qt采用opengl显示yuv视频数据

xiaoxiao2026-01-12 0

作者：使徒保罗

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应用场景：qt opengl渲染yuv420p数据开发环境：win7 64位 qt-opensource-windows-x86-msvc2010-5.5.1.exe（即qt5.5.1 32位版本）功能：下面的核心代码都有详细注释，学术名词不清楚请自行百度。本例通过PlayOneFrame（）接口从yuv文件中读取一帧yuv图像数据显示,每调用一次，就显示下一帧图像。

#ifndef GLPLAYWIDGET_H #define GLPLAYWIDGET_H #include <QOpenGLWidget> #include <QOpenGLShaderProgram> #include <QOpenGLFunctions> #include <QOpenGLTexture> #include <QFile> #define ATTRIB_VERTEX 3 #define ATTRIB_TEXTURE 4 class CPlayWidget:public QOpenGLWidget,protected QOpenGLFunctions { Q_OBJECT public: CPlayWidget(QWidget* parent); ~CPlayWidget(); void PlayOneFrame(); protected: void initializeGL() Q_DECL_OVERRIDE; void resizeGL(int w, int h) Q_DECL_OVERRIDE; void paintGL() Q_DECL_OVERRIDE; private: GLuint textureUniformY; //y纹理数据位置 GLuint textureUniformU; //u纹理数据位置 GLuint textureUniformV; //v纹理数据位置 GLuint id_y; //y纹理对象ID GLuint id_u; //u纹理对象ID GLuint id_v; //v纹理对象ID QOpenGLTexture* m_pTextureY; //y纹理对象 QOpenGLTexture* m_pTextureU; //u纹理对象 QOpenGLTexture* m_pTextureV; //v纹理对象 QOpenGLShader *m_pVSHader; //顶点着色器程序对象 QOpenGLShader *m_pFSHader; //片段着色器对象 QOpenGLShaderProgram *m_pShaderProgram; //着色器程序容器 int m_nVideoW; //视频分辨率宽 int m_nVideoH; //视频分辨率高 unsigned char* m_pBufYuv420p; FILE* m_pYuvFile; }; #endif

