FFmpeg播放视频类，可复用

音频播放类可以点这里：音频播放类
原理介绍：视频播放类都是基于音频播放类改变过来的，加上了音频视频同步，基本做出了效果

.h头文件

#ifndef FFMPEGPLAYER_H#define FFMPEGPLAYER_H#define MAX_AUDIO_FRAME_SIZE  192000#define SDL_AUDIO_BUFFER_SIZE  1024#define MAX_AUDIO_SIZE ( 10*16 * 1024)#define MAX_VIDEO_SIZE ( 10*256 * 1024)#define FLUSH_DATA "FLUSH"extern "C"{    #include <libavcodec\avcodec.h>    #include <libavformat\avformat.h>    #include <libswscale\swscale.h>    #include <libswresample\swresample.h>    #include <include/SDL2/SDL.h>    #include <include/SDL2/SDL_thread.h>}extern int VOL;#include<QThread>#include<QTimer>#include<QImage>enum PlayerStatus{playingStatus,pausingStatus,stopStatus,bufferingStatus};typedef struct PacketQueue {    AVPacketList *first_pkt, *last_pkt;    int nb_packets;    int size;    SDL_mutex *mutex;    SDL_cond *cond;} PacketQueue;typedef struct{    AVFormatContext* afct; //    AVPacket pkt; //    ////////////////////////////common part    SwrContext* swr_ctx ;//    AVFrame *wanted_frame;//    uint8_t* audio_pkt_data;    int audio_pkt_size; //    AVFrame *frame; //    AVCodecContext *acct;//    AVStream *audio_st;    int audiostream;    double audio_clock;    unsigned int audio_buf_size; //    unsigned int audio_buf_index; //    bool isBuffering;    bool seek_req;    qint64 seek_pos;    PacketQueue audioq; //    ///////////////////// audio and video    AVCodecContext *vcct;    int videostream;    double video_clock;    PacketQueue videoq;    AVStream *video_st;    SDL_Thread *video_tid;  //视频线程id}mediaState;class FFmpegPlayer : public QThread{    Q_OBJECTpublic:    explicit FFmpegPlayer(QObject *parent = 0);    void setMedia(const QString,bool isMV=false);    void stop();    void pause(){SDL_PauseAudio(1);}    void play(){ SDL_PauseAudio(0);}    inline void updateStatus(){ if(!m_MS.acct)return;emit sig_CurrentMediaStatus(getPlayerStatus());}    /*zero  means pause ,one means playing*/    PlayerStatus getPlayerStatus() const;    /*duration with now playing the media */    inline qint64 getDuration(){ if(!m_MS.acct)return 0;return m_MS.afct->duration;}    /*get current media time value*/    inline qint64 getCurrentTime(){return m_MS.audio_clock*1000000;}    QTimer *m_timer;    void FreeAllocSpace();protected:    virtual void run();signals:    void sig_BufferingPrecent(double);    void sig_CurImageChange(QImage);    void sig_CurrentMediaChange(const QString&,bool isMv);    void sig_CurrentMediaDurationChange(qint64);    void sig_PositionChange(qint64);    void sig_CurrentMediaFinished();    void sig_CurrentMediaStatus(PlayerStatus);    void sig_CurrentMediaError();public slots:    void slot_timerWork();    void setVol(int vol){VOL=vol;}    void seek(qint64 );private:    QString m_url;    mediaState m_MS;};

.cpp

#include "FFmpegPlayer.h"#include<QDebug>#include<windows.h>#include<QTime>#include<QImage>static FFmpegPlayer *ffplayerPointer=NULL; //保存对象地址#define USE_MUTE 1static bool isquit=false; //清空了int VOL=80;// 包队列初始化void packet_queue_init(PacketQueue* q){    q->last_pkt = NULL;    q->first_pkt = NULL;#if USE_MUTE    q->mutex = SDL_CreateMutex();    q->cond = SDL_CreateCond();#endif}// 放入packet到队列中，不带头指针的队列int packet_queue_put(PacketQueue*q, AVPacket *pkt){    AVPacketList *pktl;    if (av_dup_packet(pkt) < 0)        return -1;    pktl = (AVPacketList*)av_malloc(sizeof(AVPacketList));    if (!pktl)        return -1;    pktl->pkt = *pkt;    pktl->next = nullptr;#if USE_MUTE    SDL_LockMutex(q->mutex);#endif    if (!q->last_pkt) // 队列为空，新插入元素为第一个元素        q->first_pkt = pktl;    else // 插入队尾        q->last_pkt->next = pktl;    q->last_pkt = pktl;    