使用OpenGL 和 opengl ES 渲染YUV图片文件的QT示例

OpenGL ES的示例：

头文件：CPlayWidget.h

#ifndef CPLAYWIDGET_H
#define CPLAYWIDGET_H

#include <QOpenGLWidget>
#include <QOpenGLShaderProgram>
#include <QOpenGLFunctions>
#include <QOpenGLTexture>
#include <QFile>
#include <QTimer>

#define ATTRIB_VERTEX 3
#define ATTRIB_TEXTURE 4

class CPlayWidget : public QOpenGLWidget, protected QOpenGLFunctions
{
    Q_OBJECT
public:
    CPlayWidget(QWidget* parent);
    ~CPlayWidget();

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;
    QTimer timer;
    FILE* m_pYuvFile;
protected slots:
    void on_timeout();
};

#endif // CPLAYWIDGET_H

cpp文件：CPlayWidget.cpp

默认打开 ./test.yuv文件

#include "CPlayWidget.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()
{   // fclose(m_pYuvFile);

    delete [] m_pBufYuv420p;

}

void CPlayWidget::initializeGL()
{ if(NULL == m_pYuvFile)
    {
        // 打开yuv视频文件 注意修改文件路径
        // m_pYuvFile = fopen("/home/enpht/Documents/test/176_144.yuv", "rb");
        m_pYuvFile = fopen("./test.yuv", "rb");
        // 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 = 176;
        // m_nVideoH = 144;
        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

    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 = "#version 320 es\n\
        in vec4 vertexIn;\n\
        in vec2 textureIn;\n\
        out vec2 textureOut;\n\
        void main(void)\n\
        {\n\
            gl_Position = vertexIn;\n\
            textureOut = textureIn;\n\
    }";
    //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 = "#version 320 es\n\
    precision mediump float;\n\
    in vec2 textureOut;\n\
    uniform sampler2D tex_y;\n\
    uniform sampler2D tex_u;\n\
    uniform sampler2D tex_v;\n\
    out vec4 fragColor;\n\
    void main(void)\n\
    {\n\
        vec3 yuv;\n\
        vec3 rgb;\n\
        yuv.x = texture(tex_y, textureOut).r;\n\
        yuv.y = texture(tex_u, textureOut).r - 0.5;\n\
        yuv.z = texture(tex_v, textureOut).r - 0.5;\n\
        rgb = mat3(1.0, 1.0, 1.0,\n\
                   0.0, -0.39465, 2.03211,\n\
                   1.13983, -0.58060, 0.0) * yuv;\n\
        fragColor = vec4(rgb, 1.0);\n\
    }";
    //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);
    connect(&timer, SIGNAL(timeout()), this, SLOT(on_timeout()));
    timer.setInterval(25);
    timer.start();
}

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()
{
    int nLen = m_nVideoW*m_nVideoH*3/2;
    if(NULL == m_pBufYuv420p)
    {
        m_pBufYuv420p = new unsigned char[nLen];
        qDebug("  Len=%d width=%d height=%d\n",
               nLen, m_nVideoW, m_nVideoH);
    }
    //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;
    }

//    m_pBufYuv420p+=position;
//    position += nLen;
    // fread(m_pBufYuv420p, 1, nLen, m_pYuvFile);
    fread(m_pBufYuv420p, 1, nLen, m_pYuvFile);

    //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;
 }

void CPlayWidget::on_timeout()
{       update();
}

OpenGL 示例：

头文件：CPlayWidget.h  与上面没有差别

cpp文件：只替换了着色器代码：

#include "CPlayWidget.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()
{   // fclose(m_pYuvFile);

    delete [] m_pBufYuv420p;

}

void CPlayWidget::initializeGL()
{ if(NULL == m_pYuvFile)
    {
        // 打开yuv视频文件 注意修改文件路径
        // m_pYuvFile = fopen("/home/enpht/Documents/test/176_144.yuv", "rb");
        m_pYuvFile = fopen("./test.yuv", "rb");
        // 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 = 176;
        // m_nVideoH = 144;
        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

    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
#if 0
    // opengles
    const char *vsrc = "#version 320 es\n\
        in vec4 vertexIn;\n\
        in vec2 textureIn;\n\
        out vec2 textureOut;\n\
        void main(void)\n\
        {\n\
            gl_Position = vertexIn;\n\
            textureOut = textureIn;\n\
    }";
#else
    // opengl
    const char *vsrc = "attribute vec4 vertexIn; \
        attribute vec2 textureIn; \
        varying vec2 textureOut;  \
        void main(void)           \
        {                         \
            gl_Position = vertexIn; \
            textureOut = textureIn; \
        }";
#endif
    //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

#if 0
    // opengl es:
    const char *fsrc = "#version 320 es\
        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); \
        }";
#else
    // opengl
    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); \
        }";

#endif

    //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);
    connect(&timer, SIGNAL(timeout()), this, SLOT(on_timeout()));
    timer.setInterval(25);
    timer.start();
}

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()
{
    int nLen = m_nVideoW*m_nVideoH*3/2;
    if(NULL == m_pBufYuv420p)
    {
        m_pBufYuv420p = new unsigned char[nLen];
        qDebug("  Len=%d width=%d height=%d\n",
               nLen, m_nVideoW, m_nVideoH);
    }
    //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;
    }

//    m_pBufYuv420p+=position;
//    position += nLen;
    // fread(m_pBufYuv420p, 1, nLen, m_pYuvFile);
    fread(m_pBufYuv420p, 1, nLen, m_pYuvFile);

    //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;
 }

void CPlayWidget::on_timeout()
{       update();
}