Frame sequence

[bmn]

Hi all
I am trying to load a sequence of images having .png extension similar to playing a video. I have described a text file which contains the absolute path of the images. Now I was able to open the text file and read line by line data using readLine function but when I try to display it in a loop using setPixmap function, only the path of the last line in the text is being displayed.Can anyone help me.

[patrik08]

How do you swap frame next() pixmap you set a timer event? on frame total
can you post this piece of code?

[louis_xx]

Its a long time since ive done things like this, but you may need to tell whatever it is to redraw itself. update() ?

[bmn]

There are two files
window.h

#ifndef UI_WINDOW_H
#define UI_WINDOW_H
 
#include <QtGui>
 
class QPushButton;
class QSplitter;
class QGridLayout;
 
class Custom_window : public QWidget
{
    Q_OBJECT
 
    public:
        Custom_window();
 
    private slots:
        void new_dialog();
    private:
        QPushButton *createButton(const QString &text,QWidget *receiver,
                const char *member);
        void Button_Layout();
 
        QLabel *old_window;
        QPushButton *start;
        QPushButton *stop;
        QVBoxLayout *mainLayout;
        QHBoxLayout *box;
        QGridLayout *buttonsLayout;
        QLabel *address;
        QLineEdit *url;
        QSpacerItem *spacerItem;
        QTextEdit *message;
        QFile *file;
        QPixmap *p;
};
#endif

#ifndef UI_WINDOW_H
#define UI_WINDOW_H

#include <QtGui>

class QPushButton;
class QSplitter;
class QGridLayout;

class Custom_window : public QWidget
{
    Q_OBJECT

    public:
        Custom_window();

    private slots:
        void new_dialog();
    private:
        QPushButton *createButton(const QString &text,QWidget *receiver,
                const char *member);
        void Button_Layout();

        QLabel *old_window;
        QPushButton *start;
        QPushButton *stop;
        QVBoxLayout *mainLayout;
        QHBoxLayout *box;
        QGridLayout *buttonsLayout;
        QLabel *address;
        QLineEdit *url;
        QSpacerItem *spacerItem;
        QTextEdit *message;
        QFile *file;
        QPixmap *p;
};
#endif

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window.cpp

#include<QtGui>
#include<stdio.h>
 
#include "window.h"
 
Custom_window::Custom_window()
{
    old_window = new QLabel;
    old_window->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);
    old_window->setAlignment(Qt::AlignCenter);
    old_window->setText("Press Start");
    address = new QLabel;
    address->setText("Server I.P");
    QFont font;
    font.setPointSize(11);
    address->setFont(font);
    url = new QLineEdit;
    url->setObjectName(QString::fromUtf8("url"));
    message = new QTextEdit;
    message->setSizePolicy(QSizePolicy::Preferred,QSizePolicy::Preferred);
    Button_Layout();
 
    mainLayout = new QVBoxLayout;
    mainLayout->addWidget(old_window);
    mainLayout->addLayout(buttonsLayout);
    mainLayout->addWidget(message);
    setLayout(mainLayout);
    setWindowTitle(tr("Client GUI"));
    resize(640,800);
}
 
QPushButton *Custom_window::createButton(const QString &text,QWidget *receiver,
        const char *member)
{
    QPushButton *button = new QPushButton(text);
    button->connect(button,SIGNAL(clicked()),receiver,member);
    return button;
}
 
void Custom_window::Button_Layout()
{
    start = createButton(tr("Start"), this, SLOT(new_dialog()));
    stop = createButton(tr("Stop"), this, SLOT(close()));
    buttonsLayout = new QGridLayout;
    buttonsLayout->addWidget(address,0,0,1,1);
    buttonsLayout->addWidget(url,0,1,1,1);
    buttonsLayout->addWidget(start,0,2,1,1);
    buttonsLayout->addWidget(stop,0,3,1,1);
 
