Update changelog

v1.2.4
Reformat using black
2026-07-18 13:40:27 +02:00 · 2025-11-28 05:17:31 +03:00 · 2025-11-28 05:16:39 +03:00 · 2025-11-28 05:07:26 +03:00 · 2025-11-28 05:06:51 +03:00 · 2025-11-28 04:58:13 +03:00
19 changed files with 2774 additions and 381 deletions
@@ -1,3 +1,32 @@
+# 1.2.4
+- **Subtitle generation is now available for all languages!** Abogen now supports subtitle generation for non-English languages using audio duration-based timing. Available modes include `Line`, `Sentence`, and `Sentence + Comma`. (Note: Word-level subtitle modes remain English-only due to Kokoro's timestamp token limitations.)
+- New option: **"Use spaCy for sentence segmentation"** You can now use [spaCy](https://spacy.io/) to automatically detect sentence boundaries and produce cleaner, more readable subtitles. Quick summary:
+    - **What it does:** Splits text into natural sentences so subtitle entries read better and align more naturally with speech.
+    - **Why this helps:** The previous punctuation-based splitting could break sentences incorrectly at common abbreviations (e.g. "Mr.", "Dr.", "Prof.") or initials, producing wrong subtitle breaks. spaCy avoids those false splits by using linguistic rules to detect real sentence boundaries.
+    - **For Non-English:** spaCy runs **before** audio generation to create better sentence chunks for TTS.
+    - **For English:** spaCy runs **during** subtitle generation to find accurate sentence breaks after TTS.
+    - **Note:** spaCy segmentation is only applied when subtitle mode is `Sentence` or `Sentence + Comma`. When turned off, it falls back to simple punctuation-based splitting.
+- New option: **Pre-download models and voices for offline use** You can now pre-download all required Kokoro models, voices, and spaCy language models using this option in the settings menu. Allowing you to use Abogen completely offline without any internet connection.
+- Added support for `.` separator in timestamps (e.g. `HH:MM:SS.ms`) for timestamp-based text files.
+- Optimized regex compilation and eliminated busy-wait loops.
+- Possibly fixed `Silent truncation of long paragraphs` issue mentioned in [#91](https://github.com/denizsafak/abogen/issues/91) by [@xklzlxr](https://github.com/xklzlxr)
+- Fixed unused regex patterns and variable naming conventions.
+- Improvements in code and documentation.
+
+# 1.2.3
+- Same as 1.2.2, re-released to fix an issue with subtitle timing when using timestamp-based text files.
+
+# 1.2.2
+- **You can now voice your subtitle files!** Simply add `.srt`, `.ass` or `.vtt` files to generate timed audio. Alternatively, add a text file with timestamps in `HH:MM:SS` or `HH:MM:SS,ms` format to generate audio that matches the timestamps. See [here](https://github.com/denizsafak/abogen?tab=readme-ov-file#about-timestamp-based-text-files) for detailed instructions.
+    - New option: **"Use silent gaps between subtitles"**: Prevents unnecessary audio speed-up by letting speech continue into the silent gaps between subtitles.
+    - New option: **"Subtitle speed adjustment method"**: Choose how to speed up audio when needed:
+        - **TTS Regeneration (better quality):** Re-generates the audio at a faster speed for more natural sound.
+        - **FFmpeg Time-stretch (better speed):** Quickly speeds up the generated audio.
+- Added support for embedding cover images in M4B files. Abogen now automatically extracts cover images from EPUB and PDF files. You can also manually specify a cover image using the `<<METADATA_COVER_PATH:path>>` tag in your text file. (To prevent MPV from showing the cover image, you can add `audio-display=no` to your MPV config file.)
+- Fixed `[WinError 1114] A dynamic link library (DLL) initialization routine failed` error on Windows, pre-loading PyTorch DLLs before initializing PyQt6 to avoid DLL initialization errors, mentioned in #98 by @ephr0n.
+- Potential fix for `CUDA GPU is not available` issue, by ensuring PyTorch is installed correctly with CUDA support on Windows using the installer script.
+- Improvements in code and documentation.
+
 # 1.2.1
 - Upgraded Abogen's interface from PyQt5 to PyQt6 for better compatibility and long-term support.
 - Added tooltip indicators in queue manager to display book handler options (`Save chapters separately` and `Merge chapters at the end`) for queued items.
@@ -9,7 +9,7 @@

 <a href="https://trendshift.io/repositories/14433" target="_blank"><img src="https://trendshift.io/api/badge/repositories/14433" alt="denizsafak%2Fabogen | Trendshift" style="width: 250px; height: 55px;" width="250" height="55"/></a>

-Abogen is a powerful text-to-speech conversion tool that makes it easy to turn ePub, PDF, text or markdown files into high-quality audio with matching subtitles in seconds. Use it for audiobooks, voiceovers for Instagram, YouTube, TikTok, or any project that needs natural-sounding text-to-speech, using [Kokoro-82M](https://huggingface.co/hexgrad/Kokoro-82M).
+Abogen is a powerful text-to-speech conversion tool that makes it easy to turn ePub, PDF, text, markdown, or subtitle files into high-quality audio with matching subtitles in seconds. Use it for audiobooks, voiceovers for Instagram, YouTube, TikTok, or any project that needs natural-sounding text-to-speech, using [Kokoro-82M](https://huggingface.co/hexgrad/Kokoro-82M).

 <img title="Abogen Main" src='https://raw.githubusercontent.com/denizsafak/abogen/refs/heads/main/demo/abogen.png' width="380"> <img title="Abogen Processing" src='https://raw.githubusercontent.com/denizsafak/abogen/refs/heads/main/demo/abogen2.png' width="380">

@@ -42,7 +42,8 @@ python -m venv venv
 venv\Scripts\activate

 # For NVIDIA GPUs:
-pip install torch torchvision torchaudio --index-url https://download.pytorch.org/whl/cu128
+# We need to use an older version of PyTorch (2.8.0) until this issue is fixed: https://github.com/pytorch/pytorch/issues/166628
+pip install torch==2.8.0+cu128 torchvision==0.23.0+cu128 torchaudio==2.8.0 --index-url https://download.pytorch.org/whl/cu128

 # For AMD GPUs:
 # Not supported yet, because ROCm is not available on Windows. Use Linux if you have AMD GPU.
@@ -114,7 +115,7 @@ abogen
 > If you installed Abogen using the Windows installer `(WINDOWS_INSTALL.bat)`, It should have created a shortcut in the same folder, or your desktop. You can run it from there. If you lost the shortcut, Abogen is located in `python_embedded/Scripts/abogen.exe`. You can run it from there directly.

 ## `How to use?`
-1) Drag and drop any ePub, PDF, text or markdown file (or use the built-in text editor)
+1) Drag and drop any ePub, PDF, text, markdown, or subtitle file (or use the built-in text editor)
 2) Configure the settings:
    - Set speech speed
    - Select a voice (or create a custom voice using voice mixer)
@@ -132,7 +133,7 @@ Here’s Abogen in action: in this demo, it processes ∼3,000 characters of tex

 | Options | Description |
 |---------|-------------|
-| **Input Box** | Drag and drop `ePub`, `PDF`, `.TXT` or `.MD` files (or use built-in text editor) |
+| **Input Box** | Drag and drop `ePub`, `PDF`, `.TXT`, `.MD`, `.SRT`, `.ASS` or `.VTT` files (or use built-in text editor) |
 | **Queue options** | Add multiple files to a queue and process them in batch, with individual settings for each file. See [Queue mode](#queue-mode) for more details. |
 | **Speed** | Adjust speech rate from `0.1x` to `2.0x` |
 | **Select Voice** | First letter of the language code (e.g., `a` for American English, `b` for British English, etc.), second letter is for `m` for male and `f` for female. |
@@ -168,8 +169,12 @@ Here’s Abogen in action: in this demo, it processes ∼3,000 characters of tex
 | **Open config directory** | Opens the directory where the configuration file is stored. |
 | **Open cache directory** | Opens the cache directory where converted text files are stored. |
 | **Clear cache files** | Deletes cache files created during the conversion or preview. |
-| **Check for updates at startup** | Automatically checks for updates when the program starts. |
+| **Use silent gaps between subtitles** | Prevents unnecessary audio speed-up by letting speech continue into the silent gaps between subtitle etries. In short, it ignores the end times in subtitle entries and uses the silent space until the beginning of the next subtitle entry. When disabled, it speeds up the audio to fit the exact time interval specified in the subtitle. (for subtitle files). |
+| **Subtitle speed adjustment method** | Choose how to speed up audio when needed: `TTS Regeneration (better quality)` re-generates the audio at a faster speed, while `FFmpeg Time-stretch (better speed)` quickly speeds up the generated audio. (for subtitle files). |
+| **Use spaCy for sentence segmentation** | When this option is enabled, Abogen uses [spaCy](https://spacy.io/) to detect sentence boundaries more accurately, instead of using punctuation marks (like periods, question marks, etc.) to split sentences, which could incorrectly cut off phrases like "Mr." or "Dr.". With spaCy, sentences are divided more accurately. For non-English text, spaCy runs **before** audio generation to create sentence chunks. For English text, spaCy runs **during** subtitle generation to improve timing and readability. spaCy is only used when subtitle mode is `Sentence` or `Sentence + Comma`. If you prefer the old punctuation splitting method, you can turn this option off. |
+| **Pre-download models and voices for offline use** | Opens a window that displays the available models and voices. Click `Download all` button to download all required models and voices, allowing you to use Abogen completely offline without any internet connection. |
 | **Disable Kokoro's internet access** | Prevents Kokoro from downloading models or voices from HuggingFace Hub, useful for offline use. |
+| **Check for updates at startup** | Automatically checks for updates when the program starts. |
 | **Reset to default settings** | Resets all settings to their default values. |

 > Special thanks to [@robmckinnon](https://github.com/robmckinnon) for adding Sentence + Highlighting feature in PR [#65](https://github.com/denizsafak/abogen/pull/65)
@@ -227,7 +232,30 @@ Similar to chapter markers, it is possible to add metadata tags for `M4B` files.
 <<METADATA_ALBUM_ARTIST:Album Artist>>
 <<METADATA_COMPOSER:Narrator>>
 <<METADATA_GENRE:Audiobook>>
+<<METADATA_COVER_PATH:path/to/cover.jpg>>
 ```
+> Note: `METADATA_COVER_PATH` is used to embed a cover image into the generated M4B file. Abogen automatically extracts the cover from EPUB and PDF files and adds this tag for you.
+
+## `About Timestamp-based Text Files`
+Similar to converting subtitle files to audio, Abogen can automatically detect text files that contain timestamps in `HH:MM:SS`, `HH:MM:SS,ms` or `HH:MM:SS.ms` format. When timestamps are found inside your text file, Abogen will ask if you want to use them for audio timing. This is useful for creating timed narrations, scripts, or transcripts where you need exact control over when each segment is spoken.
+
+Format your text file like this:
+```
+00:00:00
+This is the first segment of text.
+
+00:00:15
+This is the second segment, starting at 15 seconds.
+
+00:00:45
+And this is the third segment, starting at 45 seconds.
+```
+
+**Important notes:**
+- Timestamps must be in `HH:MM:SS`, `HH:MM:SS,ms` or `HH:MM:SS.ms` format (e.g., `00:05:30` for 5 minutes 30 seconds, or `00:05:30.500` for 5 minutes 30.5 seconds)
+- Milliseconds are optional and provide precision up to 1/1000th of a second
+- Text before the first timestamp (if any) will automatically start at `00:00:00`
+- When using timestamps, the subtitle generation mode setting is ignored

 ## `Supported Languages`
 ```
@@ -250,6 +278,7 @@ I highly recommend using [MPV](https://mpv.io/installation/) to play your audio
 # --- MPV Settings ---
 save-position-on-quit
 keep-open=yes
+audio-display=no
 # --- Subtitle ---
 sub-ass-override=no
 sub-margin-y=50
@@ -345,14 +374,20 @@ This will start Abogen in command-line mode and display detailed error messages.
 <a name="cuda-warning">How to fix "CUDA GPU is not available. Using CPU" warning?</a>
 </b></summary>

