support for the WebP image format (tdf#114532)

This commit implements a WebP reader and writer for both lossless
and lossy WebP, export dialog options for selecting lossless/lossy
and quality for lossy, and various internal support for the format.

Since writing WebP to e.g. ODT documents would make those images
unreadable by previous versions with no WebP support, support
for that is explicitly disabled in GraphicFilter, to be enabled
somewhen later.

Change-Id: I9b10f6da6faa78a0bb74415a92e9f163c14685f7
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/128920
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/vcl/source/filter/graphicfilter.cxx b/vcl/source/filter/graphicfilter.cxx
index ae04ede2dacf..6e486035b777 100644
--- a/vcl/source/filter/graphicfilter.cxx
+++ b/vcl/source/filter/graphicfilter.cxx
@@ -64,6 +64,8 @@
 #include <filter/GifWriter.hxx>
 #include <filter/BmpReader.hxx>
 #include <filter/BmpWriter.hxx>
+#include <filter/WebpReader.hxx>
+#include <filter/WebpWriter.hxx>
 #include <osl/module.hxx>
 #include <com/sun/star/uno/Reference.h>
 #include <com/sun/star/awt/Size.hpp>
@@ -82,6 +84,7 @@
 #include <memory>
 #include <mutex>
 #include <string_view>
+#include <o3tl/string_view.hxx>
 #include <vcl/TypeSerializer.hxx>
 
 #include "FilterConfigCache.hxx"
@@ -90,6 +93,24 @@
 #include <graphic/GraphicFormatDetector.hxx>
 #include <graphic/GraphicReader.hxx>
 
+// Support for GfxLinkType::NativeWebp is so far disabled,
+// as enabling it would write .webp images e.g. to .odt documents,
+// making those images unreadable for older readers. So for now
+// disable the support so that .webp images will be written out as .png,
+// and somewhen later enable the support unconditionally.
+static bool supportNativeWebp()
+{
+    const char* const testname = getenv("LO_TESTNAME");
+    if(testname == nullptr)
+        return false;
+    // Enable support only for those unittests that test it.
+    if( std::string_view("_anonymous_namespace___GraphicTest__testUnloadedGraphicLoading_") == testname
+        || std::string_view("VclFiltersTest__testExportImport_") == testname
+        || o3tl::starts_with(std::string_view(testname), "WebpFilterTest__"))
+        return true;
+    return false;
+}
+
 static std::vector< GraphicFilter* > gaFilterHdlList;
 
 static std::mutex& getListMutex()
@@ -899,6 +920,13 @@ Graphic GraphicFilter::ImportUnloadedGraphic(SvStream& rIStream, sal_uInt64 size
         {
             eLinkType = GfxLinkType::NativeMet;
         }
+        else if (aFilterName.equalsIgnoreAsciiCase(IMP_WEBP))
+        {
+            if(supportNativeWebp())
+                eLinkType = GfxLinkType::NativeWebp;
+            else
+                nStatus = ERRCODE_GRFILTER_FILTERERROR;
+        }
         else
         {
             nStatus = ERRCODE_GRFILTER_FILTERERROR;
@@ -1305,6 +1333,18 @@ ErrCode GraphicFilter::readDXF(SvStream & rStream, Graphic & rGraphic)
         return ERRCODE_GRFILTER_FILTERERROR;
 }
 
+ErrCode GraphicFilter::readWEBP(SvStream & rStream, Graphic & rGraphic, GfxLinkType & rLinkType)
+{
+    if (ImportWebpGraphic(rStream, rGraphic))
+    {
+        if(supportNativeWebp())
+            rLinkType = GfxLinkType::NativeWebp;
+        return ERRCODE_NONE;
+    }
+    else
+        return ERRCODE_GRFILTER_FILTERERROR;
+}
+
 ErrCode GraphicFilter::ImportGraphic( Graphic& rGraphic, const OUString& rPath, SvStream& rIStream,
                                      sal_uInt16 nFormat, sal_uInt16* pDeterminedFormat, GraphicFilterImportFlags nImportFlags,
                                      const css::uno::Sequence< css::beans::PropertyValue >* /*pFilterData*/,
@@ -1455,6 +1495,10 @@ ErrCode GraphicFilter::ImportGraphic( Graphic& rGraphic, const OUString& rPath,
         {
             nStatus = readDXF(rIStream, rGraphic);
         }
+        else if (aFilterName.equalsIgnoreAsciiCase(IMP_WEBP))
+        {
+            nStatus = readWEBP(rIStream, rGraphic, eLinkType);
+        }
         else
             nStatus = ERRCODE_GRFILTER_FILTERERROR;
     }
@@ -1840,6 +1884,14 @@ ErrCode GraphicFilter::ExportGraphic( const Graphic& rGraphic, const OUString& r
                     }
                 }
             }
+            else if (aFilterName.equalsIgnoreAsciiCase(EXP_WEBP))
+            {
+                if (!ExportWebpGraphic(rOStm, aGraphic, &aConfigItem))
+                    nStatus = ERRCODE_GRFILTER_FORMATERROR;
+
+                if( rOStm.GetError() )
+                    nStatus = ERRCODE_GRFILTER_IOERROR;
+            }
             else
                 nStatus = ERRCODE_GRFILTER_FILTERERROR;
     }
@@ -1882,6 +1934,7 @@ IMPL_LINK( GraphicFilter, FilterCallback, ConvertData&, rData, bool )
         case ConvertDataFormat::WMF: aShortName = WMF_SHORTNAME; break;
         case ConvertDataFormat::EMF: aShortName = EMF_SHORTNAME; break;
         case ConvertDataFormat::SVG: aShortName = SVG_SHORTNAME; break;
+        case ConvertDataFormat::WEBP: aShortName = WEBP_SHORTNAME; break;
 
         default:
         break;