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Custom image plugin testing difficulties

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  • C Offline
    C Offline
    ChrisM87
    wrote on last edited by
    #5

    Well as I showed above, with the QT_DEBUG_PLUGINS variable set, the program is picking it up. However, it still refuses to load it. Is the IID or keys array invalid? I figured if it was choking on the plugin code itself, it would either error, segfault, or spit out a corrupt PNG.

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    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #6

      Without seeing your code, it's pretty much Crystal Ball Debugging (™) I can't say

      Interested in AI ? www.idiap.ch
      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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      • C Offline
        C Offline
        ChrisM87
        wrote on last edited by ChrisM87
        #7

        Well, I had posted my code in the original post. However, my handler class was tweaked a bit after spotting some errors, so here's the updated class code:

        EDIT: I did a few tests on QImageReader that should fail with unsupported format error, but I keep getting "unknown error." I attempted to load my ".pro" qmake file to see which error it would get but still unknown error. However, I compiled qtraw from Github, dropped it into an imageformats subdirectory and it ran fine.

        #include <QDataStream>
        #include <QImage>
        #include <QIODevice>
        #include <QtGlobal>
        #include <QtMath>
        #include <QVariant>
        #include <QVector>
        #include <QImageIOHandler>
        
        class TimHandler final: public QImageIOHandler
        {
        public:
        	bool canRead() const;
        	bool read(QImage *img);
        	QVariant option(ImageOption op) const override;
        	bool supportsOption(ImageOption op) const override;
        };
        
        #define BIT16 0.121568627451
        
        bool TimHandler::canRead() const
        {
        	return device()->peek(4) == "\x10\x0\x0\x0";
        }
        
        static inline quint32 rgba5551ToArgb32(quint16 c)
        {
        	quint32 r = ((c & 0xf800) >> 11) / BIT16;
        	quint32 g = ((c & 0x7c0) >> 6) / BIT16;
        	quint32 b = ((c & 0x3e) >> 1) / BIT16;
        	quint32 a = c & 1 ? 0 : 0xff;
        	
        	return ((a << 24) | (r << 16) | (g << 8) | b);
        }
        
        bool TimHandler::read(QImage *img)
        {
        	QDataStream ds(device());
        	ds.setByteOrder(QDataStream::LittleEndian);
        	quint32 magic, flags;
        	
        	ds >> magic >> flags;
        	if (ds.status() != QDataStream::Ok || magic != 0x10)
        		return false;
        	bool hasClut = flags & 0x8 ? true : false;
        	quint8 pxlMode = flags & 0x7;
        	
        	quint8 bpp;
        	switch (pxlMode)
        	{
        		case 0: bpp = 4; break;
        		case 1: bpp = 8; break;
        		case 2: bpp = 16; break;
        		case 3: bpp = 24; break;
        		default: bpp = 4;
        	}
        	
        	QVector<QRgb> clut;
        	if (hasClut)
        	{
        		quint32 colors, npals;
        		ds.skipRawData(12);
        		ds >> colors >> npals;
        		
        		for (quint16 i = 0; i < (colors*npals); i++)
        		{
        			quint16 c;
        			ds >> c;
        			clut.append(rgba5551ToArgb32(c));
        		}
        	}
        	
        	ds.skipRawData(8);
        	quint16 w, h;
        	ds >> w >> h;
        	w = (w*16)/bpp;
        	
        	if (img) delete img;
        	img = new QImage(w, h, QImage::Format_ARGB32);
        	if (hasClut) img->setColorTable(clut);
        	
        	for (quint16 y = 0; y < h; y++)
        	{
        		for (quint16 x = 0; x < w; x++)
        		{
        			switch (bpp)
        			{
        				case 4:
        				{
        					quint8 p;
        					ds >> p;
        					img->setPixel(x++, y, p & 0xf0);
        					img->setPixel(x, y, p & 0xf);
        				}
        					break;
        				case 8:
        				{
        					quint8 p;
        					ds >> p;
        					img->setPixel(x, y, p);
        				}
        					break;
        				case 16:
        				{
        					quint16 p;
        					ds >> p;
        					img->setPixel(x, y, rgba5551ToArgb32(p));
        				}
        					break;
        			}
        		}
        	}
        	
        	return true;
        }
        
        bool TimHandler::supportsOption(ImageOption op) const
        {
        	switch (op)
        	{
        		case Size:
        			return true;
        		default:
        			return false;
        	}
        }
        
