如何将PBO与Qt OpenGL结合使用

我正在尝试使用QOpenGLBuffer作为像素缓冲区对象。目标是显示高分辨率的视频流（4K，60FPS），所以我需要良好的性能。

由于我刚开始使用OpenGL，我首先尝试以最好的方式显示一个简单的2D纹理。我已经包含了VBO和VAO，下一步（正如我所读的）将是使用PBO来获得更好的性能。

有PBO的教程，但有glGenBufferARB（），而不是QOpenGLBuffer。

这是我的代码：

glwidget.h

#ifndef GLWIDGET_H
#define GLWIDGET_H
#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <QOpenGLBuffer>
#include <QDebug>
#include <QOpenGLTexture>
#include <QOpenGLShader>
#include <QOpenGLShaderProgram>
#include <QOpenGLVertexArrayObject>


class GLWidget : public QOpenGLWidget, protected QOpenGLFunctions
{
    Q_OBJECT
public:
    explicit GLWidget(QWidget *parent = 0);
    ~GLWidget();
    void initializeGL();
    void paintGL();
    void resizeGL(int w, int h);
    void LoadGLTextures();
private :
    QOpenGLShaderProgram *program;
    QOpenGLBuffer vbo;
    QOpenGLVertexArrayObject vao;
    GLuint tex;
    GLint vertexLocation;
    GLint texcoordLocation;
    int tailleVerticesBytes;
    int tailleCoordTexturesBytes;
    float vertices[8];
    float coordTexture[8];

public slots:

private slots:

};
#endif // GLWIDGET_H

glwidget.cpp

#ifndef BUFFER_OFFSET
#define BUFFER_OFFSET(offset) ((char*)NULL + (offset))
#include "glwidget.h"
#include <QElapsedTimer>

GLWidget::GLWidget(QWidget *parent) :
        QOpenGLWidget(parent)
{
    tailleVerticesBytes = 8*sizeof(float);
    tailleCoordTexturesBytes = 8*sizeof(float);
}
GLWidget::~GLWidget(){
    vao.destroy();
    vbo.destroy();
    delete program;
    glDeleteTextures(1, &tex);
}
void GLWidget::LoadGLTextures(){
    QImage img;
    if(!img.load("C:\Users\Adrien\Desktop\open3.bmp")){
        qDebug()<<"Image loading failed";
    }
    QImage t = (img.convertToFormat(QImage::Format_RGBA8888)).mirrored();
    glGenTextures(1, &tex);
    glBindTexture(GL_TEXTURE_2D, tex);
        glTexImage2D(GL_TEXTURE_2D, 0, 3, t.width(), t.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, t.bits());
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glBindTexture( GL_TEXTURE_2D, 0);

}
void GLWidget::initializeGL(){

    float verticesTmp[] = {-1.0,-1.0,  1.0,-1.0,  1.0,1.0,  -1.0,1.0};
    float coordTextureTmp[] = {0.0,0.0,  1.0,0.0,  1.0,1.0,  0.0,1.0};
    for(int i = 0; i<8; i++){
        vertices[i] = verticesTmp[i];
        coordTexture[i] = coordTextureTmp[i];
    }
    initializeOpenGLFunctions();
    glClear(GL_COLOR_BUFFER_BIT);
    glEnable(GL_TEXTURE_2D);
    LoadGLTextures();
    //Shader setup
    QOpenGLShader *vshader = new QOpenGLShader(QOpenGLShader::Vertex, this);
    const char *vsrc =
        "#version 150 coren"
        "in vec2 in_Vertex;n"
        "in vec2 vertTexCoord;n"
        "out vec2 fragTexCoord;n"
        "void main(void)n"
        "{n"
        "    gl_Position = vec4(in_Vertex, 0.0, 1.0);n"
        "    fragTexCoord = vertTexCoord;n"
        "}n";
    vshader->compileSourceCode(vsrc);
    QOpenGLShader *fshader = new QOpenGLShader(QOpenGLShader::Fragment, this);
    const char *fsrc =
            "#version 150 coren"
            "uniform sampler2D tex;n"
            "in vec2 fragTexCoord;n"
            "void main(void)n"
            "{n"
            "    gl_FragColor = texture2D(tex,fragTexCoord);n"
            "}n";
    fshader->compileSourceCode(fsrc);
    program = new QOpenGLShaderProgram;
    program->addShader(vshader);
    program->addShader(fshader);
    program->link();
    program->bind();
    glActiveTexture(GL_TEXTURE0);
    program->setUniformValue("tex", 0);
    vertexLocation = glGetAttribLocation(program->programId(), "in_Vertex");
    texcoordLocation = glGetAttribLocation(program->programId(), "vertTexCoord");
    //VAO setup
    vao.create();
    vao.bind();
    //VBO setup
    vbo.create();
    vbo.setUsagePattern(QOpenGLBuffer::StaticDraw);
    vbo.bind();
    vbo.allocate(tailleVerticesBytes + tailleCoordTexturesBytes);
    vbo.write(0, vertices, tailleVerticesBytes);
    vbo.write(tailleVerticesBytes, coordTexture, tailleCoordTexturesBytes);
    program->enableAttributeArray(vertexLocation);
    program->setAttributeBuffer(vertexLocation, GL_FLOAT, 0, 2);
    program->enableAttributeArray(texcoordLocation);
    program->setAttributeBuffer(texcoordLocation, GL_FLOAT, tailleVerticesBytes, 2);
    vbo.release();
    vao.release();
    program->release();

}
void GLWidget::paintGL(){
    glClear(GL_COLOR_BUFFER_BIT);
    program->bind();
    {
        vao.bind();
            glBindTexture(GL_TEXTURE_2D, tex);
                glDrawArrays(GL_QUADS, 0, 4);
            glBindTexture(GL_TEXTURE_2D, 0);
        vao.release();
    }
    program->release();
}
void GLWidget::resizeGL(int w, int h){
    glViewport(0, 0, (GLint)w, (GLint)h);
}

#endif

那么，基本上，我该如何在这个代码中使用PBO呢？

首先要做的是在指定类型（QOpenGLBuffer:：PixelUnpackBuffer）的同时创建一个QOpenGLBuffer对象，然后我想我需要上传缓冲区上的像素，并最终使用它而不是glTexImage2D？这只是一个全球性的想法，我不知道该怎么做

谢谢。