Merge pull request #572 from Enet4/bug/pixeldata/transcode-update-met…

…a-length

Update meta information group length in dicom-transcode + add FileDicomObject::update_meta

object/src/lib.rs

@@ -417,10 +417,26 @@ impl<O> FileDicomObject<O> {
     ///
     /// Considerable care should be taken when modifying this table,
     /// as it may influence object reading and writing operations.
+    /// When modifying the table through this method,
+    /// the user is responsible for updating the meta information group length as well,
+    /// which can be done by calling
+    /// [`update_information_group_length`](FileMetaTable::update_information_group_length).
+    ///
+    /// See also [`update_meta`](Self::update_meta).
     pub fn meta_mut(&mut self) -> &mut FileMetaTable {
         &mut self.meta
     }
 
+    /// Update the processed meta header table through a function.
+    ///
+    /// Considerable care should be taken when modifying this table,
+    /// as it may influence object reading and writing operations.
+    /// The meta information group length is updated automatically.
+    pub fn update_meta(&mut self, f: impl FnOnce(&mut FileMetaTable)) {
+        f(&mut self.meta);
+        self.meta.update_information_group_length();
+    }
+
     /// Retrieve the inner DICOM object structure, discarding the meta table.
     pub fn into_inner(self) -> O {
         self.obj
@@ -870,4 +886,27 @@ mod tests {
         );
         assert_eq!(iter.next(), None);
     }
+
+    #[test]
+    pub fn file_dicom_can_update_meta() {
+        let meta = FileMetaTableBuilder::new()
+            .transfer_syntax(
+                dicom_transfer_syntax_registry::entries::EXPLICIT_VR_LITTLE_ENDIAN.uid(),
+            )
+            .media_storage_sop_class_uid("1.2.840.10008.5.1.4.1.1.1")
+            .media_storage_sop_instance_uid("2.25.280986007517028771599125034987786349815")
+            .implementation_class_uid("1.2.345.6.7890.1.234")
+            .build()
+            .unwrap();
+        let mut obj = FileDicomObject::new_empty_with_meta(meta);
+
+        obj.update_meta(|meta| {
+            meta.receiving_application_entity_title = Some("SOMETHING".to_string());
+        });
+
+        assert_eq!(
+            obj.meta().receiving_application_entity_title.as_deref(),
+            Some("SOMETHING"),
+        );
+    }
 }

pixeldata/src/bin/dicom-transcode.rs

@@ -156,10 +156,11 @@ fn run() -> Result<(), Whatever> {
 
     // override implementation class UID and version name
     if !retain_implementation {
-        obj.meta_mut().implementation_class_uid =
-            dicom_object::IMPLEMENTATION_CLASS_UID.to_string();
-        obj.meta_mut().implementation_version_name =
-            Some(dicom_object::IMPLEMENTATION_VERSION_NAME.to_string());
+        obj.update_meta(|meta| {
+            meta.implementation_class_uid = dicom_object::IMPLEMENTATION_CLASS_UID.to_string();
+            meta.implementation_version_name =
+                Some(dicom_object::IMPLEMENTATION_VERSION_NAME.to_string());
+        });
     }
 
     // write to file