v1.2.1

Add `Line` option for subtitle generation

Thank you, merged!

CHANGELOG.md

@@ -1,3 +1,28 @@
+# 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.
+- Added `Open processed file` and `Open input file` options for items in the queue manager, instead of just `Open file` option.
+- Added loading gif animation to book handler window.
+- Fixed light theme slider colors in voice mixer for better visibility (for non-Windows users).
+- Fixed subtitle word-count splitting logic for more accurate segmentation.
+- Improvements in code and documentation.
+
+# 1.2.0
+- Added `Line` option to subtitle generation modes, allowing subtitles to be generated based on line breaks in the text, by @mleg in #94.
+- Added a loading indicator to the book handler window for better user experience during book preprocessing.
+- Fixed `cannot access local variable 'is_narrow'` error when subtitle format `SRT` was selected, mentioned by @Kinasa0096 in #88.
+- Fixed folder and filename sanitization to properly handle OS-specific illegal characters (Windows, Linux, macOS), ensuring compatibility across all platforms when creating chapter folders and files.
+- Fixed `/` and `\` path display by normalizing paths.
+- Fixed book reprocessing issue where books were being processed every time the chapters window was opened, improving performance when reopening the same book.
+- Fixed taskbar icon not appearing correctly in Windows.
+- Fixed “Go to folder” button not opening the chapter output directory when only separate chapters were generated.
+- Improvements in code and documentation.
+
+# 1.1.9
+- Fixed the issue where spaces were deleted before punctuation marks while generating subtitles.
+- Fixed markdown TOC generation breaks when "Replace single newlines" is enabled.
+- Improvements in code and documentation.
+
 # 1.1.8
 - Added `.md` (Markdown) file extension support by @brianxiadong in PR #75
 - Added new option `Configure silence between chapters` that lets you configure the silence between chapters, mentioned by @lfperez1982 in #79

README.md

@@ -7,6 +7,8 @@
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
 [![License: MIT](https://img.shields.io/badge/License-MIT-maroon.svg)](https://opensource.org/licenses/MIT)
 
+<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).
 
 <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">
@@ -90,11 +92,15 @@ pip3 uninstall torch
 pip3 install --pre torch torchvision torchaudio --index-url https://download.pytorch.org/whl/nightly/rocm6.4
 ```
 
+> See [How to fix "CUDA GPU is not available. Using CPU" warning?](#cuda-warning)
+
 > See [How  to fix "WARNING: The script abogen-cli is installed in '/home/username/.local/bin' which is not on PATH" error in Linux?](#path-warning)
 
 > See [How to fix "No matching distribution found" error?](#no-matching-distribution-found)
 
-> See [How to fix "CUDA GPU is not available. Using CPU" warning?](#cuda-warning)
+> See [How to fix "[WinError 1114] A dynamic link library (DLL) initialization routine failed" error?](#WinError-1114)
+
+> See [How to use "uv" instead of "pip"?](#use-uv-instead-of-pip)
 
 > Special thanks to [@hg000125](https://github.com/hg000125) for his contribution in [#23](https://github.com/denizsafak/abogen/issues/23). AMD GPU support is possible thanks to his work.
 
@@ -132,15 +138,18 @@ Here’s Abogen in action: in this demo, it processes ∼3,000 characters of tex
 | **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. |
 | **Voice mixer** | Create custom voices by mixing different voice models with a profile system. See [Voice Mixer](#voice-mixer) for more details. |
 | **Voice preview** | Listen to the selected voice before processing. |
-| **Generate subtitles** | `Disabled`, `Sentence`, `Sentence + Comma`, `Sentence + Highlighting`, `1 word`, `2 words`, `3 words`, etc. (Represents the number of words in each subtitle entry) |
+| **Generate subtitles** | `Disabled`, `Line`, `Sentence`, `Sentence + Comma`, `Sentence + Highlighting`, `1 word`, `2 words`, `3 words`, etc. (Represents the number of words in each subtitle entry) |
 | **Output voice format** | `.WAV`, `.FLAC`, `.MP3`, `.OPUS (best compression)` and `M4B (with chapters)` |
 | **Output subtitle format** | Configures the subtitle format as `SRT (standard)`, `ASS (wide)`, `ASS (narrow)`, `ASS (centered wide)`, or `ASS (centered narrow)`. |
 | **Replace single newlines with spaces** | Replaces single newlines with spaces in the text. This is useful for texts that have imaginary line breaks. |
 | **Save location** | `Save next to input file`, `Save to desktop`, or `Choose output folder` |
 
 > Special thanks to [@brianxiadong](https://github.com/brianxiadong) for adding markdown support in PR [#75](https://github.com/denizsafak/abogen/pull/75)
+
 > Special thanks to [@jborza](https://github.com/jborza) for chapter support in PR [#10](https://github.com/denizsafak/abogen/pull/10)
 
+> Special thanks to [@mleg](https://github.com/mleg) for adding `Line` option in subtitle generation in PR [#94](https://github.com/denizsafak/abogen/pull/94)
+
 | Book handler options | Description |
 |---------|-------------|
 | **Chapter Control** | Select specific `chapters` from ePUBs or markdown files or `chapters + pages` from PDFs. |
@@ -318,7 +327,19 @@ abogen-cli.exe
 
 This will start Abogen in command-line mode and display detailed error messages. Please open a new issue on the [Issues](https://github.com/denizsafak/abogen/issues) page with the error message and a description of your problem.
 
-## `Tips and Solutions`
+## `Common Issues & Solutions`
+
+<details><summary><b>
+<a name="about-abogen">About the name "abogen"</a>
+</b></summary>
+
+> The name **"abogen"** comes from a shortened form of **"audiobook generator"**, which is the purpose of this project.  
+>
+> After releasing the project, I learned from [community feedback](https://news.ycombinator.com/item?id=44853064#44857237) that the prefix *"abo"* can unfortunately be understood as an ethnic slur in certain regions (particularly Australia and New Zealand). This was something I was not aware of when naming the project, as English is not my first language.  
+>
+> I want to make it clear that the name was chosen only for its technical meaning, with **no offensive intent**. I’m grateful to those who kindly pointed this out, as it helps ensure the project remains respectful and welcoming to everyone.  
+
+</details>
 
 <details><summary><b>
 <a name="cuda-warning">How to fix "CUDA GPU is not available. Using CPU" warning?</a>
@@ -354,6 +375,22 @@ This will start Abogen in command-line mode and display detailed error messages.
 
 </details>
 
+<details><summary><b>
+<a name="WinError-1114">How to fix "[WinError 1114] A dynamic link library (DLL) initialization routine failed" error?</a>
+</b></summary>
+
+> 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
+> ```
+> If you installed Abogen using pip, open your terminal in the virtual environment and run:
+> ```bash
+> pip install torch==2.8.0 torchaudio==2.8.0 torchvision==0.23.0
+> ```
+
+</details>
+
 <details><summary><b>
 <a name="japanese-audio-not-working">How to fix Japanese audio not working?</a>
 </b></summary>
@@ -363,6 +400,34 @@ This will start Abogen in command-line mode and display detailed error messages.
 
 </details>
 
+<details><summary><b>
+<a name="use-uv-instead-of-pip">How to use "uv" instead of "pip"?</a>
+</b></summary>
+
+> Abogen needs "pip", because Kokoro uses pip to download voice models from HuggingFace Hub. If you want to use "uv" instead of "pip", you can use the following command to run Abogen:
+>
+> ```bash
+> uvx --with pip abogen
+> ```
+
+</details>
+
+<details><summary><b>
+<a name="use-uv-instead-of-pip">How to uninstall Abogen?</a>
+</b></summary>
+
+> - From the settings menu, go to `Open configuration directory` and delete the directory.
+> - From the settings menu, go to `Open cache directory` and delete the directory.
+> - If you installed Abogen using pip, type:
+>```bash
+>pip uninstall abogen # uninstalls abogen
+>pip cache purge # removes pip cache
+>```
+> - If you installed Abogen using the Windows installer (WINDOWS_INSTALL.bat), just remove the folder that contains Abogen. It installs everything inside `python_embedded` folder, no other directories are created.
+> - If you installed espeak-ng, you need to remove it separately.
+
+</details>
+
 ## `Contributing`
 I welcome contributions! If you have ideas for new features, improvements, or bug fixes, please fork the repository and submit a pull request.
 ### For developers and contributors
@@ -387,6 +452,9 @@ Feel free to explore the code and make any changes you like.
 This project is available under the MIT License - see the [LICENSE](https://github.com/denizsafak/abogen/blob/main/LICENSE) file for details.
 [Kokoro](https://github.com/hexgrad/kokoro) is licensed under [Apache-2.0](https://github.com/hexgrad/kokoro/blob/main/LICENSE) which allows commercial use, modification, distribution, and private use.
 
+## `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.
