feat: allow MAP command to use textstart-textend range

merge_srt.py

@@ -99,16 +99,34 @@ class SRTMerger:
         return ('COPY', source, start, end)
 
     def parse_map(self, parts):
-        if len(parts) != 5:
+        if len(parts) not in (4, 5):
             return None
         try:
             text_source = int(parts[1])
             if text_source not in (1, 2):
                 return None
-            text_start = int(parts[2])
-            time_start = int(parts[3])
-            count = int(parts[4])
-            if text_start < 1 or time_start < 1 or count < 1:
+            if len(parts) == 4:
+                # New syntax: textstart-textend
+                range_str = parts[2]
+                start_end = range_str.split('-')
+                if len(start_end) != 2:
+                    return None
+                text_start = int(start_end[0])
+                text_end = int(start_end[1])
+                if text_start < 1 or text_end < text_start:
+                    return None
+                count = text_end - text_start + 1
+                time_start = int(parts[3])
+            else:
+                # Original syntax: textstart, timestart, count
+                text_start = int(parts[2])
+                time_start = int(parts[3])
+                count = int(parts[4])
+                if text_start < 1 or time_start < 1 or count < 1:
+                    return None
+                text_end = text_start + count - 1
+            # Common checks
+            if time_start < 1 or count < 1:
                 return None
         except (ValueError, AttributeError, TypeError):
             return None