IFF: add support for CD-i YUVS chunk (and minor code improvements)

README.md

@@ -357,11 +357,15 @@ The plugin supports the following image data:
   type 4.
 - FORM PBM: PBM is a chunky version of IFF pictures. It supports 8-bit images 
   with color map only.
-- FORM IMAG (Compact Disc-Interactive): It supports CLut4, CLut8 and DYuv
+- FORM IMAG (Compact Disc-Interactive): It supports CLut4, CLut7, CLut8 and 
-  formats.
+  DYuv formats.
 - FOR4 CIMG (Maya Image File Format): It supports 24/48-bit RGB and 32/64-bit 
   RGBA images.
 
+> [!note]
+> The plugin only supports the IFF, ILBM, and LBM file extensions. You'll 
+> need to rename files with different extensions to open them.
+
 ### The JP2 plugin
 
 **This plugin can be disabled by setting `KIMAGEFORMATS_JP2` to `OFF` 

autotests/read/iff/cdi_dyuv_each.iff.json

@@ -0,0 +1,9 @@
+[
+    {
+        "fileName" : "cdi_dyuv_each.iff",
+        "resolution" : {
+            "dotsPerMeterX" : 3937,
+            "dotsPerMeterY" : 5249
+        }
+    }
+]

src/imageformats/chunks.cpp

@@ -337,6 +337,8 @@ IFFChunk::ChunkList IFFChunk::innerFromDevice(QIODevice *d, bool *ok, IFFChunk *
             chunk = QSharedPointer<IFFChunk>(new XBMIChunk());
         } else if (cid == XMP0_CHUNK) {
             chunk = QSharedPointer<IFFChunk>(new XMP0Chunk());
+        } else if (cid == YUVS_CHUNK) {
+            chunk = QSharedPointer<IFFChunk>(new YUVSChunk());
         } else { // unknown chunk
             chunk = QSharedPointer<IFFChunk>(new IFFChunk());
             qCDebug(LOG_IFFPLUGIN) << "IFFChunk::innerFromDevice(): unknown chunk" << cid;
@@ -922,11 +924,11 @@ CAMGChunk::ModeIds BODYChunk::safeModeId(const BMHDChunk *header, const CAMGChun
     auto cmapCount = cmap ? cmap->count() : 0;
     auto bitplanes = header->bitplanes();
     if (bitplanes >= BITPLANES_HALFBRIDE_MIN && bitplanes <= BITPLANES_HALFBRIDE_MAX) {
-        if (cmapCount == (1 << (header->bitplanes() - 1)))
+        if (cmapCount == (1 << (bitplanes - 1)))
             return CAMGChunk::ModeIds(CAMGChunk::ModeId::HalfBrite);
     }
     if (bitplanes >= BITPLANES_HAM_MIN && bitplanes <= BITPLANES_HAM_MAX) {
-        if (cmapCount == (1 << (header->bitplanes() - 2)))
+        if (cmapCount == (1 << (bitplanes - 2)))
             return CAMGChunk::ModeIds(CAMGChunk::ModeId::Ham);
     }
     return CAMGChunk::ModeIds();
@@ -1488,13 +1490,13 @@ QImage::Format FORMChunk::cdiFormat() const
         }
 
         if (h->depth() == 8) {
-            if (h->model() == IHDRChunk::CLut8 || h->model() == IHDRChunk::CLut7) { // CLut7: no test case
+            if (h->model() == IHDRChunk::CLut8 || h->model() == IHDRChunk::CLut7) {
                 return QImage::Format_Indexed8;
             }
             if (h->model() == IHDRChunk::Rgb888) { // no test case
                 return FORMAT_RGB_8BIT;
             }
-            if (h->model() == IHDRChunk::DYuv && h->yuvKind() == IHDRChunk::One) {
+            if (h->model() == IHDRChunk::DYuv) {
                 return FORMAT_RGB_8BIT;
             }
         }
@@ -1938,7 +1940,7 @@ QImage RGBAChunk::compressedTile(QIODevice *d, const TBHDChunk *header) const
             }
         }
     } else if (bpc == 2) {
-        auto cs = header->channels();
+        auto cs = std::max(1, header->channels());
         if (cs < 4) { // alpha on 64-bit images must be 0xFF
             std::memset(img.bits(), 0xFF, img.sizeInBytes());
         }
@@ -2512,7 +2514,7 @@ IHDRChunk::Yuv IHDRChunk::yuvStart() const
     if (!isValid()) {
         return{};
     }
-    return(Yuv(data().at(11), data().at(12), data().at(13)));
+    return Yuv(data().at(11), data().at(12), data().at(13));
 }
 
 bool IHDRChunk::innerReadStructure(QIODevice *d)
@@ -2683,6 +2685,44 @@ QList<QRgb> PLTEChunk::innerPalette() const
 }
 
 
+/* ******************
+ * *** YUVS Chunk ***
+ * ****************** */
+
+YUVSChunk::~YUVSChunk()
+{
+
+}
+
+YUVSChunk::YUVSChunk()
+{
+
+}
+
+bool YUVSChunk::isValid() const
+{
+    return chunkId() == YUVSChunk::defaultChunkId();
+}
+
+qint32 YUVSChunk::count() const
+{
+    return dataBytes() / 3;
+}
+
+IHDRChunk::Yuv YUVSChunk::yuvStart(qint32 y) const
+{
+    if (!isValid() || y >= count()) {
+        return{};
+    }
+    return IHDRChunk::Yuv(data().at(y * 3), data().at(y * 3 + 1), data().at(y * 3 + 2));
+}
+
+bool YUVSChunk::innerReadStructure(QIODevice *d)
+{
+    return cacheData(d);
+}
+
+
 /* ******************
  * *** IDAT Chunk ***
  * ****************** */
@@ -2721,9 +2761,8 @@ inline IPARChunk::Rgb yuvToRgb(IHDRChunk::Yuv yuv) {
 }
 