 

WINDOWS_INSTALL.bat

@@ -139,10 +139,10 @@ if exist "%VERSION_FILE%" (
 REM Python embedded download configuration for different architectures
 if "%PROCESSOR_ARCHITECTURE%"=="x86" (
     set PYTHON_EMBEDDED_FILE=%PROJECTFOLDER%\python_embedded_win32.zip
-    set PYTHON_EMBEDDED_URL=https://github.com/wojiushixiaobai/Python-Embed-Win64/releases/download/3.12.8/python-3.12.8-embed-win32.zip
+    set PYTHON_EMBEDDED_URL=https://github.com/wojiushixiaobai/Python-Embed-Win64/releases/download/3.12.12/python-3.12.12-embed-win32.zip
 ) else (
     set PYTHON_EMBEDDED_FILE=%PROJECTFOLDER%\python_embedded_amd64.zip
-    set PYTHON_EMBEDDED_URL=https://github.com/wojiushixiaobai/Python-Embed-Win64/releases/download/3.12.8/python-3.12.8-embed-amd64.zip
+    set PYTHON_EMBEDDED_URL=https://github.com/wojiushixiaobai/Python-Embed-Win64/releases/download/3.12.12/python-3.12.12-embed-amd64.zip
 )
 
 :: Check if Python exists

abogen/Dockerfile

@@ -12,7 +12,7 @@ RUN apt-get update \
         python3 \
         python3-venv \
         python3-pip \
-        python3-pyqt5 \
+        python3-pyqt6 \
         espeak-ng \
  && apt-get clean \
  && rm -rf /var/lib/apt/lists/*

abogen/VERSION

@@ -1 +1 @@
-1.1.8
+1.2.1

abogen/constants.py

@@ -148,6 +148,7 @@ COLORS = {
     "BLUE_BORDER_HOVER": "#6ab0de",
     "YELLOW_BACKGROUND": "rgba(255, 221, 51, 0.40)",
     "GREY_BACKGROUND": "rgba(128, 128, 128, 0.15)",
+    "GREY_BORDER": "#808080",
     "RED_BACKGROUND": "rgba(232, 78, 60, 0.15)",
     "RED_BG": "rgba(232, 78, 60, 0.10)",
     "RED_BG_HOVER": "rgba(232, 78, 60, 0.15)",

abogen/conversion.py

@@ -3,10 +3,15 @@ import re
 import time
 import hashlib  # For generating unique cache filenames
 from platformdirs import user_desktop_dir
-from PyQt5.QtCore import QThread, pyqtSignal, Qt, QTimer
-from PyQt5.QtWidgets import QCheckBox, QVBoxLayout, QDialog, QLabel, QDialogButtonBox
+from PyQt6.QtCore import QThread, pyqtSignal, Qt, QTimer
+from PyQt6.QtWidgets import QCheckBox, QVBoxLayout, QDialog, QLabel, QDialogButtonBox
 import soundfile as sf
-from abogen.utils import clean_text, create_process, get_user_cache_path, detect_encoding
+from abogen.utils import (
+    clean_text,
+    create_process,
+    get_user_cache_path,
+    detect_encoding,
+)
 from abogen.constants import (
     LANGUAGE_DESCRIPTIONS,
     SAMPLE_VOICE_TEXTS,
@@ -28,6 +33,68 @@ def get_sample_voice_text(lang_code):
     return SAMPLE_VOICE_TEXTS.get(lang_code, SAMPLE_VOICE_TEXTS["a"])
 
 
+def sanitize_name_for_os(name, is_folder=True):
+    """
+    Sanitize a filename or folder name based on the operating system.
+
+    Args:
+        name: The name to sanitize
+        is_folder: Whether this is a folder name (default: True)
+
+    Returns:
+        Sanitized name safe for the current OS
+    """
+    if not name:
+        return "audiobook"
+
+    system = platform.system()
+
+    if system == "Windows":
+        # Windows illegal characters: < > : " / \ | ? *
+        # Also can't end with space or dot
+        sanitized = re.sub(r'[<>:"/\\|?*]', "_", name)
+        # Remove control characters (0-31)
+        sanitized = re.sub(r"[\x00-\x1f]", "_", sanitized)
+        # Remove trailing spaces and dots
+        sanitized = sanitized.rstrip(". ")
+        # Windows reserved names (CON, PRN, AUX, NUL, COM1-9, LPT1-9)
+        reserved = (
+            ["CON", "PRN", "AUX", "NUL"]
+            + [f"COM{i}" for i in range(1, 10)]
+            + [f"LPT{i}" for i in range(1, 10)]
+        )
+        if sanitized.upper() in reserved or sanitized.upper().split(".")[0] in reserved:
+            sanitized = f"_{sanitized}"
+    elif system == "Darwin":  # macOS
+        # macOS illegal characters: : (colon is converted to / by the system)
+        # Also can't start with dot (hidden file) for folders typically
+        sanitized = re.sub(r"[:]", "_", name)
+        # Remove control characters
+        sanitized = re.sub(r"[\x00-\x1f]", "_", sanitized)
+        # Avoid leading dot for folders (creates hidden folders)
+        if is_folder and sanitized.startswith("."):
+            sanitized = "_" + sanitized[1:]
+    else:  # Linux and others
+        # Linux illegal characters: / and null character
+        # Though / is illegal, most other chars are technically allowed
+        sanitized = re.sub(r"[/\x00]", "_", name)
+        # Remove other control characters for safety
+        sanitized = re.sub(r"[\x01-\x1f]", "_", sanitized)
+        # Avoid leading dot for folders (creates hidden folders)
+        if is_folder and sanitized.startswith("."):
+            sanitized = "_" + sanitized[1:]
+
+    # Ensure the name is not empty after sanitization
+    if not sanitized or sanitized.strip() == "":
+        sanitized = "audiobook"
+
+    # Limit length to 255 characters (common limit across filesystems)
+    if len(sanitized) > 255:
+        sanitized = sanitized[:255].rstrip(". ")
+
+    return sanitized
+
+
 class ChapterOptionsDialog(QDialog):
     def __init__(self, chapter_count, parent=None):
         super().__init__(parent)
@@ -36,8 +103,8 @@ class ChapterOptionsDialog(QDialog):
         # Prevent closing with the X button and remove the help button
         self.setWindowFlags(
             self.windowFlags()
-            & ~Qt.WindowCloseButtonHint
-            & ~Qt.WindowContextHelpButtonHint
+            & ~Qt.WindowType.WindowCloseButtonHint
+            & ~Qt.WindowType.WindowContextHelpButtonHint
         )
 
         layout = QVBoxLayout(self)
@@ -71,7 +138,7 @@ class ChapterOptionsDialog(QDialog):
         layout.addWidget(self.countdown_label)
 
         # Add OK button
-        button_box = QDialogButtonBox(QDialogButtonBox.Ok)
+        button_box = QDialogButtonBox(QDialogButtonBox.StandardButton.Ok)
         button_box.accepted.connect(self.accept)
         layout.addWidget(button_box)
 
@@ -120,7 +187,7 @@ class ChapterOptionsDialog(QDialog):
 
     # Prevent escape key from closing the dialog
     def keyPressEvent(self, event):
-        if event.key() == Qt.Key_Escape:
+        if event.key() == Qt.Key.Key_Escape:
             event.ignore()
         else:
             super().keyPressEvent(event)
@@ -248,13 +315,23 @@ class ConversionThread(QThread):
                 input_file = self.display_path if self.display_path else self.file_name
                 processing_file = self.file_name
 
+            # Normalize paths for consistent display (fixes Windows path separator issues)
+            input_file = os.path.normpath(input_file) if input_file else input_file
+            processing_file = (
+                os.path.normpath(processing_file)
+                if processing_file
+                else processing_file
+            )
+
             self.log_updated.emit(f"- Input File: {input_file}")
             if input_file != processing_file:
                 self.log_updated.emit(f"- Processing File: {processing_file}")
 
             # Use file_name for logs if from_queue, otherwise use display_path if available
             if getattr(self, "from_queue", False):
-                base_path = self.save_base_path or self.file_name  # Use save_base_path if available
+                base_path = (
+                    self.save_base_path or self.file_name
+                )  # Use save_base_path if available
             else:
                 base_path = self.display_path if self.display_path else self.file_name
 
@@ -412,11 +489,16 @@ class ConversionThread(QThread):
 
             # Use file_name for logs if from_queue, otherwise use display_path if available
             if getattr(self, "from_queue", False):
-                base_path = self.save_base_path or self.file_name  # Use save_base_path if available
+                base_path = (
+                    self.save_base_path or self.file_name
+                )  # Use save_base_path if available
             else:
                 base_path = self.display_path if self.display_path else self.file_name
 
             base_name = os.path.splitext(os.path.basename(base_path))[0]
+            # Sanitize base_name for folder/file creation based on OS
+            sanitized_base_name = sanitize_name_for_os(base_name, is_folder=True)
+
             if self.save_option == "Save to Desktop":
                 parent_dir = user_desktop_dir()
             elif self.save_option == "Save next to input file":
@@ -437,11 +519,11 @@ class ConversionThread(QThread):
             while True:
                 suffix = f"_{counter}" if counter > 1 else ""
                 chapters_out_dir_candidate = os.path.join(
-                    parent_dir, f"{base_name}{suffix}_chapters"
+                    parent_dir, f"{sanitized_base_name}{suffix}_chapters"
                 )
                 # Only check for files with allowed extensions (extension without dot, case-insensitive)
                 clash = any(
-                    os.path.splitext(fname)[0] == f"{base_name}{suffix}"
+                    os.path.splitext(fname)[0] == f"{sanitized_base_name}{suffix}"
                     and os.path.splitext(fname)[1][1:].lower() in allowed_exts
                     for fname in os.listdir(parent_dir)
                 )
@@ -461,7 +543,9 @@ class ConversionThread(QThread):
             # Prepare merged output file for incremental writing ONLY if merge_chapters_at_end is True
             if merge_chapters_at_end:
                 out_dir = parent_dir
-                base_filepath_no_ext = os.path.join(out_dir, f"{base_name}{suffix}")
+                base_filepath_no_ext = os.path.join(
+                    out_dir, f"{sanitized_base_name}{suffix}"
+                )
                 merged_out_path = f"{base_filepath_no_ext}.{self.output_format}"
                 subtitle_entries = []
                 current_time = 0.0
@@ -554,6 +638,13 @@ class ConversionThread(QThread):
                     merged_subtitle_path = (
                         os.path.splitext(merged_out_path)[0] + f".{file_extension}"
                     )
+                    # Default subtitle layout flags/strings so they exist regardless
+                    # of whether ASS-specific handling runs. This prevents runtime
+                    # errors when non-ASS formats (like SRT) are selected.
+                    is_centered = False
+                    is_narrow = False
+                    merged_subtitle_margin = ""
+                    merged_subtitle_alignment_tag = ""
                     if "ass" in subtitle_format:
                         merged_subtitle_file = open(
                             merged_subtitle_path,
@@ -568,8 +659,12 @@ class ConversionThread(QThread):
                         # Add style definitions for karaoke highlighting
                         if self.subtitle_mode == "Sentence + Highlighting":
                             merged_subtitle_file.write("[V4+ Styles]\n")
-                            merged_subtitle_file.write("Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding\n")
-                            merged_subtitle_file.write("Style: Default,Arial,24,&H00FFFFFF,&H00808080,&H00000000,&H00404040,0,0,0,0,100,100,0,0,3,2,0,5,10,10,10,1\n\n")
+                            merged_subtitle_file.write(
+                                "Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding\n"
+                            )
+                            merged_subtitle_file.write(
+                                "Style: Default,Arial,24,&H00FFFFFF,&H00808080,&H00000000,&H00404040,0,0,0,0,100,100,0,0,3,2,0,5,10,10,10,1\n\n"
+                            )
                         merged_subtitle_file.write("[Events]\n")
                         merged_subtitle_file.write(
                             "Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\n"
@@ -644,8 +739,13 @@ class ConversionThread(QThread):
                     loaded_voice = self.voice
                 # Prepare per-chapter output file if needed
                 if save_chapters_separately and total_chapters > 1:
+                    # First pass: keep alphanumeric, spaces, hyphens, and underscores
                     sanitized = re.sub(r"[^\w\s\-]", "", chapter_name)
+                    # Replace multiple spaces/hyphens with single underscore
                     sanitized = re.sub(r"[\s\-]+", "_", sanitized).strip("_")
+                    # Apply OS-specific sanitization
+                    sanitized = sanitize_name_for_os(sanitized, is_folder=False)
+                    # Limit length (leaving room for the chapter number prefix)
                     MAX_LEN = 80
                     if len(sanitized) > MAX_LEN:
                         pos = sanitized[:MAX_LEN].rfind("_")
@@ -705,13 +805,20 @@ class ConversionThread(QThread):
                         chapter_subtitle_path = os.path.join(
                             chapters_out_dir, f"{chapter_filename}.{file_extension}"
                         )
-                        if "ass" in subtitle_format:
+                        # Ensure these variables exist even when not using ASS so
+                        # later code can safely reference them.
