTexParameteri(GL_TEXTURE_RECTANGLE_NV,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
        glTexParameteri(GL_TEXTURE_RECTANGLE_NV,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
        glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_DECAL);
        glTexImage2D(GL_TEXTURE_RECTANGLE_NV,0,GL_LUMINANCE,376,288,0,GL_LUMINANCE,GL_UNSIGNED_BYTE,Vtex);
    
        /* Select texture unit 0 as the active unit and bind the Y texture. */
        glActiveTexture(GL_TEXTURE0);
        i=glGetUniformLocationARB(PHandle,"Ytex");
        glUniform1iARB(i,0);  /* Bind Ytex to texture unit 0 */
        glBindTexture(GL_TEXTURE_RECTANGLE_NV,3);
    
        glTexParameteri(GL_TEXTURE_RECTANGLE_NV,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
        glTexParameteri(GL_TEXTURE_RECTANGLE_NV,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
        glTexEnvf(GL_TEXTURE_ENV,GL_TEXTURE_ENV_MODE,GL_DECAL);
        glTexImage2D(GL_TEXTURE_RECTANGLE_NV,0,GL_LUMINANCE,752,576,0,GL_LUMINANCE,GL_UNSIGNED_BYTE,Ytex);
    
        /* Simple loop, just draws the image and waits for quit. */
        while(!Quit) {
          if(SDL_PollEvent(&evt)) {
            switch(evt.type) {
            case  SDL_KEYDOWN:
            case  SDL_QUIT:
              Quit=1;
            break;
            }
          }
    
          glClear(GL_COLOR_BUFFER_BIT);
    
          /* Draw image (again and again). */
    
          glBegin(GL_QUADS);
            glTexCoord2i(0,0);
            glVertex2i(0,0);
            glTexCoord2i(720,0);
            glVertex2i(B_WIDTH,0);
            glTexCoord2i(720,576);
            glVertex2i(B_WIDTH,B_HEIGHT);
            glTexCoord2i(0,576);
            glVertex2i(0,B_HEIGHT);
          glEnd();
    
          /* Flip buffers. */
    
          glFlush();
          SDL_GL_SwapBuffers();
    
          sleep(1);
        } /* while(!Quit) */
    
        /* Clean up before exit. */
    
        glUseProgramObjectARB(0);
        glDeleteObjectARB(sprog);
    
        free(Ytex);
        free(Utex);
        free(Vtex);
    
      } else {
        fprintf(stderr,"Unable to create primary surface. \"%s\".\n",SDL_GetError());
      }
      SDL_Quit();
    } else {
      fprintf(stderr,"Initialisation failed. \"%s\".\n",SDL_GetError());
    }
    
    return(0);
    }
    
    Que todavía se ve como es la división de la Y y de la UV planos y la presentación por separado de texturas, que el autor de la pregunta ya tiene trabajo. Ellos están tratando de encontrar una manera de tomar una sola YUV marco y analizar que para convertir a RGB.
    Por lo que hace. Mi mal, lo voy a borrar.

    OriginalEl autor

  2. 0

    Tal vez está fuera de los temas, pero aquí he implementado un YUV 4:2:2 v210 de 10 bits decodificador en GLSL.

    OriginalEl autor

Dejar respuesta

Please enter your comment!
Please enter your name here