main.cpp

/******************************************************************************
    VideoGroup:  this file is part of QtAV examples
    Copyright (C) 2014-2015 Wang Bin <wbsecg1@gmail.com>

*   This file is part of QtAV

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
******************************************************************************/

#include <QtAV/VideoFrameExtractor.h>
#include <QApplication>
#include <QWidget>
#include <QtAVWidgets>
#include <QtDebug>
#include <QtCore/QElapsedTimer>
#include <QtCore/QTimer>

using namespace QtAV;
class VideoFrameObserver : public QObject
{
    Q_OBJECT
public:
    VideoFrameObserver(QObject *parent = 0) : QObject(parent)
      , pos(0)
      , nb(1)
      , extracted(0)
    {
        view = VideoRenderer::create(VideoRendererId_GLWidget2);
        view->widget()->resize(400, 300);
        view->widget()->show();
        connect(&extractor, SIGNAL(frameExtracted(QtAV::VideoFrame)), this, SLOT(onVideoFrameExtracted(QtAV::VideoFrame)));
    }
    void setParameters(qint64 msec, int count) {
        pos = msec;
        nb = count;
    }
    void start(const QString& file) {
        extractor.setAsync(false);
        extractor.setSource(file);
        startTimer(20);
        timer.start();
        extractor.setPosition(pos);
    }
    void startAsync(const QString& file) {
        extractor.setAsync(true);
        extractor.setSource(file);
        startTimer(20);
        timer.start();
        extractor.setPosition(pos);
    }

public Q_SLOTS:
    void onVideoFrameExtracted(const QtAV::VideoFrame& frame) {
        view->receive(frame);
        qApp->processEvents();
        frame.toImage().save(QString::fromLatin1("%1.png").arg(frame.timestamp()));
        qDebug("frame %dx%d @%f", frame.width(), frame.height(), frame.timestamp());
        if (++extracted >= nb) {
            qDebug("elapsed: %lld.", timer.elapsed());
            return;
        }
        extractor.setPosition(pos + extracted*1000);
    }
protected:
    void timerEvent(QTimerEvent *) {
        qApp->processEvents(); // avoid ui blocking if async is not used
    }

private:
    VideoRenderer *view;
    qint64 pos;
    int nb;
    int extracted;
    VideoFrameExtractor extractor;
    QElapsedTimer timer;
};

int main(int argc, char** argv)
{
    QApplication a(argc, argv);
    int idx = a.arguments().indexOf(QLatin1String("-f"));
    if (idx < 0) {
        qDebug("-f file -t sec -n count -asyc");
        return -1;
    }
    QString file = a.arguments().at(idx+1);
    idx = a.arguments().indexOf(QLatin1String("-t"));
    int t = 0;
    if (idx > 0)
        t = a.arguments().at(idx+1).toInt();
    int n = 1;
    idx = a.arguments().indexOf(QLatin1String("-n"));
    if (idx > 0)
        n = a.arguments().at(idx+1).toInt();
    bool async = a.arguments().contains(QString::fromLatin1("-async"));


    VideoFrameObserver obs;
    obs.setParameters(t*1000, n);
    if (async)
        obs.startAsync(file);
    else
        obs.start(file);
    return a.exec();
}

#include "main.moc"