Add equality option for vertical subtitle position.v1.8.34

2 files changed, 10 insertions, 3 deletions

diff --git a/src/subtitle.cc b/src/subtitle.cc
index 522b0e5f..de3fe03f 100644
--- a/src/subtitle.cc
+++ b/src/subtitle.cc
@@ -37,6 +37,7 @@
  */
 
 
+#include "compose.hpp"
 #include "subtitle.h"
 #include "dcp_time.h"
 
@@ -72,7 +73,7 @@ Subtitle::Subtitle (
 
 
 bool
-Subtitle::equals(shared_ptr<const Subtitle> other, EqualityOptions, NoteHandler note) const
+Subtitle::equals(shared_ptr<const Subtitle> other, EqualityOptions options, NoteHandler note) const
 {
 	bool same = true;
 
@@ -96,8 +97,12 @@ Subtitle::equals(shared_ptr<const Subtitle> other, EqualityOptions, NoteHandler
 		same = false;
 	}
 
-	if (v_position() != other->v_position()) {
-		note(NoteType::ERROR, "subtitle vertical positions differ");
+	auto const vpos = std::abs(v_position() - other->v_position());
+	if (vpos > options.max_subtitle_vertical_position_error)  {
+		note(
+			NoteType::ERROR,
+			String::compose("subtitle vertical positions differ by %1 (more than the allowed difference of %2)", vpos, options.max_subtitle_vertical_position_error)
+		    );
 		same = false;
 	}
 
diff --git a/src/types.h b/src/types.h
index 32f1bfc4..a60193a4 100644
--- a/src/types.h
+++ b/src/types.h
@@ -259,6 +259,8 @@ struct EqualityOptions
 	bool keep_going = false;
 	/** true to save the first pair of differeng image subtitles to the current working directory */
 	bool export_differing_subtitles = false;
+	/** The maximum allowable absolute difference between the vertical position of subtitles */
+	float max_subtitle_vertical_position_error = 0;
 };