heif-dec: show parsing warnings (#1306)

libheif/box.cc

@@ -1059,6 +1059,11 @@ std::string Box_Error::dump(Indent& indent) const
   return sstr.str();
 }
 
+parse_error_fatality Box_Error::get_parse_error_fatality() const
+{
+  return m_fatality;
+}
+
 
 Error Box_ftyp::parse(BitstreamRange& range)
 {

libheif/box.h

@@ -348,6 +348,10 @@ class Box_Error : public Box
 
   std::string dump(Indent&) const override;
 
+  [[nodiscard]] parse_error_fatality get_parse_error_fatality() const override;
+
+  [[nodiscard]] Error get_error() const { return m_error; }
+
 protected:
   Error parse(BitstreamRange& range) override { assert(false); return Error::Ok; }
 

libheif/codecs/image_item.h

@@ -342,6 +342,10 @@ class ImageItem : public ErrorBuffer
   const std::vector<heif_item_id>& get_region_item_ids() const { return m_region_item_ids; }
 
 
+  void add_decoding_warning(Error err) { m_decoding_warnings.emplace_back(std::move(err)); }
+
+  const std::vector<Error>& get_decoding_warnings() const { return m_decoding_warnings; }
+
 private:
   HeifContext* m_heif_context;
 
@@ -382,6 +386,8 @@ class ImageItem : public ErrorBuffer
   bool m_has_extrinsic_matrix = false;
   Box_cmex::ExtrinsicMatrix m_extrinsic_matrix{};
 
+  std::vector<Error> m_decoding_warnings;
+
 protected:
   static Result<std::shared_ptr<HeifPixelImage>> decode_from_compressed_data(heif_compression_format compression_format,
                                                                              const struct heif_decoding_options& options,

libheif/context.cc

@@ -331,7 +331,6 @@ Error HeifContext::interpret_heif_file()
 
     // --- are there any 'essential' properties that we did not parse?
 
-
     for (const auto& prop : properties) {
       if (std::dynamic_pointer_cast<Box_other>(prop) &&
           get_heif_file()->get_ipco_box()->is_property_essential_for_item(pair.first, prop, get_heif_file()->get_ipma_box())) {
@@ -343,6 +342,17 @@ Error HeifContext::interpret_heif_file()
     }
 
 
+    // --- Are there any parse errors in optional properties? Attach the errors as warnings to the images.
+
+    for (const auto& prop : properties) {
+      if (auto errorbox = std::dynamic_pointer_cast<Box_Error>(prop)) {
+        if (errorbox->get_parse_error_fatality() == parse_error_fatality::optional) {
+          image->add_decoding_warning(errorbox->get_error());
+        }
+      }
+    }
+
+
     // --- extract image resolution
 
     bool ispe_read = false;
@@ -997,6 +1007,8 @@ Result<std::shared_ptr<HeifPixelImage>> HeifContext::decode_image(heif_item_id I
     }
   }
 
+  img->add_warnings(imginfo->get_decoding_warnings());
+
   return img;
 }
 

libheif/pixelimage.h

@@ -233,6 +233,8 @@ class HeifPixelImage : public std::enable_shared_from_this<HeifPixelImage>,
 
   void add_warning(Error warning) { m_warnings.emplace_back(std::move(warning)); }
 
+  void add_warnings(const std::vector<Error>& warning) { for (const auto& err : warning) m_warnings.emplace_back(err); }
+
   const std::vector<Error>& get_warnings() const { return m_warnings; }
 
 private: