Audiblez: EPUB-to-audiobook tool powered by Kokoro TTS
Audiblez uses the Kokoro-82M model to split EPUBs, synthesize high-quality speech and package m4b audiobooks, offering both CLI and GUI with CUDA support; it is ideal for local, efficient batch audiobook generation for developers and accessibility use-cases, but the lack of formal releases and a small contributor base warrants caution for production deployment.
GitHub santinic/audiblez Updated 2025-08-28 Branch main Stars 5.1K Forks 330
Python Text-to-Speech Audiobook generation CLI & GUI tool

💡 Deep Analysis

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For converting a medium-length (~160k characters) English book, what's the real time and resource difference between CPU and GPU? How to choose the right runtime environment?

Core Analysis

Quantified comparison: README reports ~600 chars/sec on a Colab T4 (≈5 minutes for 160k chars) versus ~60 chars/sec on an M2 CPU (≈1 hour), implying roughly a 10–12x wall-clock speedup with GPU.

Technical Analysis

  • Time cost: GPU inference benefits from parallel tensor ops; CPU is limited by vectorized/multi-threaded performance.
  • Resource usage: GPU runs are constrained by VRAM (model + buffers); both CPU and GPU workflows need disk for intermediate WAV files, and IO can affect overall time.

Practical Recommendations

  1. Short books/experiments: Use CPU if no GPU is available, but split into small chapters and expect longer processing time.
  2. Long books/batches: Prefer CUDA-enabled GPUs (local or Colab/cloud) to significantly reduce turnaround time.
  3. Resource management: Monitor VRAM and disk; delete intermediate WAVs after m4b creation or use larger temp storage.

Caveats

  • VRAM limits & parallelism: If VRAM is low, reduce concurrency or process by chapter.
  • Cost tradeoff: For occasional short conversions, CPU time may be acceptable; for frequent use, GPU rental/purchase is cost-effective.

Important Notice: Based on README numbers, GPU gives ~10x speed advantage—critical for long books or batch processing.

Summary: Use CUDA GPUs for timely full-book generation; otherwise accept longer CPU runtimes and manage disk/cleanup accordingly.

88.0%
Can audiblez fully convert an EPUB into a playable m4b audiobook? Under what conditions does it work best?

Core Analysis

Project Positioning: audiblez implements an end-to-end pipeline to parse .epub into chapter wav files, synthesize speech with Kokoro-82M via PyTorch, and package the output into a standard .m4b using ffmpeg.

Technical Features

  • Complete pipeline: parsing -> text normalization (optionally using espeak-ng) -> PyTorch/Kokoro synthesis -> ffmpeg packaging to m4b.
  • Performance options: CPU and GPU (--cuda) supported; README reports ~600 chars/sec on T4 and ~60 chars/sec on M2 CPU.

Usage Recommendations

  1. Prerequisites: ensure EPUB is not DRM-protected, install ffmpeg and espeak-ng, and configure PyTorch/CUDA properly.
  2. Pilot run: convert a single chapter first to tune voice, speed, and normalization.
  3. Hardware: use a CUDA-enabled GPU for long books or faster turnaround.

Caveats

  • Disk: intermediate chapter_x.wav files are large; plan disk space and cleanup.
  • Content/format: complex layout (footnotes/tables) may require manual preprocessing or exclusion via --pick.

Important Notice: DRM-protected or corrupted EPUBs cannot be processed; ensure legal compliance.

Summary: Given proper dependencies, hardware, and light preprocessing, audiblez can reliably produce playable m4b audiobooks; GPU use yields major speed gains.

87.0%
What common user experience issues arise when using audiblez locally (no cloud)? How to avoid or resolve them?

Core Analysis

User Pain Points: Key local usage issues for audiblez are environment dependencies, disk/memory resource management, cross-platform GUI dependencies, and parsing failures due to DRM or complex layout.

Technical Analysis

  • Dependency issues: ffmpeg and espeak-ng are required; missing them blocks packaging or causes poor normalization.
  • Resource management: Chapter wav files are large; long books can quickly exhaust disk space.
  • Platform compatibility: wxPython/Pillow and PyTorch/CUDA versions may require extra configuration; Apple Silicon support is limited.

Practical Recommendations

  1. Environment prep: Install ffmpeg/espeak-ng via OS package manager and use a Python venv (README recommends venv for Windows).
  2. Pilot & tune: Convert one chapter first to validate voice, speed (-s), and text normalization.
  3. Disk strategy: Set an output folder and delete intermediate WAV files after m4b creation, or use temp/external storage.
  4. GUI install: Only install wxpython and pillow if you need the GUI; prefer CLI to reduce complexity.

Caveats

  • DRM & legality: DRM or copyrighted books cannot be processed without permission.
  • Performance expectations: No-GPU runs are slow; consider Colab or a local GPU if needed.

Important Notice: Following standard installation steps, running samples first, and planning disk usage will significantly improve local UX.

Summary: Most local issues stem from environment and resources; following README guidance and testing reduces failure rates.

86.0%
How does audiblez perform on EPUBs with complex layout (footnotes) or multilingual mixing? What preprocessing steps are needed to improve reading quality?

Core Analysis

Issue: Complex layouts (footnotes, tables, annotations) and multilingual mixing challenge automated parsing and TTS, causing awkward pauses, mispronunciations, or context confusion that degrade listening quality.

Technical Analysis

  • Parsing limits: EPUB is HTML—if the parser does not strip footnotes/annotations, TTS may read them as body text.
  • Pronunciation/language detection: Kokoro supports multiple languages but not all cases; mixed-language passages need explicit segmentation to avoid wrong pronunciations.
  • Normalization role: espeak-ng can assist with pronunciation hints and special character handling but is not a cure-all.