q->nb_packets++;    q->size += pkt->size;#if USE_MUTE    SDL_CondSignal(q->cond);    SDL_UnlockMutex(q->mutex);#endif    return 0;}// 从队列中取出packetint packet_queue_get(PacketQueue *q, AVPacket *pkt, int block) {    AVPacketList *pkt1=NULL;    int ret;#if USE_MUTE    SDL_LockMutex(q->mutex);#endif    for (;;)    {        if (isquit)         return -1;        pkt1 = q->first_pkt;        if (pkt1) {            q->first_pkt = pkt1->next;            if (!q->first_pkt) {                q->last_pkt = NULL;            }            q->nb_packets--;            q->size -= pkt1->pkt.size;            *pkt = pkt1->pkt;            av_free(pkt1);            ret = 1;            break;        } else if (!block) {            ret = 0;            break;        } else {#if USE_MUTE            SDL_CondWait(q->cond, q->mutex);#endif        }    }#if USE_MUTE    SDL_UnlockMutex(q->mutex);#endif    return ret;}void packet_queue_flush(PacketQueue *q){#if USE_MUTE    SDL_LockMutex(q->mutex);#endif    AVPacketList *pkt=NULL, *pkt1=NULL;    for(pkt = q->first_pkt; pkt != NULL; pkt = pkt1)    {        pkt1 = pkt->next;        if(pkt1->pkt.data != (uint8_t *)"FLUSH")        {        }        av_free_packet(&pkt->pkt);        av_freep(&pkt);    }    q->last_pkt = NULL;    q->first_pkt = NULL;    q->nb_packets = 0;    q->size = 0;#if USE_MUTE    SDL_UnlockMutex(q->mutex);#endif}//////////////////////////////////////////////解码音频数据int audio_decode_frame(mediaState* MS, uint8_t* audio_buf, int buf_size){    int len1;    int data_size = 0;    if (isquit)        return -1;    while (true)    {        while (MS->audio_pkt_size > 0)        {            int got_frame = 0;            len1 = avcodec_decode_audio4(MS->acct, MS->frame, &got_frame, &MS->pkt);            if (len1 < 0) // 出错，跳过            {                MS->audio_pkt_size = 0;                break;            }            MS->audio_pkt_data += len1;            MS->audio_pkt_size -= len1;            data_size = 0;            if (got_frame)                data_size = av_samples_get_buffer_size(nullptr, MS->acct->channels,MS-> frame->nb_samples, MS->acct->sample_fmt, 1);            if (MS->frame->channels > 0 && MS->frame->channel_layout == 0)                MS->frame->channel_layout = av_get_default_channel_layout(MS->frame->channels);            else if (MS->frame->channels == 0 && MS->frame->channel_layout > 0)                MS->frame->channels = av_get_channel_layout_nb_channels(MS->frame->channel_layout);            if (MS->swr_ctx)            {                swr_free(&MS->swr_ctx);                MS->swr_ctx = nullptr;            }            MS->swr_ctx = swr_alloc_set_opts(nullptr, MS->wanted_frame->channel_layout,                                         (AVSampleFormat)MS->wanted_frame->format,                                         MS->wanted_frame->sample_rate,                                         MS->frame->channel_layout,                                         (AVSampleFormat)MS->frame->format,                                         MS->frame->sample_rate, 0, nullptr);            if (!MS->swr_ctx || swr_init(MS->swr_ctx) < 0)            {                qDebug() << "swr_init failed:" << endl;                break;            }            int dst_nb_samples = av_rescale_rnd(swr_get_delay(MS->swr_ctx, MS->frame->sample_rate) + MS->frame->nb_samples, MS->frame->sample_rate, MS->frame->sample_rate, AVRounding(1));            int len2 = swr_convert(MS->swr_ctx, &audio_buf, dst_nb_samples,(const uint8_t**)MS->frame->data, MS->frame->nb_samples);//这个才是最重要的~前面所做的工作都是为这个            if (len2 < 0)            {                qDebug() << "swr_convert failed\n";                break;            }//[][]相当重要的一步，转换成时间            int resampled_data_size = len2 * MS->wanted_frame->channels* av_get_bytes_per_sample((AVSampleFormat)MS->wanted_frame->format);            int n = 2 * MS->audio_st->codec->channels;            MS->audio_clock += (double)resampled_data_size/(double)(n * MS->audio_st->codec->sample_rate);//[][]            return MS->wanted_frame->channels * len2 * av_get_bytes_per_sample((AVSampleFormat)MS->wanted_frame->format);        } //end while        if (MS->pkt.buf)            av_free_packet(&MS->pkt); //删除包        if (packet_queue_get(&MS->audioq,&MS->pkt,0)<=0) //重新从队列中获取包        {            return -1;        }        //收到这个数据 说明刚刚执行过跳转 现在需要把解码器的数据 清除一下        if(strcmp((char*)MS->pkt.data,FLUSH_DATA) == 0)        {            avcodec_flush_buffers(MS->audio_st->codec);            av_free_packet(&MS->pkt);            continue;        }        if (MS->pkt.pts != AV_NOPTS_VALUE)        {            MS->audio_clock = (double)av_q2d(MS->audio_st->time_base) * (double)MS->pkt.pts;        }        MS->audio_pkt_data =MS->pkt.data;        MS->audio_pkt_size = MS->pkt.size;    }}// 解码后的回调函数void audio_callback(void* userdata, Uint8* stream, int len){    mediaState* MS = (mediaState*)userdata;    int len1, audio_size;    SDL_memset(stream, 0, len);    if (isquit)        return;    while (len > 0)    {        uint8_t audio_buff[MAX_AUDIO_FRAME_SIZE*2];        if (MS->audio_buf_index >= MS->audio_buf_size)        {            audio_size = audio_decode_frame(MS, audio_buff, sizeof(audio_buff));            if (isquit)                return;            if (audio_size < 0)            {                MS->audio_buf_size = 1024;                SDL_memset(audio_buff, 0, MS->audio_buf_size);            }            else                MS->audio_buf_size = audio_size;            MS->audio_buf_index = 0;        }        len1 = MS->audio_buf_size - MS->audio_buf_index;        if (len1 > len)            len1 = len;        SDL_MixAudio(stream, audio_buff + MS->audio_buf_index, len, VOL);        len -= len1;        stream += len1;        MS->audio_buf_index += len1;    }}static double synchronize_video(mediaState *MS, AVFrame *src_frame, double pts)//用于音视频同步 {    double frame_delay;    if (pts != 0)    {        /* if we have pts, set video clock to it */        MS->video_clock = pts;    } else    {        /* if we aren't given a pts, set it to the clock */        pts = MS->video_clock;    }    /* update the video clock */    frame_delay = av_q2d(MS->video_st->codec->time_base);    /* if we are repeating a frame, adjust clock accordingly */    frame_delay += src_frame->repeat_pict * (frame_delay * 0.5);    MS->video_clock += frame_delay;    return pts;}int video_thread(void *arg){    mediaState *is = (mediaState *) arg;    AVPacket pkt1, *packet = &pkt1;    int ret, got_picture, numBytes;    double video_pts = 0; //当前视频的pts    double audio_pts = 0; //音频pts    ///解码视频相关    AVFrame *pFrame, *pFrameRGB;    uint8_t *out_buffer_rgb; //解码后的rgb数据    struct SwsContext *img_convert_ctx;  //用于解码后的视频格式转换    AVCodecContext *pCodecCtx = is->video_st->codec; //视频解码器    pFrame = av_frame_alloc();    pFrameRGB = av_frame_alloc();    ///这里我们改成了 将解码后的YUV数据转换成RGB32    img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height,            pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height,            AV_PIX_FMT_RGB32, SWS_BICUBIC, NULL, NULL, NULL);    numBytes = avpicture_get_size(AV_PIX_FMT_RGB32, pCodecCtx->width,pCodecCtx->height);    out_buffer_rgb = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t));    avpicture_fill((AVPicture *) pFrameRGB, out_buffer_rgb, AV_PIX_FMT_RGB32,            pCodecCtx->width, pCodecCtx->height);    while(1)    {        if (isquit)        {            break;        }        if (SDL_AUDIO_PAUSED == SDL_GetAudioStatus()) //判断暂停        {            SDL_Delay(1);            continue;        }        if (packet_queue_get(&is->videoq, packet, 0) <= 0) //非block        {            SDL_Delay(1); //队列只是暂时没有数据而已            continue;        }        //收到这个数据 说明刚刚执行过跳转 现在需要把解码器的数据 清除一下        if(strcmp((char*)packet->data,FLUSH_DATA) == 0)        {            avcodec_flush_buffers(is->video_st->codec);            av_free_packet(packet);            continue;        }        ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture,packet);        if (ret < 0) {            qDebug()<<"decode error.\n";            av_free_packet(packet);            continue;        }//音视频同步        if (packet->dts == AV_NOPTS_VALUE && pFrame->opaque&& *(uint64_t*) pFrame->opaque != AV_NOPTS_VALUE)        {            video_pts = *(uint64_t *) pFrame->opaque;        }        else if (packet->dts != AV_NOPTS_VALUE)        {            video_pts = packet->dts;        }        else        {            video_pts = 0;        }        video_pts *= av_q2d(is->video_st->time_base);        video_pts = synchronize_video(is, pFrame, video_pts);       /* if (is->seek_flag_video)        {            //发生了跳转 则跳过关键帧到目的时间的这几帧           if (video_pts < is->seek_time)           {               av_free_packet(packet);               continue;           }           else           {               is->seek_flag_video = 0;           }        }*/        while(1)        {            if (isquit)            {                break;            }            audio_pts = is->audio_clock;            //主要是 跳转的时候 我们把video_clock设置成0了            //因此这里需要更新video_pts            //否则当从后面跳转到前面的时候 会卡在这里            video_pts = is->video_clock;            if (video_pts <= audio_pts)                break;            int delayTime = (video_pts - audio_pts) * 1000;            delayTime = delayTime > 5 ? 5:delayTime;            SDL_Delay(delayTime);        }//同步结束        if (got_picture)        {            sws_scale(img_convert_ctx,                    (uint8_t const * const *) pFrame->data,                    pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data,                    pFrameRGB->linesize);            //把这个RGB数据 用QImage加载            QImage tmpImg((uchar *)out_buffer_rgb,pCodecCtx->width,pCodecCtx->height,QImage::Format_RGB32);            QImage image = tmpImg.copy(); //把图像复制一份 传递给界面显示            emit ffplayerPointer->sig_CurImageChange(image); //调用激发信号的函数        }        av_free_packet(packet);    }    av_free(pFrame);    av_free(pFrameRGB);    av_free(out_buffer_rgb);    emit ffplayerPointer->sig_CurImageChange(QImage()); //刷新下MV背景}int interrupt_cb(void *ctx)//网络不畅就会一直做这里 ，正在播放也会call这里但频率不如网络不畅高{   mediaState *MS=(mediaState*)ctx;   return 0;}FFmpegPlayer::FFmpegPlayer(QObject *parent) : QThread(parent){    ffplayerPointer=this;    m_timer=new QTimer;    connect(m_timer,SIGNAL(timeout()),this,SLOT(slot_timerWork()));    m_timer->start(30);    av_register_all();    avformat_network_init();    #ifndef Q_OS_WIN32    CoInitializeEx(NULL, COINIT_MULTITHREADED);//防止有些windows64找不到audio设备    #endif    packet_queue_init(&m_MS.audioq);    packet_queue_init(&m_MS.videoq);    m_MS={0};//自动将能初始化为0的都初始化为0}void FFmpegPlayer::setMedia(const QString url, bool isMV){    stop();    emit sig_CurrentMediaChange(url,isMV);    m_url=url;    start();    setPriority(QThread::HighestPriority);}void FFmpegPlayer::stop(){    isquit=1;    m_url="";    Sleep(200);//等待退出线程}PlayerStatus FFmpegPlayer::getPlayerStatus() const{    if(m_MS.isBuffering)        return PlayerStatus::bufferingStatus;    if(SDL_AUDIO_PLAYING ==SDL_GetAudioStatus())            return PlayerStatus::playingStatus;    return PlayerStatus::pausingStatus;}void FFmpegPlayer::FreeAllocSpace() //存在内在{    SDL_CloseAudio();//Close SDL    SDL_Quit();    if(m_MS.wanted_frame) //avframe freee    {        av_frame_free(&m_MS.wanted_frame);    }    if(m_MS.frame) //avframe freee    {       av_frame_free(&m_MS.frame);    }    if(m_MS.afct) //format context    {        avformat_close_input(&m_MS.afct);        avformat_free_context(m_MS.afct);    }    if(m_MS.acct)//audio context    {        avcodec_close(m_MS.acct);        avcodec_free_context(&m_MS.acct);    }    if(m_MS.vcct)//video context    {        avcodec_close(m_MS.vcct);        avcodec_free_context(&m_MS.vcct);    }    if(m_MS.swr_ctx) //重采样 freee    {        swr_free(&m_MS.swr_ctx);    }    if(m_MS.audio_pkt_data)//buff free    {        av_freep(m_MS.audio_pkt_data);    }    packet_queue_flush(&m_MS.audioq);//队列freee    packet_queue_flush(&m_MS.videoq);//队列freee    m_MS={0};//自动将能初始化为0的都初始化为NULL}void FFmpegPlayer::slot_timerWork(){    if(m_MS.frame&&!m_MS.isBuffering)    emit sig_PositionChange(getCurrentTime());    updateStatus();}void FFmpegPlayer::seek(qint64 pos){    if(!m_MS.seek_req)    {        m_MS.seek_pos=pos;        m_MS.seek_req=true;    }}void FFmpegPlayer::run(){    isquit=0;    SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER);    // 读取文件头，将格式相关信息存放在AVFormatContext结构体中    if (avformat_open_input(&m_MS.afct, m_url.toUtf8().data(), nullptr, nullptr) != 0)    {        FreeAllocSpace();        return; // 打开失败    }    m_MS.afct->interrupt_callback.callback = interrupt_cb;//--------注册回调函数    m_MS.afct->interrupt_callback.opaque = &m_MS;    // 检测文件的流信息    if (avformat_find_stream_info(m_MS.afct, nullptr) < 0)    {        FreeAllocSpace();        return; // 没有检测到流信息 stream infomation    }    //查找第一个视频流 video stream    m_MS.audiostream = -1;    m_MS.videostream = -1;    for (unsigned int i = 0; i < m_MS.afct->nb_streams; i++)    {        if (m_MS.afct->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)        {            m_MS.videostream = i;        }        if (m_MS.afct->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO  && m_MS.audiostream < 0)        {            m_MS.audiostream = i;        }    }    // 3. 根据读取到的流信息查找相应的解码器并打开    if (m_MS.audiostream == -1&&m_MS.videostream==-1)    {        FreeAllocSpace();        return; // 没有检测到流信息 stream infomation    }//[0][1] for audio    if(m_MS.audiostream!=-1)    {        m_MS.acct = m_MS.afct->streams[m_MS.audiostream]->codec; // codec context        AVCodec* acodec = avcodec_find_decoder(m_MS.acct->codec_id);        if (!acodec)        {            qDebug() << "Unsupported codec!" << endl;            FreeAllocSpace();            return;        }        m_MS.audio_st=m_MS.afct->streams[m_MS.audiostream];        avcodec_open2(m_MS.acct, acodec, nullptr); //open    }//[2][3]for video    if(m_MS.videostream!