fix(subtitle): resolve SDH stripping crash with VTT files

Fixes #34

unshackle/commands/dl.py

@@ -845,20 +845,22 @@ class dl:
 
             # strip SDH subs to non-SDH if no equivalent same-lang non-SDH is available
             # uses a loose check, e.g, wont strip en-US SDH sub if a non-SDH en-GB is available
-            for subtitle in title.tracks.subtitles:
+            # Check if automatic SDH stripping is enabled in config
-                if subtitle.sdh and not any(
+            if config.subtitle.get("strip_sdh", True):
-                    is_close_match(subtitle.language, [x.language])
+                for subtitle in title.tracks.subtitles:
-                    for x in title.tracks.subtitles
+                    if subtitle.sdh and not any(
-                    if not x.sdh and not x.forced
+                        is_close_match(subtitle.language, [x.language])
-                ):
+                        for x in title.tracks.subtitles
-                    non_sdh_sub = deepcopy(subtitle)
+                        if not x.sdh and not x.forced
-                    non_sdh_sub.id += "_stripped"
+                    ):
-                    non_sdh_sub.sdh = False
+                        non_sdh_sub = deepcopy(subtitle)
-                    title.tracks.add(non_sdh_sub)
+                        non_sdh_sub.id += "_stripped"
-                    events.subscribe(
+                        non_sdh_sub.sdh = False
-                        events.Types.TRACK_MULTIPLEX,
+                        title.tracks.add(non_sdh_sub)
-                        lambda track: (track.strip_hearing_impaired()) if track.id == non_sdh_sub.id else None,
+                        events.subscribe(
-                    )
+                            events.Types.TRACK_MULTIPLEX,
+                            lambda track: (track.strip_hearing_impaired()) if track.id == non_sdh_sub.id else None,
+                        )
 
             with console.status("Sorting tracks by language and bitrate...", spinner="dots"):
                 video_sort_lang = v_lang or lang

unshackle/core/tracks/subtitle.py

@@ -979,20 +979,33 @@ class Subtitle(Track):
                 stdout=subprocess.DEVNULL,
             )
         else:
-            sub = Subtitles(self.path)
+            if config.subtitle.get("convert_before_strip", True) and self.codec != Subtitle.Codec.SubRip:
+                self.path = self.convert(Subtitle.Codec.SubRip)
+                self.codec = Subtitle.Codec.SubRip
+
             try:
-                sub.filter(rm_fonts=True, rm_ast=True, rm_music=True, rm_effects=True, rm_names=True, rm_author=True)
+                sub = Subtitles(self.path)
-            except ValueError as e:
+                try:
-                if "too many values to unpack" in str(e):
-                    # Retry without name removal if the error is due to multiple colons in time references
-                    # This can happen with lines like "at 10:00 and 2:00"
-                    sub = Subtitles(self.path)
                     sub.filter(
-                        rm_fonts=True, rm_ast=True, rm_music=True, rm_effects=True, rm_names=False, rm_author=True
+                        rm_fonts=True, rm_ast=True, rm_music=True, rm_effects=True, rm_names=True, rm_author=True
                     )
+                except ValueError as e:
+                    if "too many values to unpack" in str(e):
+                        # Retry without name removal if the error is due to multiple colons in time references
+                        # This can happen with lines like "at 10:00 and 2:00"
+                        sub = Subtitles(self.path)
+                        sub.filter(
+                            rm_fonts=True, rm_ast=True, rm_music=True, rm_effects=True, rm_names=False, rm_author=True
+                        )
+                    else:
+                        raise
+                sub.save()
+            except (IOError, OSError) as e:
+                if "is not valid subtitle file" in str(e):
+                    self.log.warning(f"Failed to strip SDH from {self.path.name}: {e}")
+                    self.log.warning("Continuing without SDH stripping for this subtitle")
                 else:
                     raise
-            sub.save()
 
     def reverse_rtl(self) -> None:
         """

unshackle/unshackle-example.yaml

@@ -1,3 +1,10 @@
+# API key for The Movie Database (TMDB)
+tmdb_api_key: ""
+
+# Client ID for SIMKL API (optional, improves metadata matching)
+# Get your free client ID at: https://simkl.com/settings/developer/
+simkl_client_id: ""
+
 # Group or Username to postfix to the end of all download filenames following a dash
 tag: user_tag
 
@@ -333,22 +340,26 @@ filenames:
   chapters: "Chapters_{title}_{random}.txt"
   subtitle: "Subtitle_{id}_{language}.srt"
 
-# API key for The Movie Database (TMDB)
-tmdb_api_key: ""
-
-# Client ID for SIMKL API (optional, improves metadata matching)
-# Get your free client ID at: https://simkl.com/settings/developer/
-simkl_client_id: ""
-
 # conversion_method:
-# - auto (default): Smart routing - subby for WebVTT/SAMI, standard for others
+# - auto (default): Smart routing - subby for WebVTT/SAMI, pycaption for others
 # - subby: Always use subby with advanced processing
 # - pycaption: Use only pycaption library (no SubtitleEdit, no subby)
 # - subtitleedit: Prefer SubtitleEdit when available, fall back to pycaption
 # - pysubs2: Use pysubs2 library (supports SRT/SSA/ASS/WebVTT/TTML/SAMI/MicroDVD/MPL2/TMP)
 subtitle:
   conversion_method: auto
+  # sdh_method: Method to use for SDH (hearing impaired) stripping
+  # - auto (default): Try subby (SRT only), then SubtitleEdit (if available), then subtitle-filter
+  # - subby: Use subby library (SRT only)
+  # - subtitleedit: Use SubtitleEdit tool (Windows only, falls back to subtitle-filter)
+  # - filter-subs: Use subtitle-filter library directly
   sdh_method: auto
+  # strip_sdh: Automatically create stripped (non-SDH) versions of SDH subtitles
+  # Set to false to disable automatic SDH stripping entirely (default: true)
+  strip_sdh: true
+  # convert_before_strip: Auto-convert VTT/other formats to SRT before using subtitle-filter
+  # This ensures compatibility when subtitle-filter is used as fallback (default: true)
+  convert_before_strip: true
 
 # Configuration for pywidevine's serve functionality
 serve: