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    1er décembre 2010, par

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    Lors de l’installation de MediaSPIP, celui-ci est préconfiguré pour les usages les plus fréquents.
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Sur d’autres sites (6425)

  • Fragment shader does not show any colour when compiled with vs2013

    11 juin 2015, par 5mayfive

    When compiled with vs2010, the fragment shader works, but when I compiled and run in vs 2013, it’s grey.

    My fragment shader converts the yuv texture into rgb

    Below is my fragment code

        const char *FProgram =
    
    "uniform sampler2D Ytex;\n"
    
    "uniform sampler2D Utex;\n"
    
    "uniform sampler2D Vtex;\n"
    
    "void main(void) {\n"
    
    "  vec4 c = vec4((texture2D(Ytex, gl_TexCoord[0]).r - 16./255.) * 1.164);\n"
    
    "  vec4 U = vec4(texture2D(Utex, gl_TexCoord[0]).r - 128./255.);\n"
    
    "  vec4 V = vec4(texture2D(Vtex, gl_TexCoord[0]).r - 128./255.);\n"
    
    "  c += V * vec4(1.596, -0.813, 0, 0);\n"
    
    "  c += U * vec4(0, -0.392, 2.017, 0);\n"
    
    "  c.a = 1.0;\n"
    
    "  gl_FragColor = c;\n"
    
    "}\n";
    

    

    

    

    

    
glClearColor(0, 0, 0, 0);
    

    
PHandle = glCreateProgram();
    
FSHandle = glCreateShader(GL_FRAGMENT_SHADER);
    

    

    

    
glShaderSource(FSHandle, 1, &FProgram, NULL);
    
glCompileShader(FSHandle);
    

    
glAttachShader(PHandle, FSHandle);
    
glLinkProgram(PHandle);
    

    

    
glUseProgram(PHandle);
    
glDeleteProgram(PHandle);
    
glDeleteProgram(FSHandle);

    This is my texture code, I receive linesize and yuv frame data from ffmpeg and make into texture. Everything works fine in VS 2010 computer, but when compiled and run in vs2013 computer, it is grey (black n white), no colour

        /* Select texture unit 1 as the active unit and bind the U texture. */
    
glPixelStorei(GL_UNPACK_ROW_LENGTH, linesize1);
    
glActiveTexture(GL_TEXTURE1);
    
i = glGetUniformLocation(PHandle, "Utex");
    
glUniform1i(i, 1);  /* Bind Utex to texture unit 1 */
    
glBindTexture(GL_TEXTURE_2D, 1);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    
glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, width / 2, height / 2, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, frame1);
    
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    

    

    
/* Select texture unit 2 as the active unit and bind the V texture. */
    
glPixelStorei(GL_UNPACK_ROW_LENGTH, linesize2);
    
glActiveTexture(GL_TEXTURE2);
    
i = glGetUniformLocation(PHandle, "Vtex");
    
glUniform1i(i, 2);  /* Bind Vtext to texture unit 2 */
    
glBindTexture(GL_TEXTURE_2D, 2);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    
glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, width / 2, height / 2, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, frame2);
    
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    

    

    
/* Select texture unit 0 as the active unit and bind the Y texture. */
    

    

    

    
glPixelStorei(GL_UNPACK_ROW_LENGTH, linesize0);
    
glActiveTexture(GL_TEXTURE0);
    
i = glGetUniformLocation(PHandle, "Ytex");
    
glUniform1i(i, 0);
    
glBindTexture(GL_TEXTURE_2D, 0);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    
glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, width, height, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, frame0);
    
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    

    

    

    
glClear(GL_COLOR_BUFFER_BIT);
    

    
/* Draw image (again and again). */
    

    
glBegin(GL_QUADS);
    
glTexCoord2i(0, 0);
    
glVertex2i(-w / 2, h / 2);
    
glTexCoord2i(1, 0);
    
glVertex2i(w / 2, h / 2);
    
glTexCoord2i(1, 1);
    
glVertex2i(w / 2, -h / 2);
    
glTexCoord2i(0, 1);
    
glVertex2i(-w / 2, -h / 2);
    
glEnd();

    Need guidance here, thanks in advance !

  • Overlay transparent video over an image with FFMPEG

    17 janvier 2021, par Dilip Suvagiya

    I have a transparent video, now I want to add an image in the transparent part of the video.
The below command helps to overlay image in video but it covers full part of the video and few portions of video become invisible. Anyone, please suggest a way to fix this ? Many thank in advance.

