OpenGLWidget RGB problem
-
Hello , i used OpenGLWidget for video stream but RGB is very bad .can you help me ?
void OpenGLDisplay::initializeGL() { initializeOpenGLFunctions(); glEnable(GL_DEPTH_TEST); /* Modern opengl rendering pipeline relies on shaders to handle incoming data. * Shader: is a small function written in OpenGL Shading Language (GLSL). * GLSL is the language that makes up all OpenGL shaders. * The syntax of the specific GLSL language requires the reader to find relevant information. */ // Initialize the vertex shader object impl->mVShader = new QOpenGLShader(QOpenGLShader::Vertex, this); //Vertex shader source const char *vsrc = "attribute vec4 vertexIn; \ attribute vec2 textureIn; \ varying vec2 textureOut; \ void main(void) \ { \ gl_Position = vertexIn; \ textureOut = textureIn; \ }"; //Compile the vertex shader program bool bCompile = impl->mVShader->compileSourceCode(vsrc); if(!bCompile) { throw OpenGlException(); } // Initialize the fragment shader function yuv converted to rgb impl->mFShader = new QOpenGLShader(QOpenGLShader::Fragment, this); // Fragment shader source code const char *fsrc = "varying vec2 textureOut; \ uniform sampler2D tex_y; \ uniform sampler2D tex_u; \ uniform sampler2D tex_v; \ void main(void) \ { \ vec3 yuv; \ vec3 rgb; \ yuv.x = texture2D(tex_y, textureOut).r; \ yuv.y = texture2D(tex_u, textureOut).r - 0.5; \ yuv.z = texture2D(tex_v, textureOut).r - 0.5; \ rgb = mat3( 1, 1, 1, \ 0, -0.39465, 2.03211, \ 1.13983, -0.58060, 0) * yuv; \ gl_FragColor = vec4(rgb, 0); \ }"; bCompile = impl->mFShader->compileSourceCode(fsrc); if(!bCompile) { throw OpenGlException(); } // Create a shader program container impl->mShaderProgram = new QOpenGLShaderProgram(this); // Add the fragment shader to the program container impl->mShaderProgram->addShader(impl->mFShader); // Add a vertex shader to the program container impl->mShaderProgram->addShader(impl->mVShader); // Bind the property vertexIn to the specified location ATTRIB_VERTEX, this property // has a declaration in the vertex shader source impl->mShaderProgram->bindAttributeLocation("vertexIn", ATTRIB_VERTEX); // Bind the attribute textureIn to the specified location ATTRIB_TEXTURE, the attribute // has a declaration in the vertex shader source impl->mShaderProgram->bindAttributeLocation("textureIn", ATTRIB_TEXTURE); //Link all the shader programs added to impl->mShaderProgram->link(); //activate all links impl->mShaderProgram->bind(); // Read the position of the data variables tex_y, tex_u, tex_v in the shader, the declaration // of these variables can be seen in // fragment shader source impl->textureUniformY = impl->mShaderProgram->uniformLocation("tex_y"); impl->textureUniformU = impl->mShaderProgram->uniformLocation("tex_u"); impl->textureUniformV = impl->mShaderProgram->uniformLocation("tex_v"); //Vertex matrix static const GLfloat vertexVertices[] = { -1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f, }; //Texture matrix static const GLfloat textureVertices[] = { 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, }; // Set the value of the vertex matrix of the attribute ATTRIB_VERTEX and format glVertexAttribPointer(ATTRIB_VERTEX, 2, GL_FLOAT, 0, 0, vertexVertices); // Set the texture matrix value and format of the attribute ATTRIB_TEXTURE glVertexAttribPointer(ATTRIB_TEXTURE, 2, GL_FLOAT, 0, 0, textureVertices); // Enable the ATTRIB_VERTEX attribute data, the default is off glEnableVertexAttribArray(ATTRIB_VERTEX); // Enable the ATTRIB_TEXTURE attribute data, the default is off glEnableVertexAttribArray(ATTRIB_TEXTURE); // Create y, u, v texture objects respectively impl->mTextureY = new QOpenGLTexture(QOpenGLTexture::Target2D); impl->mTextureU = new QOpenGLTexture(QOpenGLTexture::Target2D); impl->mTextureV = new QOpenGLTexture(QOpenGLTexture::Target2D); impl->mTextureY->create(); impl->mTextureU->create(); impl->mTextureV->create(); // Get the texture index value of the return y component impl->id_y = impl->mTextureY->textureId(); // Get the texture index value of the returned u component impl->id_u = impl->mTextureU->textureId(); // Get the texture index value of the returned v component impl->id_v = impl->mTextureV->textureId(); // glClearColor(0.5f, 0.5f, 0.5f, 1.0f); glClearColor(1.0f, 0.0f, 1.0f, 1.0f); // set the background color }
-
The problem is not in initialization. The problem is that Red and Blue channels are swapped. Are your receiving RGB or BGR images?
-
@ollarch my painGL part like this ;
void OpenGLDisplay::paintGL() { if(!paintPlay) { return; } // Load y data texture // Activate the texture unit GL_TEXTURE0 glActiveTexture(GL_TEXTURE0); // Use the texture generated from y to generate texture glBindTexture(GL_TEXTURE_2D, impl->id_y); // Use the memory mBufYuv data to create a real y data texture glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, impl->mVideoW, impl->mVideoH, 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, impl->mBufYuv); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); // Load u data texture glActiveTexture(GL_TEXTURE1);//Activate texture unit GL_TEXTURE1 glBindTexture(GL_TEXTURE_2D, impl->id_u); glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, impl->mVideoW/2, impl->mVideoH/2 , 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, (char*)impl->mBufYuv + impl->mVideoW * impl->mVideoH); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); // Load v data texture glActiveTexture(GL_TEXTURE2);//Activate texture unit GL_TEXTURE2 glBindTexture(GL_TEXTURE_2D, impl->id_v); glTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, impl->mVideoW / 2, impl->mVideoH / 2 , 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, (char*)impl->mBufYuv + impl->mVideoW * impl->mVideoH * 5/4); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); // Specify y texture to use the new value can only use 0, 1, 2, etc. to represent // the index of the texture unit, this is the place where opengl is not humanized //0 corresponds to the texture unit GL_TEXTURE0 1 corresponds to the // texture unit GL_TEXTURE1 2 corresponds to the texture unit GL_TEXTURE2 glUniform1i(impl->textureUniformY, 0); // Specify the u texture to use the new value glUniform1i(impl->textureUniformU, 1); // Specify v texture to use the new value glUniform1i(impl->textureUniformV, 2); // Use the vertex array way to draw graphics glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); }
-
Hi,
What type of YUV images do you get exactly ?
Did you try to reverse the R and B channels for your output ?
-
@SGaist yuv12 for h264 video images . i will try reverse r and b channels
