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• Qt Open Source Product 2 - Vlc Demo [closed]

  3 juin 2021, par cool code

  Ⅰ. Preface

  


  The previous work was made by the FFmpeg kernel, and FFmpeg is too powerful for many beginners to understand. There are also a lot of users only need a simple video stream can be played, do not need to be involved in the responsible decoding and transcoding, so VLC came in handy, it directly made FFMPEG deep encapsulation, to provide a friendly interface. There's an MPV that does the same thing, and MPV is even better than VLC in that it's just one library file, and it looks like it's packaged as a static library, unlike VLC, VLC comes with a bunch of dynamic library files and plug-in files.
Of course, the simplicity of VLC is that it only needs a few lines of code to start, so that beginners immediately see the effect is very important, very excited, you can more quickly carry out the next step of coding, experience the fun of coding.

  


  Ⅱ. Code framework

  


  #include "ffmpeg.h"

FFmpegThread::FFmpegThread(QObject *parent) : QThread(parent)
{
    setObjectName("FFmpegThread");
    stopped = false;
    isPlay = false;

    frameFinish = false;
    videoWidth = 0;
    videoHeight = 0;
    oldWidth = 0;
    oldHeight = 0;
    videoStreamIndex = -1;
    audioStreamIndex = -1;

    url = "rtsp://192.168.1.128:554/1";

    buffer = NULL;
    avPacket = NULL;
    avFrame = NULL;
    avFrame2 = NULL;
    avFrame3 = NULL;
    avFormatContext = NULL;
    videoCodec = NULL;
    audioCodec = NULL;
    swsContext = NULL;

    options = NULL;
    videoDecoder = NULL;
    audioDecoder = NULL;

    //Initial registration, only register once in a software
    FFmpegThread::initlib();
}

//Only need to initialize once in a software
void FFmpegThread::initlib()
{
    static QMutex mutex;
    QMutexLocker locker(&mutex);
    static bool isInit = false;
    if (!isInit) {
        //Register all available file formats and decoders in the library
        av_register_all();
        //Register all devices, mainly for local camera playback support
#ifdef ffmpegdevice
        avdevice_register_all();
#endif
        //Initialize the network stream format, which must be executed first when using the network stream
        avformat_network_init();

        isInit = true;
        qDebug() << TIMEMS << "init ffmpeg lib ok" << " version:" << FFMPEG_VERSION;
#if 0
        //Output all supported decoder names
        QStringList listCodeName;
        AVCodec *code = av_codec_next(NULL);
        while (code != NULL) {
            listCodeName << code->name;
            code = code->next;
        }

        qDebug() << TIMEMS << listCodeName;
#endif
    }
}

bool FFmpegThread::init()
{
    //Before opening the code stream, specify various parameters such as: detection time/timeout time/maximum delay, etc.
    //Set the cache size, 1080p can increase the value
    av_dict_set(&options, "buffer_size", "8192000", 0);
    //Open in tcp mode, if open in udp mode, replace tcp with udp
    av_dict_set(&options, "rtsp_transport", "tcp", 0);
    //Set the timeout disconnection time, the unit is microseconds, 3000000 means 3 seconds
    av_dict_set(&options, "stimeout", "3000000", 0);
    //Set the maximum delay, in microseconds, 1000000 means 1 second
    av_dict_set(&options, "max_delay", "1000000", 0);
    //Automatically start the number of threads
    av_dict_set(&options, "threads", "auto", 0);

    //Open video stream
    avFormatContext = avformat_alloc_context();

    int result = avformat_open_input(&avFormatContext, url.toStdString().data(), NULL, &options);
    if (result < 0) {
        qDebug() << TIMEMS << "open input error" << url;
        return false;
    }

    //Release setting parameters
    if (options != NULL) {
        av_dict_free(&options);
    }

    //Get flow information
    result = avformat_find_stream_info(avFormatContext, NULL);
    if (result < 0) {
        qDebug() << TIMEMS << "find stream info error";
        return false;
    }

    //----------At the beginning of the video stream part, make a mark to facilitate the folding of the code----------
    if (1) {
        videoStreamIndex = av_find_best_stream(avFormatContext, AVMEDIA_TYPE_VIDEO, -1, -1, &videoDecoder, 0);
        if (videoStreamIndex < 0) {
            qDebug() << TIMEMS << "find video stream index error";
            return false;
        }

        //Get video stream
        AVStream *videoStream = avFormatContext->streams[videoStreamIndex];

        //Get the video stream decoder, or specify the decoder
        videoCodec = videoStream->codec;
        videoDecoder = avcodec_find_decoder(videoCodec->codec_id);
        //videoDecoder = avcodec_find_decoder_by_name("h264_qsv");
        if (videoDecoder == NULL) {
            qDebug() << TIMEMS << "video decoder not found";
            return false;
        }

        //Set up accelerated decoding
        videoCodec->lowres = videoDecoder->max_lowres;
        videoCodec->flags2 |= AV_CODEC_FLAG2_FAST;