Practical Recommendations (preprocessing checklist)

  1. Clean the EPUB: Use Calibre or scripts to remove frontmatter, indices, or move footnotes to the end.
  2. Chapter/segment selection: Use --pick to read only selected chapters or split complex chapters into smaller segments.
  3. Multilingual handling: Segment multilingual passages by language and synthesize them using matching voices, then merge.
  4. Normalize text: Run a cleaning script to replace special symbols and standardize punctuation to reduce unnatural pauses.

Caveats

  • Manual review: Important chapters benefit from human proofreading before synthesis, especially dialogues or technical sections.
  • Extra time required: Fully automated perfect output is unlikely for intricate layouts.

Important Notice: Pre-cleaning and language-segmentation greatly improve output but cannot fully replace human intervention.

Summary: For complex layout or multilingual EPUBs, text-level cleaning and segmentation are essential; audiblez supplies helpful tools (e.g., --pick, espeak-ng) but human preprocessing yields the best listening quality.

86.0%
Why was Kokoro-82M with PyTorch chosen as the core TTS implementation? What are the advantages and limitations of this technical choice?

Core Analysis

Project Positioning: The Kokoro-82M (82M params) + PyTorch stack is chosen to balance local deployability and natural-sounding speech, while enabling GPU acceleration for whole-book synthesis performance.

Technical Features

  • Advantage 1 (lightweight & good quality): Kokoro-82M is compact for easier local runs and loading, and README highlights its natural sounding output.
  • Advantage 2 (ecosystem & acceleration): PyTorch offers robust GPU/CUDA support, enabling significant speedups (README example: Colab/T4).
  • Limitations: Smaller models may lag in emotional expressiveness or dramatic reading compared to larger models; coverage and naturalness can vary across languages/voices; native support on Apple Silicon is limited per project notes.

Usage Recommendations

  1. Match goals: If your goal is local, privacy-preserving TTS without theatrical performance, Kokoro is appropriate.
  2. Hardware planning: Use CUDA-enabled GPUs for long books or batch jobs; expect slower CPU-only conversion.
  3. Quality validation: Test representative passages in target language/voice to confirm acceptability.

Caveats

  • Emotive performance: Do not expect professional voice acting quality.
  • Environment compatibility: Watch PyTorch/CUDA version compatibility; Windows users should prefer a venv.

Important Notice: The selection favors controllable, cost-effective local synthesis rather than ultimate fidelity or universal platform support.

Summary: Kokoro-82M + PyTorch is a pragmatic choice for privacy-focused, cost-efficient local audiobook generation, with trade-offs in expressiveness and platform universality.

85.0%
When evaluating audiblez for small publishers or content creators, how should one judge applicability and limits? What alternative options should be compared?

Core Analysis

Fit: audiblez is well-suited for individuals, small publishers, and creators to quickly produce internal samples, demos, or non-commercial evaluation audiobooks. Its strengths are local operation, low recurring cost, and privacy control.

Tech & business evaluation points

  • Pros: Directly outputs standard .m4b from EPUB, multi-language/multi-voice support, avoids cloud costs and privacy exposure.
  • Limits: Kokoro has natural output but limited emotional/dramatic expressiveness; commercial use requires attention to copyright/DRM and possible licensing; Apple Silicon support is limited.

Alternatives (brief)

  1. Cloud closed-source TTS (Amazon Polly, Google TTS): Better prosody/emotion and SLAs but ongoing cost and privacy tradeoffs.
  2. Larger local models: Higher fidelity but require more compute and VRAM.
  3. Professional voice actors: Best quality, highest cost—appropriate for commercial release.

Practical recommendations

  1. Match use: Use audiblez for sample generation, internal review, and rapid iteration; for a final commercial release, evaluate upgrade to professional audio or paid TTS.
  2. Compliance: Confirm copyright licenses before commercial use and document generation steps.
  3. Hybrid strategy: Generate drafts with audiblez, then humanize key chapters with professional talent or cloud services to balance cost and quality.

Important Notice: audiblez is not a one-size-fits-all tool—its value is strongest for quick, local, low-cost generation; commercial release requires further QA and licensing checks.

Summary: Treat audiblez as a cost-effective prototyping/internal tool; for production-grade commercial audiobooks, consider augmenting with paid TTS or human narration.

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✨ Highlights

  • Generates natural-sounding voices using the Kokoro-82M compact model
  • Provides both CLI and GUI with optional CUDA acceleration
  • Outputs standard .m4b audiobooks compatible with common players
  • Depends on system binaries (ffmpeg, espeak-ng) that require separate installation
  • No official releases and a small contributor base; long-term maintenance and release stability are uncertain

🔧 Engineering

  • Automatically splits EPUB into chapters, synthesizes speech and packages into m4b; supports multiple languages and voices
  • Runs on CPU and CUDA; GPU significantly speeds up processing and setup is low-effort
  • Includes cross-platform install instructions and a GUI targeting macOS, Linux and Windows

⚠️ Risks

  • No release tags; relying on the latest repository commits may introduce compatibility risks
  • Limited contributors and commits may slow issue response and feature development
  • Audiobook generation may implicate copyrighted texts; users are responsible for compliance

👥 For who?

  • Suited for developers and automation users who need fast batch conversion of ebooks to audio
  • Directly valuable for accessibility use-cases, personal audiobook creation, or voice sample generation
  • Particularly appropriate for users who want to run high-quality TTS locally rather than relying on cloud services