-> This message means PyTorch couldn't use your GPU. On Windows, Abogen supports NVIDIA GPUs with CUDA. AMD GPUs are supported only on Linux. Abogen will still run on the CPU, but it will be slower.
+> This message means PyTorch could not use your GPU and has fallen back to the CPU. On Windows, Abogen only supports NVIDIA GPUs with CUDA. AMD GPUs are not supported on Windows (they are only supported on Linux with ROCm). Abogen will still work on the CPU, but processing will be slower compared to a supported GPU.
 >
 > If you have a compatible NVIDIA GPU on Windows and still see this warning:
 > Open your terminal in the Abogen folder (the folder that contains `python_embedded`) and type:
 > ```bash
-> python_embedded\python.exe -m pip install torch torchvision torchaudio --index-url https://download.pytorch.org/whl/cu128
+> python_embedded\python.exe -m pip install --force-reinstall torch==2.8.0+cu128 torchvision==0.23.0+cu128 torchaudio==2.8.0 --index-url https://download.pytorch.org/whl/cu128
 > ```
-> If you have an AMD GPU, use Linux and follow the Linux/ROCm [instructions](#how-to-install-). If you want to keep running on CPU, no action is required, but performance will just be reduced. See [#32](https://github.com/denizsafak/abogen/issues/32) for more details.
+>
+> If this does not resolve the issue and you are using an older NVIDIA GPU that does not support CUDA 12.8, you can try installing an older version of PyTorch that supports your GPU. For example, for CUDA 12.6, run:
+> ```bash
+> python_embedded\python.exe -m pip install --force-reinstall torch==2.8.0+cu126 torchvision==0.23.0+cu126 torchaudio==2.8.0 --index-url https://download.pytorch.org/whl/cu126
+> ```
+> 
+> If you have an AMD GPU, you need to use Linux and follow the Linux/ROCm [instructions](#linux). If you want to keep running on CPU, no action is required, but performance will just be reduced. See [#32](https://github.com/denizsafak/abogen/issues/32) for more details.

 </details>

@@ -382,7 +417,7 @@ This will start Abogen in command-line mode and display detailed error messages.
 > I faced this error when trying to run Abogen in a virtual Windows machine without GPU support. Here's how I fixed it:
 > If you installed Abogen using the Windows installer `(WINDOWS_INSTALL.bat)`, go to Abogen's folder (that contains `python_embedded`), open your terminal there and run:
 > ```bash
-> python_embedded\python.exe -m pip install torch==2.8.0 torchaudio==2.8.0 torchvision==0.23.0
+> python_embedded\python.exe -m pip install --force-reinstall torch==2.8.0+cu128 torchvision==0.23.0+cu128 torchaudio==2.8.0 --index-url https://download.pytorch.org/whl/cu128
 > ```
 > If you installed Abogen using pip, open your terminal in the virtual environment and run:
 > ```bash
@@ -443,6 +478,7 @@ Feel free to explore the code and make any changes you like.

 ## `Credits`
 - Abogen uses [Kokoro](https://github.com/hexgrad/kokoro) for its high-quality, natural-sounding text-to-speech synthesis. Huge thanks to the Kokoro team for making this possible.
+- Thanks to the [spaCy](https://spacy.io/) project for its sentence-segmentation tools, which help Abogen produce cleaner, more natural sentence segmentation.
 - Thanks to [@wojiushixiaobai](https://github.com/wojiushixiaobai) for [Embedded Python](https://github.com/wojiushixiaobai/Python-Embed-Win64) packages. These modified packages include pip pre-installed, enabling Abogen to function as a standalone application without requiring users to separately install Python in Windows.
 - Thanks to creators of [EbookLib](https://github.com/aerkalov/ebooklib), a Python library for reading and writing ePub files, which is used for extracting text from ePub files.
 - Special thanks to the [PyQt](https://www.riverbankcomputing.com/software/pyqt/) team for providing the cross-platform GUI toolkit that powers Abogen's interface.
@@ -455,7 +491,7 @@ This project is available under the MIT License - see the [LICENSE](https://gith
 ## `Star History`
 [![Star History Chart](https://api.star-history.com/svg?repos=denizsafak/abogen&type=Date)](https://www.star-history.com/#denizsafak/abogen&Date)

-> [!IMPORTANT]
-> Subtitle generation currently works only for English. This is because Kokoro provides timestamp tokens only for English text. If you want subtitles in other languages, please request this feature in the [Kokoro project](https://github.com/hexgrad/kokoro). For more technical details, see [this line](https://github.com/hexgrad/kokoro/blob/6d87f4ae7abc2d14dbc4b3ef2e5f19852e861ac2/kokoro/pipeline.py#L383) in the Kokoro's code.
+> [!NOTE]
+> Abogen supports subtitle generation for all languages. However, word-level subtitle modes (e.g., "1 word", "2 words", "3 words", etc.) are only available for English because [Kokoro provides timestamp tokens only for English text](https://github.com/hexgrad/kokoro/blob/6d87f4ae7abc2d14dbc4b3ef2e5f19852e861ac2/kokoro/pipeline.py#L383). For non-English languages, Abogen uses a duration-based fallback that supports sentence-level and comma-based subtitle modes ("Line", "Sentence", "Sentence + Comma"). If you need word-level subtitles for other languages, please request that feature in the [Kokoro project](https://github.com/hexgrad/kokoro).

-> Tags: audiobook, kokoro, text-to-speech, TTS, audiobook generator, audiobooks, text to speech, audiobook maker, audiobook creator, audiobook generator, voice-synthesis, text to audio, text to audio converter, text to speech converter, text to speech generator, text to speech software, text to speech app, epub to audio, pdf to audio, markdown to audio, content-creation, media-generation
+> Tags: audiobook, kokoro, text-to-speech, TTS, audiobook generator, audiobooks, text to speech, audiobook maker, audiobook creator, audiobook generator, voice-synthesis, text to audio, text to audio converter, text to speech converter, text to speech generator, text to speech software, text to speech app, epub to audio, pdf to audio, markdown to audio, subtitle to audio, srt to audio, ass to audio, vtt to audio, webvtt to audio, content-creation, media-generation
@@ -8,9 +8,6 @@ cd /d "%~dp0"
 :: Japanese: "ja"
 set MISAKI_LANG=en

-:: Set PyTorch CUDA version
-set CUDA_VERSION=128
-
 :::
 :::      _    ____   ___   ____  _____ _   _ 
 :::     / \  | __ ) / _ \ / ___|| ____| \ | |
@@ -281,8 +278,10 @@ if /I "%IS_NVIDIA%"=="true" (
    for /f %%i in ('%PYTHON_CONSOLE_PATH% -c "from torch.cuda import is_available; print(is_available())"') do set cuda_available=%%i

    if "%cuda_available%"=="False" (
-        echo Installing PyTorch with CUDA %CUDA_VERSION% support...
-        %PYTHON_CONSOLE_PATH% -m pip install torch torchvision torchaudio --extra-index-url https://download.pytorch.org/whl/cu%CUDA_VERSION% --no-warn-script-location
+        echo "Installing PyTorch with CUDA (12.8) support..."
+        :: We need to use an older version of PyTorch (2.8.0) until this issue is fixed: https://github.com/pytorch/pytorch/issues/166628
+        :: Solution mentioned by @mazenemam19 in #99:
+        %PYTHON_CONSOLE_PATH% -m pip install torch==2.8.0+cu128 torchvision==0.23.0+cu128 torchaudio==2.8.0 --index-url https://download.pytorch.org/whl/cu128 --no-warn-script-location
        echo.
        if errorlevel 1 (
            echo Failed to install PyTorch.
@@ -305,8 +304,10 @@ if /I "%IS_NVIDIA%"=="true" (
    if errorlevel 2 (
        echo Skipping PyTorch installation.
    ) else (
-        echo Installing PyTorch with CUDA %CUDA_VERSION% support...
-        %PYTHON_CONSOLE_PATH% -m pip install torch torchvision torchaudio --extra-index-url https://download.pytorch.org/whl/cu%CUDA_VERSION% --no-warn-script-location
+        echo "Installing PyTorch with CUDA (12.8) support..."
+        :: We need to use an older version of PyTorch (2.8.0) until this issue is fixed: https://github.com/pytorch/pytorch/issues/166628
+        :: Solution mentioned by @mazenemam19 in #99:
+        %PYTHON_CONSOLE_PATH% -m pip install torch==2.8.0+cu128 torchvision==0.23.0+cu128 torchaudio==2.8.0 --index-url https://download.pytorch.org/whl/cu128 --no-warn-script-location
        if errorlevel 1 (
            echo Failed to install PyTorch.
            pause
@@ -14,6 +14,8 @@ RUN apt-get update \
        python3-pip \
        python3-pyqt6 \
        espeak-ng \
+        libxcb-cursor0 \
+        libgl1 \
 && apt-get clean \
 && rm -rf /var/lib/apt/lists/*

@@ -1 +1 @@
-1.2.1
+1.2.4
@@ -44,6 +44,17 @@ logging.basicConfig(
    level=logging.INFO, format="%(asctime)s - %(levelname)s - %(message)s"
 )

+# Pre-compile frequently used regex patterns for better performance
+_BRACKETED_NUMBERS_PATTERN = re.compile(r"\[\s*\d+\s*\]")
+_STANDALONE_PAGE_NUMBERS_PATTERN = re.compile(r"^\s*\d+\s*$", re.MULTILINE)
+_PAGE_NUMBERS_AT_END_PATTERN = re.compile(r"\s+\d+\s*$", re.MULTILINE)
+_PAGE_NUMBERS_WITH_DASH_PATTERN = re.compile(
+    r"\s+[-–—]\s*\d+\s*[-–—]?\s*$", re.MULTILINE
+)
+_HTML_TAG_PATTERN = re.compile(r"<[^>]+>")
+_LEADING_DASH_PATTERN = re.compile(r"^\s*[-–—]\s*")
+_LEADING_SIMPLE_DASH_PATTERN = re.compile(r"^\s*-\s*")
+

 class HandlerDialog(QDialog):
    # Class variables to remember checkbox states between dialog instances
@@ -89,6 +100,9 @@ class HandlerDialog(QDialog):
    def __init__(self, book_path, file_type=None, checked_chapters=None, parent=None):
        super().__init__(parent)

+        # Normalize path
+        book_path = os.path.normpath(os.path.abspath(book_path))
+
        # Determine file type if not explicitly provided
        if file_type:
            self.file_type = file_type
@@ -374,6 +388,7 @@ class HandlerDialog(QDialog):

        # Include replace_single_newlines in cache key since it affects text cleaning
        from abogen.utils import load_config
+
        cfg = load_config()
        replace_single_newlines = cfg.get("replace_single_newlines", False)

@@ -424,19 +439,12 @@ class HandlerDialog(QDialog):
        """Pre-process all page contents from PDF document"""
        for page_num in range(len(self.pdf_doc)):
            text = clean_text(self.pdf_doc[page_num].get_text())
-            # Remove bracketed numbers (citations, footnotes)
-            text = re.sub(r"\[\s*\d+\s*\]", "", text)
-
-            # Remove standalone page numbers (numbers alone on a line)
-            text = re.sub(r"^\s*\d+\s*$", "", text, flags=re.MULTILINE)
-
-            # Remove page numbers at the end of paragraphs
-            # This pattern looks for digits surrounded by whitespace at the end of paragraphs
-            text = re.sub(r"\s+\d+\s*$", "", text, flags=re.MULTILINE)
-
-            # Also remove page numbers followed by a hyphen or dash at paragraph end
-            # (common in headers/footers like "- 42 -")
-            text = re.sub(r"\s+[-–—]\s*\d+\s*[-–—]?\s*$", "", text, flags=re.MULTILINE)
+            # Remove bracketed numbers, page numbers, etc. using pre-compiled patterns
+            # Combine all regex operations for better performance
+            text = _BRACKETED_NUMBERS_PATTERN.sub("", text)
+            text = _STANDALONE_PAGE_NUMBERS_PATTERN.sub("", text)
+            text = _PAGE_NUMBERS_AT_END_PATTERN.sub("", text)
+            text = _PAGE_NUMBERS_WITH_DASH_PATTERN.sub("", text)

            page_id = f"page_{page_num + 1}"
            self.content_texts[page_id] = text
@@ -565,7 +573,7 @@ class HandlerDialog(QDialog):
                text = clean_text(soup.get_text()).strip()
                if text:
                    self.content_texts[doc_href] = text
-                    self.content_lengths[doc_href] = len(text)
+                    self.content_lengths[doc_href] = calculate_text_length(text)

                    title = None
                    if soup.title and soup.title.string:
@@ -888,7 +896,7 @@ class HandlerDialog(QDialog):
                text = clean_text(slice_soup.get_text()).strip()
                if text:
                    self.content_texts[current_src] = text
-                    self.content_lengths[current_src] = len(text)
+                    self.content_lengths[current_src] = calculate_text_length(text)
                else:
                    self.content_texts[current_src] = ""
                    self.content_lengths[current_src] = 0
@@ -2011,7 +2019,8 @@ class HandlerDialog(QDialog):
        html_content += "<hr/>"

        if self.book_metadata["description"]:
-            desc = re.sub(r"<[^>]+>", "", self.book_metadata["description"])
+            # Use pre-compiled pattern for better performance
+            desc = _HTML_TAG_PATTERN.sub("", self.book_metadata["description"])
            html_content += f"<h3>Description:</h3><p>{desc}</p>"

        if self.file_type == "pdf":
@@ -2211,6 +2220,7 @@ class HandlerDialog(QDialog):
    def _format_metadata_tags(self):
        """Format metadata tags for insertion at the beginning of the text"""
        import datetime
+        from abogen.utils import get_user_cache_path

        metadata = self.book_metadata
        filename = os.path.splitext(os.path.basename(self.book_path))[0]
@@ -2231,6 +2241,21 @@ class HandlerDialog(QDialog):
            f"{total_chapters} {'Chapters' if self.file_type == 'epub' else 'Pages'}"
        )

+        # Handle cover image
+        cover_tag = ""
+        if metadata.get("cover_image"):
+            try:
+                import uuid
+
+                cache_dir = get_user_cache_path()
+                cover_path = os.path.join(cache_dir, f"cover_{uuid.uuid4()}.jpg")
+                cover_path = os.path.normpath(cover_path)
+                with open(cover_path, "wb") as f:
+                    f.write(metadata["cover_image"])
+                cover_tag = f"<<METADATA_COVER_PATH:{cover_path}>>"
+            except Exception as e:
+                logging.warning(f"Failed to save cover image: {e}")
+
        # Format metadata tags
        metadata_tags = [
            f"<<METADATA_TITLE:{title}>>",
@@ -2242,6 +2267,9 @@ class HandlerDialog(QDialog):
            f"<<METADATA_GENRE:Audiobook>>",
        ]

+        if cover_tag:
+            metadata_tags.append(cover_tag)
+
        return "\n".join(metadata_tags)

    def _get_markdown_selected_text(self):
@@ -2273,8 +2301,8 @@ class HandlerDialog(QDialog):
            text = self.content_texts.get(identifier)
            if text and text.strip():
                title = item.text(0)
-                # Remove leading dashes from title
-                title = re.sub(r"^\s*[-–—]\s*", "", title).strip()
+                # Remove leading dashes from title using pre-compiled pattern
+                title = _LEADING_DASH_PATTERN.sub("", title).strip()
                marker = f"<<CHAPTER_MARKER:{title}>>"
                chapter_texts.append(marker + "\n" + text)

@@ -2308,7 +2336,8 @@ class HandlerDialog(QDialog):
            text = self.content_texts.get(identifier)
            if text and text.strip():
                title = item.text(0)
-                title = re.sub(r"^\s*[-–—]\s*", "", title).strip()
+                # Use pre-compiled pattern for better performance
+                title = _LEADING_DASH_PATTERN.sub("", title).strip()
                marker = f"<<CHAPTER_MARKER:{title}>>"
                chapter_texts.append(marker + "\n" + text)

@@ -2378,12 +2407,16 @@ class HandlerDialog(QDialog):
                            combined_text += "\n\n" + child_text
                        included_text_ids.add(child_id)
                    if combined_text.strip():
-                        title = re.sub(r"^\s*-\s*", "", parent_title).strip()
+                        # Use pre-compiled pattern for better performance
+                        title = _LEADING_SIMPLE_DASH_PATTERN.sub(
+                            "", parent_title
+                        ).strip()
                        marker = f"<<CHAPTER_MARKER:{title}>>"
                        section_titles.append((title, marker + "\n" + combined_text))
                        included_text_ids.add(parent_id)
                elif not parent_checked and checked_children:
-                    title = re.sub(r"^\s*-\s*", "", parent_title).strip()
+                    # Use pre-compiled pattern for better performance
+                    title = _LEADING_SIMPLE_DASH_PATTERN.sub("", parent_title).strip()
                    marker = f"<<CHAPTER_MARKER:{title}>>"
                    for idx, (child, child_id) in enumerate(checked_children):
                        text = self.content_texts.get(child_id, "")
@@ -2403,7 +2436,8 @@ class HandlerDialog(QDialog):
                    text = self.content_texts.get(identifier, "")
                    if text:
                        title = item.text(0)
-                        title = re.sub(r"^\s*-\s*", "", title).strip()
+                        # Use pre-compiled pattern for better performance
+                        title = _LEADING_SIMPLE_DASH_PATTERN.sub("", title).strip()
                        marker = f"<<CHAPTER_MARKER:{title}>>"
                        section_titles.append((title, marker + "\n" + text))
                        included_text_ids.add(identifier)
@@ -2,9 +2,7 @@ from abogen.utils import get_version

 # Program Information
 PROGRAM_NAME = "abogen"
-PROGRAM_DESCRIPTION = (
-    "Generate audiobooks from EPUBs, PDFs and text with synchronized captions."
-)
+PROGRAM_DESCRIPTION = "Generate audiobooks from EPUBs, PDFs, text and subtitles with synchronized captions."
 GITHUB_URL = "https://github.com/denizsafak/abogen"
 VERSION = get_version()

@@ -44,6 +42,7 @@ SUPPORTED_SOUND_FORMATS = [
 SUPPORTED_SUBTITLE_FORMATS = [
    "srt",
    "ass",
+    "vtt",
 ]

 # Supported input formats
@@ -51,6 +50,9 @@ SUPPORTED_INPUT_FORMATS = [
    "epub",
    "pdf",
    "txt",
+    "srt",
+    "ass",
+    "vtt",
 ]

 # Supported languages for subtitle generation
@@ -59,10 +61,7 @@ SUPPORTED_INPUT_FORMATS = [
 # Please refer to: https://github.com/hexgrad/kokoro/blob/6d87f4ae7abc2d14dbc4b3ef2e5f19852e861ac2/kokoro/pipeline.py
 # 383 English processing (unchanged)
 # 384 if self.lang_code in 'ab':
-SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION = [
-    "a",
-    "b",
-]
+SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION = list(LANGUAGE_DESCRIPTIONS.keys())

 # Voice and sample text constants
 VOICES_INTERNAL = [
@@ -1,5 +1,6 @@
 import os
 import time
+import sys
 import tempfile
 import platform
 import base64
@@ -161,7 +162,7 @@ class InputBox(QLabel):
        self.setAlignment(Qt.AlignmentFlag.AlignCenter)
        self.setAcceptDrops(True)
        self.setText(
-            "Drag and drop your file here or click to browse.\n(.txt, .epub, .pdf, .md)"
+            "Drag and drop your file here or click to browse.\n(.txt, .epub, .pdf, .md, .srt, .ass, .vtt)"
        )
        self.setStyleSheet(
            f"QLabel {{ {self.STYLE_DEFAULT} }} QLabel:hover {{ {self.STYLE_DEFAULT_HOVER} }}"
@@ -255,7 +256,7 @@ class InputBox(QLabel):
            except Exception:
                return str(n)

-        doc_extensions = (".epub", ".pdf", ".md", ".markdown")
+        doc_extensions = (".epub", ".pdf", ".md", ".markdown", ".srt", ".ass", ".vtt")
        char_source_path = file_path
        cached_char_count = None

@@ -321,11 +322,11 @@ class InputBox(QLabel):
            else:  # PDF - always use Pages
                self.chapters_btn.setText(f"Pages ({chapter_count})")

-        # Hide textbox and show edit only for .txt files
+        # Hide textbox and show edit only for .txt, .srt, .ass, .vtt files
        self.textbox_btn.hide()
-        # Show edit button for txt files directly
+        # Show edit button for txt/subtitle files directly
        # Or for epub/pdf files that have generated a temp txt file
-        should_show_edit = file_path.lower().endswith(".txt")
+        should_show_edit = file_path.lower().endswith((".txt", ".srt", ".ass", ".vtt"))

        # For epub/pdf files, show edit if we have a selected_file (temp txt)
        if (
@@ -337,6 +338,12 @@ class InputBox(QLabel):

        self.edit_btn.setVisible(should_show_edit)
        self.go_to_folder_btn.show()
+
+        # Disable subtitle generation for subtitle input files
+        is_subtitle_input = file_path.lower().endswith((".srt", ".ass", ".vtt"))
+        if hasattr(window, "subtitle_combo"):
+            window.subtitle_combo.setEnabled(not is_subtitle_input)
+
        # Enable add to queue button only when file is accepted (input box is green)
        self.resizeEvent(None)
        if hasattr(window, "btn_add_to_queue"):
@@ -367,7 +374,7 @@ class InputBox(QLabel):
        self.window().save_chapters_separately = None
        self.window().merge_chapters_at_end = None
        self.setText(
-            "Drag and drop your file here or click to browse.\n(.txt, .epub, .pdf, .md)"
+            "Drag and drop your file here or click to browse.\n(.txt, .epub, .pdf, .md, .srt, .ass, .vtt)"
        )
        self.setStyleSheet(
            f"QLabel {{ {self.STYLE_DEFAULT} }} QLabel:hover {{ {self.STYLE_DEFAULT_HOVER} }}"
@@ -379,9 +386,21 @@ class InputBox(QLabel):
        self.textbox_btn.show()
        self.edit_btn.hide()
        self.go_to_folder_btn.hide()
+
+        # Re-enable subtitle and replace newlines controls when cleared
+        window = self.window()
+        if hasattr(window, "subtitle_combo"):
+            # Only enable if language supports it
+            current_lang = getattr(window, "selected_lang", "a")
+            window.subtitle_combo.setEnabled(
+                current_lang in SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION
+            )
+        if hasattr(window, "replace_newlines_combo"):
+            window.replace_newlines_combo.setEnabled(True)
+
        # Disable add to queue button when input is cleared
-        if hasattr(self.window(), "btn_add_to_queue"):
-            self.window().btn_add_to_queue.setEnabled(False)
+        if hasattr(window, "btn_add_to_queue"):
+            window.btn_add_to_queue.setEnabled(False)
        # Reset the input_box_cleared_by_queue flag after setting file info
        if hasattr(self.window(), "input_box_cleared_by_queue"):
            self.window().input_box_cleared_by_queue = True
@@ -407,6 +426,7 @@ class InputBox(QLabel):
                    or ext.endswith(".epub")
                    or ext.endswith(".pdf")
                    or ext.endswith((".md", ".markdown"))
+                    or ext.endswith((".srt", ".ass", ".vtt"))
                ):
                    event.acceptProposedAction()
                    # Set hover style based on current state
@@ -460,12 +480,20 @@ class InputBox(QLabel):
                file_path.lower().endswith(".epub")
                or file_path.lower().endswith(".pdf")
                or file_path.lower().endswith((".md", ".markdown"))
+                or file_path.lower().endswith((".srt", ".ass", ".vtt"))
            ):
                # Determine file type
                if file_path.lower().endswith(".epub"):
                    file_type = "epub"
                elif file_path.lower().endswith(".pdf"):
                    file_type = "pdf"
+                elif file_path.lower().endswith((".srt", ".ass", ".vtt")):
+                    # For subtitle files, treat them like txt files (direct processing)
+                    win.selected_file, win.selected_file_type = file_path, "txt"
+                    win.displayed_file_path = file_path
+                    self.set_file_info(file_path)
+                    event.acceptProposedAction()
+                    return
                else:
                    file_type = "markdown"

@@ -477,7 +505,9 @@ class InputBox(QLabel):
                )
                event.acceptProposedAction()
            else:
-                self.set_error("Please drop a .txt, .epub, .pdf, or .md file.")
+                self.set_error(
+                    "Please drop a .txt, .epub, .pdf, .md, .srt, .ass, or .vtt file."
+                )
                event.ignore()
        else:
            event.ignore()
@@ -795,7 +825,10 @@ class abogen(QWidget):
        self.use_gpu = self.config.get(
            "use_gpu", True  # Load GPU setting with default True
        )
-        self.replace_single_newlines = self.config.get("replace_single_newlines", False)
+        self.replace_single_newlines = self.config.get("replace_single_newlines", True)
+        self.use_silent_gaps = self.config.get("use_silent_gaps", True)
+        self.subtitle_speed_method = self.config.get("subtitle_speed_method", "tts")
+        self.use_spacy_segmentation = self.config.get("use_spacy_segmentation", True)
        self._pending_close_event = None
        self.gpu_ok = False  # Initialize GPU availability status

@@ -1031,9 +1064,6 @@ class abogen(QWidget):
        )
        self.subtitle_combo.setCurrentText(self.subtitle_mode)
        self.subtitle_combo.currentTextChanged.connect(self.on_subtitle_mode_changed)
-        # Enable/disable subtitle options based on selected language (profile or voice)
-        enable = self.selected_lang in SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION
-        self.subtitle_combo.setEnabled(enable)
        subtitle_layout.addWidget(self.subtitle_combo)
        controls_layout.addLayout(subtitle_layout)

@@ -1115,10 +1145,10 @@ class abogen(QWidget):
        except Exception:
            # Fail-safe: don't crash UI if model manipulation isn't supported on some platforms
            pass
-        # Enable/disable subtitle format based on selected language
-        self.subtitle_format_combo.setEnabled(
-            self.selected_lang in SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION
-        )
+
+        # Enable/disable subtitle options based on selected language (profile or voice)
+        self.update_subtitle_options_availability()
+
        controls_layout.addLayout(subtitle_format_layout)

        # Replace single newlines dropdown (acts like checkbox)
@@ -1291,7 +1321,10 @@ class abogen(QWidget):
            return
        try:
            file_path, _ = QFileDialog.getOpenFileName(
-                self, "Select File", "", "Supported Files (*.txt *.epub *.pdf *.md)"
+                self,
+                "Select File",
+                "",
+                "Supported Files (*.txt *.epub *.pdf *.md *.srt *.ass *.vtt)",
            )
            if not file_path:
                return
@@ -1312,6 +1345,11 @@ class abogen(QWidget):
                # Don't set file info immediately, open_book_file will handle it after dialog is accepted
                if not self.open_book_file(file_path):
                    return
+            elif file_path.lower().endswith((".srt", ".ass", ".vtt")):
+                # Handle subtitle files like text files
+                self.selected_file, self.selected_file_type = file_path, "txt"
+                self.displayed_file_path = file_path
+                self.input_box.set_file_info(file_path)
            else:
                self.selected_file, self.selected_file_type = file_path, "txt"
                self.displayed_file_path = (
@@ -1551,19 +1589,69 @@ class abogen(QWidget):
        self.config["speed"] = s
        save_config(self.config)

+    def update_subtitle_options_availability(self):
+        """
+        Update the enabled state of subtitle options based on the selected language.
+        For non-English languages, only sentence-based and line-based modes are supported.
+        """
+        # Check if current file is a subtitle file
+        is_subtitle_input = False
+        if self.selected_file and self.selected_file.lower().endswith(
+            (".srt", ".ass", ".vtt")
+        ):
+            is_subtitle_input = True
+
+        if self.selected_lang not in SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION:
+            self.subtitle_combo.setEnabled(False)
+            self.subtitle_format_combo.setEnabled(False)
+            return
+
+        # Only enable subtitle_combo if it's NOT a subtitle input
+        self.subtitle_combo.setEnabled(not is_subtitle_input)
+        self.subtitle_format_combo.setEnabled(True)
+
+        is_english = self.selected_lang in ["a", "b"]
+
+        # Items to keep enabled for non-English
+        allowed_modes = ["Disabled", "Line", "Sentence", "Sentence + Comma"]
+
+        model = self.subtitle_combo.model()
+        for i in range(self.subtitle_combo.count()):
+            text = self.subtitle_combo.itemText(i)
+            item = model.item(i)
+            if not item:
+                continue
+
+            if is_english:
+                item.setEnabled(True)
+            else:
+                if text in allowed_modes:
+                    item.setEnabled(True)
+                else:
+                    item.setEnabled(False)
+
+        # If current selection is disabled, switch to a valid one
+        current_text = self.subtitle_combo.currentText()
+        current_idx = self.subtitle_combo.currentIndex()
+        current_item = model.item(current_idx)
+
+        if current_item and not current_item.isEnabled():
+            # Switch to "Sentence" if available, else "Disabled"
+            sentence_idx = self.subtitle_combo.findText("Sentence")
+            if sentence_idx >= 0:
+                self.subtitle_combo.setCurrentIndex(sentence_idx)
+            else:
+                self.subtitle_combo.setCurrentIndex(0)  # Disabled
+
+        self.subtitle_mode = self.subtitle_combo.currentText()
+
    def on_voice_changed(self, index):
        voice = self.voice_combo.itemData(index)
        self.selected_voice, self.selected_lang = voice, voice[0]
        self.config["selected_voice"] = voice
        save_config(self.config)
        # Enable/disable subtitle options based on language
-        if self.selected_lang in SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION:
-            self.subtitle_combo.setEnabled(True)
-            self.subtitle_format_combo.setEnabled(True)
-            self.subtitle_mode = self.subtitle_combo.currentText()
-        else:
-            self.subtitle_combo.setEnabled(False)
-            self.subtitle_format_combo.setEnabled(False)
+        self.update_subtitle_options_availability()

    def on_voice_combo_changed(self, index):
        data = self.voice_combo.itemData(index)
@@ -1585,12 +1673,7 @@ class abogen(QWidget):
            self.config.pop("selected_voice", None)
            save_config(self.config)
            # enable subtitles based on profile language
-            self.subtitle_combo.setEnabled(
-                self.selected_lang in SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION
-            )
-            self.subtitle_format_combo.setEnabled(
-                self.selected_lang in SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION
-            )
+            self.update_subtitle_options_availability()
        else:
            self.mixed_voice_state = None
            self.selected_profile_name = None
@@ -1599,13 +1682,7 @@ class abogen(QWidget):
            if "selected_profile_name" in self.config:
                del self.config["selected_profile_name"]
            save_config(self.config)
-            if self.selected_lang in SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION:
-                self.subtitle_combo.setEnabled(True)
-                self.subtitle_format_combo.setEnabled(True)
-                self.subtitle_mode = self.subtitle_combo.currentText()
-            else:
-                self.subtitle_combo.setEnabled(False)
-                self.subtitle_format_combo.setEnabled(False)
+            self.update_subtitle_options_availability()

    def update_subtitle_combo_for_profile(self, profile_name):
        from abogen.voice_profiles import load_profiles
@@ -1817,6 +1894,8 @@ class abogen(QWidget):
            output_format=self.selected_format,
            total_char_count=self.char_count,
            replace_single_newlines=self.replace_single_newlines,
+            use_silent_gaps=self.use_silent_gaps,
+            subtitle_speed_method=self.subtitle_speed_method,
            save_base_path=save_base_path,
            save_chapters_separately=getattr(self, "save_chapters_separately", None),
            merge_chapters_at_end=getattr(self, "merge_chapters_at_end", None),
@@ -1900,6 +1979,7 @@ class abogen(QWidget):
            self.replace_single_newlines = getattr(
                queued_item, "replace_single_newlines", False
            )
+            self.use_silent_gaps = getattr(queued_item, "use_silent_gaps", False)
            # Restore the original file path for save location
            self.displayed_file_path = (
                queued_item.save_base_path or queued_item.file_name
@@ -2002,7 +2082,7 @@ class abogen(QWidget):
        # pipeline_loaded_callback remains unchanged
        def pipeline_loaded_callback(np_module, kpipeline_class, error):
            if error:
-                self.update_log((f"Error loading numpy or KPipeline: {error}", False))
+                self.update_log((f"Error loading numpy or KPipeline: {error}", "red"))
                prevent_sleep_end()
                return

@@ -2045,6 +2125,12 @@ class abogen(QWidget):
            self.conversion_thread.replace_single_newlines = (
                self.replace_single_newlines
            )
+            # Pass use_silent_gaps setting
+            self.conversion_thread.use_silent_gaps = self.use_silent_gaps
+            # Pass subtitle_speed_method setting
+            self.conversion_thread.subtitle_speed_method = self.subtitle_speed_method
+            # Pass use_spacy_segmentation setting
+            self.conversion_thread.use_spacy_segmentation = self.use_spacy_segmentation
            # Pass separate_chapters_format setting
            self.conversion_thread.separate_chapters_format = (
                self.separate_chapters_format
@@ -2181,7 +2267,7 @@ class abogen(QWidget):
        self.is_converting = False
        elapsed = int(time.time() - self.start_time)
        h, m, s = elapsed // 3600, (elapsed % 3600) // 60, elapsed % 60
-        self.update_log(f"\nTime elapsed: {h:02d}:{m:02d}:{s:02d}")
+        self.update_log((f"\nTime elapsed: {h:02d}:{m:02d}:{s:02d}", "grey"))

        # Default to showing the button
        show_open_file_button = True
@@ -2744,6 +2830,33 @@ class abogen(QWidget):
            self.conversion_thread.cancel()
            self.conversion_thread.wait()

+    def cleanup_preview_threads(self):
+        # Stop preview generation thread
+        if (
+            hasattr(self, "preview_thread")
+            and self.preview_thread is not None
+            and self.preview_thread.isRunning()
+        ):
+            self.preview_thread.terminate()
+            self.preview_thread.wait()
+
+        # Stop audio playback thread
+        if (
+            hasattr(self, "play_audio_thread")
+            and self.play_audio_thread is not None
+            and self.play_audio_thread.isRunning()
+        ):
+            self.play_audio_thread.stop()
+            self.play_audio_thread.wait()
+
+        # Cleanup pygame mixer if initialized
+        try:
+            pygame = sys.modules.get("pygame")
+            if pygame and pygame.mixer.get_init():
+                pygame.mixer.quit()
+        except Exception:
+            pass
+
    def closeEvent(self, event):
        if self.is_converting:
            box = QMessageBox(self)
@@ -2758,21 +2871,40 @@ class abogen(QWidget):
            box.setDefaultButton(QMessageBox.StandardButton.No)
            if box.exec() == QMessageBox.StandardButton.Yes:
                self.cleanup_conversion_thread()
+                self.cleanup_preview_threads()
                event.accept()
            else:
                event.ignore()
        else:
            self.cleanup_conversion_thread()
+            self.cleanup_preview_threads()
            event.accept()

    def show_chapter_options_dialog(self, chapter_count):
        """Show dialog to ask user about chapter processing options when chapters are detected in a .txt file"""
+        # Check if this is a timestamp detection (-1) or chapter detection
+        if chapter_count == -1:
+            from abogen.conversion import TimestampDetectionDialog
+
+            dialog = TimestampDetectionDialog(parent=self)
+            dialog.setWindowModality(Qt.WindowModality.ApplicationModal)
+
+            # Dialog always accepts (Yes or No), never cancels the conversion
+            dialog.exec()
+            treat_as_subtitle = dialog.use_timestamps()
+            if (
+                hasattr(self, "conversion_thread")
+                and self.conversion_thread.isRunning()
+            ):
+                self.conversion_thread.set_timestamp_response(treat_as_subtitle)
+            return
+
+        # Normal chapter detection
        from abogen.conversion import ChapterOptionsDialog

        dialog = ChapterOptionsDialog(chapter_count, parent=self)
        dialog.setWindowModality(Qt.WindowModality.ApplicationModal)

-        # If dialog is accepted, pass the options to the conversion thread
        if dialog.exec() == QDialog.DialogCode.Accepted:
            options = dialog.get_options()
            if (
@@ -2781,7 +2913,6 @@ class abogen(QWidget):
            ):
                self.conversion_thread.set_chapter_options(options)
        else:
-            # If dialog is rejected, cancel the conversion
            self.cancel_conversion()

    def apply_theme(self, theme):
@@ -3040,6 +3171,63 @@ class abogen(QWidget):
        # Add separator
        menu.addSeparator()