        //Open the video decoder
        result = avcodec_open2(videoCodec, videoDecoder, NULL);
        if (result < 0) {
            qDebug() << TIMEMS << "open video codec error";
            return false;
        }

        //Get the resolution size
        videoWidth = videoStream->codec->width;
        videoHeight = videoStream->codec->height;

        //If the width and height are not obtained, return
        if (videoWidth == 0 || videoHeight == 0) {
            qDebug() << TIMEMS << "find width height error";
            return false;
        }

        QString videoInfo = QString("Video stream info -> index: %1  decode: %2  format: %3  duration: %4 s  Resolution: %5*%6")
                            .arg(videoStreamIndex).arg(videoDecoder->name).arg(avFormatContext->iformat->name)
                            .arg((avFormatContext->duration) / 1000000).arg(videoWidth).arg(videoHeight);
        qDebug() << TIMEMS << videoInfo;
    }
    //----------The video stream part starts----------

    //----------Start the audio stream part, mark it to facilitate the code folding----------
    if (1) {
        //Loop to find audio stream index
        audioStreamIndex = -1;
        for (uint i = 0; i < avFormatContext->nb_streams; i++) {
            if (avFormatContext->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
                audioStreamIndex = i;
                break;
            }
        }

        //Some have no audio stream, so there is no need to return here
        if (audioStreamIndex == -1) {
            qDebug() << TIMEMS << "find audio stream index error";
        } else {
            //Get audio stream
            AVStream *audioStream = avFormatContext->streams[audioStreamIndex];
            audioCodec = audioStream->codec;

            //Get the audio stream decoder, or specify the decoder
            audioDecoder = avcodec_find_decoder(audioCodec->codec_id);
            //audioDecoder = avcodec_find_decoder_by_name("aac");
            if (audioDecoder == NULL) {
                qDebug() << TIMEMS << "audio codec not found";
                return false;
            }

            //Open the audio decoder
            result = avcodec_open2(audioCodec, audioDecoder, NULL);
            if (result < 0) {
                qDebug() << TIMEMS << "open audio codec error";
                return false;
            }

            QString audioInfo = QString("Audio stream information -> index: %1  decode: %2  Bit rate: %3  channel num: %4  sampling: %5")
                                .arg(audioStreamIndex).arg(audioDecoder->name).arg(avFormatContext->bit_rate)
                                .arg(audioCodec->channels).arg(audioCodec->sample_rate);
            qDebug() << TIMEMS << audioInfo;
        }
    }
    //----------End of audio stream----------

    //Pre-allocated memory
    avPacket = av_packet_alloc();
    avFrame = av_frame_alloc();
    avFrame2 = av_frame_alloc();
    avFrame3 = av_frame_alloc();

    //Compare the width and height of the last file. When changing, you need to reallocate the memory
    if (oldWidth != videoWidth || oldHeight != videoHeight) {
        int byte = avpicture_get_size(AV_PIX_FMT_RGB32, videoWidth, videoHeight);
        buffer = (uint8_t *)av_malloc(byte * sizeof(uint8_t));
        oldWidth = videoWidth;
        oldHeight = videoHeight;
    }

    //Define pixel format
    AVPixelFormat srcFormat = AV_PIX_FMT_YUV420P;
    AVPixelFormat dstFormat = AV_PIX_FMT_RGB32;
    //Get the decoded format through the decoder
    srcFormat = videoCodec->pix_fmt;

    //The SWS_FAST_BILINEAR parameter used by the default fastest decoding may lose part of the picture data, and you can change it to other parameters by yourself
    int flags = SWS_FAST_BILINEAR;

    //Open up a cache to store one frame of data
    //The following two methods are ok, avpicture_fill has been gradually abandoned
    //avpicture_fill((AVPicture *)avFrame3, buffer, dstFormat, videoWidth, videoHeight);
    av_image_fill_arrays(avFrame3->data, avFrame3->linesize, buffer, dstFormat, videoWidth, videoHeight, 1);

    //Image conversion
    swsContext = sws_getContext(videoWidth, videoHeight, srcFormat, videoWidth, videoHeight, dstFormat, flags, NULL, NULL, NULL);

    //Output video information
    //av_dump_format(avFormatContext, 0, url.toStdString().data(), 0);

    //qDebug() << TIMEMS << "init ffmpeg finsh";
    return true;
}

void FFmpegThread::run()
{
    while (!stopped) {
        //Perform initialization based on the flag bit
        if (isPlay) {
            this->init();
            isPlay = false;
            continue;
        }

        if (av_read_frame(avFormatContext, avPacket) >= 0) {
            //Determine whether the current package is video or audio
            int index = avPacket->stream_index;
            if (index == videoStreamIndex) {
                //Decode video stream avcodec_decode_video2 method has been deprecated
#if 0
                avcodec_decode_video2(videoCodec, avFrame2, &frameFinish, avPacket);
#else
                frameFinish = avcodec_send_packet(videoCodec, avPacket);
                if (frameFinish < 0) {
                    continue;
                }

                frameFinish = avcodec_receive_frame(videoCodec, avFrame2);
                if (frameFinish < 0) {
                    continue;
                }
#endif

                if (frameFinish >= 0) {
                    //Turn the data into a picture
                    sws_scale(swsContext, (const uint8_t *const *)avFrame2->data, avFrame2->linesize, 0, videoHeight, avFrame3->data, avFrame3->linesize);

