用QOpenGLwidget播放本地yuv文件

可以使用OpenGL来播放本地yuv文件，具体步骤如下：

1. 创建一个继承自QOpenGLWidget的类，并在其构造函数中初始化OpenGL相关设置：

class YUVPlayer : public QOpenGLWidget, protected QOpenGLFunctions
{
public:
    YUVPlayer(QWidget *parent = nullptr);
    ~YUVPlayer();

protected:
    void initializeGL() override;
    void paintGL() override;
    void resizeGL(int w, int h) override;
    void cleanupGL() override;

private:
    GLuint m_textureY;
    GLuint m_textureU;
    GLuint m_textureV;
    GLsizei m_videoWidth;
    GLsizei m_videoHeight;
};

YUVPlayer::YUVPlayer(QWidget *parent)
    : QOpenGLWidget(parent)
{
    // 初始化OpenGL函数
    initializeOpenGLFunctions();

    // 设置背景色
    glClearColor(0, 0, 0, 1);

    // 创建纹理
    glGenTextures(1, &m_textureY);
    glGenTextures(1, &m_textureU);
    glGenTextures(1, &m_textureV);
}

2. 在initializeGL()函数中加载yuv文件，创建纹理并绑定到对应的纹理单元上：

void YUVPlayer::initializeGL()
{
    // 加载yuv文件
    QFile file("test.yuv");
    if (!file.open(QIODevice::ReadOnly))
        return;

    QByteArray data = file.readAll();
    file.close();

    m_videoWidth = 640;
    m_videoHeight = 480;

    // 创建纹理
    glBindTexture(GL_TEXTURE_2D, m_textureY);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, m_videoWidth, m_videoHeight, 0, GL_RED, GL_UNSIGNED_BYTE, data.data());

    glBindTexture(GL_TEXTURE_2D, m_textureU);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, m_videoWidth / 2, m_videoHeight / 2, 0, GL_RED, GL_UNSIGNED_BYTE, data.data() + m_videoWidth * m_videoHeight);

    glBindTexture(GL_TEXTURE_2D, m_textureV);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, m_videoWidth / 2, m_videoHeight / 2, 0, GL_RED, GL_UNSIGNED_BYTE, data.data() + m_videoWidth * m_videoHeight * 5 / 4);

    // 设置纹理过滤方式
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    // 绑定纹理单元
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, m_textureY);

    glActiveTexture(GL_TEXTURE1);
    glBindTexture(GL_TEXTURE_2D, m_textureU);

    glActiveTexture(GL_TEXTURE2);
    glBindTexture(GL_TEXTURE_2D, m_textureV);
}

3. 在paintGL()函数中绘制纹理：

void YUVPlayer::paintGL()
{
    glClear(GL_COLOR_BUFFER_BIT);

    // 绑定纹理并绘制
    glBindTexture(GL_TEXTURE_2D, m_textureY);
    glActiveTexture(GL_TEXTURE0);
    glBegin(GL_QUADS);
    glTexCoord2i(0, 0); glVertex3f(-1, -1, 0);
    glTexCoord2i(1, 0); glVertex3f(1, -1, 0);
    glTexCoord2i(1, 1); glVertex3f(1, 1, 0);
    glTexCoord2i(0, 1); glVertex3f(-1, 1, 0);
    glEnd();

    glBindTexture(GL_TEXTURE_2D, m_textureU);
    glActiveTexture(GL_TEXTURE1);
    glBegin(GL_QUADS);
    glTexCoord2i(0, 0); glVertex3f(-1, -1, 0);
    glTexCoord2i(1, 0); glVertex3f(1, -1, 0);
    glTexCoord2i(1, 1); glVertex3f(1, 1, 0);
    glTexCoord2i(0, 1); glVertex3f(-1, 1, 0);
    glEnd();

    glBindTexture(GL_TEXTURE_2D, m_textureV);
    glActiveTexture(GL_TEXTURE2);
    glBegin(GL_QUADS);
    glTexCoord2i(0, 0); glVertex3f(-1, -1, 0);
    glTexCoord2i(1, 0); glVertex3f(1, -1, 0);
    glTexCoord2i(1, 1); glVertex3f(1, 1, 0);
    glTexCoord2i(0, 1); glVertex3f(-1, 1, 0);
    glEnd();
}

4. 在resizeGL()函数中设置视口：

void YUVPlayer::resizeGL(int w, int h)
{
    glViewport(0, 0, w, h);
}

5. 在程序中创建YUVPlayer类的对象，并显示：

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    YUVPlayer player;
    player.show();

    return a.exec();
}

这样就可以使用OpenGL来播放本地yuv文件了。