+        # Add use silent gaps option (for subtitle files)
+        self.silent_gaps_action = QAction("Use silent gaps between subtitles", self)
+        self.silent_gaps_action.setCheckable(True)
+        self.silent_gaps_action.setChecked(self.use_silent_gaps)
+        self.silent_gaps_action.triggered.connect(
+            lambda checked: self.toggle_use_silent_gaps(checked)
+        )
+        menu.addAction(self.silent_gaps_action)
+
+        # Subtitle speed adjustment method
+        speed_method_menu = menu.addMenu("Subtitle speed adjustment method")
+        speed_method_menu.setToolTip(
+            "Choose speed adjustment method:\n"
+            "TTS Regeneration: Better quality\n"
+            "FFmpeg Time-stretch: Faster processing"
+        )
+
+        speed_method_group = QActionGroup(self)
+        speed_method_group.setExclusive(True)
+
+        for method, label in [
+            ("tts", "TTS Regeneration (better quality)"),
+            ("ffmpeg", "FFmpeg Time-stretch (better speed)"),
+        ]:
+            action = QAction(label, speed_method_menu)
+            action.setCheckable(True)
+            action.setChecked(self.subtitle_speed_method == method)
+            action.triggered.connect(
+                lambda checked, m=method: self.toggle_subtitle_speed_method(m)
+            )
+            speed_method_group.addAction(action)
+            speed_method_menu.addAction(action)
+
+        self.speed_method_group = speed_method_group
+
+        # Add separator
+        menu.addSeparator()
+
+        # Add spaCy sentence segmentation option
+        spacy_action = QAction("Use spaCy for sentence segmentation", self)
+        spacy_action.setCheckable(True)
+        spacy_action.setChecked(self.use_spacy_segmentation)
+        spacy_action.triggered.connect(
+            lambda checked: self.toggle_spacy_segmentation(checked)
+        )
+        menu.addAction(spacy_action)
+
+        # Add separator
+        menu.addSeparator()
+
+        # Add "Pre-download models and voices for offline use" option
+        predownload_action = QAction(
+            "Pre-download models and voices for offline use", self
+        )
+        predownload_action.triggered.connect(self.show_predownload_dialog)
+        menu.addAction(predownload_action)
+
        # Add "Disable Kokoro's internet access" option
        disable_kokoro_action = QAction("Disable Kokoro's internet access", self)
        disable_kokoro_action.setCheckable(True)
@@ -3075,6 +3263,40 @@ class abogen(QWidget):
        self.config["replace_single_newlines"] = enabled
        save_config(self.config)

+    def toggle_use_silent_gaps(self, enabled):
+        # Show confirmation dialog with explanation
+        action = "enable" if enabled else "disable"
+        message = (
+            "When enabled, allows speech to continue naturally into the silent periods between subtitles, "
+            "preventing unnecessary audio speed-up based on subtitle end timestamps.\n\nWhen disabled, ensures strict subtitle timing where "
+            f"audio ends exactly when the subtitle ends.\n\nDo you want to {action} this option?"
+        )
+
+        reply = QMessageBox.question(
+            self,
+            "Use Silent Gaps Between Subtitles",
+            message,
+            QMessageBox.StandardButton.Ok | QMessageBox.StandardButton.Cancel,
+        )
+
+        if reply == QMessageBox.StandardButton.Ok:
+            self.use_silent_gaps = enabled
+            self.config["use_silent_gaps"] = enabled
+            save_config(self.config)
+        else:
+            # Revert the checkbox state if cancelled
+            self.silent_gaps_action.setChecked(not enabled)
+
+    def toggle_subtitle_speed_method(self, method):
+        self.subtitle_speed_method = method
+        self.config["subtitle_speed_method"] = method
+        save_config(self.config)
+
+    def toggle_spacy_segmentation(self, enabled):
+        self.use_spacy_segmentation = enabled
+        self.config["use_spacy_segmentation"] = enabled
+        save_config(self.config)
+
    def restart_app(self):

        import sys
@@ -3370,6 +3592,13 @@ Categories=AudioVideo;Audio;Utility;
                    self.voice_combo.setCurrentIndex(idx)
            self.mixed_voice_state = dialog.get_selected_voices()

+    def show_predownload_dialog(self):
+        """Show the pre-download models and voices dialog."""
+        from abogen.predownload_gui import PreDownloadDialog
+
+        dialog = PreDownloadDialog(self)
+        dialog.exec()
+
    def show_about_dialog(self):
        """Show an About dialog with program information including GitHub link."""
        # Get application icon for dialog
@@ -3521,9 +3750,9 @@ Categories=AudioVideo;Audio;Utility;
            # Get the abogen cache directory
            cache_dir = get_user_cache_path()

-            # Find all .txt files in the abogen cache directory
-            pattern = os.path.join(cache_dir, "*.txt")
-            cache_files = glob.glob(pattern)
+            # Find all .txt files and cover images in the abogen cache directory
+            cache_files = glob.glob(os.path.join(cache_dir, "*.txt"))
+            cache_files.extend(glob.glob(os.path.join(cache_dir, "cover_*.jpg")))

            # Count the files
            file_count = len(cache_files)
@@ -3555,7 +3784,7 @@ Categories=AudioVideo;Audio;Utility;
            msg_box.setText(msg_text + "\nDo you want to delete them?")

            # Add checkbox for preview cache
-            preview_cache_checkbox = QCheckBox("Clean preview cache", msg_box)
+            preview_cache_checkbox = QCheckBox("Also clean preview cache", msg_box)
            preview_cache_checkbox.setChecked(False)
            # Only enable checkbox if preview files exist
            preview_cache_checkbox.setEnabled(preview_count > 0)
@@ -4,6 +4,23 @@ import platform
 import atexit
 import signal

+# Fix PyTorch DLL loading issue ([WinError 1114]) on Windows before importing PyQt6
+if platform.system() == "Windows":
+    import ctypes
+    from importlib.util import find_spec
+
+    try:
+        if (
+            (spec := find_spec("torch"))
+            and spec.origin
+            and os.path.exists(
+                dll_path := os.path.join(os.path.dirname(spec.origin), "lib", "c10.dll")
+            )
+        ):
+            ctypes.CDLL(os.path.normpath(dll_path))
+    except Exception:
+        pass
+
 # Qt platform plugin detection (fixes #59)
 try:
    from PyQt6.QtCore import QLibraryInfo
@@ -134,7 +151,7 @@ def main():
    # Set the .desktop name on Linux
    if platform.system() == "Linux":
        try:
-            app.setDesktopFileName("abogen.desktop")
+            app.setDesktopFileName("abogen")
        except AttributeError:
            pass

@@ -0,0 +1,590 @@
+"""
+Pre-download dialog and worker for Abogen
+
+This module consolidates pre-download logic for Kokoro voices and model
+and spaCy language models. The code favors clarity, avoids duplication,
+and handles optional dependencies gracefully.
+"""
+
+from typing import List, Optional, Tuple
+import importlib
+import importlib.util
+
+from PyQt6.QtWidgets import (
+    QDialog,
+    QVBoxLayout,
+    QHBoxLayout,
+    QLabel,
+    QPushButton,
+    QSpacerItem,
+    QSizePolicy,
+)
+from PyQt6.QtCore import QThread, pyqtSignal
+
+from abogen.constants import COLORS, VOICES_INTERNAL
+from abogen.spacy_utils import SPACY_MODELS
+import abogen.hf_tracker
+
+
+# Helpers
+def _unique_sorted_models() -> List[str]:
+    """Return a sorted list of unique spaCy model package names."""
+    return sorted(set(SPACY_MODELS.values()))
+
+
+def _is_package_installed(pkg_name: str) -> bool:
+    """Return True if a package with the given name can be imported (site-packages)."""
+    try:
+        return importlib.util.find_spec(pkg_name) is not None
+    except Exception:
+        return False
+
+
+# NOTE: explicit HF cache helper removed; we use try_to_load_from_cache in-scope where needed
+
+
+class PreDownloadWorker(QThread):
+    """Worker thread to download required models/voices.
+
+    Emits human-readable messages via `progress`. Uses `category_done` to indicate
+    a category (voices/model/spacy) finished successfully. Emits `error` on exception
+    and `finished` after all work completes.
+    """
+
+    # Emit (category, status, message)
+    progress = pyqtSignal(str, str, str)
+    category_done = pyqtSignal(str)
+    finished = pyqtSignal()
+    error = pyqtSignal(str)
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self._cancelled = False
+        # repo and filenames used for Kokoro model
+        self._repo_id = "hexgrad/Kokoro-82M"
+        self._model_files = ["kokoro-v1_0.pth", "config.json"]
+        # Track download success per category
+        self._voices_success = False
+        self._model_success = False
+        self._spacy_success = False
+        # Suppress HF tracker warnings during downloads
+        self._original_emitter = abogen.hf_tracker.show_warning_signal_emitter
+
+    def cancel(self) -> None:
+        self._cancelled = True
+
+    def run(self) -> None:
+        # Suppress HF tracker warnings during downloads
+        abogen.hf_tracker.show_warning_signal_emitter = None
+        try:
+            self._download_kokoro_voices()
+            if self._cancelled:
+                return
+            if self._voices_success:
+                self.category_done.emit("voices")
+
+            self._download_kokoro_model()
+            if self._cancelled:
+                return
+            if self._model_success:
+                self.category_done.emit("model")
+
+            self._download_spacy_models()
+            if self._cancelled:
+                return
+            if self._spacy_success:
+                self.category_done.emit("spacy")
+
+            self.finished.emit()
+        except Exception as exc:  # pragma: no cover - best-effort reporting
+            self.error.emit(str(exc))
+        finally:
+            # Restore original emitter
+            abogen.hf_tracker.show_warning_signal_emitter = self._original_emitter
+
+    # Kokoro voices
+    def _download_kokoro_voices(self) -> None:
+        self._voices_success = True
+        try:
+            from huggingface_hub import hf_hub_download, try_to_load_from_cache
+        except Exception:
+            self.progress.emit(
+                "voice", "warning", "huggingface_hub not installed, skipping voices..."
+            )
+            self._voices_success = False
+            return
+
+        voice_list = VOICES_INTERNAL
+        for idx, voice in enumerate(voice_list, start=1):
+            if self._cancelled:
+                self._voices_success = False
+                return
+            filename = f"voices/{voice}.pt"
+            if try_to_load_from_cache(repo_id=self._repo_id, filename=filename):
+                self.progress.emit(
+                    "voice",
+                    "installed",
+                    f"{idx}/{len(voice_list)}: {voice} already present",
+                )
+                continue
+            self.progress.emit(
+                "voice", "downloading", f"{idx}/{len(voice_list)}: {voice}..."
+            )
+            try:
+                hf_hub_download(repo_id=self._repo_id, filename=filename)
+                self.progress.emit("voice", "downloaded", f"{voice} downloaded")
+            except Exception as exc:
+                self.progress.emit(
+                    "voice", "warning", f"could not download {voice}: {exc}"
+                )
+                self._voices_success = False
+
+    # Kokoro model
+    def _download_kokoro_model(self) -> None:
+        self._model_success = True
+        try:
+            from huggingface_hub import hf_hub_download, try_to_load_from_cache
+        except Exception:
+            self.progress.emit(
+                "model", "warning", "huggingface_hub not installed, skipping model..."
+            )
+            self._model_success = False
+            return
+        for fname in self._model_files:
+            if self._cancelled:
+                self._model_success = False
+                return
+            category = "config" if fname == "config.json" else "model"
+            if try_to_load_from_cache(repo_id=self._repo_id, filename=fname):
+                self.progress.emit(
+                    category, "installed", f"file {fname} already present"
+                )
+                continue
+            self.progress.emit(category, "downloading", f"file {fname}...")
+            try:
+                hf_hub_download(repo_id=self._repo_id, filename=fname)
+                self.progress.emit(category, "downloaded", f"file {fname} downloaded")
+            except Exception as exc:
+                self.progress.emit(
+                    category, "warning", f"could not download file {fname}: {exc}"
+                )
+                self._model_success = False
+
+    # spaCy models
+    def _download_spacy_models(self) -> None:
+        """Download spaCy models. Prefer missing models provided by parent.
+
+        Parent dialog will populate _spacy_models_missing during checking.
+        """
+        self._spacy_success = True
+        # Determine which models to process: prefer parent-provided missing list to avoid
+        # re-checking everything; otherwise use the full unique list.
+        parent = self.parent()
+        models_to_process: List[str] = _unique_sorted_models()
+        try:
+            if (
+                parent is not None
+                and hasattr(parent, "_spacy_models_missing")
+                and parent._spacy_models_missing
+            ):
+                models_to_process = list(dict.fromkeys(parent._spacy_models_missing))
+        except Exception:
+            pass
+
+        # If spaCy is not available to run the CLI, skip gracefully
+        try:
+            import spacy.cli as _spacy_cli
+        except Exception:
+            self.progress.emit(
+                "spacy", "warning", "spaCy not available, skipping spaCy models..."
+            )
+            self._spacy_success = False
+            return
+
+        for idx, model_name in enumerate(models_to_process, start=1):
+            if self._cancelled:
+                self._spacy_success = False
+                return
+            if _is_package_installed(model_name):
+                self.progress.emit(
+                    "spacy",
+                    "installed",
+                    f"{idx}/{len(models_to_process)}: {model_name} already installed",
+                )
+                continue
+            self.progress.emit(
+                "spacy",
+                "downloading",
+                f"{idx}/{len(models_to_process)}: {model_name}...",
+            )
+            try:
+                _spacy_cli.download(model_name)
+                self.progress.emit("spacy", "downloaded", f"{model_name} downloaded")
+            except Exception as exc:
+                self.progress.emit(
+                    "spacy", "warning", f"could not download {model_name}: {exc}"
+                )
+                self._spacy_success = False
+
+
+class PreDownloadDialog(QDialog):
+    """Dialog to show and control pre-download process."""
+
+    VOICE_PREFIX = "Kokoro voices: "
+    MODEL_PREFIX = "Kokoro model: "
+    CONFIG_PREFIX = "Kokoro config: "
+    SPACY_PREFIX = "spaCy models: "
+
+    def __init__(self, parent=None):
+        super().__init__(parent)
+        self.setWindowTitle("Pre-download Models and Voices")
+        self.setMinimumWidth(500)
+        self.worker: Optional[PreDownloadWorker] = None
+        self.has_missing = False
+        self._spacy_models_checked: List[tuple] = []
+        self._spacy_models_missing: List[str] = []
+        self._status_worker = None
+
+        # Map keywords to (label, prefix) - labels filled after UI creation
+        self.status_map = {
+            "voice": (None, self.VOICE_PREFIX),
+            "spacy": (None, self.SPACY_PREFIX),
+            "model": (None, self.MODEL_PREFIX),
+            "config": (None, self.CONFIG_PREFIX),
+        }
+
+        self.category_map = {
+            "voices": ["voice"],
+            "model": ["model", "config"],
+            "spacy": ["spacy"],
+        }
+
+        self._setup_ui()
+        self._start_status_check()
+
+    def _setup_ui(self) -> None:
+        layout = QVBoxLayout(self)
+        layout.setSpacing(0)
+        layout.setContentsMargins(15, 0, 15, 15)
+
+        desc = QLabel(
+            "You can pre-download all required models and voices for offline use.\n"
+            "This includes Kokoro voices, Kokoro model (and config), and spaCy models."
+        )
+        desc.setWordWrap(True)
+        layout.addWidget(desc)
+
+        # Status rows
+        status_layout = QVBoxLayout()
+        status_title = QLabel("<b>Current Status:</b>")
+        status_layout.addWidget(status_title)
+
+        self.voices_status = QLabel(self.VOICE_PREFIX + "⏳ Checking...")
+        row = QHBoxLayout()
+        row.addWidget(self.voices_status)
+        row.addStretch()
+        status_layout.addLayout(row)
+
+        self.model_status = QLabel(self.MODEL_PREFIX + "⏳ Checking...")
+        row = QHBoxLayout()
+        row.addWidget(self.model_status)
+        row.addStretch()
+        status_layout.addLayout(row)
+
+        self.config_status = QLabel(self.CONFIG_PREFIX + "⏳ Checking...")
+        row = QHBoxLayout()
+        row.addWidget(self.config_status)
+        row.addStretch()
+        status_layout.addLayout(row)
+
+        self.spacy_status = QLabel(self.SPACY_PREFIX + "⏳ Checking...")
+        row = QHBoxLayout()
+        row.addWidget(self.spacy_status)
+        row.addStretch()
+        status_layout.addLayout(row)
+
+        # register labels
+        self.status_map["voice"] = (self.voices_status, self.VOICE_PREFIX)
+        self.status_map["model"] = (self.model_status, self.MODEL_PREFIX)
+        self.status_map["config"] = (self.config_status, self.CONFIG_PREFIX)
+        self.status_map["spacy"] = (self.spacy_status, self.SPACY_PREFIX)
+
+        layout.addLayout(status_layout)
+
+        layout.addItem(
+            QSpacerItem(0, 20, QSizePolicy.Policy.Minimum, QSizePolicy.Policy.Fixed)
+        )
+
+        # Buttons
+        button_row = QHBoxLayout()
+        button_row.setSpacing(10)
+        self.download_btn = QPushButton("Download all")
+        self.download_btn.setMinimumWidth(100)
+        self.download_btn.setMinimumHeight(35)
+        self.download_btn.setEnabled(False)
+        self.download_btn.clicked.connect(self._start_download)
+        button_row.addWidget(self.download_btn)
+
+        self.close_btn = QPushButton("Close")
+        self.close_btn.setMinimumWidth(100)
+        self.close_btn.setMinimumHeight(35)
+        self.close_btn.clicked.connect(self._handle_close)
+        button_row.addWidget(self.close_btn)
+
+        layout.addLayout(button_row)
+        self.adjustSize()
+
+    # Status checking worker
+    class StatusCheckWorker(QThread):
+        voices_checked = pyqtSignal(bool, list)
+        model_checked = pyqtSignal(bool)
+        config_checked = pyqtSignal(bool)
+        spacy_model_checking = pyqtSignal(str)
+        spacy_model_result = pyqtSignal(str, bool)
+        spacy_checked = pyqtSignal(bool, list)
+
+        def run(self):
+            parent = self.parent()
+            if parent is None:
+                return
+
+            voices_ok, missing_voices = parent._check_kokoro_voices()
+            self.voices_checked.emit(voices_ok, missing_voices)
+
+            model_ok = parent._check_kokoro_model()
+            self.model_checked.emit(model_ok)
+
+            config_ok = parent._check_kokoro_config()
+            self.config_checked.emit(config_ok)
+
+            # Check spaCy models by package name to detect site-package installs
+            unique = _unique_sorted_models()
+            missing: List[str] = []
+            for name in unique:
+                self.spacy_model_checking.emit(name)
+                ok = _is_package_installed(name)
+                self.spacy_model_result.emit(name, ok)
+                if not ok:
+                    missing.append(name)
+            parent._spacy_models_missing = missing
+            self.spacy_checked.emit(len(missing) == 0, missing)
+
+    def _start_status_check(self) -> None:
+        self._status_worker = self.StatusCheckWorker(self)
+        self._status_worker.voices_checked.connect(self._update_voices_status)
+        self._status_worker.model_checked.connect(self._update_model_status)
+        self._status_worker.config_checked.connect(self._update_config_status)
+        self._status_worker.spacy_model_checking.connect(self._spacy_model_checking)
+        self._status_worker.spacy_model_result.connect(self._spacy_model_result)
+        self._status_worker.spacy_checked.connect(self._update_spacy_status)
+
+        # These are initialized in __init__ to keep consistent object state
+
+        # Set checking visual state
+        for lbl in (
+            self.voices_status,
+            self.model_status,
+            self.config_status,
+            self.spacy_status,
+        ):
+            lbl.setStyleSheet(f"color: {COLORS['ORANGE']};")
+
+        self.spacy_status.setText(self.SPACY_PREFIX + "⏳ Checking...")
+        self._status_worker.start()
+
+    # UI update callbacks
+    def _spacy_model_checking(self, name: str) -> None:
+        self.spacy_status.setText(f"{self.SPACY_PREFIX}Checking {name}...")
+
+    def _spacy_model_result(self, name: str, ok: bool) -> None:
+        self._spacy_models_checked.append((name, ok))
+        if not ok and name not in self._spacy_models_missing:
+            self._spacy_models_missing.append(name)
+        checked = len(self._spacy_models_checked)
+        missing_count = len(self._spacy_models_missing)
+        if missing_count:
+            self.spacy_status.setText(
+                f"{self.SPACY_PREFIX}{checked} checked, {missing_count} missing..."
+            )
+        else:
+            self.spacy_status.setText(f"{self.SPACY_PREFIX}{checked} checked...")
+
+    def _update_voices_status(self, ok: bool, missing: List[str]) -> None:
+        if ok:
+            self._set_status("voice", "✓ Downloaded", COLORS["GREEN"])
+        else:
+            self.has_missing = True
+            if missing:
+                self._set_status(
+                    "voice", f"✗ Missing {len(missing)} voices", COLORS["RED"]
+                )
+            else:
+                self._set_status("voice", "✗ Not downloaded", COLORS["RED"])
+
+    def _update_model_status(self, ok: bool) -> None:
+        if ok:
+            self._set_status("model", "✓ Downloaded", COLORS["GREEN"])
+        else:
+            self.has_missing = True
+            self._set_status("model", "✗ Not downloaded", COLORS["RED"])
+
+    def _update_config_status(self, ok: bool) -> None:
+        if ok:
+            self._set_status("config", "✓ Downloaded", COLORS["GREEN"])
+        else:
+            self.has_missing = True
+            self._set_status("config", "✗ Not downloaded", COLORS["RED"])
+
+    def _update_spacy_status(self, ok: bool, missing: List[str]) -> None:
+        if ok:
+            self._set_status("spacy", "✓ Downloaded", COLORS["GREEN"])
+        else:
+            self.has_missing = True
+            if missing:
+                self._set_status(
+                    "spacy", f"✗ Missing {len(missing)} model(s)", COLORS["RED"]
+                )
+            else:
+                self._set_status("spacy", "✗ Not downloaded", COLORS["RED"])
+        self.download_btn.setEnabled(self.has_missing)
+
+    def _set_status(self, key: str, text: str, color: str) -> None:
+        lbl, prefix = self.status_map.get(key, (None, ""))
+        if not lbl:
+            return
+        lbl.setText(prefix + text)
+        lbl.setStyleSheet(f"color: {color};")
+
+    # Helper checks
+    def _check_kokoro_voices(self) -> Tuple[bool, List[str]]:
+        """Return (ok, missing_list) for Kokoro voices check."""
+        missing = []
+        try:
+            from huggingface_hub import try_to_load_from_cache
+
+            for voice in VOICES_INTERNAL:
+                if not try_to_load_from_cache(
+                    repo_id="hexgrad/Kokoro-82M", filename=f"voices/{voice}.pt"
+                ):
+                    missing.append(voice)
+        except Exception:
+            # If HF missing, report all as missing
+            return False, list(VOICES_INTERNAL)
+        return (len(missing) == 0), missing
+
+    def _check_kokoro_model(self) -> bool:
+        try:
+            from huggingface_hub import try_to_load_from_cache
+
+            return (
+                try_to_load_from_cache(
+                    repo_id="hexgrad/Kokoro-82M", filename="kokoro-v1_0.pth"
+                )
+                is not None
+            )
+        except Exception:
+            return False
+
+    def _check_kokoro_config(self) -> bool:
+        try:
+            from huggingface_hub import try_to_load_from_cache
+
+            return (
+                try_to_load_from_cache(
+                    repo_id="hexgrad/Kokoro-82M", filename="config.json"
+                )
+                is not None
+            )
+        except Exception:
+            return False
+
+    def _check_spacy_models(self) -> bool:
+        unique = _unique_sorted_models()
+        missing = [m for m in unique if not _is_package_installed(m)]
+        self._spacy_models_missing = missing
+        return len(missing) == 0
+
+    # Download control
+    def _start_download(self) -> None:
+        self.download_btn.setEnabled(False)
+        self.download_btn.setText("Downloading...")
+        # mark the start of downloads; this triggers the labels
+        self._on_progress("system", "starting", "Processing, please wait...")
+        self.worker = PreDownloadWorker(self)
+        self.worker.progress.connect(self._on_progress)
+        self.worker.category_done.connect(self._on_category_done)
+        self.worker.finished.connect(self._on_download_finished)
+        self.worker.error.connect(self._on_download_error)
+        self.worker.start()
+
+    def _on_progress(self, category: str, status: str, message: str) -> None:
+        """Map worker (category, status, message) to UI label updates.
+
+        Status is one of: 'downloading', 'installed', 'downloaded', 'warning', 'starting'.
+        Category is one of: 'voice', 'model', 'spacy', 'config', or 'system'.
+        """
+        try:
+            # If the category targets a specific label, update directly
+            if category in self.status_map:
+                lbl, prefix = self.status_map[category]
+                if not lbl:
+                    return
+                # Compose message and set color based on status token
+                full_text = prefix + message
+                if len(full_text) > 60:
+                    display_text = full_text[:57] + "..."
+                    lbl.setText(display_text)
+                    lbl.setToolTip(full_text)
+                else:
+                    lbl.setText(full_text)
+                    lbl.setToolTip("")  # Clear tooltip if not needed
+                if status == "downloading":
+                    lbl.setStyleSheet(f"color: {COLORS['ORANGE']};")
+                elif status in ("installed", "downloaded"):
+                    lbl.setStyleSheet(f"color: {COLORS['GREEN']};")
+                elif status == "warning":
+                    lbl.setStyleSheet(f"color: {COLORS['RED']};")
+                elif status == "error":
+                    lbl.setStyleSheet(f"color: {COLORS['RED']};")
+                return
+
+            # System-level messages
+            if category == "system":
+                if status == "starting":
+                    for k in self.status_map:
+                        lbl, prefix = self.status_map[k]
+                        if lbl:
+                            lbl.setText(prefix + "Processing, please wait...")
+                            lbl.setStyleSheet(f"color: {COLORS['ORANGE']};")
+                # other system statuses don't require action
+                return
+        except Exception:
+            # Do not let UI thread crash on unexpected worker message
+            pass
+
+    def _on_category_done(self, category: str) -> None:
+        for key in self.category_map.get(category, []):
+            self._set_status(key, "✓ Downloaded", COLORS["GREEN"])
+
+    def _on_download_finished(self) -> None:
+        self.has_missing = False
+        self.download_btn.setText("Download all")
+        self.download_btn.setEnabled(False)
+
+    def _on_download_error(self, error_msg: str) -> None:
+        self.download_btn.setText("Download all")
+        self.download_btn.setEnabled(True)
+        for key in self.status_map:
+            self._set_status(key, f"✗ Error - {error_msg}", COLORS["RED"])
+
+    def _handle_close(self) -> None:
+        if self.worker and self.worker.isRunning():
+            self.worker.cancel()
+            self.worker.wait(2000)
+        self.accept()
+
+    def closeEvent(self, event) -> None:
+        if self.worker and self.worker.isRunning():
+            self.worker.cancel()
+            self.worker.wait(2000)
+        super().closeEvent(event)
@@ -87,7 +87,11 @@ class DroppableQueueListWidget(QListWidget):
    def dragEnterEvent(self, event):
        if event.mimeData().hasUrls():
            for url in event.mimeData().urls():
-                if url.isLocalFile() and url.toLocalFile().lower().endswith(".txt"):
+                file_path = url.toLocalFile().lower()
+                if url.isLocalFile() and (
+                    file_path.endswith(".txt")
+                    or file_path.endswith((".srt", ".ass", ".vtt"))
+                ):
                    self.drag_overlay.resize(self.size())
                    self.drag_overlay.setVisible(True)
                    event.acceptProposedAction()
@@ -98,7 +102,11 @@ class DroppableQueueListWidget(QListWidget):
    def dragMoveEvent(self, event):
        if event.mimeData().hasUrls():
            for url in event.mimeData().urls():
-                if url.isLocalFile() and url.toLocalFile().lower().endswith(".txt"):
+                file_path = url.toLocalFile().lower()
+                if url.isLocalFile() and (
+                    file_path.endswith(".txt")
+                    or file_path.endswith((".srt", ".ass", ".vtt"))
+                ):
                    event.acceptProposedAction()
                    return
        event.ignore()
@@ -113,7 +121,11 @@ class DroppableQueueListWidget(QListWidget):
            file_paths = [
                url.toLocalFile()
                for url in event.mimeData().urls()
-                if url.isLocalFile() and url.toLocalFile().lower().endswith(".txt")
+                if url.isLocalFile()
+                and (
+                    url.toLocalFile().lower().endswith(".txt")
+                    or url.toLocalFile().lower().endswith((".srt", ".ass", ".vtt"))
+                )
            ]
            if file_paths:
                self.parent_dialog.add_files_from_paths(file_paths)
@@ -151,7 +163,7 @@ class QueueManager(QDialog):
        # Add informative instructions at the top
        instructions = QLabel(
            "<h2>How Queue Works?</h2>"
-            "You can add text files (.txt) directly using the '<b>Add files</b>' button below. "
+            "You can add text and subtitle files (.txt, .srt, .ass, .vtt) directly using the '<b>Add files</b>' button below. "
            "To add PDF, EPUB or markdown files, use the input box in the main window and click the <b>'Add to Queue'</b> button. "
            "Each file in the queue keeps the configuration settings active when it was added. "
            "Changing the main window configuration afterward <b>does not</b> affect files already in the queue. "
@@ -163,7 +175,7 @@ class QueueManager(QDialog):
        layout.addWidget(instructions)
        # Overlay label for empty queue
        self.empty_overlay = QLabel(
-            "Drag and drop your text files here or use the 'Add files' button.",
+            "Drag and drop your text or subtitle files here or use the 'Add files' button.",
            self.listwidget,
        )
        self.empty_overlay.setAlignment(Qt.AlignmentFlag.AlignCenter)
@@ -290,7 +302,9 @@ class QueueManager(QDialog):
                f"<b>Subtitle Mode:</b> {getattr(item, 'subtitle_mode', '')}<br>"
                f"<b>Output Format:</b> {getattr(item, 'output_format', '')}<br>"
                f"<b>Characters:</b> {getattr(item, 'total_char_count', '')}<br>"
-                f"<b>Replace Single Newlines:</b> {getattr(item, 'replace_single_newlines', False)}"
+                f"<b>Replace Single Newlines:</b> {getattr(item, 'replace_single_newlines', False)}<br>"
+                f"<b>Use Silent Gaps:</b> {getattr(item, 'use_silent_gaps', False)}<br>"
+                f"<b>Speed Method:</b> {getattr(item, 'subtitle_speed_method', 'tts')}"
            )
            # Add book handler options if present
            save_chapters_separately = getattr(item, "save_chapters_separately", None)
@@ -403,6 +417,12 @@ class QueueManager(QDialog):
            attrs["replace_single_newlines"] = getattr(
                parent, "replace_single_newlines", False
            )
+            # use_silent_gaps
+            attrs["use_silent_gaps"] = getattr(parent, "use_silent_gaps", False)
+            # subtitle_speed_method
+            attrs["subtitle_speed_method"] = getattr(
+                parent, "subtitle_speed_method", "tts"
+            )
            # book handler options
            attrs["save_chapters_separately"] = getattr(
                parent, "save_chapters_separately", None
@@ -449,6 +469,9 @@ class QueueManager(QDialog):
            )
            for attr, value in current_attrs.items():
                setattr(item, attr, value)
+            # Override subtitle_mode to "Disabled" for subtitle files
+            if file_path.lower().endswith((".srt", ".ass", ".vtt")):
+                item.subtitle_mode = "Disabled"
            # Read file content and calculate total_char_count using calculate_text_length
            try:
                with open(file_path, "r", encoding="utf-8", errors="ignore") as f:
@@ -480,6 +503,10 @@ class QueueManager(QDialog):
                    == getattr(item, "total_char_count", None)
                    and getattr(queued_item, "replace_single_newlines", False)
                    == getattr(item, "replace_single_newlines", False)
+                    and getattr(queued_item, "use_silent_gaps", False)
+                    == getattr(item, "use_silent_gaps", False)
+                    and getattr(queued_item, "subtitle_speed_method", "tts")
+                    == getattr(item, "subtitle_speed_method", "tts")
                    and getattr(queued_item, "save_base_path", None)
                    == getattr(item, "save_base_path", None)
                    and getattr(queued_item, "save_chapters_separately", None)
@@ -506,9 +533,12 @@ class QueueManager(QDialog):
        from PyQt6.QtWidgets import QFileDialog
        from abogen.utils import calculate_text_length  # import the function