        QVariant TimHandler::option(ImageOption op) const
        {
        	switch (op)
        	{
        		case Size:
        		{
        			quint32 size;
        			quint16 w, h;
        			QDataStream ds(device());
        			ds.skipRawData(8);
        			ds >> size;
        			size -= 4; // 12 - image size - palette x - palette y
        			ds.skipRawData(size);
        			ds >> w >> h;
        			return QSize(w, h);
        		}
        		default:
        			return QVariant();
        	}
        }
        
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        • SGaistS Offline
          SGaistS Offline
          SGaist
          Lifetime Qt Champion
          wrote on last edited by
          #8

          Sorry about the code part, I had a problem when I read it first and only saw the end of it.
          What about a more simple json ?

          {
              "Keys": [ "tim" ],
              "MimeTypes": [ "image/x-tim" ]
          }
          
          

          Interested in AI ? www.idiap.ch
          Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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          • C Offline
            C Offline
            ChrisM87
            wrote on last edited by ChrisM87
            #9

            Well, while I could try that, I don't know if that's the mime type for TIM files. A Google search doesn't help either. My examination of qtraw shows that it too lacks a mime type entry. Thus, I thought it was unnecessary.

            EDIT: tried it anyway, still nothing

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            • SGaistS Offline
              SGaistS Offline
              SGaist
              Lifetime Qt Champion
              wrote on last edited by
              #10

              Just thought of something… Your plugin code is correct but:

              img.load("0025.tim", "tim");

              "0025.tim" is a relative path, is that image in the same folder as your executable ? You should rather give the full path to it.

              Interested in AI ? www.idiap.ch
              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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              • C Offline
                C Offline
                ChrisM87
                wrote on last edited by ChrisM87
                #11

                Same directory, yep. Though of course in a real world scenario this would be different.

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                • SGaistS Offline
                  SGaistS Offline
                  SGaist
                  Lifetime Qt Champion
                  wrote on last edited by
                  #12

                  I forgot a correction I made:

                  Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QImageIOHandlerFactoryInterface" FILE "tim.json")

                  Interested in AI ? www.idiap.ch
                  Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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                  • C Offline
                    C Offline
                    ChrisM87
                    wrote on last edited by
                    #13

                    Yeah, I changed it to that in my progress trying to fix it, but no go. I booted up QtCreator and created a new project from Qt plugin template but I see nothing unusual in comparison with my code, aside from the constructor with QObject* parameter, which I skipped in my code because I saw no point for an empty constructor/destructor.

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                    • C Offline
                      C Offline
                      ChrisM87
                      wrote on last edited by
                      #14

                      So after a little tinkering, I got qmake to generate main.moc which I thought was needed, but I'm still having issues with the plugin not being discovered. Additionally, the RGBA5551 conversion function was incorrect, which I fixed, but that shouldn't be the make-or-break factor.

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                      • SGaistS Offline
                        SGaistS Offline
                        SGaist
                        Lifetime Qt Champion
                        wrote on last edited by
                        #15

                        Not being discovered or not loaded ? Did you put your plugin in a imageformats subfolder ?

                        Interested in AI ? www.idiap.ch
                        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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                        • C Offline
                          C Offline
                          ChrisM87
                          wrote on last edited by ChrisM87
                          #16

                          Yep. Even set target.path in my .pro file thinking that was the issue. Qt seems very nitpicky.

                          EDIT: Just debugged again, found this gem of an error:

                          QLibraryPrivate::loadPlugin failed on "/home/admin/Documents/Qt-extra/imageformats/qtim/timtest/imageformats/libqtim.so" : "Cannot load library /home/admin/Documents/Qt-extra/imageformats/qtim/timtest/imageformats/libqtim.so: (/home/admin/Documents/Qt-extra/imageformats/qtim/timtest/imageformats/libqtim.so: undefined symbol: _ZN11QTimHandler9setOptionEN15QImageIOHandler11ImageOptionERK8QVariant)"
                          
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                          • SGaistS Offline
                            SGaistS Offline
                            SGaist
                            Lifetime Qt Champion
                            wrote on last edited by
                            #17

                            Which version of Qt are you using ?
                            What happens if you try to load it by hand using QLibrary ?

                            Interested in AI ? www.idiap.ch
                            Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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