Merge pull request #1175 from dukesook/unique_ispe

Reuse matching ispe box if one exists.

libheif/box.cc

@@ -740,6 +740,42 @@ std::vector<std::shared_ptr<Box>> Box::get_child_boxes(uint32_t short_type) cons
 }
 
 
+int Box::find_or_append_child_box(const std::shared_ptr<Box>& box)
+{
+  for (int i = 0; i < (int) m_children.size(); i++) {
+    if (Box::equal(m_children[i], box)) {
+      return i;
+    }
+  }
+  return append_child_box(box);
+}
+
+
+bool Box::operator==(const Box& other) const
+{
+  if (this->get_short_type() != other.get_short_type()) {
+    return false;
+  }
+
+  StreamWriter writer1;
+  StreamWriter writer2;
+
+  this->write(writer1);
+  other.write(writer2);
+
+  return writer1.get_data() == writer2.get_data();
+}
+
+
+bool Box::equal(const std::shared_ptr<Box>& box1, const std::shared_ptr<Box>& box2)
+{
+    if (!box1 || !box2) {
+        return false;
+    }
+    return *box1 == *box2;
+}
+
+
 Error Box::read_children(BitstreamRange& range, int max_number)
 {
   int count = 0;

libheif/box.h

@@ -194,6 +194,13 @@ class Box : public BoxHeader
     return (int) m_children.size() - 1;
   }
 
+  int find_or_append_child_box(const std::shared_ptr<Box>& box);
+
+  bool operator==(const Box& other) const;
+
+  static bool equal(const std::shared_ptr<Box>& box1, const std::shared_ptr<Box>& box2);
+
+
 protected:
   virtual Error parse(BitstreamRange& range);
 

libheif/file.cc

@@ -969,7 +969,7 @@ void HeifFile::add_ispe_property(heif_item_id id, uint32_t width, uint32_t heigh
   auto ispe = std::make_shared<Box_ispe>();
   ispe->set_size(width, height);
 
-  int index = m_ipco_box->append_child_box(ispe);
+  int index = m_ipco_box->find_or_append_child_box(ispe);
 
   m_ipma_box->add_property_for_item_ID(id, Box_ipma::PropertyAssociation{false, uint16_t(index + 1)});
 }
@@ -1067,7 +1067,7 @@ void HeifFile::add_pixi_property(heif_item_id id, uint8_t c1, uint8_t c2, uint8_
     pixi->add_channel_bits(c3);
   }
 
-  int index = m_ipco_box->append_child_box(pixi);
+  int index = m_ipco_box->find_or_append_child_box(pixi);
 
   m_ipma_box->add_property_for_item_ID(id, Box_ipma::PropertyAssociation{false, uint16_t(index + 1)});
 }