=-1)    {        m_MS.vcct = m_MS.afct->streams[m_MS.videostream]->codec; // codec context        AVCodec* vcodec = avcodec_find_decoder(m_MS.vcct->codec_id);        if (!vcodec)        {            qDebug() << "Unsupported codec!" << endl;            FreeAllocSpace();            return;        }        m_MS.video_st=m_MS.afct->streams[m_MS.videostream];        avcodec_open2(m_MS.vcct, vcodec, nullptr); //open    }//[][]    // Set audio settings from codec info    SDL_AudioSpec wanted_spec, spec;    wanted_spec.freq = m_MS.acct->sample_rate;    wanted_spec.format = AUDIO_S16SYS;    wanted_spec.channels = m_MS.acct->channels;    wanted_spec.silence = 0;    wanted_spec.samples = SDL_AUDIO_BUFFER_SIZE;    wanted_spec.callback = audio_callback;    wanted_spec.userdata = &m_MS;    if (SDL_OpenAudio(&wanted_spec, &spec) < 0)    {        qDebug() << "Open audio failed:" << SDL_GetError() << endl;        FreeAllocSpace();        return ;    }    m_MS.wanted_frame=av_frame_alloc();    m_MS.frame=av_frame_alloc();    m_MS.wanted_frame->format = AV_SAMPLE_FMT_S16;    m_MS.wanted_frame->sample_rate = spec.freq;    m_MS.wanted_frame->channel_layout = av_get_default_channel_layout(spec.channels);    m_MS.wanted_frame->channels = spec.channels;    if(m_MS.videostream!=-1)        m_MS.video_tid = SDL_CreateThread(video_thread, "video_thread", &m_MS);    SDL_PauseAudio(0);    int get=0;    AVPacket packet;    while (true) //这里有一个顺序！先判断退出线程信号~再 读 再写入    {        SDL_Delay(1);        if (isquit)        {            wanted_spec.callback=NULL;            wanted_spec.userdata=NULL;            break;        }        if(get<0&&!m_MS.audioq.first_pkt)//end of the file 队列不为空！而且完成@！        {            wanted_spec.callback=NULL;            wanted_spec.userdata=NULL;            break;        }        //seek part        if (m_MS.seek_req)        {            int stream_index = -1;            if (m_MS.videostream >= 0)                stream_index = m_MS.videostream;            else if (m_MS.audiostream >= 0)                stream_index = m_MS.audiostream;            AVRational aVRational = {1, AV_TIME_BASE};            if (stream_index >= 0)            {                m_MS.seek_pos = av_rescale_q(m_MS.seek_pos, aVRational,                                m_MS.afct->streams[stream_index]->time_base);            }            if (av_seek_frame(m_MS.afct, stream_index, m_MS.seek_pos, AVSEEK_FLAG_BACKWARD) < 0)            {                  fprintf(stderr, "%s: error while seeking\n",m_MS.afct->filename);            }            else            {                AVPacket packet; //分配一个packet                av_new_packet(&packet, 10);                strcpy((char*)packet.data,FLUSH_DATA);                if (m_MS.audiostream >= 0) //audio                {                    packet_queue_flush(&m_MS.audioq); //清除队列                    packet_queue_put(&m_MS.audioq, &packet); //往队列中存入用来清除的包                }                if (m_MS.videostream >= 0)                {                    packet_queue_flush(&m_MS.videoq); //清除队列                    packet_queue_put(&m_MS.videoq, &packet); //往队列中存入用来清除的包                    m_MS.video_clock = 0;                }            }            m_MS.seek_req = 0;        }        if (m_MS.audioq.size > MAX_AUDIO_SIZE || m_MS.videoq.size > MAX_VIDEO_SIZE)//防止一下子把音频全部读完了~            continue;        get= av_read_frame(m_MS.afct, &packet); //read frame        if(get==0)//=0就是正确的~再添加进队列        {            if(packet.stream_index == m_MS.videostream)                  packet_queue_put(&m_MS.videoq,&packet);            else if (packet.stream_index == m_MS.audiostream)                     packet_queue_put(&m_MS.audioq, &packet);            else                av_free_packet(&packet);            m_MS.isBuffering=false; //显示界面显示有无缓冲        }    }    if(!isquit) //It finished automatically when played to end of the media    emit sig_CurrentMediaFinished();    isquit=1;    FreeAllocSpace();}

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