}
 
void Custom_window::new_dialog()
{
    QFile file("in.txt");
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text ))
        return;
    QTextStream in(&file);
    while (!in.atEnd()) {
          QString line = in.readLine();
          url->setText(line);
          QPixmap p(line);
          p=p.scaled ( old_window->width(),old_window->height(), Qt::IgnoreAspectRatio,               Qt::SmoothTransformation );
        old_window->resize(500,480);
        old_window->setPixmap(p);
        message->append("The path of the file is");
        message->append(line);
    }
}

#include<QtGui>
#include<stdio.h>

#include "window.h"

Custom_window::Custom_window()
{
    old_window = new QLabel;
    old_window->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Expanding);
    old_window->setAlignment(Qt::AlignCenter);
    old_window->setText("Press Start");
    address = new QLabel;
    address->setText("Server I.P");
    QFont font;
    font.setPointSize(11);
    address->setFont(font);
    url = new QLineEdit;
    url->setObjectName(QString::fromUtf8("url"));
    message = new QTextEdit;
    message->setSizePolicy(QSizePolicy::Preferred,QSizePolicy::Preferred);
    Button_Layout();

    mainLayout = new QVBoxLayout;
    mainLayout->addWidget(old_window);
    mainLayout->addLayout(buttonsLayout);
    mainLayout->addWidget(message);
    setLayout(mainLayout);
    setWindowTitle(tr("Client GUI"));
    resize(640,800);
}

QPushButton *Custom_window::createButton(const QString &text,QWidget *receiver,
        const char *member)
{
    QPushButton *button = new QPushButton(text);
    button->connect(button,SIGNAL(clicked()),receiver,member);
    return button;
}

void Custom_window::Button_Layout()
{
    start = createButton(tr("Start"), this, SLOT(new_dialog()));
    stop = createButton(tr("Stop"), this, SLOT(close()));
    buttonsLayout = new QGridLayout;
    buttonsLayout->addWidget(address,0,0,1,1);
    buttonsLayout->addWidget(url,0,1,1,1);
    buttonsLayout->addWidget(start,0,2,1,1);
    buttonsLayout->addWidget(stop,0,3,1,1);

}

void Custom_window::new_dialog()
{
    QFile file("in.txt");
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text ))
        return;
    QTextStream in(&file);
    while (!in.atEnd()) {
          QString line = in.readLine();
          url->setText(line);
          QPixmap p(line);
          p=p.scaled ( old_window->width(),old_window->height(), Qt::IgnoreAspectRatio,               Qt::SmoothTransformation );
        old_window->resize(500,480);
        old_window->setPixmap(p);
        message->append("The path of the file is");
        message->append(line);
    }
}

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[patrik08]

And how you define time to display one pixmap?
If you open 100 file by setpixmap you can see only the last!

You must create a data struct from image

struct frame
{
  QByteArray extension;  /* png jpg ...*/
  QByteArray data;  /* pixmap data  */ 
  int timetolive;   /* time to show */
  QRect display;  /* 100x100 */
  int age;
};

struct frame
{
  QByteArray extension;  /* png jpg ...*/
  QByteArray data;  /* pixmap data  */ 
  int timetolive;   /* time to show */
  QRect display;  /* 100x100 */
  int age;
};

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or better make a struct like MNG image format and you can display on QMovie

or have a look on
http://wiki.qtcentre.org/index.php?t..._types_with_Qt
or other image class to serialize image:
http://www.qtforum.de/forum/viewtopic.php?t=6600

After create a QDataStream wo contain all your single frame the virtual AVI file
and at end play its... from a timer event

if your choise the MNG format all needed info is inside:
QDIR\4.4.0_src\src\3rdparty\libmng

[bmn]

Can u be more specific i.e where can I place the data struct. Plz post the code also

[patrik08]