+                        is_centered = False
+                        is_narrow = False
+                        chapter_subtitle_margin = ""
+                        chapter_subtitle_alignment_tag = ""
+                        # Open the chapter subtitle file for writing for both SRT and ASS
                         chapter_subtitle_file = open(
                             chapter_subtitle_path,
                             "w",
                             encoding="utf-8",
                             errors="replace",
                         )
+                        if "ass" in subtitle_format:
                             # Minimal ASS header
                             chapter_subtitle_file.write("[Script Info]\n")
                             chapter_subtitle_file.write("Title: Generated by Abogen\n")
@@ -720,8 +827,12 @@ class ConversionThread(QThread):
                             # Add style definitions for karaoke highlighting
                             if self.subtitle_mode == "Sentence + Highlighting":
                                 chapter_subtitle_file.write("[V4+ Styles]\n")
-                                chapter_subtitle_file.write("Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding\n")
-                                chapter_subtitle_file.write("Style: Default,Arial,24,&H00FFFFFF,&H00808080,&H00000000,&H00404040,0,0,0,0,100,100,0,0,3,2,0,5,10,10,10,1\n\n")
+                                chapter_subtitle_file.write(
+                                    "Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding\n"
+                                )
+                                chapter_subtitle_file.write(
+                                    "Style: Default,Arial,24,&H00FFFFFF,&H00808080,&H00000000,&H00404040,0,0,0,0,100,100,0,0,3,2,0,5,10,10,10,1\n\n"
+                                )
 
                             chapter_subtitle_file.write("[Events]\n")
                             chapter_subtitle_file.write(
@@ -740,12 +851,7 @@ class ConversionThread(QThread):
                                 f"{{\\an5}}" if is_centered else ""
                             )
                     else:
-                        chapter_subtitle_file = open(
-                            chapter_subtitle_path,
-                            "w",
-                            encoding="utf-8",
-                            errors="replace",
-                        )
+                        chapter_subtitle_file = None
                 else:
                     chapter_subtitle_path = None
                     chapter_subtitle_file = None
@@ -841,7 +947,12 @@ class ConversionThread(QThread):
                                         start_time = self._ass_time(start)
                                         end_time = self._ass_time(end)
                                         # Use karaoke effect for highlighting mode
-                                        effect = "karaoke" if self.subtitle_mode == "Sentence + Highlighting" else ""
+                                        effect = (
+                                            "karaoke"
+                                            if self.subtitle_mode
+                                            == "Sentence + Highlighting"
+                                            else ""
+                                        )
                                         merged_subtitle_file.write(
                                             f"Dialogue: 0,{start_time},{end_time},Default,,{merged_subtitle_margin},{merged_subtitle_margin},0,{effect},{merged_subtitle_alignment_tag}{text}\n"
                                         )
@@ -870,7 +981,12 @@ class ConversionThread(QThread):
                                         start_time = self._ass_time(start)
                                         end_time = self._ass_time(end)
                                         # Use karaoke effect for highlighting mode
-                                        effect = "karaoke" if self.subtitle_mode == "Sentence + Highlighting" else ""
+                                        effect = (
+                                            "karaoke"
+                                            if self.subtitle_mode
+                                            == "Sentence + Highlighting"
+                                            else ""
+                                        )
                                         chapter_subtitle_file.write(
                                             f"Dialogue: 0,{start_time},{end_time},Default,,{chapter_subtitle_margin},{chapter_subtitle_margin},0,{effect},{chapter_subtitle_alignment_tag}{text}\n"
                                         )
@@ -916,7 +1032,9 @@ class ConversionThread(QThread):
 
                 # Add silence between chapters for merged output (except after the last chapter)
                 if merge_chapters_at_end and chapter_idx < total_chapters:
-                    silence_samples = int(self.silence_duration * 24000)  # Silence duration at 24,000 Hz
+                    silence_samples = int(
+                        self.silence_duration * 24000
+                    )  # Silence duration at 24,000 Hz
                     silence_audio = self.np.zeros(silence_samples, dtype="float32")
                     silence_bytes = silence_audio.tobytes()
 
@@ -1036,11 +1154,12 @@ class ConversionThread(QThread):
                         merged_out_path,
                     )
             else:
-                # If not merging, just finish after chapters
+                # If not merging, report the folder that holds the chapter files
                 self.progress_updated.emit(100, "00:00:00")
+                chapters_dir = os.path.abspath(chapters_out_dir or parent_dir)
                 self.conversion_finished.emit(
-                    ("\nAll chapters saved.", "green"),
-                    None,
+                    (f"\nAll chapters saved to: {chapters_dir}", "green"),
+                    chapters_dir,
                 )
         except Exception as e:
             # Cleanup ffmpeg subprocesses on error
@@ -1189,23 +1308,7 @@ class ConversionThread(QThread):
         if not tokens_with_timestamps:
             return
 
-        # Always combine punctuation with preceding words for consistent handling across modes
-        processed_tokens = []
-        i = 0
-        while i < len(tokens_with_timestamps):
-            token = tokens_with_timestamps[i].copy()
-
-            # Look ahead for punctuation
-            while i + 1 < len(tokens_with_timestamps) and re.match(
-                r"^[^\w\s]+$", tokens_with_timestamps[i + 1]["text"]
-            ):
-                token["text"] += tokens_with_timestamps[i + 1]["text"]
-                token["end"] = tokens_with_timestamps[i + 1]["end"]
-                token["whitespace"] = tokens_with_timestamps[i + 1]["whitespace"]
-                i += 1
-
-            processed_tokens.append(token)
-            i += 1
+        processed_tokens = tokens_with_timestamps  # Use tokens directly
 
         # Use processed_tokens instead of tokens_with_timestamps for the rest of the method
         if self.subtitle_mode == "Sentence + Highlighting":
@@ -1231,7 +1334,11 @@ class ConversionThread(QThread):
                         karaoke_text = ""
                         for t in current_sentence:
                             # Calculate duration in centiseconds
-                            duration = t["end"] - t["start"] if t["end"] and t["start"] else 0.5
+                            duration = (
+                                t["end"] - t["start"]
+                                if t["end"] and t["start"]
+                                else 0.5
+                            )
                             duration_cs = int(duration * 100)
                             # Add karaoke effect - relies on style's SecondaryColour for highlighting
                             karaoke_text += f"{{\\kf{duration_cs}}}{t['text']}{t.get('whitespace', '') or ''}"
@@ -1262,9 +1369,14 @@ class ConversionThread(QThread):
                 if end is None or end <= start or end <= 0:
                     subtitle_entries[-1] = (start, fallback_end_time, text)
 
-        elif self.subtitle_mode == "Sentence" or self.subtitle_mode == "Sentence + Comma":
+        elif self.subtitle_mode in ["Sentence", "Sentence + Comma", "Line"]:
             # Define separator pattern based on mode
-            separator = r"[.!?]" if self.subtitle_mode == "Sentence" else r"[.!?,]"
+            if self.subtitle_mode == "Line":
+                separator = r"\n"
+            elif self.subtitle_mode == "Sentence":
+                separator = r"[.!?]"
+            else:  # Sentence + Comma
+                separator = r"[.!?,]"
             current_sentence = []
             word_count = 0
 
@@ -1311,23 +1423,48 @@ class ConversionThread(QThread):
                     subtitle_entries[-1] = (start, fallback_end_time, text)
 
         else:
-            # Word count-based grouping
+            # Word count-based grouping - simply count spaces and split after N spaces
             try:
                 word_count = int(self.subtitle_mode.split()[0])
                 word_count = min(word_count, max_subtitle_words)
             except (ValueError, IndexError):
                 word_count = 1
 
-            # Group words into subtitle entries (processed_tokens already has punctuation combined)
-            for i in range(0, len(processed_tokens), word_count):
-                group = processed_tokens[i : i + word_count]
-                if group:
+            current_group = []
+            space_count = 0
+
+            for token in processed_tokens:
+                current_group.append(token)
+
+                # Count spaces after tokens (in the whitespace field)
+                if token.get("whitespace", "") == " ":
+                    space_count += 1
+
+                    # Split after counting N spaces
+                    if space_count >= word_count:
                         text = "".join(
-                        t["text"] + (t.get("whitespace", "") or "") for t in group
+                            t["text"] + (t.get("whitespace", "") or "")
+                            for t in current_group
                         )
                         subtitle_entries.append(
-                        (group[0]["start"], group[-1]["end"], text.strip())
+                            (
+                                current_group[0]["start"],
+                                current_group[-1]["end"],
+                                text.strip(),
                             )
+                        )
+                        current_group = []
+                        space_count = 0
+
+            # Add any remaining tokens
+            if current_group:
+                text = "".join(
+                    t["text"] + (t.get("whitespace", "") or "") for t in current_group
+                )
+                subtitle_entries.append(
+                    (current_group[0]["start"], current_group[-1]["end"], text.strip())
+                )
+
             # Fallback for last entry
             if subtitle_entries and fallback_end_time is not None:
                 last_entry = subtitle_entries[-1]
@@ -1335,7 +1472,6 @@ class ConversionThread(QThread):
                 if end is None or end <= start or end <= 0:
                     subtitle_entries[-1] = (start, fallback_end_time, text)
 
-
     def cancel(self):
         self.cancel_requested = True
         self.should_cancel = True

abogen/main.py

@@ -1,4 +1,3 @@
-from json import load
 import os
 import sys
 import platform
@@ -7,20 +6,43 @@ import signal
 
 # Qt platform plugin detection (fixes #59)
 try:
-    from PyQt5.QtCore import QLibraryInfo
-    plugins = QLibraryInfo.location(QLibraryInfo.PluginsPath)
-    platform_dir = os.path.join(plugins, "platforms")
+    from PyQt6.QtCore import QLibraryInfo
+
+    # Get the path to the plugins directory
+    plugins = QLibraryInfo.path(QLibraryInfo.LibraryPath.PluginsPath)
+
+    # Normalize path to use the OS-native separators and absolute path
+    platform_dir = os.path.normpath(os.path.join(plugins, "platforms"))
+
+    # Ensure we work with an absolute path for clarity
+    platform_dir = os.path.abspath(platform_dir)
+
     if os.path.isdir(platform_dir):
         os.environ["QT_QPA_PLATFORM_PLUGIN_PATH"] = platform_dir
         print("QT_QPA_PLATFORM_PLUGIN_PATH set to:", platform_dir)
     else:
-        print("PyQt5 platform plugins not found at", platform_dir)
+        print("PyQt6 platform plugins not found at", platform_dir)
 except ImportError:
-    print("PyQt5 not installed.")