                    //The following two methods can be used
                    //QImage image(avFrame3->data[0], videoWidth, videoHeight, QImage::Format_RGB32);
                    QImage image((uchar *)buffer, videoWidth, videoHeight, QImage::Format_RGB32);
                    if (!image.isNull()) {
                        emit receiveImage(image);
                    }

                    msleep(1);
                }
            } else if (index == audioStreamIndex) {
                //Decode the audio stream, it will not be processed here, and will be handed over to sdl to play
            }
        }

        av_packet_unref(avPacket);
        av_freep(avPacket);
        msleep(1);
    }

    //Release resources after the thread ends
    free();
    stopped = false;
    isPlay = false;
    qDebug() << TIMEMS << "stop ffmpeg thread";
}

void FFmpegThread::setUrl(const QString &url)
{
    this->url = url;
}

void FFmpegThread::free()
{
    if (swsContext != NULL) {
        sws_freeContext(swsContext);
        swsContext = NULL;
    }

    if (avPacket != NULL) {
        av_packet_unref(avPacket);
        avPacket = NULL;
    }

    if (avFrame != NULL) {
        av_frame_free(&avFrame);
        avFrame = NULL;
    }

    if (avFrame2 != NULL) {
        av_frame_free(&avFrame2);
        avFrame2 = NULL;
    }

    if (avFrame3 != NULL) {
        av_frame_free(&avFrame3);
        avFrame3 = NULL;
    }

    if (videoCodec != NULL) {
        avcodec_close(videoCodec);
        videoCodec = NULL;
    }

    if (audioCodec != NULL) {
        avcodec_close(audioCodec);
        audioCodec = NULL;
    }

    if (avFormatContext != NULL) {
        avformat_close_input(&avFormatContext);
        avFormatContext = NULL;
    }

    av_dict_free(&options);
    //qDebug() << TIMEMS << "close ffmpeg ok";
}

void FFmpegThread::play()
{
    //Let the thread perform initialization through the flag bit
    isPlay = true;
}

void FFmpegThread::pause()
{

}

void FFmpegThread::next()
{

}

void FFmpegThread::stop()
{
    //Stop the thread through the flag
    stopped = true;
}

//Real-time video display form class
FFmpegWidget::FFmpegWidget(QWidget *parent) : QWidget(parent)
{
    thread = new FFmpegThread(this);
    connect(thread, SIGNAL(receiveImage(QImage)), this, SLOT(updateImage(QImage)));
    image = QImage();
}

FFmpegWidget::~FFmpegWidget()
{
    close();
}

void FFmpegWidget::paintEvent(QPaintEvent *)
{
    if (image.isNull()) {
        return;
    }

    //qDebug() << TIMEMS << "paintEvent" << objectName();
    QPainter painter(this);
    painter.drawImage(this->rect(), image);
}

void FFmpegWidget::updateImage(const QImage &image)
{
    //this->image = image.copy();
    this->image = image;
    this->update();
}

void FFmpegWidget::setUrl(const QString &url)
{
    thread->setUrl(url);
}

void FFmpegWidget::open()
{
    //qDebug() << TIMEMS << "open video" << objectName();
    clear();

    thread->play();
    thread->start();
}

void FFmpegWidget::pause()
{
    thread->pause();
}

void FFmpegWidget::next()
{
    thread->next();
}

void FFmpegWidget::close()
{
    //qDebug() << TIMEMS << "close video" << objectName();
    if (thread->isRunning()) {
        thread->stop();
        thread->quit();
        thread->wait(500);
    }

    QTimer::singleShot(1, this, SLOT(clear()));
}

void FFmpegWidget::clear()
{
    image = QImage();
    update();
}



  


  Ⅲ. Renderings

  


  https://youtu.be/CLsGw2CJW-c

  


  Ⅳ. Open source code download URL

  


  1.download URL for dropbox :

  


  https://www.dropbox.com/sh/n58ucs57pscp25e/AABWBQlg4U3Oz2WF9YOJDrj1a?dl=0

  


  2.download URL for box :

  


  https://app.box.com/s/x48a7ttpk667afqqdk7t1fqok4fmvmyv

  


• Can I use FFMPEG to record ultra sonic ?

  23 février 2018, par OtakuFitness

  I use av_dump_format() to check information and I get

  Stream #0:0: Audio: pcm_s16le, 48000Hz, 2 channels, s16, 1536kb/s

  Now I can record music, it’s working well(I generated a pcm file to listen). However, in terms of ultra sonic, I can’t record any useful audio information, so can I use FFmpeg to record ultra sonic ?

• Révision 22968 : Gros bug de nom de cache dans la fonction recuperer_url_cache() qui en gros ignor...

  24 mars 2016, par cedric@yterium.com