fixed text_output for word_timestamps=False

-fixed: [word_level]=False prevented text output when word_timestamps=False (now warns user instead)
-fixed: use "\n" instead of "\n\n" between segments for ASS output
-changed: [strip] default to True for result_to_srt_vtt() to follow old behavior

stable_whisper/text_output.py

@@ -1,5 +1,6 @@
 import json
 import os
+import warnings
 from typing import List, Tuple
 from itertools import chain
 from .stabilization import valid_ts
@@ -87,13 +88,32 @@ def to_word_level(segments: List[dict]) -> List[dict]:
     return [dict(text=w['word'], start=w['start'], end=w['end']) for s in segments for w in s['words']]
 
 
+def _confirm_word_level(segments: List[dict]) -> bool:
+    is_missing_words = len(set(bool(s.get('words')) for s in segments) - {True}) == 1
+    if is_missing_words:
+        warnings.warn('Result is missing word timestamps. Word-level timing cannot be exported. '
+                      'Use `word_level=False` to avoid this warning and not export word-level timing.')
+        return False
+    return True
+
+
+def _preprocess_args(result: (dict, list),
+                     segment_level: bool,
+                     word_level: bool):
+    assert segment_level or word_level, '`segment_level` or `word_level` must be True'
+    segments = _get_segments(result)
+    if word_level:
+        word_level = _confirm_word_level(segments)
+    return segments, segment_level, word_level
+
+
 def result_to_srt_vtt(result: (dict, list),
                       filepath: str = None,
                       segment_level=True,
                       word_level=True,
                       tag: Tuple[str, str] = None,
                       vtt: bool = None,
-                      strip=False):
+                      strip=True):
     """
 
     Generate SRT/VTT from result to display segment-level and/or word-level timestamp.
@@ -122,7 +142,7 @@ def result_to_srt_vtt(result: (dict, list),
     string of content if no [filepath] is provided, else None
 
     """
-    assert segment_level or word_level
+    segments, segment_level, word_level = _preprocess_args(result, segment_level, word_level)
 
     is_srt = (filepath is None or not filepath.endswith('.vtt')) if vtt is None else vtt
     if filepath:
@@ -134,7 +154,6 @@ def result_to_srt_vtt(result: (dict, list),
 
     sub_str = '' if is_srt else 'WEBVTT\n\n'
 
-    segments = _get_segments(result)
     if word_level and segment_level:
         if tag is None:
             tag = ('<font color="#00ff00">', '</font>') if is_srt else ('<u>', '</u>')
@@ -199,6 +218,7 @@ def result_to_ass(result: (dict, list),
     string of content if no [filepath] is provided, else None
 
     """
+    segments, segment_level, word_level = _preprocess_args(result, segment_level, word_level)
 
     fmt_style_dict = {'Name': 'Default', 'Fontname': 'Arial', 'Fontsize': '48', 'PrimaryColour': '&Hffffff',
                       'SecondaryColour': '&Hffffff', 'OutlineColour': '&H0', 'BackColour': '&H0', 'Bold': '0',
@@ -224,7 +244,6 @@ def result_to_ass(result: (dict, list),
               f'[V4+ Styles]\n{fmts}\n{styles}\n\n' \
               f'[Events]\nFormat: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\n\n'
 
-    segments = _get_segments(result)
     if word_level and segment_level:
         if tag is None:
             color = 'HFF00'
@@ -235,7 +254,7 @@ def result_to_ass(result: (dict, list),
 
     valid_ts(segments)
 
-    sub_str += '\n\n'.join(segment2assblock(s, i, strip=strip) for i, s in enumerate(segments))
+    sub_str += '\n'.join(segment2assblock(s, i, strip=strip) for i, s in enumerate(segments))
 
     if filepath:
         if not filepath.lower().endswith('.ass'):