diff options
| -rw-r--r-- | vcl/source/treelist/transfer.cxx | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/vcl/source/treelist/transfer.cxx b/vcl/source/treelist/transfer.cxx index 82ffa7dbde1b..1f73b377e5a8 100644 --- a/vcl/source/treelist/transfer.cxx +++ b/vcl/source/treelist/transfer.cxx @@ -670,7 +670,23 @@ bool TransferableHelper::SetBitmapEx( const BitmapEx& rBitmapEx, const DataFlavo if(rFlavor.MimeType.equalsIgnoreAsciiCase("image/png")) { // write a PNG - vcl::PNGWriter aPNGWriter(rBitmapEx); + css::uno::Sequence<css::beans::PropertyValue> aFilterData; + +#ifdef IOS + // Use faster compression on slow devices + aFilterData.realloc(aFilterData.getLength() + 1); + aFilterData[aFilterData.getLength() - 1].Name = "Compression"; + + // We "know" that this gets passed to zlib's deflateInit2_(). 1 means best speed. For a + // typical 15 megapixel image from a DSLR, we are talking about a difference of 17 s for + // the default compression level vs 4 s for best speed, on an iPad Pro from 2017. + // + // Sure, the best would be to not have to re-encode the image at all, but have access to + // the original JPEG or PNG when there is a such. + + aFilterData[aFilterData.getLength() - 1].Value <<= 1; +#endif + vcl::PNGWriter aPNGWriter(rBitmapEx, &aFilterData); aPNGWriter.Write(aMemStm); } |