fix: handle deduped ttmps

src/ttmp_extractor.rs

@@ -52,8 +52,16 @@ impl<R: Read + Seek> TtmpExtractor<R> {
         let mut data_file = TrackingReader::new(zip.by_name("TTMPD.mpd")
             .map_err(Error::MissingDataFile)?);
 
+        let mut last_offset = None;
         let mut buf = [0; 4096];
         for mod_file in all_files {
+            // handle deduped ttmps
+            if Some(mod_file.file.mod_offset) == last_offset {
+                continue;
+            }
+
+            last_offset = Some(mod_file.file.mod_offset);
+
             let file = mod_file.file;
             data_file.read = 0;