+    print("PyQt6 not installed.")
 
-from PyQt5.QtWidgets import QApplication
-from PyQt5.QtGui import QIcon
-from PyQt5.QtCore import qInstallMessageHandler, QtMsgType
+# Set application ID for Windows taskbar icon
+if platform.system() == "Windows":
+    try:
+        from abogen.constants import PROGRAM_NAME, VERSION
+        import ctypes
+
+        app_id = f"{PROGRAM_NAME}.{VERSION}"
+        ctypes.windll.shell32.SetCurrentProcessExplicitAppUserModelID(app_id)
+    except Exception as e:
+        print("Warning: failed to set AppUserModelID:", e)
+
+from PyQt6.QtWidgets import QApplication
+from PyQt6.QtGui import QIcon
+from PyQt6.QtCore import (
+    QLibraryInfo,
+    qInstallMessageHandler,
+    QtMsgType,
+)
 
 # Add the directory to Python path
 sys.path.insert(0, os.path.join(os.path.dirname(__file__)))
@@ -69,10 +91,12 @@ if platform.system() == "Darwin" and platform.processor() == "arm":
 
 # Custom message handler to filter out specific Qt warnings
 def qt_message_handler(mode, context, message):
+    # In PyQt6, the mode is an enum, so we compare with the enum members
     if "Wayland does not support QWindow::requestActivate()" in message:
         return  # Suppress this specific message
     if "setGrabPopup called with a parent, QtWaylandClient" in message:
         return
+
     if mode == QtMsgType.QtWarningMsg:
         print(f"Qt Warning: {message}")
     elif mode == QtMsgType.QtCriticalMsg:
@@ -86,13 +110,6 @@ def qt_message_handler(mode, context, message):
 # Install the custom message handler
 qInstallMessageHandler(qt_message_handler)
 
-# Set application ID for Windows taskbar icon
-if platform.system() == "Windows":
-    import ctypes
-
-    app_id = f"{PROGRAM_NAME}.{VERSION}"
-    ctypes.windll.shell32.SetCurrentProcessExplicitAppUserModelID(app_id)
-
 # Handle Wayland on Linux GNOME
 if platform.system() == "Linux":
     xdg_session = os.environ.get("XDG_SESSION_TYPE", "").lower()
@@ -123,7 +140,7 @@ def main():
 
     ex = abogen()
     ex.show()
-    sys.exit(app.exec_())
+    sys.exit(app.exec())
 
 
 if __name__ == "__main__":

abogen/queue_manager_gui.py

@@ -2,7 +2,7 @@
 # button to remove an item from the queue
 # button to clear the queue
 
-from PyQt5.QtWidgets import (
+from PyQt6.QtWidgets import (
     QDialog,
     QVBoxLayout,
     QHBoxLayout,
@@ -14,18 +14,20 @@ from PyQt5.QtWidgets import (
     QLabel,
     QWidget,
     QSizePolicy,
+    QAbstractItemView,
 )
-from PyQt5.QtCore import QFileInfo, Qt
+from PyQt6.QtCore import QFileInfo, Qt
 from abogen.constants import COLORS
 from copy import deepcopy
-from PyQt5.QtGui import QFontMetrics
+from PyQt6.QtGui import QFontMetrics
 
 
 class ElidedLabel(QLabel):
-    def __init__(self, text, parent=None):
-        super().__init__(text, parent)
+    def __init__(self, text):
+        super().__init__(text)
         self._full_text = text
-        self.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Preferred)
+        self.setSizePolicy(QSizePolicy.Policy.Expanding, QSizePolicy.Policy.Preferred)
+        self.setTextFormat(Qt.TextFormat.PlainText)
 
     def setText(self, text):
         self._full_text = text
@@ -34,7 +36,9 @@ class ElidedLabel(QLabel):
 
     def resizeEvent(self, event):
         metrics = QFontMetrics(self.font())
-        elided = metrics.elidedText(self._full_text, Qt.ElideRight, self.width())
+        elided = metrics.elidedText(
+            self._full_text, Qt.TextElideMode.ElideRight, self.width()
+        )
         super().setText(elided)
         super().resizeEvent(event)
 
@@ -53,8 +57,12 @@ class QueueListItemWidget(QWidget):
         name_label = ElidedLabel(os.path.basename(file_name))
         char_label = QLabel(f"Chars: {char_count}")
         char_label.setStyleSheet(f"color: {COLORS['LIGHT_DISABLED']};")
-        char_label.setAlignment(Qt.AlignRight | Qt.AlignVCenter)
-        char_label.setSizePolicy(QSizePolicy.Minimum, QSizePolicy.Preferred)
+        char_label.setAlignment(
+            Qt.AlignmentFlag.AlignRight | Qt.AlignmentFlag.AlignVCenter
+        )
+        char_label.setSizePolicy(
+            QSizePolicy.Policy.Minimum, QSizePolicy.Policy.Preferred
+        )
         layout.addWidget(name_label, 1)
         layout.addWidget(char_label, 0)
         self.setLayout(layout)
@@ -67,12 +75,14 @@ class DroppableQueueListWidget(QListWidget):
         self.setAcceptDrops(True)
         # Overlay for drag hover
         self.drag_overlay = QLabel("", self)
-        self.drag_overlay.setAlignment(Qt.AlignCenter)
+        self.drag_overlay.setAlignment(Qt.AlignmentFlag.AlignCenter)
         self.drag_overlay.setStyleSheet(
             f"border:2px dashed {COLORS['BLUE_BORDER_HOVER']}; border-radius:5px; padding:20px; background:{COLORS['BLUE_BG_HOVER']};"
         )
         self.drag_overlay.setVisible(False)
-        self.drag_overlay.setAttribute(Qt.WA_TransparentForMouseEvents, True)
+        self.drag_overlay.setAttribute(
+            Qt.WidgetAttribute.WA_TransparentForMouseEvents, True
+        )
 
     def dragEnterEvent(self, event):
         if event.mimeData().hasUrls():
@@ -132,20 +142,22 @@ class QueueManager(QDialog):
         layout.setSpacing(12)  # set spacing between widgets in main layout
         # list of queued items
         self.listwidget = DroppableQueueListWidget(self)
-        self.listwidget.setSelectionMode(QListWidget.ExtendedSelection)
+        self.listwidget.setSelectionMode(
+            QAbstractItemView.SelectionMode.ExtendedSelection
+        )
         self.listwidget.setAlternatingRowColors(True)
-        self.listwidget.setContextMenuPolicy(Qt.CustomContextMenu)
+        self.listwidget.setContextMenuPolicy(Qt.ContextMenuPolicy.CustomContextMenu)
         self.listwidget.customContextMenuRequested.connect(self.show_context_menu)
         # 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. "
-            "To add PDF or EPUB files, use the input box in the main window and click the <b>'Add to Queue'</b> button. "
+            "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. "
             "You can view each file's configuration by hovering over them."
         )
-        instructions.setAlignment(Qt.AlignLeft)
+        instructions.setAlignment(Qt.AlignmentFlag.AlignLeft)
         instructions.setWordWrap(True)
         instructions.setStyleSheet("margin-bottom: 8px;")
         layout.addWidget(instructions)
@@ -154,12 +166,14 @@ class QueueManager(QDialog):
             "Drag and drop your text files here or use the 'Add files' button.",
             self.listwidget,
         )
-        self.empty_overlay.setAlignment(Qt.AlignCenter)
+        self.empty_overlay.setAlignment(Qt.AlignmentFlag.AlignCenter)
         self.empty_overlay.setStyleSheet(
             f"color: {COLORS['LIGHT_DISABLED']}; background: transparent; padding: 20px;"
         )
         self.empty_overlay.setWordWrap(True)
-        self.empty_overlay.setAttribute(Qt.WA_TransparentForMouseEvents, True)
+        self.empty_overlay.setAttribute(
+            Qt.WidgetAttribute.WA_TransparentForMouseEvents, True
+        )
         self.empty_overlay.hide()
         # add queue items to the list
         self.process_queue()
@@ -192,7 +206,10 @@ class QueueManager(QDialog):
         self.listwidget.currentItemChanged.connect(self.update_button_states)
         self.listwidget.itemSelectionChanged.connect(self.update_button_states)
 
-        buttons = QDialogButtonBox(QDialogButtonBox.Ok | QDialogButtonBox.Cancel, self)
+        buttons = QDialogButtonBox(
+            QDialogButtonBox.StandardButton.Ok | QDialogButtonBox.StandardButton.Cancel,
+            self,
+        )
         buttons.accepted.connect(self.accept)
         buttons.rejected.connect(self.reject)
 
@@ -207,9 +224,10 @@ class QueueManager(QDialog):
 
     def process_queue(self):
         """Process the queue items."""
+        import os
+
         self.listwidget.clear()
         if not self.queue:
-            self.empty_overlay.resize(self.listwidget.size())
             self.empty_overlay.show()
             self.update_button_states()
             return
@@ -221,9 +239,20 @@ class QueueManager(QDialog):
             display_file_path = getattr(item, "save_base_path", None) or item.file_name
             processing_file_path = item.file_name
 
+            # Normalize paths for consistent display (fixes Windows path separator issues)
+            display_file_path = (
+                os.path.normpath(display_file_path)
+                if display_file_path
+                else display_file_path
+            )
+            processing_file_path = (
+                os.path.normpath(processing_file_path)
+                if processing_file_path
+                else processing_file_path
+            )
+
             # Only show the file name, not the full path
             display_name = display_file_path
-            import os
 
             if os.path.sep in display_file_path:
                 display_name = os.path.basename(display_file_path)
@@ -235,13 +264,19 @@ class QueueManager(QDialog):
             # For plain .txt inputs we don't need to show a separate processing file
             show_processing = True
             try:
-                if isinstance(display_file_path, str) and display_file_path.lower().endswith('.txt'):
+                if isinstance(
+                    display_file_path, str
+                ) and display_file_path.lower().endswith(".txt"):
                     show_processing = False
             except Exception:
                 show_processing = True
 
             tooltip = f"<b>Input File:</b> {display_file_path}<br>"
-            if show_processing and processing_file_path and processing_file_path != display_file_path:
+            if (
+                show_processing
+                and processing_file_path
+                and processing_file_path != display_file_path
+            ):
                 tooltip += f"<b>Processing File:</b> {processing_file_path}<br>"
             tooltip += (
                 f"<b>Language:</b> {getattr(item, 'lang_code', '')}<br>"
@@ -257,13 +292,24 @@ class QueueManager(QDialog):
                 f"<b>Characters:</b> {getattr(item, 'total_char_count', '')}<br>"
                 f"<b>Replace Single Newlines:</b> {getattr(item, 'replace_single_newlines', False)}"
             )
+            # Add book handler options if present
+            save_chapters_separately = getattr(item, "save_chapters_separately", None)
+            merge_chapters_at_end = getattr(item, "merge_chapters_at_end", None)
+            if save_chapters_separately is not None:
+                tooltip += f"<br><b>Save chapters separately:</b> {'Yes' if save_chapters_separately else 'No'}"
+                # Only show merge option if saving chapters separately
+                if save_chapters_separately and merge_chapters_at_end is not None:
+                    tooltip += f"<br><b>Merge chapters at the end:</b> {'Yes' if merge_chapters_at_end else 'No'}"
             list_item.setToolTip(tooltip)
             list_item.setIcon(icon)
             # Store both paths for context menu
-            list_item.setData(Qt.UserRole, {
-                'display_path': display_file_path,
-                'processing_path': processing_file_path
-            })
+            list_item.setData(
+                Qt.ItemDataRole.UserRole,
+                {
+                    "display_path": display_file_path,
+                    "processing_path": processing_file_path,
+                },
+            )
             # Use custom widget for display
             char_count = getattr(item, "total_char_count", 0)
             widget = QueueListItemWidget(display_file_path, char_count)
@@ -275,7 +321,7 @@ class QueueManager(QDialog):
         items = self.listwidget.selectedItems()
         if not items:
             return
-        from PyQt5.QtWidgets import QMessageBox
+        from PyQt6.QtWidgets import QMessageBox
 
         # Remove by index to ensure correct mapping
         rows = sorted([self.listwidget.row(item) for item in items], reverse=True)
@@ -285,10 +331,10 @@ class QueueManager(QDialog):
                 self,
                 "Confirm Remove",
                 f"Are you sure you want to remove {len(rows)} selected items from the queue?",
-                QMessageBox.Yes | QMessageBox.No,
-                QMessageBox.No,
+                QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No,
+                QMessageBox.StandardButton.No,
             )
-            if reply != QMessageBox.Yes:
+            if reply != QMessageBox.StandardButton.Yes:
                 return
         for row in rows:
             if 0 <= row < len(self.queue):
@@ -297,17 +343,17 @@ class QueueManager(QDialog):
         self.update_button_states()
 
     def clear_queue(self):
-        from PyQt5.QtWidgets import QMessageBox
+        from PyQt6.QtWidgets import QMessageBox
 
         if len(self.queue) > 1:
             reply = QMessageBox.question(
                 self,
                 "Confirm Clear Queue",
                 f"Are you sure you want to clear {len(self.queue)} items from the queue?",
-                QMessageBox.Yes | QMessageBox.No,
-                QMessageBox.No,
+                QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No,
+                QMessageBox.StandardButton.No,
             )
-            if reply != QMessageBox.Yes:
+            if reply != QMessageBox.StandardButton.Yes:
                 return
         self.queue.clear()
         self.listwidget.clear()
@@ -357,6 +403,13 @@ class QueueManager(QDialog):
             attrs["replace_single_newlines"] = getattr(
                 parent, "replace_single_newlines", False
             )
+            # book handler options
+            attrs["save_chapters_separately"] = getattr(
+                parent, "save_chapters_separately", None
+            )
+            attrs["merge_chapters_at_end"] = getattr(
+                parent, "merge_chapters_at_end", None
+            )
         else:
             # fallback: empty values
             attrs = {
@@ -373,11 +426,13 @@ class QueueManager(QDialog):
                     "replace_single_newlines",
                 ]
             }
+            attrs["save_chapters_separately"] = None
+            attrs["merge_chapters_at_end"] = None
         return attrs
 
     def add_files_from_paths(self, file_paths):
         from abogen.utils import calculate_text_length
-        from PyQt5.QtWidgets import QMessageBox
+        from PyQt6.QtWidgets import QMessageBox
         import os
 
         current_attrs = self.get_current_attributes()
@@ -389,7 +444,9 @@ class QueueManager(QDialog):
 
             item = QueueItem()
             item.file_name = file_path
-            item.save_base_path = file_path  # For .txt files, processing and save paths are the same
+            item.save_base_path = (
+                file_path  # For .txt files, processing and save paths are the same
+            )
             for attr, value in current_attrs.items():
                 setattr(item, attr, value)
             # Read file content and calculate total_char_count using calculate_text_length
@@ -425,6 +482,10 @@ class QueueManager(QDialog):
                     == getattr(item, "replace_single_newlines", False)
                     and getattr(queued_item, "save_base_path", None)
                     == getattr(item, "save_base_path", None)
+                    and getattr(queued_item, "save_chapters_separately", None)
+                    == getattr(item, "save_chapters_separately", None)
+                    and getattr(queued_item, "merge_chapters_at_end", None)
+                    == getattr(item, "merge_chapters_at_end", None)
                 ):
                     is_duplicate = True
                     break
@@ -442,7 +503,7 @@ class QueueManager(QDialog):
         self.update_button_states()
 
     def add_more_files(self):
-        from PyQt5.QtWidgets import QFileDialog
+        from PyQt6.QtWidgets import QFileDialog
         from abogen.utils import calculate_text_length  # import the function
 
         # Only allow .txt files
@@ -472,9 +533,9 @@ class QueueManager(QDialog):
             self.clear_button.setEnabled(bool(self.queue))
 
     def show_context_menu(self, pos):
-        from PyQt5.QtWidgets import QMenu, QAction
-        from PyQt5.QtGui import QDesktopServices
-        from PyQt5.QtCore import QUrl
+        from PyQt6.QtWidgets import QMenu
+        from PyQt6.QtGui import QAction, QDesktopServices
+        from PyQt6.QtCore import QUrl
         import os
 
         global_pos = self.listwidget.viewport().mapToGlobal(pos)
@@ -486,75 +547,129 @@ class QueueManager(QDialog):
             remove_action.triggered.connect(self.remove_item)
             menu.addAction(remove_action)
 
-            # Add Open file action
-            open_file_action = QAction("Open file", self)
-
-            def open_file():
-                from PyQt5.QtWidgets import QMessageBox
-
+            # Get paths for determining if it's a document input
             item = selected_items[0]
-                paths = item.data(Qt.UserRole)
+            paths = item.data(Qt.ItemDataRole.UserRole)
             if isinstance(paths, dict):
-                    file_path = paths.get('display_path', paths.get('processing_path', ''))
+                display_path = paths.get("display_path", "")
+                processing_path = paths.get("processing_path", "")
             else:
-                    file_path = paths  # Fallback for old format
+                display_path = paths
+                processing_path = paths
 
-                # Find the queue item
+            doc_exts = (".md", ".markdown", ".pdf", ".epub")
+            is_document_input = (
+                isinstance(display_path, str)
+                and display_path.lower().endswith(doc_exts)
+            ) or (
+                isinstance(processing_path, str)
+                and processing_path.lower().endswith(doc_exts)
+            )
+
+            # Add Open file action(s)
+            def open_file_by_path(path_label: str):
+                from PyQt6.QtWidgets import QMessageBox
+
+                p = display_path if path_label == "display" else processing_path
+                if not p:
+                    QMessageBox.warning(
+                        self, "File Not Found", "Path is not available."
+                    )
+                    return
+
+                # Find the queue item and resolve the target path
+                target_path = None
                 for q in self.queue:
-                    if (getattr(q, "save_base_path", None) == file_path or 
-                        q.file_name == file_path):
-                        target_path = getattr(q, "save_base_path", None) or q.file_name
+                    if (
+                        getattr(q, "save_base_path", None) == display_path
+                        or q.file_name == display_path
+                    ):
+                        if path_label == "display":
+                            target_path = (
+                                getattr(q, "save_base_path", None) or q.file_name
+                            )
+                        else:
+                            target_path = q.file_name
+                        break
+                    if (
+                        getattr(q, "save_base_path", None) == processing_path
+                        or q.file_name == processing_path
+                    ):
+                        if path_label == "display":
+                            target_path = (
+                                getattr(q, "save_base_path", None) or q.file_name
+                            )
+                        else:
+                            target_path = q.file_name
+                        break
+
+                # Fallback to the raw path if resolution failed
+                if not target_path:
+                    target_path = p
+
                 if not os.path.exists(target_path):
                     QMessageBox.warning(
                         self, "File Not Found", f"The file does not exist."
                     )
                     return
                 QDesktopServices.openUrl(QUrl.fromLocalFile(target_path))
-                        break
 
-            open_file_action.triggered.connect(open_file)
+            if is_document_input:
+                # For documents, show two open options
+                open_processed_action = QAction("Open processed file", self)
+                open_processed_action.triggered.connect(
+                    lambda: open_file_by_path("processing")
+                )
+                menu.addAction(open_processed_action)
+
+                open_input_action = QAction("Open input file", self)
+                open_input_action.triggered.connect(
+                    lambda: open_file_by_path("display")
+                )
+                menu.addAction(open_input_action)
+            else:
+                # For plain text files, show single open option
+                open_file_action = QAction("Open file", self)
+                open_file_action.triggered.connect(lambda: open_file_by_path("display"))
                 menu.addAction(open_file_action)
 
             # Add Go to folder action
             # If the queued item represents a converted document (markdown, pdf, epub)
             # show two actions: Go to processed file (the cached .txt) and Go to input file (original source)
-            item = selected_items[0]
-            paths = item.data(Qt.UserRole)
-            if isinstance(paths, dict):
-                display_path = paths.get('display_path', '')
-                processing_path = paths.get('processing_path', '')
-            else:
-                display_path = paths
-                processing_path = paths
 
-            doc_exts = ('.md', '.markdown', '.pdf', '.epub')
-            is_document_input = (
-                isinstance(display_path, str) and display_path.lower().endswith(doc_exts)
-            ) or (
-                isinstance(processing_path, str) and processing_path.lower().endswith(doc_exts)
-            )
-
-            from PyQt5.QtWidgets import QMessageBox
+            from PyQt6.QtWidgets import QMessageBox
 
             def open_folder_for(path_label: str):
                 # path_label should be either 'display' or 'processing'
-                p = display_path if path_label == 'display' else processing_path
+                p = display_path if path_label == "display" else processing_path
                 if not p:
-                    QMessageBox.warning(self, "File Not Found", "Path is not available.")
+                    QMessageBox.warning(
+                        self, "File Not Found", "Path is not available."
+                    )
                     return
                 # If the stored path is the display path (original) but the actual file may be
                 # stored on the queue object differently, try to resolve via the queue entry.
                 target_path = None
                 for q in self.queue:
-                    if getattr(q, 'save_base_path', None) == display_path or q.file_name == display_path:
-                        if path_label == 'display':
-                            target_path = getattr(q, 'save_base_path', None) or q.file_name
+                    if (
+                        getattr(q, "save_base_path", None) == display_path
+                        or q.file_name == display_path
+                    ):
+                        if path_label == "display":
+                            target_path = (
+                                getattr(q, "save_base_path", None) or q.file_name
+                            )
                         else:
                             target_path = q.file_name
                         break
-                    if getattr(q, 'save_base_path', None) == processing_path or q.file_name == processing_path:
-                        if path_label == 'display':
-                            target_path = getattr(q, 'save_base_path', None) or q.file_name
+                    if (
+                        getattr(q, "save_base_path", None) == processing_path
+                        or q.file_name == processing_path
+                    ):
+                        if path_label == "display":
+                            target_path = (
+                                getattr(q, "save_base_path", None) or q.file_name
+                            )
                         else:
                             target_path = q.file_name
                         break
@@ -563,7 +678,11 @@ class QueueManager(QDialog):
                     target_path = p
 
                 if not os.path.exists(target_path):
-                    QMessageBox.warning(self, "File Not Found", f"The file does not exist: {target_path}")
+                    QMessageBox.warning(
+                        self,
+                        "File Not Found",
+                        f"The file does not exist: {target_path}",
+                    )
                     return
                 folder = os.path.dirname(target_path)
                 if os.path.exists(folder):
@@ -571,11 +690,13 @@ class QueueManager(QDialog):
 
             if is_document_input:
                 processed_action = QAction("Go to processed file", self)
-                processed_action.triggered.connect(lambda: open_folder_for('processing'))
+                processed_action.triggered.connect(
+                    lambda: open_folder_for("processing")
+                )
                 menu.addAction(processed_action)
 
                 input_action = QAction("Go to input file", self)
-                input_action.triggered.connect(lambda: open_folder_for('display'))
+                input_action.triggered.connect(lambda: open_folder_for("display"))
                 menu.addAction(input_action)
             else:
                 # Default behavior for non-document inputs: single "Go to folder" action
@@ -583,15 +704,22 @@ class QueueManager(QDialog):
 
                 def go_to_folder():
                     item = selected_items[0]
-                    paths = item.data(Qt.UserRole)
+                    paths = item.data(Qt.ItemDataRole.UserRole)
                     if isinstance(paths, dict):
-                        file_path = paths.get('display_path', paths.get('processing_path', ''))
+                        file_path = paths.get(
+                            "display_path", paths.get("processing_path", "")
+                        )
                     else:
                         file_path = paths  # Fallback for old format
                     # Find the queue item
                     for q in self.queue:
-                        if (getattr(q, "save_base_path", None) == file_path or q.file_name == file_path):
-                            target_path = getattr(q, "save_base_path", None) or q.file_name
+                        if (
+                            getattr(q, "save_base_path", None) == file_path
+                            or q.file_name == file_path
+                        ):
+                            target_path = (
+                                getattr(q, "save_base_path", None) or q.file_name
+                            )
                             if not os.path.exists(target_path):
                                 QMessageBox.warning(
                                     self, "File Not Found", f"The file does not exist."
@@ -613,7 +741,7 @@ class QueueManager(QDialog):
         clear_action = QAction("Clear Queue", self)
         clear_action.triggered.connect(self.clear_queue)
         menu.addAction(clear_action)
-        menu.exec_(global_pos)
+        menu.exec(global_pos)
 
     def accept(self):
         # Accept: keep changes
@@ -621,7 +749,7 @@ class QueueManager(QDialog):
 
     def reject(self):
         # Cancel: restore original queue
-        from PyQt5.QtWidgets import QMessageBox
+        from PyQt6.QtWidgets import QMessageBox
 
         # Warn if user changed a lot (e.g., more than 1 items difference)
         original_count = len(self._original_queue)
@@ -631,19 +759,19 @@ class QueueManager(QDialog):
                 self,
                 "Confirm Cancel",
                 f"Are you sure you want to cancel and discard all changes?",
-                QMessageBox.Yes | QMessageBox.No,
-                QMessageBox.No,
+                QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No,
+                QMessageBox.StandardButton.No,
             )
-            if reply != QMessageBox.Yes:
+            if reply != QMessageBox.StandardButton.Yes:
                 return
         self.queue.clear()
         self.queue.extend(deepcopy(self._original_queue))
         super().reject()
 
     def keyPressEvent(self, event):
-        from PyQt5.QtCore import Qt
+        from PyQt6.QtCore import Qt
 
-        if event.key() == Qt.Key_Delete:
+        if event.key() == Qt.Key.Key_Delete:
             self.remove_item()
         else:
             super().keyPressEvent(event)

abogen/queued_item.py

@@ -15,3 +15,5 @@ class QueuedItem:
     total_char_count: int
     replace_single_newlines: bool = False
     save_base_path: str = None
+    save_chapters_separately: bool = None
+    merge_chapters_at_end: bool = None

abogen/utils.py

@@ -14,6 +14,7 @@ warnings.filterwarnings("ignore")
 def detect_encoding(file_path):
     import chardet
     import charset_normalizer
+
     with open(file_path, "rb") as f:
         raw_data = f.read()
     detected_encoding = None
@@ -28,6 +29,7 @@ def detect_encoding(file_path):
     encoding = detected_encoding if detected_encoding else "utf-8"
     return encoding.lower()
 
+
 def get_resource_path(package, resource):
     """
     Get the path to a resource file, with fallback to local file system.

abogen/voice_formula_gui.py

@@ -1,6 +1,6 @@
 import json
 import os
-from PyQt5.QtWidgets import (
+from PyQt6.QtWidgets import (
     QDialog,
     QVBoxLayout,
     QCheckBox,
@@ -22,12 +22,11 @@ from PyQt5.QtWidgets import (
     QFileDialog,
     QSplitter,
     QMenu,
-    QAction,
-    QComboBox,
     QApplication,
+    QComboBox,
 )
-from PyQt5.QtCore import Qt, QTimer, QPoint, QRect, QSize
-from PyQt5.QtGui import QPixmap, QIcon
+from PyQt6.QtCore import Qt, QTimer, QPoint, QRect, QSize
+from PyQt6.QtGui import QPixmap, QIcon, QAction
 from abogen.constants import (
     VOICES_INTERNAL,
     SUPPORTED_LANGUAGES_FOR_SUBTITLE_GENERATION,
@@ -91,7 +90,7 @@ class FlowLayout(QLayout):
         return len(self._item_list)
 
     def expandingDirections(self):
-        return Qt.Orientations(Qt.Orientation(0))
+        return Qt.Orientation(0)
 
     def hasHeightForWidth(self):
         return True
@@ -132,10 +131,14 @@ class FlowLayout(QLayout):
         for item in self._item_list:
             style = self.parentWidget().style() if self.parentWidget() else QStyle()
             layout_spacing_x = style.layoutSpacing(
-                QSizePolicy.PushButton, QSizePolicy.PushButton, Qt.Horizontal
+                QSizePolicy.ControlType.PushButton,
+                QSizePolicy.ControlType.PushButton,
+                Qt.Orientation.Horizontal,
             )
             layout_spacing_y = style.layoutSpacing(
-                QSizePolicy.PushButton, QSizePolicy.PushButton, Qt.Vertical
+                QSizePolicy.ControlType.PushButton,
+                QSizePolicy.ControlType.PushButton,
+                Qt.Orientation.Vertical,
             )
             space_x = spacing if spacing >= 0 else layout_spacing_x
             space_y = spacing if spacing >= 0 else layout_spacing_y
@@ -163,7 +166,7 @@ class VoiceMixer(QWidget):
         super().__init__()
         self.voice_name = voice_name
         self.setFixedWidth(VOICE_MIXER_WIDTH)
-        self.setSizePolicy(QSizePolicy.Expanding, QSizePolicy.Expanding)
+        self.setSizePolicy(QSizePolicy.Policy.Expanding, QSizePolicy.Policy.Expanding)
 
         # TODO Set CSS for rounded corners
         # self.setObjectName("VoiceMixer")
@@ -173,7 +176,7 @@ class VoiceMixer(QWidget):
 
         # Name label at the top
         name = voice_name
-        layout.addWidget(QLabel(name), alignment=Qt.AlignCenter)
+        layout.addWidget(QLabel(name), alignment=Qt.AlignmentFlag.AlignCenter)
 
         # Voice name label with gender icon
         is_female = self.voice_name in VOICES_INTERNAL and self.voice_name[1] == "f"
@@ -181,7 +184,9 @@ class VoiceMixer(QWidget):
         # Icons layout (flag and gender)
         icons_layout = QHBoxLayout()
         icons_layout.setSpacing(3)
-        icons_layout.setAlignment(Qt.AlignCenter)  # Center the icons horizontally
+        icons_layout.setAlignment(
+            Qt.AlignmentFlag.AlignCenter
+        )  # Center the icons horizontally
 
         # Flag icon
         flag_icon_path = get_resource_path(
@@ -194,11 +199,21 @@ class VoiceMixer(QWidget):
         gender_label = QLabel()
         flag_pixmap = QPixmap(flag_icon_path)
         flag_label.setPixmap(
-            flag_pixmap.scaled(16, 16, Qt.KeepAspectRatio, Qt.SmoothTransformation)
+            flag_pixmap.scaled(
+                16,
+                16,
+                Qt.AspectRatioMode.KeepAspectRatio,
+                Qt.TransformationMode.SmoothTransformation,
+            )
         )
         gender_pixmap = QPixmap(gender_icon_path)
         gender_label.setPixmap(
-            gender_pixmap.scaled(16, 16, Qt.KeepAspectRatio, Qt.SmoothTransformation)
+            gender_pixmap.scaled(
+                16,
+                16,
+                Qt.AspectRatioMode.KeepAspectRatio,
+                Qt.TransformationMode.SmoothTransformation,
+            )
         )
         icons_layout.addWidget(flag_label)
         icons_layout.addWidget(gender_label)
@@ -210,7 +225,7 @@ class VoiceMixer(QWidget):
         self.checkbox = QCheckBox()
         self.checkbox.setChecked(initial_status)
         self.checkbox.stateChanged.connect(self.toggle_inputs)
-        layout.addWidget(self.checkbox, alignment=Qt.AlignCenter)
+        layout.addWidget(self.checkbox, alignment=Qt.AlignmentFlag.AlignCenter)
 
         # Spinbox and slider
         self.spin_box = QDoubleSpinBox()
@@ -219,12 +234,51 @@ class VoiceMixer(QWidget):
         self.spin_box.setDecimals(2)
         self.spin_box.setValue(initial_weight)
 
-        self.slider = QSlider(Qt.Vertical)
+        self.slider = QSlider(Qt.Orientation.Vertical)
         self.slider.setRange(0, 100)
         self.slider.setValue(int(initial_weight * 100))
-        self.slider.setSizePolicy(QSizePolicy.Fixed, QSizePolicy.Expanding)
+        self.slider.setSizePolicy(
+            QSizePolicy.Policy.Fixed, QSizePolicy.Policy.Expanding
+        )
         self.slider.setFixedWidth(SLIDER_WIDTH)
 
+        # Apply slider styling after widget is added to window (see showEvent)
+        self._slider_style_applied = False
+
+        # Connect controls
+        self.slider.valueChanged.connect(lambda val: self.spin_box.setValue(val / 100))
+        self.spin_box.valueChanged.connect(
+            lambda val: self.slider.setValue(int(val * 100))
+        )
+
+        # Layout for slider and labels
+        slider_layout = QVBoxLayout()
+        slider_layout.addWidget(self.spin_box)
+        slider_layout.addWidget(QLabel("1", alignment=Qt.AlignmentFlag.AlignCenter))
+
+        slider_center_layout = QHBoxLayout()
+        slider_center_layout.addWidget(
+            self.slider, alignment=Qt.AlignmentFlag.AlignHCenter
+        )
+        slider_center_layout.setContentsMargins(0, 0, 0, 0)
+
+        slider_center_widget = QWidget()
+        slider_center_widget.setLayout(slider_center_layout)
+
+        slider_layout.addWidget(slider_center_widget, stretch=1)
+        slider_layout.addWidget(QLabel("0", alignment=Qt.AlignmentFlag.AlignCenter))
+        slider_layout.setStretch(2, 1)
+
+        layout.addLayout(slider_layout, stretch=1)
+        self.setLayout(layout)
+        self.toggle_inputs()
+
+    def showEvent(self, event):
+        super().showEvent(event)
+        # Apply slider styling once when widget is shown and has access to parent
+        if not self._slider_style_applied:
+            self._slider_style_applied = True
+            
             # Fix slider in Windows
             if platform.system() == "Windows":
                 appstyle = QApplication.instance().style().objectName().lower()
@@ -239,33 +293,28 @@ class VoiceMixer(QWidget):
                         }}
                     """
                     )
+            else:
+                # Apply same fix for Light theme on non-Windows systems
+                # Get theme from parent window's config
+                parent_window = self.window()
+                theme = "system"
+                while parent_window:
+                    if hasattr(parent_window, "config"):
+                        theme = parent_window.config.get("theme", "system")
+                        break
+                    parent_window = parent_window.parent()
                 
-        # Connect controls
-        self.slider.valueChanged.connect(lambda val: self.spin_box.setValue(val / 100))
-        self.spin_box.valueChanged.connect(
-            lambda val: self.slider.setValue(int(val * 100))
+                if theme == "light":
+                    self.slider.setStyleSheet(
+                        f"""
+                        QSlider::groove:vertical:disabled {{
+                            background: {COLORS.get("GREY_BACKGROUND")};
+                            width: 4px;
+                            border-radius: 4px;
+                        }}
+                    """
                     )
 
-        # Layout for slider and labels
-        slider_layout = QVBoxLayout()
-        slider_layout.addWidget(self.spin_box)
-        slider_layout.addWidget(QLabel("1", alignment=Qt.AlignCenter))
-
-        slider_center_layout = QHBoxLayout()
-        slider_center_layout.addWidget(self.slider, alignment=Qt.AlignHCenter)
-        slider_center_layout.setContentsMargins(0, 0, 0, 0)
-
-        slider_center_widget = QWidget()
-        slider_center_widget.setLayout(slider_center_layout)
-
-        slider_layout.addWidget(slider_center_widget, stretch=1)
-        slider_layout.addWidget(QLabel("0", alignment=Qt.AlignCenter))
-        slider_layout.setStretch(2, 1)
-
-        layout.addLayout(slider_layout, stretch=1)
-        self.setLayout(layout)
-        self.toggle_inputs()
-
     def toggle_inputs(self):
         is_enabled = self.checkbox.isChecked()
         self.spin_box.setEnabled(is_enabled)
@@ -307,9 +356,11 @@ class HoverLabel(QLabel):
             """
         )
         # Make sure the entire button is clickable, not just the text
-        self.delete_button.setFocusPolicy(Qt.NoFocus)
-        self.delete_button.setAttribute(Qt.WA_TransparentForMouseEvents, False)
-        self.delete_button.setCursor(Qt.PointingHandCursor)
+        self.delete_button.setFocusPolicy(Qt.FocusPolicy.NoFocus)
+        self.delete_button.setAttribute(
+            Qt.WidgetAttribute.WA_TransparentForMouseEvents, False
+        )
+        self.delete_button.setCursor(Qt.CursorShape.PointingHandCursor)
         self.delete_button.hide()
 
     def resizeEvent(self, event):
@@ -357,7 +408,7 @@ class VoiceFormulaDialog(QDialog):
         if parent is not None and hasattr(parent, "subtitle_combo"):
             self.subtitle_combo = parent.subtitle_combo
         # Create main container layout with profile section and mixer section
-        splitter = QSplitter(Qt.Horizontal)
+        splitter = QSplitter(Qt.Orientation.Horizontal)
         # Profile section
         profile_widget = QWidget()
         profile_layout = QVBoxLayout(profile_widget)
@@ -371,8 +422,8 @@ class VoiceFormulaDialog(QDialog):
         profile_layout.addLayout(header_layout)
         # Profile list
         self.profile_list = QListWidget()
-        self.profile_list.setSelectionMode(QListWidget.SingleSelection)
-        self.profile_list.setSelectionBehavior(QListWidget.SelectRows)
+        self.profile_list.setSelectionMode(QListWidget.SelectionMode.SingleSelection)
+        self.profile_list.setSelectionBehavior(QListWidget.SelectionBehavior.SelectRows)
         self.profile_list.setStyleSheet(
             "QListWidget::item:selected { background: palette(highlight); color: palette(highlighted-text); }"
         )
@@ -388,7 +439,7 @@ class VoiceFormulaDialog(QDialog):
             idx = list(profiles.keys()).index(self.current_profile)
             self.profile_list.setCurrentRow(idx)
         profile_layout.addWidget(self.profile_list)
-        self.profile_list.setContextMenuPolicy(Qt.CustomContextMenu)
+        self.profile_list.setContextMenuPolicy(Qt.ContextMenuPolicy.CustomContextMenu)
         self.profile_list.customContextMenuRequested.connect(
             self.show_profile_context_menu
         )
@@ -409,7 +460,9 @@ class VoiceFormulaDialog(QDialog):
 
         self.setWindowTitle("Voice Mixer")
         self.setWindowFlags(
-            Qt.Window | Qt.WindowCloseButtonHint | Qt.WindowMaximizeButtonHint
+            Qt.WindowType.Window
+            | Qt.WindowType.WindowCloseButtonHint
+            | Qt.WindowType.WindowMaximizeButtonHint
         )
         self.setMinimumSize(MIN_WINDOW_WIDTH, MIN_WINDOW_HEIGHT)
         self.resize(INITIAL_WINDOW_WIDTH, INITIAL_WINDOW_HEIGHT)
@@ -468,21 +521,25 @@ class VoiceFormulaDialog(QDialog):
 
         # Separator
         separator = QFrame()
-        separator.setFrameShadow(QFrame.Sunken)
+        separator.setFrameShadow(QFrame.Shadow.Sunken)
         mixer_layout.addWidget(separator)
 
         # Voice list scroll area
         self.scroll_area = QScrollArea()
         self.scroll_area.setWidgetResizable(True)
-        self.scroll_area.setHorizontalScrollBarPolicy(Qt.ScrollBarAsNeeded)
-        self.scroll_area.setVerticalScrollBarPolicy(Qt.ScrollBarAsNeeded)
+        self.scroll_area.setHorizontalScrollBarPolicy(
+            Qt.ScrollBarPolicy.ScrollBarAsNeeded
+        )
+        self.scroll_area.setVerticalScrollBarPolicy(
+            Qt.ScrollBarPolicy.ScrollBarAsNeeded
+        )
         self.scroll_area.viewport().installEventFilter(self)
 
         self.voice_list_widget = QWidget()
         self.voice_list_layout = QHBoxLayout()
         self.voice_list_widget.setLayout(self.voice_list_layout)
         self.voice_list_widget.setSizePolicy(
-            QSizePolicy.Expanding, QSizePolicy.Expanding
+            QSizePolicy.Policy.Expanding, QSizePolicy.Policy.Expanding
         )
         self.scroll_area.setWidget(self.voice_list_widget)
         mixer_layout.addWidget(self.scroll_area, stretch=1)
@@ -497,6 +554,9 @@ class VoiceFormulaDialog(QDialog):
         ok_button.setDefault(True)
         ok_button.setFocus()
 
+        # Connect buttons
+        clear_all_button.clicked.connect(self.clear_all_voices)
+        ok_button.clicked.connect(self.accept)
         # Connect buttons
         clear_all_button.clicked.connect(self.clear_all_voices)
         ok_button.clicked.connect(self.accept)
@@ -533,7 +593,7 @@ class VoiceFormulaDialog(QDialog):
 
     def keyPressEvent(self, event):
         # Bind Delete key to delete_profile when a profile is selected
-        if event.key() == Qt.Key_Delete and self.profile_list.hasFocus():
+        if event.key() == Qt.Key.Key_Delete and self.profile_list.hasFocus():
             item = self.profile_list.currentItem()
             if item:
                 self.delete_profile(item)
@@ -562,10 +622,12 @@ class VoiceFormulaDialog(QDialog):
                 self,
                 "Unsaved Changes",
                 msg,
-                QMessageBox.Save | QMessageBox.Discard | QMessageBox.Cancel,
-                QMessageBox.Save,
+                QMessageBox.StandardButton.Save
+                | QMessageBox.StandardButton.Discard
+                | QMessageBox.StandardButton.Cancel,
+                QMessageBox.StandardButton.Save,
             )
-            if ret == QMessageBox.Save:
+            if ret == QMessageBox.StandardButton.Save:
                 # Save all using stored states
                 profiles = load_profiles()
                 for i in dirty_indices:
@@ -590,7 +652,7 @@ class VoiceFormulaDialog(QDialog):
                 self.update_profile_save_buttons()
                 self.update_profile_list_colors()
                 return True
-            elif ret == QMessageBox.Discard:
+            elif ret == QMessageBox.StandardButton.Discard:
                 # Discard all modifications
                 self._profile_states.clear()
                 for i in dirty_indices:
@@ -612,17 +674,19 @@ class VoiceFormulaDialog(QDialog):
         else:
             # Fallback to original logic for 0 or 1 dirty profile
             box = QMessageBox(self)
-            box.setIcon(QMessageBox.Warning)
+            box.setIcon(QMessageBox.Icon.Warning)
             box.setWindowTitle("Unsaved Changes")
             box.setText(
                 "You have unsaved changes in your profile. Do you want to save the changes?"
