#include <qapplication.h>
#include <qwidget.h>

#include <X11/Xlib.h>
#include <X11/extensions/Xv.h>
#include <X11/extensions/Xvlib.h>

#define FOURCC_YUY2 0x32595559

static int xv_port_has_yuy2( XvPortID port )
{
    XvImageFormatValues *formatValues;
    int formats;
    int i;

    formatValues = XvListImageFormats( qt_xdisplay(), port, &formats );
    for( i = 0; i < formats; i++ ) {
        if((formatValues[ i ].id == FOURCC_YUY2) && (!(strcmp( formatValues[ i ].guid, "YUY2" )))) {
            XFree (formatValues);
            return 1;
        }
    }
    XFree( formatValues );
    return 0;
}

static int xv_check_extension( XvPortID &xv_port, Window win )
{
    unsigned int version;
    unsigned int release;
    unsigned int dummy;
    unsigned int adaptors;
    unsigned int i;
    unsigned long j;
    int has_yuy2 = 0;
    XvAdaptorInfo *adaptorInfo;

    if( ( XvQueryExtension( qt_xdisplay(), &version, &release,
                            &dummy, &dummy, &dummy) != Success ) ||
         ( version < 2 ) || ( ( version == 2 ) && ( release < 2 ) ) ) {

        fprintf( stderr, "xvoutput: XVIDEO extension not found: X too old? didn't load extmod?\n" );
        return 0;
    }

    XvQueryAdaptors( qt_xdisplay(), win, &adaptors, &adaptorInfo );

    for( i = 0; i < adaptors; i++ ) {
        if( adaptorInfo[ i ].type & XvImageMask ) {
            for( j = 0; j < adaptorInfo[ i ].num_ports; j++ ) {
                if( xv_port_has_yuy2( adaptorInfo[ i ].base_id + j ) ) {
                    if( XvGrabPort( qt_xdisplay(), adaptorInfo[ i ].base_id + j, 0 ) == Success ) {
                        xv_port = adaptorInfo[ i ].base_id + j;
                        fprintf( stderr, "xvoutput: Using XVIDEO adaptor %lu: %s.\n",
                                 adaptorInfo[ i ].base_id + j, adaptorInfo[ i ].name );
                        XvFreeAdaptorInfo( adaptorInfo );
                        return 1;
                    }
                    has_yuy2 = 1;
                }
            }
        }
    }

    XvFreeAdaptorInfo( adaptorInfo );

    if( has_yuy2 )
        fprintf( stderr, "xvoutput: No YUY2 XVIDEO port available.\n" );
    else
        fprintf( stderr, "xvoutput: No XVIDEO port found which supports YUY2 images.\n" );
    return 0;
}



#define W 768
#define H 576

#define Kr 0.2126
#define Kb 0.0722

#define L(r,g,b) (Kr * r + Kb * b + (1 - Kr - Kb) * g)
#define YUY2(r,g,b) \
	(((int)(219*L(r,g,b)/255 + 16.5)) | \
	 (((int)(112*(b - L(r,g,b))/((1-Kb)*255) + 128.5)) << 8) | \
	 (((int)(219*L(r,g,b)/255 + 16.5)) << 16) | \
	 (((int)(112*(r - L(r,g,b))/((1-Kr)*255) + 128.5)) << 24))

static unsigned long pix[] = {
	YUY2( 255, 0, 0 ),
	YUY2( 0, 155, 0 ),
	YUY2( 0, 0, 255 ),
};

class MyWidget : public QWidget {
  public:

	MyWidget() : QWidget( 0, 0, WRepaintNoErase ), sz( qApp->desktop()->screen( 0 )->size() )
	{
		if (!xv_check_extension( xv_port, winId() ))
			exit( 1 );
        xv_image = XvCreateImage( qt_xdisplay(), xv_port, FOURCC_YUY2,
                               (char *)buf, W, H );
		l = x1 = y1 = 0;
		x2 = W - 1;
		y2 = H - 1;
		showFullScreen();
	}

  protected:

	void closeEvent( QCloseEvent * )
	{
		qApp->quit();
	}

	void paintEvent( QPaintEvent * )
	{
		for (int i = 0; i < W * H / 2; i++)
			buf[i] = pix[l];
		XvPutImage( qt_xdisplay(), xv_port, winId(),
		            DefaultGC( qt_xdisplay(), 0 ), xv_image,
                    x1, y1, x2 - x1 + 1, y2 - y1 + 1,
		            0, 0, width(), height() );
	}

	void keyPressEvent( QKeyEvent *e )
	{
		int dx, dy, tlf, brf, nx1, ny1, nx2, ny2;
		switch (e->key()) {
		case Key_Escape:
		case Key_Q:
			qApp->quit();
			break;
		case Key_Up:
			dy = -1, dx = 0;
			goto com;
		case Key_Down:
			dy = 1, dx = 0;
			goto com;
		case Key_Left:
			dx = -1, dy = 0;
			goto com;
		case Key_Right:
			dx = 1, dy = 0;
		  com:
			if (e->state() & ControlButton)
				tlf = 1, brf = 0;
			else if (e->state() & AltButton)
				tlf = 0, brf = 1;
			else
				tlf = brf = 1;
			nx1 = x1 + tlf * dx;
			ny1 = y1 + tlf * dy;
			nx2 = x2 + brf * dx;
			ny2 = y2 + brf * dy;
			if (nx1 >= 0 && nx2 >= nx1 && nx2 < W &&
				ny1 >= 0 && ny2 >= ny1 && ny2 < H)
			{
				x1 = nx1, y1 = ny1, x2 = nx2, y2 = ny2;
				printf( "%dx%d @ %d,%d\n", x2 - x1 + 1, y2 - y1 + 1, x1, y1 );
		case Key_Space:
				if (++l >= (int)(sizeof(pix)/sizeof(pix[0])))
					l = 0;
		case Key_Return:
				update();
			}
		}
		e->ignore();
	}

  private:
	QSize sz;
	int l, x1, y1, x2, y2;
	unsigned long buf[W * H / 2];
	XvImage *xv_image;
	XvPortID xv_port;
};

int main(int argc, char **argv)
{
    QApplication app( argc, argv );
	MyWidget win;

	app.exec();
    return 0;
}