videoplaywidget.cpp

#include "videoplaywidget.h"

#define GET_STR(x) #x
// 顶点shader
const char* vertexStr = GET_STR(
                            attribute vec4 vertexIn;
                            attribute vec2 textureIn;
                            varying vec2 textureOut;
                            void main(void)
{
    gl_Position = vertexIn;
    textureOut = textureIn;
}
                        );

// 片元shader
const char* fragmentStr = GET_STR(
                              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(1.0, 1.0, 1.0,
               0.0, -0.39465, 2.03211,
               1.13983, -0.58060, 0.0) * yuv;
    gl_FragColor = vec4(rgb, 1.0);
}
                          );

VideoPlayWidget::VideoPlayWidget(QWidget* parent)
    : QOpenGLWidget(parent)
{
}

VideoPlayWidget::~VideoPlayWidget() {}

void VideoPlayWidget::Init(int width, int height)
{
    lock.lock();
    this->width = width;
    this->height = height;
    delete pixels[0];
    delete pixels[1];
    delete pixels[2];
    // 分配材质内存空间
    pixels[0] = new unsigned char[width * height];
    pixels[1] = new unsigned char[width * height / 4];
    pixels[2] = new unsigned char[width * height / 4];
    if (textures[0])
    {
        glDeleteTextures(3, textures);
    }
    // 创建材质
    glGenTextures(3, textures);
    // Y
    glBindTexture(GL_TEXTURE_2D, textures[0]);
    // 放大过滤，线性插值
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    // 创建材质显卡空间
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
    // U
    glBindTexture(GL_TEXTURE_2D, textures[1]);
    // 放大过滤，线性插值
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    // 创建材质显卡空间
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width / 2, height / 2, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
    // V
    glBindTexture(GL_TEXTURE_2D, textures[2]);
    // 放大过滤，线性插值
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    // 创建材质显卡空间
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, width / 2, height / 2, 0, GL_RED, GL_UNSIGNED_BYTE, nullptr);
    lock.unlock();
}

void VideoPlayWidget::Repaint(AVFrame* frame)
{
    if (!frame)
    {
        return;
    }
    lock.lock();
    if (!pixels[0] || this->width * this->height == 0 || frame->width != this->width || frame->height != this->height)
    {
        av_frame_free(&frame);
        lock.unlock();
        return;
    }
    if (width == frame->linesize[0])
    {
        memcpy(pixels[0], frame->data[0], width * height);
        memcpy(pixels[1], frame->data[1], width * height / 4);
        memcpy(pixels[2], frame->data[2], width * height / 4);
    }
    else
    {
        // 行对齐问题
        for (int i = 0; i < height; i++)
        {
            memcpy(pixels[0] + width * i, frame->data[0] + frame->linesize[0] * i, width);
        }
        for (int i = 0; i < height / 2; i++)
        {
            memcpy(pixels[1] + width / 2 * i, frame->data[1] + frame->linesize[1] * i, width / 2);
        }
        for (int i = 0; i < height / 2; i++)
        {
            memcpy(pixels[2] + width / 2 * i, frame->data[2] + frame->linesize[2] * i, width / 2);
        }
    }
    lock.unlock();
    av_frame_free(&frame);
    update();
}

void VideoPlayWidget::initializeGL()
{
    qDebug() << QString::fromLocal8Bit("initializeGL执行");
    lock.lock();
    // 初始化OpenGL
    initializeOpenGLFunctions();
    // 加载shader脚本（顶点和片元）
    shaderProgram.addShaderFromSourceCode(QGLShader::Vertex, vertexStr);
    shaderProgram.addShaderFromSourceCode(QGLShader::Fragment, fragmentStr);
    // 设置顶点坐标
    shaderProgram.bindAttributeLocation("vertexIn", 3);
    // 设置材质坐标
    shaderProgram.bindAttributeLocation("textureIn", 4);
    qDebug() << QString::fromLocal8Bit("shaderProgram.link()") << shaderProgram.link();
    qDebug() << QString::fromLocal8Bit("shaderProgram.bind()") << shaderProgram.bind();
    //传递顶点和材质坐标
    // 顶点坐标
    static const GLfloat vertexLocation[] =
    {
        -1.0f, -1.0f,
            1.0f, -1.0f,
            -1.0f, 1.0f,
            1.0f, 1.0f
        };
    // 材质坐标
    static const GLfloat textureLocation[] =
    {
        0.0f, 1.0f,
        1.0f, 1.0f,
        0.0f, 0.0f,
        1.0f, 0.0f
    };
    // 顶点
    glVertexAttribPointer(3, 2, GL_FLOAT, 0, 0, vertexLocation);
    glEnableVertexAttribArray(3);
    // 材质
    glVertexAttribPointer(4, 2, GL_FLOAT, 0, 0, textureLocation);
    glEnableVertexAttribArray(4);
    // 从shader获取材质
    uniformLocations[0] = shaderProgram.uniformLocation("tex_y");
    uniformLocations[1] = shaderProgram.uniformLocation("tex_u");
    uniformLocations[2] = shaderProgram.uniformLocation("tex_v");
    lock.unlock();
}
void VideoPlayWidget::resizeGL(int w, int h)
{
    lock.lock();
    qDebug() << QString::fromLocal8Bit("重绘") << w << "x" << h;
    lock.unlock();
}
void VideoPlayWidget::paintGL()
{
    lock.lock();
    glActiveTexture(GL_TEXTURE0);
    // 0层绑定到Y材质
    glBindTexture(GL_TEXTURE_2D, textures[0]);
    // 修改材质内容
    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GL_RED, GL_UNSIGNED_BYTE, pixels[0]);
    // 与shader uniform关联
    glUniform1i(uniformLocations[0], 0);
    glActiveTexture(GL_TEXTURE0 + 1);
    // 1层绑定到U材质
    glBindTexture(GL_TEXTURE_2D, textures[1]);
    // 修改材质内容
    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width / 2, height / 2, GL_RED, GL_UNSIGNED_BYTE, pixels[1]);
    // 与shader uniform关联
    glUniform1i(uniformLocations[1], 1);
    glActiveTexture(GL_TEXTURE0 + 2);
    // 2层绑定到V材质
    glBindTexture(GL_TEXTURE_2D, textures[2]);
    // 修改材质内容
    glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width / 2, height / 2, GL_RED, GL_UNSIGNED_BYTE, pixels[2]);
    // 与shader uniform关联
    glUniform1i(uniformLocations[2], 2);
    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
    lock.unlock();
}