#include "PlayWidget.h" #include <QOpenGLTexture> #include <QOpenGLBuffer> #include <QMouseEvent> CPlayWidget::CPlayWidget(QWidget *parent):QOpenGLWidget(parent) { textureUniformY = 0; textureUniformU = 0; textureUniformV = 0; id_y = 0; id_u = 0; id_v = 0; m_pBufYuv420p = NULL; m_pVSHader = NULL; m_pFSHader = NULL; m_pShaderProgram = NULL; m_pTextureY = NULL; m_pTextureU = NULL; m_pTextureV = NULL; m_pYuvFile = NULL; m_nVideoH = 0; m_nVideoW = 0; } CPlayWidget::~CPlayWidget() { } void CPlayWidget::PlayOneFrame() {//函数功能读取一张yuv图像数据进行显示,每单击一次，就显示一张图片 if(NULL == m_pYuvFile) { //打开yuv视频文件注意修改文件路径 // m_pYuvFile = fopen("F://OpenglYuvDemo//1920_1080.yuv", "rb"); m_pYuvFile = fopen("F://OpenglYuvDemo//test_yuv420p_320x180.yuv", "rb"); m_nVideoW = 320; m_nVideoH = 180; //根据yuv视频数据的分辨率设置宽高,demo当中是1080p，这个地方要注意跟实际数据分辨率对应上 // m_nVideoW = 1920; // m_nVideoH = 1080; } //申请内存存一帧yuv图像数据,其大小为分辨率的1.5倍 int nLen = m_nVideoW*m_nVideoH*3/2; if(NULL == m_pBufYuv420p) { m_pBufYuv420p = new unsigned char[nLen]; qDebug("CPlayWidget::PlayOneFrame new data memory. Len=%d width=%d height=%d\n", nLen, m_nVideoW, m_nVideoW); } //将一帧yuv图像读到内存中 if(NULL == m_pYuvFile) { qFatal("read yuv file err.may be path is wrong!\n"); return; } fread(m_pBufYuv420p, 1, nLen, m_pYuvFile); //刷新界面,触发paintGL接口 update(); return; } void CPlayWidget::initializeGL() { initializeOpenGLFunctions(); glEnable(GL_DEPTH_TEST); //现代opengl渲染管线依赖着色器来处理传入的数据 //着色器：就是使用openGL着色语言(OpenGL Shading Language, GLSL)编写的一个小函数, // GLSL是构成所有OpenGL着色器的语言,具体的GLSL语言的语法需要读者查找相关资料 //初始化顶点着色器对象 m_pVSHader = new QOpenGLShader(QOpenGLShader::Vertex, this); //顶点着色器源码 const char *vsrc = "attribute vec4 vertexIn; \ attribute vec2 textureIn; \ varying vec2 textureOut; \ void main(void) \ { \ gl_Position = vertexIn; \ textureOut = textureIn; \ }"; //编译顶点着色器程序 bool bCompile = m_pVSHader->compileSourceCode(vsrc); if(!bCompile) { } //初始化片段着色器功能gpu中yuv转换成rgb m_pFSHader = new QOpenGLShader(QOpenGLShader::Fragment, this); //片段着色器源码 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, 1); \ }"; //将glsl源码送入编译器编译着色器程序 bCompile = m_pFSHader->compileSourceCode(fsrc); if(!bCompile) { } #define PROGRAM_VERTEX_ATTRIBUTE 0 #define PROGRAM_TEXCOORD_ATTRIBUTE 1 //创建着色器程序容器 m_pShaderProgram = new QOpenGLShaderProgram; //将片段着色器添加到程序容器 m_pShaderProgram->addShader(m_pFSHader); //将顶点着色器添加到程序容器 m_pShaderProgram->addShader(m_pVSHader); //绑定属性vertexIn到指定位置ATTRIB_VERTEX,该属性在顶点着色源码其中有声明 m_pShaderProgram->bindAttributeLocation("vertexIn", ATTRIB_VERTEX); //绑定属性textureIn到指定位置ATTRIB_TEXTURE,该属性在顶点着色源码其中有声明 m_pShaderProgram->bindAttributeLocation("textureIn", ATTRIB_TEXTURE); //链接所有所有添入到的着色器程序 m_pShaderProgram->link(); //激活所有链接 m_pShaderProgram->bind(); //读取着色器中的数据变量tex_y, tex_u, tex_v的位置,这些变量的声明可以在 //片段着色器源码中可以看到 textureUniformY = m_pShaderProgram->uniformLocation("tex_y"); textureUniformU = m_pShaderProgram->uniformLocation("tex_u"); textureUniformV = m_pShaderProgram->uniformLocation("tex_v"); // 顶点矩阵 static const GLfloat vertexVertices[] = { -1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f, }; //纹理矩阵 static const GLfloat textureVertices[] = { 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, }; //设置属性ATTRIB_VERTEX的顶点矩阵值以及格式 glVertexAttribPointer(ATTRIB_VERTEX, 2, GL_FLOAT, 0, 0, vertexVertices); //设置属性ATTRIB_TEXTURE的纹理矩阵值以及格式 glVertexAttribPointer(ATTRIB_TEXTURE, 2, GL_FLOAT, 0, 0, textureVertices); //启用ATTRIB_VERTEX属性的数据,默认是关闭的 glEnableVertexAttribArray(ATTRIB_VERTEX); //启用ATTRIB_TEXTURE属性的数据,默认是关闭的 glEnableVertexAttribArray(ATTRIB_TEXTURE); //分别创建y,u,v纹理对象 m_pTextureY = new QOpenGLTexture(QOpenGLTexture::Target2D); m_pTextureU = new QOpenGLTexture(QOpenGLTexture::Target2D); m_pTextureV = new QOpenGLTexture(QOpenGLTexture::Target2D); m_pTextureY->create(); m_pTextureU->create(); m_pTextureV->create(); //获取返回y分量的纹理索引值 id_y = m_pTextureY->textureId(); //获取返回u分量的纹理索引值 id_u = m_pTextureU->textureId(); //获取返回v分量的纹理索引值 id_v = m_pTextureV->textureId(); glClearColor(0.3,0.3,0.3,0.0);//设置背景色 //qDebug("addr=%x id_y = %d id_u=%d id_v=%d\n", this, id_y, id_u, id_v); } void CPlayWidget::resizeGL(int w, int h) { if(h == 0)// 防止被零除 { h = 1;// 将高设为1 } //设置视口 glViewport(0,0, w,h); } void CPlayWidget::paintGL() { //加载y数据纹理 //激活纹理单元GL_TEXTURE0 glActiveTexture(GL_TEXTURE0); //使用来自y数据生成纹理 glBindTexture(GL_TEXTURE_2D, id_y); //使用内存中m_pBufYuv420p数据创建真正的y数据纹理 glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, m_nVideoW, m_nVideoH, 0, GL_RED, GL_UNSIGNED_BYTE, m_pBufYuv420p); 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); //加载u数据纹理 glActiveTexture(GL_TEXTURE1);//激活纹理单元GL_TEXTURE1 glBindTexture(GL_TEXTURE_2D, id_u); glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, m_nVideoW/2, m_nVideoH/2, 0, GL_RED, GL_UNSIGNED_BYTE, (char*)m_pBufYuv420p+m_nVideoW*m_nVideoH); 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); //加载v数据纹理 glActiveTexture(GL_TEXTURE2);//激活纹理单元GL_TEXTURE2 glBindTexture(GL_TEXTURE_2D, id_v); glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, m_nVideoW/2, m_nVideoH/2, 0, GL_RED, GL_UNSIGNED_BYTE, (char*)m_pBufYuv420p+m_nVideoW*m_nVideoH*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); //指定y纹理要使用新值只能用0,1,2等表示纹理单元的索引，这是opengl不人性化的地方 //0对应纹理单元GL_TEXTURE0 1对应纹理单元GL_TEXTURE1 2对应纹理的单元 glUniform1i(textureUniformY, 0); //指定u纹理要使用新值 glUniform1i(textureUniformU, 1); //指定v纹理要使用新值 glUniform1i(textureUniformV, 2); //使用顶点数组方式绘制图形 glDrawArrays(GL_TRIANGLE_STRIP, 0, 4); return; }

效果图:

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