             )
             box.setStandardButtons(
-                QMessageBox.Save | QMessageBox.Discard | QMessageBox.Cancel
+                QMessageBox.StandardButton.Save
+                | QMessageBox.StandardButton.Discard
+                | QMessageBox.StandardButton.Cancel
             )
-            box.setDefaultButton(QMessageBox.Save)
-            ret = box.exec_()
-            if ret == QMessageBox.Save:
+            box.setDefaultButton(QMessageBox.StandardButton.Save)
+            ret = box.exec()
+            if ret == QMessageBox.StandardButton.Save:
                 for i in range(self.profile_list.count()):
                     item = self.profile_list.item(i)
                     name = item.text().lstrip("*")
@@ -636,7 +700,7 @@ class VoiceFormulaDialog(QDialog):
                 if hasattr(parent, "populate_profiles_in_voice_combo"):
                     parent.populate_profiles_in_voice_combo()
                 return True
-            elif ret == QMessageBox.Discard:
+            elif ret == QMessageBox.StandardButton.Discard:
                 profiles = load_profiles()
                 for i in range(self.profile_list.count()):
                     item = self.profile_list.item(i)
@@ -717,7 +781,7 @@ class VoiceFormulaDialog(QDialog):
         return voice_mixer
 
     def handle_voice_checkbox(self, voice_mixer, state):
-        if state == Qt.Checked:
+        if state == Qt.CheckState.Checked.value:
             self.last_enabled_voice = voice_mixer.voice_name
         self.update_weighted_sums()
 
@@ -767,7 +831,9 @@ class VoiceFormulaDialog(QDialog):
                     f'<b><span style="color:{COLORS.get("BLUE")}">{name}: {percentage:.1f}%</span></b>',
                     name,
                 )
-                voice_label.setSizePolicy(QSizePolicy.Preferred, QSizePolicy.Preferred)
+                voice_label.setSizePolicy(
+                    QSizePolicy.Policy.Preferred, QSizePolicy.Policy.Preferred
+                )
                 voice_label.delete_button.clicked.connect(
                     lambda _, vn=name: self.disable_voice_by_name(vn)
                 )
@@ -787,7 +853,7 @@ class VoiceFormulaDialog(QDialog):
             mixer.checkbox.setChecked(False)
 
     def eventFilter(self, source, event):
-        if source is self.scroll_area.viewport() and event.type() == event.Wheel:
+        if source is self.scroll_area.viewport() and event.type() == event.Type.Wheel:
             # Skip if over an enabled slider
             if any(
                 mixer.slider.underMouse() and mixer.slider.isEnabled()
@@ -890,10 +956,10 @@ class VoiceFormulaDialog(QDialog):
             self,
             "Invalid Profiles",
             msg,
-            QMessageBox.Yes | QMessageBox.Cancel,
-            QMessageBox.Yes,
+            QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.Cancel,
+            QMessageBox.StandardButton.Yes,
         )
-        if reply == QMessageBox.Yes:
+        if reply == QMessageBox.StandardButton.Yes:
             for i, name in reversed(zero):
                 self.profile_list.takeItem(i)
                 delete_profile(name)
@@ -980,8 +1046,8 @@ class VoiceFormulaDialog(QDialog):
         super().closeEvent(event)
 
     def _parse_rgba_to_qcolor(self, rgba_str):
-        from PyQt5.QtCore import Qt
-        from PyQt5.QtGui import QColor
+        from PyQt6.QtCore import Qt
+        from PyQt6.QtGui import QColor
 
         """Helper to convert 'rgba(R,G,B,A_float)' string to QColor."""
         match = re.match(r"rgba\((\d+),\s*(\d+),\s*(\d+),\s*([\d.]+)\)", rgba_str)
@@ -1136,9 +1202,12 @@ class VoiceFormulaDialog(QDialog):
                     msg += f"\nThis will overwrite an existing profile."
                 msg += "\nContinue?"
                 reply = QMessageBox.question(
-                    self, "Import Profile", msg, QMessageBox.Yes | QMessageBox.No
+                    self,
+                    "Import Profile",
+                    msg,
+                    QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No,
                 )
-                if reply != QMessageBox.Yes:
+                if reply != QMessageBox.StandardButton.Yes:
                     return
                 profiles.update(imported_profiles)
                 save_profiles(profiles)
@@ -1153,9 +1222,12 @@ class VoiceFormulaDialog(QDialog):
                     msg += f"\n{len(collisions)} profile(s) will be overwritten."
                 msg += "\nContinue?"
                 reply = QMessageBox.question(
-                    self, "Import Profiles", msg, QMessageBox.Yes | QMessageBox.No
+                    self,
+                    "Import Profiles",
+                    msg,
+                    QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No,
                 )
-                if reply != QMessageBox.Yes:
+                if reply != QMessageBox.StandardButton.Yes:
                     return
                 profiles.update(imported_profiles)
                 save_profiles(profiles)
@@ -1196,7 +1268,7 @@ class VoiceFormulaDialog(QDialog):
         menu.addAction(dup_act)
         menu.addAction(export_act)
         menu.addAction(delete_act)
-        act = menu.exec_(self.profile_list.viewport().mapToGlobal(pos))
+        act = menu.exec(self.profile_list.viewport().mapToGlobal(pos))
         if act == rename_act:
             self.rename_profile(item)
         elif act == delete_act:
@@ -1323,9 +1395,9 @@ class VoiceFormulaDialog(QDialog):
             self,
             "Delete Profile",
             f"Delete profile '{name}'?",
-            QMessageBox.Yes | QMessageBox.No,
+            QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No,
         )
-        if reply == QMessageBox.Yes:
+        if reply == QMessageBox.StandardButton.Yes:
             delete_profile(name)
             row = self.profile_list.row(item)
             self.profile_list.takeItem(row)
@@ -1378,7 +1450,7 @@ class VoiceFormulaDialog(QDialog):
                 self.profile_list.setItemWidget(item, widget)
 
     def update_profile_list_colors(self):
-        from PyQt5.QtCore import Qt
+        from PyQt6.QtCore import Qt
 
         profiles = load_profiles()
         for i in range(self.profile_list.count()):
@@ -1386,13 +1458,14 @@ class VoiceFormulaDialog(QDialog):
             name = item.text().lstrip("*")
             if self._virtual_new_profile and name == "New profile":
                 color = self._parse_rgba_to_qcolor(COLORS.get("YELLOW_BACKGROUND"))
-                item.setData(Qt.BackgroundRole, color)
+                item.setData(Qt.ItemDataRole.BackgroundRole, color)
             elif item.text().startswith("*"):
                 color = self._parse_rgba_to_qcolor(COLORS.get("YELLOW_BACKGROUND"))
-                item.setData(Qt.BackgroundRole, color)
+                item.setData(Qt.ItemDataRole.BackgroundRole, color)
             else:
                 item.setData(
-                    Qt.BackgroundRole, self.profile_list.palette().base().color()
+                    Qt.ItemDataRole.BackgroundRole,
+                    self.profile_list.palette().base().color(),
                 )
                 weights = profiles.get(name, {}).get("voices", [])
                 total = 0
@@ -1406,7 +1479,7 @@ class VoiceFormulaDialog(QDialog):
                             total += entry[1]
                 if total == 0:
                     color = self._parse_rgba_to_qcolor(COLORS.get("RED_BACKGROUND"))
-                    item.setData(Qt.BackgroundRole, color)
+                    item.setData(Qt.ItemDataRole.BackgroundRole, color)
         self.update_profile_save_buttons()
 
     def preview_current_mix(self):

pyproject.toml

@@ -13,7 +13,7 @@ license = "MIT"
 requires-python = ">=3.10, <3.13"
 keywords = ["audiobook", "epub", "pdf", "text-to-speech", "subtitle", "tts", "kokoro", "accessibility", "book-converter", "voice-synthesis", "multilingual", "chapter-management", "subtitles", "content-creation", "media-generation"]
 dependencies = [
-    "PyQt5>=5.15.11",
+    "PyQt6>=6.10.0",
     "kokoro>=0.9.4",
     "misaki[zh]>=0.9.4",
     "ebooklib>=0.19",