 
-QByteArray IDATChunk::strideRead(QIODevice *d, qint32 y, const IHDRChunk *header, const IPARChunk *params) const
+QByteArray IDATChunk::strideRead(QIODevice *d, qint32 y, const IHDRChunk *header, const IPARChunk *params, const YUVSChunk *yuvs) const
 {
-    Q_UNUSED(y)
     Q_UNUSED(params)
     if (!isValid() || header == nullptr || d == nullptr) {
         return {};
@@ -2765,6 +2804,10 @@ QByteArray IDATChunk::strideRead(QIODevice *d, qint32 y, const IHDRChunk *header
             };
 
             auto yuv = header->yuvStart();
+            if (header->yuvKind() == IHDRChunk::Each && yuvs) {
+                yuv = yuvs->yuvStart(y);
+            }
+
             QByteArray tmp(header->width() * 3, char());
             for (auto x = 0, w = header->width() - 1; x < w; x += 2) {
                 // nibble order from Green Book Cap. V Par. 6.5.1.1

src/imageformats/chunks_p.h

@@ -60,6 +60,7 @@ Q_DECLARE_LOGGING_CATEGORY(LOG_IFFPLUGIN)
 #define IPAR_CHUNK QByteArray("IPAR")
 #define PLTE_CHUNK QByteArray("PLTE")
 #define XBMI_CHUNK QByteArray("XBMI")
+#define YUVS_CHUNK QByteArray("YUVS")
 
 // Different palette for scanline
 #define BEAM_CHUNK QByteArray("BEAM")
@@ -1630,6 +1631,31 @@ protected:
     virtual QList<QRgb> innerPalette() const override;
 };
 
+
+/*!
+ * \brief The YUVSChunk class
+ */
+class YUVSChunk : public IFFChunk
+{
+public:
+    virtual ~YUVSChunk() override;
+    YUVSChunk();
+    YUVSChunk(const YUVSChunk& other) = default;
+    YUVSChunk& operator =(const YUVSChunk& other) = default;
+
+    virtual bool isValid() const override;
+
+    qint32 count() const;
+
+    IHDRChunk::Yuv yuvStart(qint32 y) const;
+
+    CHUNKID_DEFINE(YUVS_CHUNK)
+
+protected:
+    virtual bool innerReadStructure(QIODevice *d) override;
+};
+
+
 /*!
  * \brief The IDATChunk class
  */
@@ -1657,7 +1683,8 @@ public:
     QByteArray strideRead(QIODevice *d,
                           qint32 y,
                           const IHDRChunk *header,
-                          const IPARChunk *params = nullptr) const;
+                          const IPARChunk *params = nullptr,
+                          const YUVSChunk *yuvs = nullptr) const;
 
     /*!
      * \brief resetStrideRead

src/imageformats/iff.cpp

@@ -334,7 +334,6 @@ bool IFFHandler::readStandardImage(QImage *image)
     // show the first one (I don't have a sample with many images)
     auto headers = IFFChunk::searchT<BMHDChunk>(form);
     if (headers.isEmpty()) {
-        qCWarning(LOG_IFFPLUGIN) << "IFFHandler::readStandardImage(): no supported image found";
         return false;
     }
 
@@ -433,7 +432,6 @@ bool IFFHandler::readMayaImage(QImage *image)
     // show the first one (I don't have a sample with many images)
     auto headers = IFFChunk::searchT<TBHDChunk>(form);
     if (headers.isEmpty()) {
-        qCWarning(LOG_IFFPLUGIN) << "IFFHandler::readMayaImage(): no supported image found";
         return false;
     }
 
@@ -494,7 +492,6 @@ bool IFFHandler::readCDIImage(QImage *image)
     // show the first one (I don't have a sample with many images)
     auto headers = IFFChunk::searchT<IHDRChunk>(form);
     if (headers.isEmpty()) {
-        qCWarning(LOG_IFFPLUGIN) << "IFFHandler::readCDIImage(): no supported image found";
         return false;
     }
 
@@ -525,9 +522,12 @@ bool IFFHandler::readCDIImage(QImage *image)
             return false;
         }
         auto pars = IFFChunk::searchT<IPARChunk>(form);
+        auto yuvs = IFFChunk::searchT<YUVSChunk>(form);
         for (auto y = 0, h = img.height(); y < h; ++y) {
             auto line = reinterpret_cast<char*>(img.scanLine(y));
-            auto ba = body->strideRead(device(), y, header, pars.isEmpty() ? nullptr : pars.first());
+            auto ba = body->strideRead(device(), y, header,
+                                       pars.isEmpty() ? nullptr : pars.first(),
+                                       yuvs.isEmpty() ? nullptr : yuvs.first());
             if (ba.isEmpty()) {
                 qCWarning(LOG_IFFPLUGIN) << "IFFHandler::readCDIImage(): error while reading image scanline";
                 return false;