Generate subtitles dynamically like sound files, improvements in code

CHANGELOG.md

@@ -1,6 +1,6 @@
 # v1.1.2 (pre-release)
 - Now you can play the audio files while they are processing.
-- While generating audio files, now it directly writes to audio file instead of RAM, which significantly reduces memory usage and prevents memory outage issues.
+- Audio and subtitle files are now written directly to disk during generation, which significantly reduces memory usage.
 - Added a better logic for detecting chapters from the epub, mentioned by @jefro108 in #33
 - Added a new option: `Reset to default settings`, allowing users to reset all settings to their default values.
 - Added a new option: `Disable Kokoro's internet access`. This lets you prevent Kokoro from downloading models or voices from HuggingFace Hub, which can help avoid long waiting times if your computer is offline.

abogen/book_handler.py

@@ -1908,5 +1908,13 @@ class HandlerDialog(QDialog):
 
     def closeEvent(self, event):
         if self.pdf_doc is not None:
-            self.pdf_doc.close()
+            try:
+                if hasattr(self.pdf_doc, "is_closed"):
+                    if not self.pdf_doc.is_closed:
+                        self.pdf_doc.close()
+                else:
+                    # Fallback: try/except close
+                    self.pdf_doc.close()
+            except Exception:
+                pass
         event.accept()

abogen/conversion.py

@@ -305,8 +305,9 @@ class ConversionThread(QThread):
 
             if self.save_option == "Choose output folder":
                 self.log_updated.emit(
-                    f"  - Output folder: {self.output_folder or os.getcwd()}"
+                    f"- Output folder: {self.output_folder or os.getcwd()}"
                 )
+                
             self.log_updated.emit("\nInitializing TTS pipeline...")
 
             # Set device based on use_gpu setting
@@ -490,6 +491,30 @@ class ConversionThread(QThread):
                     self.log_updated.emit((f"Unsupported output format: {self.output_format}", "red"))
                     self.conversion_finished.emit(("Audio generation failed.", "red"), None)
                     return
+                # Open merged subtitle file for incremental writing if needed
+                merged_subtitle_file = None
+                if self.subtitle_mode != "Disabled":
+                    subtitle_format = getattr(self, "subtitle_format", "srt")
+                    file_extension = "ass" if "ass" in subtitle_format else "srt"
+                    merged_subtitle_path = os.path.splitext(merged_out_path)[0] + f".{file_extension}"
+                    if "ass" in subtitle_format:
+                        merged_subtitle_file = open(merged_subtitle_path, "w", encoding="utf-8", errors="replace")
+                        # Minimal ASS header
+                        merged_subtitle_file.write("[Script Info]\n")
+                        merged_subtitle_file.write("Title: Generated by Abogen\n")
+                        merged_subtitle_file.write("ScriptType: v4.00+\n\n")
+                        merged_subtitle_file.write("[Events]\n")
+                        merged_subtitle_file.write("Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\n")
+                        # Set margin/alignment for ASS
+                        is_centered = subtitle_format in ("ass_centered_wide", "ass_centered_narrow")
+                        is_narrow = subtitle_format in ("ass_narrow", "ass_centered_narrow")
+                        merged_subtitle_margin = "90" if is_narrow else ""
+                        merged_subtitle_alignment_tag = f"{{\\an5}}" if is_centered else ""
+                    else:
+                        merged_subtitle_file = open(merged_subtitle_path, "w", encoding="utf-8", errors="replace")
+                else:
+                    merged_subtitle_path = None
+                    merged_subtitle_file = None
             else:
                 # If not merging, set merged_out_file and related variables to None
                 merged_out_file = None
@@ -557,10 +582,37 @@ class ConversionThread(QThread):
                     else:
                         self.log_updated.emit((f"Unsupported chapter format: {separate_chapters_format}", "red"))
                         continue
+                    # Open chapter subtitle file for incremental writing if needed
+                    chapter_subtitle_file = None
+                    if self.subtitle_mode != "Disabled":
+                        subtitle_format = getattr(self, "subtitle_format", "srt")
+                        file_extension = "ass" if "ass" in subtitle_format else "srt"
+                        chapter_subtitle_path = os.path.join(
+                            chapters_out_dir, f"{chapter_filename}.{file_extension}"
+                        )
+                        if "ass" in subtitle_format:
+                            chapter_subtitle_file = open(chapter_subtitle_path, "w", encoding="utf-8", errors="replace")
+                            # Minimal ASS header
+                            chapter_subtitle_file.write("[Script Info]\n")
+                            chapter_subtitle_file.write("Title: Generated by Abogen\n")
+                            chapter_subtitle_file.write("ScriptType: v4.00+\n\n")
+                            chapter_subtitle_file.write("[Events]\n")
+                            chapter_subtitle_file.write("Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\n")
+                            is_centered = subtitle_format in ("ass_centered_wide", "ass_centered_narrow")
+                            is_narrow = subtitle_format in ("ass_narrow", "ass_centered_narrow")
+                            chapter_subtitle_margin = "90" if is_narrow else ""
+                            chapter_subtitle_alignment_tag = f"{{\\an5}}" if is_centered else ""
+                        else:
+                            chapter_subtitle_file = open(chapter_subtitle_path, "w", encoding="utf-8", errors="replace")
+                    else:
+                        chapter_subtitle_path = None
+                        chapter_subtitle_file = None
                 else:
                     chapter_out_file = None
                     chapter_out_path = None
                     chapter_ffmpeg_proc = None
+                    chapter_subtitle_file = None
+                    chapter_subtitle_path = None
                 for result in tts(
                     chapter_text,
                     voice=loaded_voice,
@@ -631,18 +683,49 @@ class ConversionThread(QThread):
                         # Process tokens according to subtitle mode
                         # Global subtitle processing ONLY if merging
                         if merge_chapters_at_end:
+                            # Incremental subtitle writing for merged output
+                            new_entries = []
                             self._process_subtitle_tokens(
                                 tokens_with_timestamps,
-                                subtitle_entries,
+                                new_entries,
                                 self.max_subtitle_words,
                             )
+                            if merged_subtitle_file:
+                                subtitle_format = getattr(self, "subtitle_format", "srt")
+                                if "ass" in subtitle_format:
+                                    for (start, end, text) in new_entries:
+                                        start_time = self._ass_time(start)
+                                        end_time = self._ass_time(end)
+                                        merged_subtitle_file.write(
+                                            f"Dialogue: 0,{start_time},{end_time},Default,,{merged_subtitle_margin},{merged_subtitle_margin},0,,{merged_subtitle_alignment_tag}{text}\n"
+                                        )
+                                else:
+                                    for i, (start, end, text) in enumerate(new_entries, 1):
+                                        merged_subtitle_file.write(
+                                            f"{i}\n{self._srt_time(start)} --> {self._srt_time(end)}\n{text}\n\n"
+                                        )
                         # Per-chapter subtitle processing for both file and ffmpeg_proc
                         if chapter_out_file or chapter_ffmpeg_proc:
+                            new_chapter_entries = []
                             self._process_subtitle_tokens(
                                 chapter_tokens_with_timestamps,
-                                chapter_subtitle_entries,
+                                new_chapter_entries,
                                 self.max_subtitle_words,
                             )
+                            if chapter_subtitle_file:
+                                subtitle_format = getattr(self, "subtitle_format", "srt")
+                                if "ass" in subtitle_format:
+                                    for (start, end, text) in new_chapter_entries:
+                                        start_time = self._ass_time(start)
+                                        end_time = self._ass_time(end)
+                                        chapter_subtitle_file.write(
+                                            f"Dialogue: 0,{start_time},{end_time},Default,,{chapter_subtitle_margin},{chapter_subtitle_margin},0,,{chapter_subtitle_alignment_tag}{text}\n"
+                                        )
+                                else:
+                                    for i, (start, end, text) in enumerate(new_chapter_entries, 1):
+                                        chapter_subtitle_file.write(
+                                            f"{i}\n{self._srt_time(start)} --> {self._srt_time(end)}\n{text}\n\n"
+                                        )
                     if merge_chapters_at_end:
                         current_time += chunk_dur
                         if chapter_out_file or chapter_ffmpeg_proc:
@@ -687,41 +770,10 @@ class ConversionThread(QThread):
                     chapter_ffmpeg_proc.wait()
                 if chapter_out_file:
                     chapter_out_file.close()
-                # Subtitle file for chapter
+                # Close chapter subtitle file if open
-                if save_chapters_separately and total_chapters > 1 and self.subtitle_mode != "Disabled" and chapter_subtitle_entries:
+                if chapter_subtitle_file:
-                    subtitle_format = getattr(self, "subtitle_format", "srt")
+                    chapter_subtitle_file.close()
-                    file_extension = "ass" if "ass" in subtitle_format else "srt"
+                if save_chapters_separately and total_chapters > 1 and self.subtitle_mode != "Disabled" and chapter_subtitle_path:
-                    chapter_subtitle_path = os.path.join(
-                        chapters_out_dir, f"{chapter_filename}.{file_extension}"
-                    )
-                    if "ass" in subtitle_format:
-                        is_centered = subtitle_format in (
-                            "ass_centered_wide",
-                            "ass_centered_narrow",
-                        )
-                        is_narrow = subtitle_format in (
-                            "ass_narrow",
-                            "ass_centered_narrow",
-                        )
-                        self._write_ass_subtitle(
-                            chapter_subtitle_path,
-                            chapter_subtitle_entries,
-                            is_centered,
-                            is_narrow,
-                        )
-                    else:
-                        with open(
-                            chapter_subtitle_path,
-                            "w",
-                            encoding="utf-8",
-                            errors="replace",
-                        ) as srt_file:
-                            for i, (start, end, text) in enumerate(
-                                chapter_subtitle_entries, 1
-                            ):
-                                srt_file.write(
-                                    f"{i}\n{self._srt_time(start)} --> {self._srt_time(end)}\n{text}\n\n"
-                                )
                     self.log_updated.emit(
                         (
                             f"\nChapter {chapter_idx} saved to: {chapter_out_path}\n\nChapter subtitle saved to: {chapter_subtitle_path}",
@@ -735,7 +787,6 @@ class ConversionThread(QThread):
                             "green",
                         )
                     )
-        
             # Finalize merged output file ONLY if merging
             if merge_chapters_at_end:
                 self.log_updated.emit(("\nFinalizing audio...", "grey"))
@@ -787,40 +838,15 @@ class ConversionThread(QThread):
                     ffmpeg_proc.stdin.close()
                     ffmpeg_proc.wait()
                 self.progress_updated.emit(100, "00:00:00")
-
+                # Close merged subtitle file if open
+                if merged_subtitle_file:
+                    merged_subtitle_file.close()
             # Subtitle and final message logic
             if merge_chapters_at_end:
                 if self.subtitle_mode != "Disabled":
-                    subtitle_format = getattr(self, "subtitle_format", "srt")
-                    file_extension = "ass" if "ass" in subtitle_format else "srt"
-                    subtitle_path = (
-                        os.path.splitext(merged_out_path)[0] + f".{file_extension}"
-                    )
-                    if "ass" in subtitle_format:
-                        is_centered = subtitle_format in (
-                            "ass_centered_wide",
-                            "ass_centered_narrow",
-                        )
-                        is_narrow = subtitle_format in (
-                            "ass_narrow",
-                            "ass_centered_narrow",
-                        )
-                        self._write_ass_subtitle(
-                            subtitle_path, subtitle_entries, is_centered, is_narrow
-                        )
-                    else:
-                        with open(
-                            subtitle_path, "w", encoding="utf-8", errors="replace"
-                        ) as srt_file:
-                            for i, (start, end, text) in enumerate(
-                                subtitle_entries, 1
-                            ):
-                                srt_file.write(
-                                    f"{i}\n{self._srt_time(start)} --> {self._srt_time(end)}\n{text}\n\n"
-                                )
                     self.conversion_finished.emit(
                         (
-                            f"\nAudiobook saved to: {merged_out_path}\n\nSubtitle saved to: {subtitle_path}",
+                            f"\nAudiobook saved to: {merged_out_path}\n\nSubtitle saved to: {merged_subtitle_path}",
                             "green",
                         ),
                         merged_out_path,
@@ -991,7 +1017,7 @@ class ConversionThread(QThread):
                 word_count += 1
 
