/******************************************************************************
    QtAV:  Multimedia framework based on Qt and FFmpeg
    Copyright (C) 2012-2016 Wang Bin <wbsecg1@gmail.com>

*   This file is part of QtAV (from 2016)

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
******************************************************************************/
#ifndef QTAV_FRAMEREADER_H
#define QTAV_FRAMEREADER_H

#include <QtCore/QObject>
#include "VideoFrame.h"

namespace FAV {
/*!
 * \brief The FrameReader class
 * while (reader->readMore()) {
 *      while (reader->hasVideoFrame()) { //or hasEnoughVideoFrames()
 *          reader->getVideoFrame();
 *          ...
 *      }
 * }
 * or (faster)
 * while (reader->readMore()) {
 *     reader->getVideoFrame(); //we can ensure 1 frame is available, but may block here
 * }
 * while (r.hasVideoFrame()) { //get buffered frames
 *     reader->getVideoFrame();
 * }
 * TODO: multiple tracks
 */
class Q_AV_EXPORT FrameReader : public QObject
{
    Q_OBJECT
public:
    // TODO: load and get info
    // TODO: asnyc option
    explicit FrameReader(QObject *parent = 0);
    ~FrameReader();
    void setMedia(const QString& url);
    QString mediaUrl() const;
    void setVideoDecoders(const QStringList& names);
    QStringList videoDecoders() const;
    VideoFrame getVideoFrame();
    bool hasVideoFrame() const;
    bool hasEnoughVideoFrames() const;
    // return false if eof
    bool readMore();
    // TODO: tryLoad on seek even at eof
    // TODO: compress seek requests
    bool seek(qint64 pos);

Q_SIGNALS:
    void frameRead(const FAV::VideoFrame& frame);
    void readEnd();
    void seekFinished(qint64 pos);

    // internal
    void readMoreRequested();
    void seekRequested(qint64);

private Q_SLOTS:
    void readMoreInternal();
    bool seekInternal(qint64 value);

private:
    class Private;
    QScopedPointer<Private> d;
};
} //namespace FAV
#endif // QTAV_FRAMEREADER_H