In QPDFWriter::writeLinearized remember whether streams are filtered

m-holger
1 parent 634d9249
Showing 1 changed file with 13 additions and 7 deletions
libqpdf/QPDFWriter.cc
@@ -2544,14 +2544,20 @@ QPDFWriter::writeLinearized()
 {
     // Optimize file and enqueue objects in order
  
-    auto skip_stream_parameters = [this](QPDFObjectHandle& stream) {
-        bool compress_stream;
-        bool is_metadata;
-        if (willFilterStream(stream, compress_stream, is_metadata, nullptr)) {
-            return 2;
-        } else {
-            return 1;
+    std::map<int, int> stream_cache;
+
+    auto skip_stream_parameters = [this, &stream_cache](QPDFObjectHandle& stream) {
+        auto& result = stream_cache[stream.getObjectID()];
+        if (result == 0) {
+            bool compress_stream;
+            bool is_metadata;
+            if (willFilterStream(stream, compress_stream, is_metadata, nullptr)) {
+                result = 2;
+            } else {
+                result = 1;
+            }
         }
+        return result;
     };
  
     QPDF::Writer::optimize(m->pdf, m->obj, skip_stream_parameters);