OpenReader

✨ What's New

🚀 New

• Canonical EPUB Segment Planning: Transitioned from a client-side preview-based model to a viewport-independent chapter-level canonical planning architecture. Chapters are segmented exactly once, with viewport pages acting as contiguous, non-overlapping windows. This eliminates repeated/skipped segments on page turns, stabilizes highlights, and enables prefetching of exact upcoming segments using stable keys/locators (epub:${spineIndex}:${spineHref}:${charOffset}).
• WAV & OGG Audio Normalization: Added automatic format sniffing and on-the-fly MP3 transcoding for custom OpenAI-compatible TTS responses. Audio is transcoded to VBR q2 via ffmpeg using seekable temp files to guarantee accurate Xing/Info duration headers. This fixes HTML5 <audio> duration bugs so the ended event fires reliably.

⚡ Improved

• Multi-Route OpenAI Voice Probing: Upgraded custom OpenAI voice resolution to query multiple candidate endpoints (/audio/voices, /voices, /styles) and extract names from flat arrays, styles lists, or object structures. Falls back to canonical OpenAI voices if no endpoints resolve.
• Robust OpenAI-Compatible Gateway Support: Allowed empty API keys by using placeholder authorization headers. Also, if a WAV-only server rejects response_format: "mp3" (returning 400/422), the gateway automatically retries without it, caches the decision, and normalizes the WAV response to MP3.
• Unified EPUB Text Highlighting: Unified character mappings and word-region alignment under a new character offset map (highlight-char-map.ts). Refactored sentence alignment fallbacks and URL replacements, and added cache invalidation on viewport resize or layout changes.
• Smooth Word-Sync UX: Improved word synchronization to snap the active highlight to the last started word when the play head lands in a temporal gap, preventing highlighting freezes on silence. Increased live TTS audio quality from 64k CBR to VBR q2.
• Compute Worker Build Context: Included the local .npmrc file in the compute worker Dockerfile build context to allow dependency resolution for private registry packages.

🐛 Fixed

• Prevent Anonymous Sessions on Auth Pages: Blocked guest session generation on auth-related pages (login/signup) to prevent session leaks and keep database records clean.
• FFmpeg Spawn Abort Race Condition: Fixed a race condition when aborting TTS requests during lazy imports of the ffmpeg binary module by registering the abort listeners prior to spawning.

Full Changelog: https://github.com/richardr1126/openreader/compare/v4.2.0...v4.2.1