                 # Split sentences based on separator or word count
-                if (re.search(separator, token["text"])) or word_count >= max_subtitle_words:
+                if (re.search(separator, token["text"]) and token["whitespace"] == " ") or word_count >= max_subtitle_words:
                     if current_sentence:
                         # Create subtitle entry for this sentence
                         start_time = current_sentence[0]["start"]

abogen/gui.py

@@ -2808,10 +2808,22 @@ class abogen(QWidget):
         save_config(self.config)
 
     def toggle_kokoro_internet_access(self, disabled):
+        if disabled:
+            message = (
+                "Disabling Kokoro's internet access will block downloads of models and voices from Hugging Face Hub. "
+                "This can make processing faster when there is no internet connection, since no requests will be made. "
+                "The app needs to restart to apply this change.\n\nDo you want to continue?"
+            )
+        else:
+            message = (
+                "Enabling Kokoro's internet access will allow it to download models and voices from Hugging Face Hub. "
+                "The app needs to restart to apply this change.\n\nDo you want to continue?"
+            )
         reply = QMessageBox.question(
             self,
             "Restart Required",
-            "Changing Kokoro's internet access requires restarting the application.\nDo you want to continue?",
+
+            message,
             QMessageBox.Yes | QMessageBox.No,
             QMessageBox.No,
         )
@@ -2834,7 +2846,7 @@ class abogen(QWidget):
         reply = QMessageBox.question(
             self,
             "Reset Settings",
-            "This will reset all settings to their default values and restart the application.\nDo you want to continue?",
+            "This will reset all settings to their default values and restart the application.\n\nDo you want to continue?",
             QMessageBox.Yes | QMessageBox.No,
             QMessageBox.No,
         )