播放器开发(五)：视频帧处理并用SDL渲染播放

目录

学习课题：逐步构建开发播放器【QT5 + FFmpeg6 + SDL2】

步骤

主要代码

分配缓存

    // 根据格式和视频宽高获取一张图像的字节数据大小
    int byte = av_image_get_buffer_size(AV_PIX_FMT_RGB32, videoWidth, videoHeight, 1);
    // 分配缓存空间
    buffer = (uint8_t *) av_malloc(byte * sizeof(uint8_t));
    // 类似于格式化已经申请的内存
    av_image_fill_arrays(playFrame->data, playFrame->linesize, buffer, AV_PIX_FMT_RGB32, videoWidth, videoHeight, 1);
    // 初始化分配并返回SwsContext
    swsContext = sws_getContext(decCtx->width, decCtx->height, pixelFormat, videoWidth, videoHeight, AV_PIX_FMT_RGB32, SWS_FAST_BILINEAR, nullptr, nullptr, nullptr);

执行缩放

sws_scale(swsContext, (const uint8_t *const *) frame->data, frame->linesize, 0, decCtx->height, playFrame->data, playFrame->linesize);

创建SDL窗口纹理渲染器

// 这里必须要先SDL_CreateWindowFrom，然后在设置父类为this，否则会直接把父类当成参数作为背景
    sdlWindow = SDL_CreateWindowFrom((void *) winId());
    //渲染器
    sdlRenderer = SDL_CreateRenderer(sdlWindow, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
    //纹理 大小是视频大小
    sdlTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_BGRA32, SDL_TEXTUREACCESS_STREAMING, 1920, 1080);
    SDL_SetTextureScaleMode(sdlTexture, SDL_ScaleModeLinear);

SDL渲染

    int ret = 1;
    ret = SDL_RenderClear(sdlRenderer);
    if (ret != 0) {
        qDebug() << "SDL_RenderClear error";
    }
    // 帧数据更新到纹理
    ret = SDL_UpdateTexture(sdlTexture, &m_originalSDLRect, frame->data[0], frame->linesize[0]);
    // 如果这里的帧数据已经是YUV则需要使用下面的
    //    ret = SDL_UpdateYUVTexture(sdlTexture, &sdlRect2, frame->data[0], frame->linesize[0], frame->data[1], frame->linesize[1], frame->data[2], frame->linesize[2]);
    if (ret != 0) {
        qDebug() << "SDL_UpdateYUVTexture error:" << SDL_GetError();
    }
    // 将纹理绘制到渲染器上
    ret = SDL_RenderCopy(sdlRenderer, sdlTexture, &m_originalSDLRect, nullptr);
    if (ret != 0) {
        qDebug() << "SDL_RenderCopy error";
    }
    //     刷新渲染器，将内容显示到窗口上
    SDL_RenderPresent(sdlRenderer);

QPainter渲染

// 注意这里需要使用RGB格式
QImage image((uchar *) frame->data[0], 1920, 1080, QImage::Format_RGB32);
QPainter painter(this);
painter.drawImage(this->rect(), image);

完整模块

VideoOutPut

// VideoOutPut.h
#include "FFmpegHeader.h"
#include "SDL.h"
#include "queue/AVFrameQueue.h"
#include <QDebug>
#include <QObject>
#include <QtGui>
#include <QtWidgets>
#include <thread>

class VideoOutPut : public QObject {
    Q_OBJECT
private:
    std::thread *m_thread;
    bool isStopped = true; // 是否已经停止 停止时退出线程
    bool isPlaying = false;// 是否正在播放
    bool isPause = false;  // 是否暂停

    uint8_t *buffer;//存储解码后图片buffer

    //图像缩放、颜色空间转换上下文
    SwsContext *swsContext;
    AVFrame *playFrame;      //转换后的帧对象
    AVFrameQueue *frameQueue;//解码后的帧队列

    // 解码器上下文
    AVCodecContext *decCtx;// 音频解码器上下文
public:
    VideoOutPut(AVCodecContext *dec_ctx, AVFrameQueue *frame_queue);
    int init();
    int start();
    void run();

    int videoWidth; //视频宽度
    int videoHeight;//视频高度
Q_SIGNALS:
    void refreshImage(const SDL_Rect &sdlRect, AVFrame *frame);
};


// VideoOutPut.cpp
#include "VideoOutPut.h"
VideoOutPut::VideoOutPut(AVCodecContext *dec_ctx, AVFrameQueue *frame_queue)
    : decCtx(dec_ctx), frameQueue(frame_queue) {
}
int VideoOutPut::init() {

    //获取分辨率大小
    videoWidth = decCtx->width;
    videoHeight = decCtx->height;
    playFrame = av_frame_alloc();

    AVPixelFormat pixelFormat = decCtx->pix_fmt;
    qDebug() << av_get_pix_fmt_name(pixelFormat);

    int byte = av_image_get_buffer_size(AV_PIX_FMT_RGB32, videoWidth, videoHeight, 1);
    buffer = (uint8_t *) av_malloc(byte * sizeof(uint8_t));
    av_image_fill_arrays(playFrame->data, playFrame->linesize, buffer, AV_PIX_FMT_RGB32, videoWidth, videoHeight, 1);
    swsContext = sws_getContext(decCtx->width, decCtx->height, pixelFormat, videoWidth, videoHeight, AV_PIX_FMT_RGB32, SWS_FAST_BILINEAR, nullptr, nullptr, nullptr);

    return 1;
}
int VideoOutPut::start() {
    m_thread = new std::thread(&VideoOutPut::run, this);
    if (!m_thread->joinable()) {
        qDebug() << "VideoOutPut视频帧处理线程创建失败";
        return -1;
    }
    isStopped = false;
    isPlaying = true;
    return 0;
}

void VideoOutPut::run() {
    AVFrame *frame;
    while (!isStopped) {
        frame = frameQueue->pop(10);
        if (frame) {
            //图像缩放、颜色空间转换
            sws_scale(swsContext, (const uint8_t *const *) frame->data, frame->linesize, 0, decCtx->height, playFrame->data, playFrame->linesize);
            av_frame_unref(frame);

            //视频区域
            SDL_Rect sdlRect;
            sdlRect.x = 0;
            sdlRect.y = 0;
            sdlRect.w = decCtx->width;
            sdlRect.h = decCtx->height;
            //渲染到sdl窗口
            emit refreshImage(sdlRect, playFrame);
            av_usleep(39999);
        }
    }
}

VideoWidget

//VideoWidget.h
#include "FFmpegHeader.h"
#include "SDL.h"
#include <QApplication>
#include <QDebug>
#include <QMetaType>
#include <QWidget>
#include <QtGui>

class VideoWidget : public QWidget {
    Q_OBJECT
private:
    SDL_Rect m_originalSDLRect;
    AVFrame *frame = nullptr;
    SDL_Window *sdlWindow = nullptr;
    SDL_Renderer *sdlRenderer = nullptr;
    SDL_Texture *sdlTexture = nullptr;

protected:
    void paintEvent(QPaintEvent *event) override;

public:
    VideoWidget(QWidget *parent = 0);
    ~VideoWidget();
    void initSDL();
public slots:
    void updateImage(const SDL_Rect &sdl_rect, AVFrame *frame);
};



//VideoWidget.cpp
#include "VideoWidget.h"
VideoWidget::VideoWidget(QWidget *parent)
    : QWidget(parent) {
    // 注册SDL类
    qRegisterMetaType<SDL_Rect>("SDL_Rect");
}
VideoWidget::~VideoWidget() {
    if (frame)
        av_frame_free(&frame);
    if (sdlTexture)
        SDL_DestroyTexture(sdlTexture);
    if (sdlRenderer)
        SDL_DestroyRenderer(sdlRenderer);
    if (sdlWindow)
        SDL_DestroyWindow(sdlWindow);
    SDL_Quit();
}
void VideoWidget::initSDL() {
    // SDL init
    if (SDL_Init(SDL_INIT_VIDEO) != 0) {
        qDebug() << "SDL_INIT_VIDEO error";
        return;
    }

    // 这里必须要先SDL_CreateWindowFrom，然后在设置父类为this，否则会直接把父类当成参数作为背景
    sdlWindow = SDL_CreateWindowFrom((void *) winId());
    //渲染器
    sdlRenderer = SDL_CreateRenderer(sdlWindow, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
    //纹理 大小是视频大小
    sdlTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_BGRA32, SDL_TEXTUREACCESS_STREAMING, 1920, 1080);
    SDL_SetTextureScaleMode(sdlTexture, SDL_ScaleModeLinear);
}
void VideoWidget::updateImage(const SDL_Rect &sdl_rect, AVFrame *frame) {
    this->m_originalSDLRect = sdl_rect;
    this->frame = frame;
    this->update();
}
void VideoWidget::paintEvent(QPaintEvent *event) {
    if (!frame) {
        return;
    }
#if 0//QPainter渲染
        QImage image((uchar *) frame->data[0], 1920, 1080, QImage::Format_RGB32);
        QPainter painter(this);
        painter.drawImage(this->rect(), image);
#endif