Here is a good structure to compose image frame:

qt-x11-opensource-4.0.0-b2/tools/qvfb/qanimationwriter.cpp
It is as target only linux but i rewrite it to win32

http://fop-miniscribus.googlecode.co...emo_write_mng/

Compose image sequence

void Gui_Main::setCaptureEnabled(bool enable)
{
      /* start stop QBasicTimer FrameTimeLine; */
	RRunning = enable;
  if (enable && framerate > 32) {
    FrameTimeLine.start(framerate,this);
  }  else {
    FrameTimeLine.stop();
  }
}
QImage Gui_Main::CatScreen()
{
   QDesktopWidget *desk = qApp->desktop();
   QPixmap desktopscreen = QPixmap::grabWindow(desk->screen()->winId());
	 QPixmap small =  desktopscreen.scaledToWidth(100);
	 devimg->paint( small );
	 scrollArea->setWidget(devimg);
	 delete &desktopscreen;
   return small.toImage();
}
 
void Gui_Main::StartRead()
{
	  if (RRunning) {
			StopRead();
			return;
		}
	  QString filename = QFileDialog::getSaveFileName(this, "Save animation", "animation.mng", "*.mng");
	  if (filename.size() > 0) {
    animation = new AnimationWriter(filename,"MNG");
    animation->setFrameRate(framerate);
    animation->appendFrame(CatScreen());
		setCaptureEnabled(true);
		}
}
void  Gui_Main::timerEvent(QTimerEvent *event)
{
    if (event->timerId() == FrameTimeLine.timerId()) {
      timeline++;
      qDebug() << "### timeline  " << timeline;
      animation->appendFrame(CatScreen());
    }
}
void Gui_Main::StopRead()
{
	setCaptureEnabled(false);
	delete animation;
	animation = 0;
}

void Gui_Main::setCaptureEnabled(bool enable)
{
      /* start stop QBasicTimer FrameTimeLine; */
	RRunning = enable;
  if (enable && framerate > 32) {
    FrameTimeLine.start(framerate,this);
  }  else {
    FrameTimeLine.stop();
  }
}
QImage Gui_Main::CatScreen()
{
   QDesktopWidget *desk = qApp->desktop();
   QPixmap desktopscreen = QPixmap::grabWindow(desk->screen()->winId());
	 QPixmap small =  desktopscreen.scaledToWidth(100);
	 devimg->paint( small );
	 scrollArea->setWidget(devimg);
	 delete &desktopscreen;
   return small.toImage();
}

void Gui_Main::StartRead()
{
	  if (RRunning) {
			StopRead();
			return;
		}
	  QString filename = QFileDialog::getSaveFileName(this, "Save animation", "animation.mng", "*.mng");
	  if (filename.size() > 0) {
    animation = new AnimationWriter(filename,"MNG");
    animation->setFrameRate(framerate);
    animation->appendFrame(CatScreen());
		setCaptureEnabled(true);
		}
}
void  Gui_Main::timerEvent(QTimerEvent *event)
{
    if (event->timerId() == FrameTimeLine.timerId()) {
      timeline++;
      qDebug() << "### timeline  " << timeline;
      animation->appendFrame(CatScreen());
    }
}
void Gui_Main::StopRead()
{
	setCaptureEnabled(false);
	delete animation;
	animation = 0;
}

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try it
1# svn co http://fop-miniscribus.googlecode.co...emo_write_mng/ movietest
2#
copy path from QTDIR /src/3rdparty/zlib & libpng to movietest dir

INCLUDEPATH += ui libpng zlib

and build it...

it write file .... but QMovie on read say:
MNG error 4097: Image is larger than defined maximum; chunk MHDR; subcode 0:0
MNG error 1028: Chunk-length is invalid; chunk MOVE; subcode 0:0

MHDR is a chunk format to learn and after you can register your image to a simple movie like gif animated ...

to look original search qanimationwriter.cpp on http://www.google.com/codesearch

[patrik08]

Can u be more specific i.e where can I place the data struct. Plz post the code also

QT 4.4 can write APNG image format!
http://en.wikipedia.org/wiki/Animate...twork_Graphics


I have it ready as console assembler now you can bundle all your image and display on firefox ...
and later write a QLabel to display al single frame png....

apng img1.png img2.png img3.png  [enter]

apng img1.png img2.png img3.png  [enter]

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result here...

Install Firefox 3 or GrandParadiso , Opera 9.5 if the image here is not animated and you see only the first frame....

svn co http://fop-miniscribus.googlecode.co...PNG_assembler/ APNG_assembler