node: fixed issue with "taking" values from input tables

As opposed to simply leaving all values in the table, nodes can now "take"
values that they use to free up memory (e.g. "taking" input buffers if they're
used to produce an output buffer).

This is a fairly large change, expect regressions.

app/node/input/media/media.cpp

@@ -21,6 +21,7 @@
 #include "media.h"
 
 #include "common/timecodefunctions.h"
+#include "common/tohex.h"
 
 OLIVE_NAMESPACE_ENTER
 
@@ -54,9 +55,9 @@ void MediaInput::Retranslate()
   footage_input_->set_name(tr("Footage"));
 }
 
-NodeValueTable MediaInput::Value(const NodeValueDatabase &value) const
+NodeValueTable MediaInput::Value(NodeValueDatabase &value) const
 {
-  NodeValueTable table = value.Merge();
+  NodeValueTable table;
 
   if (connected_footage_) {
     rational media_duration = Timecode::timestamp_to_time(connected_footage_->duration(),
@@ -65,6 +66,12 @@ NodeValueTable MediaInput::Value(const NodeValueDatabase &value) const
     table.Push(NodeInput::kRational, QVariant::fromValue(media_duration), "length");
   }
 
+  // Push buffer to the top of the stack
+  NodeValue buffer = value[footage_input_].GetWithMeta(NodeParam::kSamples);
+  if (buffer.type() != NodeParam::kNone) {
+    table.Push(buffer);
+  }
+
   return table;
 }