#if 1//SDL渲染
    int ret = 1;
    ret = SDL_RenderClear(sdlRenderer);
    if (ret != 0) {
        qDebug() << "SDL_RenderClear error";
    }
    // 创建SDL纹理并从表面创建
    ret = SDL_UpdateTexture(sdlTexture, &m_originalSDLRect, frame->data[0], frame->linesize[0]);
    //    ret = SDL_UpdateYUVTexture(sdlTexture, &sdlRect2, frame->data[0], frame->linesize[0], frame->data[1], frame->linesize[1], frame->data[2], frame->linesize[2]);
    if (ret != 0) {
        qDebug() << "SDL_UpdateYUVTexture error:" << SDL_GetError();
    }
    // 将纹理绘制到渲染器上
    ret = SDL_RenderCopy(sdlRenderer, sdlTexture, &m_originalSDLRect, nullptr);
    if (ret != 0) {
        qDebug() << "SDL_RenderCopy error";
    }
    //     刷新渲染器，将内容显示到窗口上
    SDL_RenderPresent(sdlRenderer);
#endif
}

PlayerMain

//PlayerMain.h
#include <QWidget>
#include <QtCore>
//-----------
#include "queue/AVFrameQueue.h"
#include "queue/AVPacketQueue.h"
#include "thread/DecodeThread.h"
#include "thread/DemuxThread.h"
#include "widget/VideoWidget.h"
#include "output/VideoOutPut.h"


QT_BEGIN_NAMESPACE
namespace Ui {
    class PlayerMain;
}
QT_END_NAMESPACE

class PlayerMain : public QWidget {
    Q_OBJECT

public:
    explicit PlayerMain(QWidget *parent = nullptr);
    ~PlayerMain() override;

private:
    Ui::PlayerMain *ui;

    // 解复用
    DemuxThread *demuxThread;
    DecodeThread *audioDecodeThread;
    DecodeThread *videoDecodeThread;

    // 解码-音频
    AVPacketQueue audioPacketQueue;
    AVFrameQueue audioFrameQueue;
    // 解码-视频
    AVPacketQueue videoPacketQueue;
    AVFrameQueue videoFrameQueue;
    VideoOutPut *videoOutPut;
};



//PlayerMain.cpp
#include "PlayerMain.h"
#include "ui_PlayerMain.h"


PlayerMain::PlayerMain(QWidget *parent)
    : QWidget(parent), ui(new Ui::PlayerMain) {
    ui->setupUi(this);


    // 解复用
    demuxThread = new DemuxThread(&audioPacketQueue, &videoPacketQueue);
    demuxThread->setUrl("/Users/mac/Downloads/0911超前派对：于文文孟佳爆笑猜词 王源欧阳靖脑洞大开.mp4");
    //    demuxThread->setUrl("/Users/mac/Downloads/23.mp4");
    demuxThread->start();
    int ret;
    // 解码-音频
    audioDecodeThread = new DecodeThread(
            demuxThread->getCodec(MediaType::Audio),
            demuxThread->getCodecParameters(MediaType::Audio),
            &audioPacketQueue,
            &audioFrameQueue);
    audioDecodeThread->init();
    audioDecodeThread->start();
    // 解码-视频
    videoDecodeThread = new DecodeThread(
            demuxThread->getCodec(MediaType::Video),
            demuxThread->getCodecParameters(MediaType::Video),
            &videoPacketQueue,
            &videoFrameQueue);
    videoDecodeThread->init();
    videoDecodeThread->start();

    // video output
    this->resize(1920/2,1080/2);
    videoOutPut = new VideoOutPut(videoDecodeThread->dec_ctx, &videoFrameQueue);
    videoOutPut->init();
    VideoWidget *videoWidget = new VideoWidget(this);
    connect(videoOutPut, &VideoOutPut::refreshImage, videoWidget, &VideoWidget::updateImage);
    videoWidget->show();
    videoWidget->initSDL();
    videoOutPut->start();
//    videoWidget->setParent(this);
}

PlayerMain::~PlayerMain() {
    delete ui;
}

测试运行结果

播放器开发(五)：视频帧处理并用SDL渲染播放 结果