-        # Only allow .txt files
+        # Allow .txt, .srt, .ass, and .vtt files
        files, _ = QFileDialog.getOpenFileNames(
-            self, "Select .txt files", "", "Text Files (*.txt)"
+            self,
+            "Select text or subtitle files",
+            "",
+            "Supported Files (*.txt *.srt *.ass *.vtt)",
        )
        if not files:
            return
@@ -14,6 +14,8 @@ class QueuedItem:
    output_format: str
    total_char_count: int
    replace_single_newlines: bool = False
+    use_silent_gaps: bool = False
+    subtitle_speed_method: str = "tts"
    save_base_path: str = None
    save_chapters_separately: bool = None
    merge_chapters_at_end: bool = None
@@ -0,0 +1,155 @@
+"""
+Lazy-loaded spaCy utilities for sentence segmentation.
+"""
+
+# Cached spaCy module and models (lazy loaded)
+_spacy = None
+_nlp_cache = {}
+
+# Language code to spaCy model mapping
+SPACY_MODELS = {
+    "a": "en_core_web_sm",  # American English
+    "b": "en_core_web_sm",  # British English
+    "e": "es_core_news_sm",  # Spanish
+    "f": "fr_core_news_sm",  # French
+    "i": "it_core_news_sm",  # Italian
+    "p": "pt_core_news_sm",  # Brazilian Portuguese
+    "z": "zh_core_web_sm",  # Mandarin Chinese
+    "j": "ja_core_news_sm",  # Japanese
+    "h": "xx_sent_ud_sm",  # Hindi (multi-language model)
+}
+
+
+def _load_spacy():
+    """Lazy load spaCy module."""
+    global _spacy
+    if _spacy is None:
+        try:
+            import spacy
+
+            _spacy = spacy
+        except ImportError:
+            return None
+    return _spacy
+
+
+def get_spacy_model(lang_code, log_callback=None):
+    """
+    Get or load a spaCy model for the given language code.
+    Downloads the model automatically if not available.
+
+    Args:
+        lang_code: Language code (a, b, e, f, etc.)
+        log_callback: Optional function to log messages
+
+    Returns:
+        Loaded spaCy model or None if unavailable
+    """
+
+    def log(msg, is_error=False):
+        # Prefer GUI log callback when provided to avoid spamming stdout.
+        if log_callback:
+            color = "red" if is_error else "grey"
+            try:
+                log_callback((msg, color))
+            except Exception:
+                # Fallback to printing if callback misbehaves
+                print(msg)
+        else:
+            print(msg)
+
+    # Check if model is cached
+    if lang_code in _nlp_cache:
+        return _nlp_cache[lang_code]
+
+    # Check if language is supported
+    model_name = SPACY_MODELS.get(lang_code)
+    if not model_name:
+        log(f"\nspaCy: No model mapping for language '{lang_code}'...")
+        return None
+
+    # Lazy load spaCy
+    spacy = _load_spacy()
+    if spacy is None:
+        log("\nspaCy: Module not installed, falling back to default segmentation...")
+        return None
+
+    # Try to load the model
+    try:
+        log(f"\nLoading spaCy model '{model_name}'...")
+        nlp = spacy.load(
+            model_name,
+            disable=["ner", "parser", "tagger", "lemmatizer", "attribute_ruler"],
+        )
+        # Enable sentence segmentation only
+        if "sentencizer" not in nlp.pipe_names:
+            nlp.add_pipe("sentencizer")
+        _nlp_cache[lang_code] = nlp
+        return nlp
+    except OSError:
+        # Model not found, attempt download
+        log(f"\nspaCy: Downloading model '{model_name}'...")
+        try:
+            from spacy.cli import download
+
+            download(model_name)
+            # Retry loading
+            nlp = spacy.load(
+                model_name,
+                disable=["ner", "parser", "tagger", "lemmatizer", "attribute_ruler"],
+            )
+            if "sentencizer" not in nlp.pipe_names:
+                nlp.add_pipe("sentencizer")
+            _nlp_cache[lang_code] = nlp
+            log(f"spaCy model '{model_name}' downloaded and loaded")
+            return nlp
+        except Exception as e:
+            log(
+                f"\nspaCy: Failed to download model '{model_name}': {e}...",
+                is_error=True,
+            )
+            return None
+    except Exception as e:
+        log(f"\nspaCy: Error loading model '{model_name}': {e}...", is_error=True)
+        return None
+
+
+def segment_sentences(text, lang_code, log_callback=None):
+    """
+    Segment text into sentences using spaCy.
+
+    Args:
+        text: Text to segment
+        lang_code: Language code
+        log_callback: Optional function to log messages
+
+    Returns:
+        List of sentence strings, or None if spaCy unavailable
+    """
+    nlp = get_spacy_model(lang_code, log_callback)
+    if nlp is None:
+        return None
+
+    # Ensure spaCy can handle large texts by adjusting max_length if necessary
+    try:
+        text_len = len(text or "")
+        if text_len and hasattr(nlp, "max_length") and text_len > nlp.max_length:
+            # increase a bit beyond the text length to be safe
+            nlp.max_length = text_len + 1000
+    except Exception:
+        pass
+
+    # Process text and extract sentences
+    doc = nlp(text)
+    return [sent.text.strip() for sent in doc.sents if sent.text.strip()]
+
+
+def is_spacy_available():
+    """Check if spaCy can be imported."""
+    return _load_spacy() is not None
+
+
+def clear_cache():
+    """Clear the model cache to free memory."""
+    global _nlp_cache
+    _nlp_cache.clear()
@@ -10,6 +10,13 @@ from threading import Thread

