Add hack for binary STL files with high MNR (maximum number of rows) values.

[libsub.git] / src / stl_binary_reader.cc

diff --git a/src/stl_binary_reader.cc b/src/stl_binary_reader.cc
index 7c5386b84789dc0f28f717e9adb74b8bc78cac9d..9a7a150fcf53b767b232ab9b7ed2375797649772 100644 (file)
--- a/src/stl_binary_reader.cc
+++ b/src/stl_binary_reader.cc
@@ -166,6 +166,17 @@ void STLBinaryReader::read (shared_ptr<InputReader> reader)
        subtitle_groups = atoi (reader->get_string(248, 3).c_str());
        maximum_characters = atoi (reader->get_string(251, 2).c_str());
        maximum_rows = atoi (reader->get_string(253, 2).c_str());
+
+       if (maximum_rows == 99) {
+               /* https://tech.ebu.ch/docs/tech/tech3360.pdf says
+                  "It is recommended that for files with a large MNR value (e.g. '99') the
+                  font size (height) should be defined as ~ 1/15 of the 'Subtitle Safe Area'
+                  and a lineHeight of 120% is used to achieve a row height of ~ 1/12 of the height
+                  of the 'Subtitle Safe Area'.
+               */
+               maximum_rows = 12;
+       }
+
        timecode_status = _tables.timecode_status_file_to_enum (reader->get_string(255, 1));
        start_of_programme = reader->get_string(256, 8);
        first_in_cue = reader->get_string(264, 8);