    


    ffmpeg -i input.avi -i image.jpg -filter_complex "[0:v][1:v] overlay=204:773:enable='between(t,0,5)'" output.avi

    


    Transparent video

    


    Output video with image overlaps some part of the video as highlighted

    


  • Fragment shader does not show any colour when compiled with vs2013

    4 septembre 2019, par 5mayfive

    When compiled with vs2010, the fragment shader works, but when I compiled and run in vs 2013, it’s grey.

    My fragment shader converts the yuv texture into rgb

    Below is my fragment code

        const char *FProgram =
    
    "uniform sampler2D Ytex;\n"
    
    "uniform sampler2D Utex;\n"
    
    "uniform sampler2D Vtex;\n"
    
    "void main(void) {\n"
    
    "  vec4 c = vec4((texture2D(Ytex, gl_TexCoord[0]).r - 16./255.) * 1.164);\n"
    
    "  vec4 U = vec4(texture2D(Utex, gl_TexCoord[0]).r - 128./255.);\n"
    
    "  vec4 V = vec4(texture2D(Vtex, gl_TexCoord[0]).r - 128./255.);\n"
    
    "  c += V * vec4(1.596, -0.813, 0, 0);\n"
    
    "  c += U * vec4(0, -0.392, 2.017, 0);\n"
    
    "  c.a = 1.0;\n"
    
    "  gl_FragColor = c;\n"
    
    "}\n";
    

    

    

    

    

    
glClearColor(0, 0, 0, 0);
    

    
PHandle = glCreateProgram();
    
FSHandle = glCreateShader(GL_FRAGMENT_SHADER);
    

    

    

    
glShaderSource(FSHandle, 1, &FProgram, NULL);
    
glCompileShader(FSHandle);
    

    
glAttachShader(PHandle, FSHandle);
    
glLinkProgram(PHandle);
    

    

    
glUseProgram(PHandle);
    
glDeleteProgram(PHandle);
    
glDeleteProgram(FSHandle);

    This is my texture code, I receive linesize and yuv frame data from ffmpeg and make into texture. Everything works fine in VS 2010 computer, but when compiled and run in vs2013 computer, it is grey (black n white), no colour

        /* Select texture unit 1 as the active unit and bind the U texture. */
    
glPixelStorei(GL_UNPACK_ROW_LENGTH, linesize1);
    
glActiveTexture(GL_TEXTURE1);
    
i = glGetUniformLocation(PHandle, "Utex");
    
glUniform1i(i, 1);  /* Bind Utex to texture unit 1 */
    
glBindTexture(GL_TEXTURE_2D, 1);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    
glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, width / 2, height / 2, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, frame1);
    
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    

    

    
/* Select texture unit 2 as the active unit and bind the V texture. */
    
glPixelStorei(GL_UNPACK_ROW_LENGTH, linesize2);
    
glActiveTexture(GL_TEXTURE2);
    
i = glGetUniformLocation(PHandle, "Vtex");
    
glUniform1i(i, 2);  /* Bind Vtext to texture unit 2 */
    
glBindTexture(GL_TEXTURE_2D, 2);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    
glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, width / 2, height / 2, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, frame2);
    
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    

    

    
/* Select texture unit 0 as the active unit and bind the Y texture. */
    

    

    

    
glPixelStorei(GL_UNPACK_ROW_LENGTH, linesize0);
    
glActiveTexture(GL_TEXTURE0);
    
i = glGetUniformLocation(PHandle, "Ytex");
    
glUniform1i(i, 0);
    
glBindTexture(GL_TEXTURE_2D, 0);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    
glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, width, height, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, frame0);
    
glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    

    

    

    
glClear(GL_COLOR_BUFFER_BIT);
    

    
/* Draw image (again and again). */
    

    
glBegin(GL_QUADS);
    
glTexCoord2i(0, 0);
    
glVertex2i(-w / 2, h / 2);
    
glTexCoord2i(1, 0);
    
glVertex2i(w / 2, h / 2);
    
glTexCoord2i(1, 1);
    
glVertex2i(w / 2, -h / 2);
    
glTexCoord2i(0, 1);
    
glVertex2i(-w / 2, -h / 2);
    
glEnd();

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