 warnings.filterwarnings("ignore")

+# Pre-compile frequently used regex patterns for better performance
+_WHITESPACE_PATTERN = re.compile(r"[^\S\n]+")
+_MULTIPLE_NEWLINES_PATTERN = re.compile(r"\n{3,}")
+_SINGLE_NEWLINE_PATTERN = re.compile(r"(?<!\n)\n(?!\n)")
+_CHAPTER_MARKER_PATTERN = re.compile(r"<<CHAPTER_MARKER:.*?>>")
+_METADATA_PATTERN = re.compile(r"<<METADATA_[^:]+:[^>]*>>")
+

 def detect_encoding(file_path):
    import chardet
@@ -128,13 +135,16 @@ def clean_text(text, *args, **kwargs):
    cfg = load_config()
    replace_single_newlines = cfg.get("replace_single_newlines", False)
    # Collapse all whitespace (excluding newlines) into single spaces per line and trim edges
-    lines = [re.sub(r"[^\S\n]+", " ", line).strip() for line in text.splitlines()]
+    # Use pre-compiled pattern for better performance
+    lines = [_WHITESPACE_PATTERN.sub(" ", line).strip() for line in text.splitlines()]
    text = "\n".join(lines)
    # Standardize paragraph breaks (multiple newlines become exactly two) and trim overall whitespace
-    text = re.sub(r"\n{3,}", "\n\n", text).strip()
+    # Use pre-compiled pattern for better performance
+    text = _MULTIPLE_NEWLINES_PATTERN.sub("\n\n", text).strip()
    # Optionally replace single newlines with spaces, but preserve double newlines
    if replace_single_newlines:
-        text = re.sub(r"(?<!\n)\n(?!\n)", " ", text)
+        # Use pre-compiled pattern for better performance
+        text = _SINGLE_NEWLINE_PATTERN.sub(" ", text)
    return text


@@ -243,20 +253,24 @@ def save_config(config):


 def calculate_text_length(text):
-    # Ignore chapter markers
-    text = re.sub(r"<<CHAPTER_MARKER:.*?>>", "", text)
-    # Ignore metadata patterns
-    text = re.sub(r"<<METADATA_[^:]+:[^>]*>>", "", text)
-    # Ignore newlines
-    text = text.replace("\n", "")
-    # Ignore leading/trailing spaces
-    text = text.strip()
+    # Use pre-compiled patterns for better performance
+    # Ignore chapter markers and metadata patterns in a single pass
+    text = _CHAPTER_MARKER_PATTERN.sub("", text)
+    text = _METADATA_PATTERN.sub("", text)
+    # Ignore newlines and leading/trailing spaces
+    text = text.replace("\n", "").strip()
    # Calculate character count
    char_count = len(text)
    return char_count


 def get_gpu_acceleration(enabled):
+    """
+    Check GPU acceleration availability.
+
+    Note: On Windows, torch DLLs must be pre-loaded in main.py before PyQt6
+    to avoid DLL initialization errors.
+    """
    try:
        import torch
        from torch.cuda import is_available as cuda_available
@@ -25,7 +25,8 @@ dependencies = [
    "charset_normalizer>=3.4.1",
    "chardet>=5.2.0",
    "static_ffmpeg>=2.13",
-    "Markdown>=3.9"
+    "Markdown>=3.9",
+    "spacy>=3.8.7"
 ]

 classifiers = [
Author	SHA1	Message	Date
Deniz Şafak	55a4f958ee	Update changelog	2025-11-28 05:17:31 +03:00
Deniz Şafak	6c633e9167	v1.2.4	2025-11-28 05:16:39 +03:00
Deniz Şafak	566158c132	Reformat using black	2025-11-28 05:07:26 +03:00
Deniz Şafak	bf43d1799d	Update readme	2025-11-28 05:06:51 +03:00
Deniz Şafak	7293b4b826	New option: Pre-download models and voices for offline use	2025-11-28 04:58:13 +03:00
Deniz Şafak	34f2d712b3	Update readme	2025-11-28 00:56:44 +03:00
Deniz Şafak	5ef2612df6	Add spaCy support for improved sentence segmentation, possible fix for #91	2025-11-28 00:49:36 +03:00
Deniz Şafak	290c265d5e	Improve cleanup_preview_threads function	2025-11-24 00:46:13 +03:00
Deniz Şafak	ed418ac11d	Added support for `.` separator in timestamps	2025-11-23 17:30:05 +03:00
Deniz Şafak	e6abf2e541	Change audiobook to audio	2025-11-23 16:07:28 +03:00
Deniz Şafak	f5d95547c5	Added subtitle generation support for non-English languages, improvements in code and documentation	2025-11-23 16:03:41 +03:00
Deniz Şafak	795bd8f1aa	Fix WINDWOS_INSTALL.bat	2025-11-22 15:41:40 +03:00
Deniz ŞafakandGitHub	c4e2a5ef0d	Merge pull request #103 from denizsafak/copilot/improve-slow-code-efficiency Optimize regex compilation and eliminate busy-wait loops	2025-11-22 15:22:15 +03:00
Deniz Şafak	f57d1994cf	Update CHANGELOG.md for pre-release 1.2.4: optimize regex compilation and eliminate busy-wait loops	2025-11-22 15:20:17 +03:00
Deniz ŞafakandGitHub	6482a56479	Remove unused import of QEventLoop	2025-11-22 15:14:41 +03:00
Deniz ŞafakandGitHub	8ddfd01dff	Delete test_performance.py	2025-11-22 15:13:50 +03:00
Deniz ŞafakandGitHub	ac551abd55	Delete PERFORMANCE_OPTIMIZATIONS.md	2025-11-22 15:13:36 +03:00
copilot-swe-agent[bot]anddenizsafak	711858ce2c	Address final code review nitpicks: improve code organization Co-authored-by: denizsafak <39929354+denizsafak@users.noreply.github.com>	2025-11-20 23:29:23 +00:00
copilot-swe-agent[bot]anddenizsafak	5cca6235e1	Fix potential division by zero in performance tests Co-authored-by: denizsafak <39929354+denizsafak@users.noreply.github.com>	2025-11-20 23:26:36 +00:00
copilot-swe-agent[bot]anddenizsafak	115ab2a0f2	Add comprehensive performance optimization documentation Co-authored-by: denizsafak <39929354+denizsafak@users.noreply.github.com>	2025-11-20 23:24:11 +00:00
copilot-swe-agent[bot]anddenizsafak	bf5dfddee6	Improve cancellation handling and use generator expressions for memory efficiency Co-authored-by: denizsafak <39929354+denizsafak@users.noreply.github.com>	2025-11-20 23:23:25 +00:00
copilot-swe-agent[bot]anddenizsafak	23a89a618b	Address code review feedback: Fix Linux control chars and improve readability Co-authored-by: denizsafak <39929354+denizsafak@users.noreply.github.com>	2025-11-20 23:20:51 +00:00
copilot-swe-agent[bot]anddenizsafak	4ad384dc9f	Add performance tests and optimize repeated path operations Co-authored-by: denizsafak <39929354+denizsafak@users.noreply.github.com>	2025-11-20 23:18:11 +00:00
copilot-swe-agent[bot]anddenizsafak	5ec06e7d49	Replace busy-wait loop with threading.Event for better efficiency Co-authored-by: denizsafak <39929354+denizsafak@users.noreply.github.com>	2025-11-20 23:13:22 +00:00
copilot-swe-agent[bot]anddenizsafak	7f75aa8209	Optimize regex patterns by pre-compiling frequently used patterns Co-authored-by: denizsafak <39929354+denizsafak@users.noreply.github.com>	2025-11-20 23:11:06 +00:00
copilot-swe-agent[bot]	cd2e5c9150	Initial plan	2025-11-20 22:59:44 +00:00
Deniz Şafak	f477703b1a	v1.2.3	2025-11-19 02:24:42 +03:00
Deniz Şafak	6b3125b624	v1.2.2	2025-11-19 02:06:33 +03:00
Deniz Şafak	bb5c4204de	Reformat using black	2025-11-19 01:54:11 +03:00
Deniz Şafak	43f5589a9d	Update changelog and images	2025-11-19 01:39:50 +03:00
Deniz Şafak	10d3f470e7	Add support for embedding cover images in M4B files and update documentation	2025-11-19 01:03:10 +03:00
Deniz ŞafakandGitHub	c72c8e777c	Update CHANGELOG	2025-11-18 15:27:09 +03:00
Deniz ŞafakandGitHub	b51e094af1	Update CHANGELOG with subtitle audio generation details Added detailed instructions for generating audio from subtitle files.	2025-11-18 15:24:44 +03:00
Deniz ŞafakandGitHub	04844997d5	Update README.md	2025-11-18 15:13:42 +03:00
Deniz ŞafakandGitHub	7835211a25	Update README.md	2025-11-18 15:07:38 +03:00
Deniz Şafak	6bb6fcb406	Add subtitle file voicing feature, improvements in code and documentation	2025-11-18 04:37:15 +03:00
Deniz ŞafakandGitHub	ad8a6e520e	Update WINDOWS_INSTALL.bat	2025-11-17 12:23:00 +03:00
Deniz Şafak	fe22fe83b0	Possible fix for "CUDA is not available" issue, improvements in code and readme	2025-11-16 01:30:32 +03:00
Deniz Şafak	afbd5203fe	Fixed `[WinError 1114] A dynamic link library (DLL) initialization routine failed`, Potential fix for `CUDA GPU is not available`	2025-10-30 12:52:46 +03:00
Deniz ŞafakandGitHub	4b175c7cf2	Update PyTorch installation instructions for version 2.8.0	2025-10-30 12:07:19 +03:00
Deniz ŞafakandGitHub	334c0654ca	Modify PyTorch installation for CUDA 12.8 Updated PyTorch installation commands to use version 2.8.0 with CUDA (12.8) support.	2025-10-30 12:06:24 +03:00
Deniz ŞafakandGitHub	42b7979585	Add libxcb-cursor0 and libgl1 to Dockerfile Mentioned in #97	2025-10-30 02:16:04 +03:00
@@ -1 +1 @@
 .2.1
 .2.4