Palash Debnath
3cae853440
The Model Catalogue put the same decision on two axes: an Engines pane with TTS/ASR/LLM tabs and a Models pane with TTS/ASR/Dictation/Diarisation sections, dictation shown in both, plus storage stats, the HF token and the voice-preview toggle parked on the model list. Settings → Voice still carried Engines and Models entries that only pointed back here. Now the page reads top-down: a SetupSummary (speech, transcription, dictation, language model — engine, device, one status word, Change), the engine list for one family, and that family's downloadable weights under it (TTS under TTS; offline ASR, streaming dictation and diarisation under ASR; nothing for LLM, whose engines bring their own). One storage line points at Settings → Storage. - ModelStoreTab takes a `family` and scopes sections and the recommendation preset to it (scopeReco); stats strip, HF-token toolbar and previews panel removed from it. - Settings: Engines/Models categories and CataloguePointer removed; models directory → Storage, HF mirror → Network (both restart-flagged), voice previews → Storage. "Manage models" in disk usage opens the catalogue. - Store: openCatalogue takes a family (pane key tolerated, ignored); pendingCatalogueTab gone. - Engine matrix title is now the locale's plain "Engines". - i18n: catalogue.* summary keys in all 21 locales; pane/pointer keys dropped. - Docs: "Model Catalogue → Engines" is "Model Catalogue"; "→ Models" is "→ Downloaded weights".
3.2 KiB
3.2 KiB
VoiceStudio — Faster-Whisper Engine
Faster-Whisper runs Whisper on CTranslate2 — the same transcription core WhisperX uses, without the wav2vec2 forced-alignment pass. It's the safe cross-platform fallback when whisperx isn't installed, and the capture/dictation fallback on non-Apple machines.
Selecting it
- Model Catalogue, ASR tab → Use on the Faster-Whisper row, or
- pin it with
OMNIVOICE_ASR_BACKEND=faster-whisper.
Auto-detect only picks it when whisperx is unavailable.
Best at
- Subtitles, dictation buffers, and batch transcription where Whisper's native word timing (±100–300 ms) is good enough.
- For dubbing lip-sync, prefer whisperx (or mlx-whisper on Apple Silicon) — their forced alignment is an order of magnitude tighter on word boundaries.
Platform support
- CUDA — float16, with automatic degradation (below).
- CPU — int8 on macOS, Windows, and Linux.
- Apple Silicon GPU / ROCm — not supported: CTranslate2 has no Metal or HIP build, so those hosts run on CPU (#1529); auto-detect routes them to mlx-whisper / pytorch-whisper instead.
Model selection
ASR_MODEL_FASTER — default Systran/faster-whisper-large-v3. Accepts the
size aliases (tiny … large-v3, distil-large-v3) or any CTranslate2
Whisper repo on HF. Weights download on first load — see
downloading-models.
Segments are cleaned up by faster-whisper's built-in Silero VAD before transcription.
Degradation chains
- GPUs without efficient fp16 (older Maxwell/Pascal, GTX 16xx, or a CTranslate2/cuDNN mismatch) fail at model construction with a compute-type error; the engine walks float16 → int8_float16 → int8 instead of failing every chunk (#551).
- A CUDA out-of-memory falls back to CPU (slower, same model and accuracy) — flushing the resident TTS model frees VRAM for GPU-speed ASR (#255).
Quirks
- cuDNN 8 required on CUDA — a missing cuDNN 8 would fast-fail the whole process, so the engine checks up front and reports itself unavailable instead (#1371). pytorch-whisper covers that case on torch's bundled cuDNN 9.
- On some hardened Linux kernels the CTranslate2 native library is rejected with "cannot enable executable stack" (an OSError, not an ImportError) — reported as unavailable rather than crashing engine selection (#692).
- CTranslate2's GPU teardown can rarely segfault the process at unload. If you hit that, switch to the crash-isolated variant — faster-whisper-isolated (#730).
- Transcribes are time-bounded:
OMNIVOICE_TRANSCRIBE_CHUNK_TIMEOUT_S(default 120 s per dub chunk) andOMNIVOICE_ASR_TRANSCRIBE_TIMEOUT_S(default 300 s whole-file).
Speed comparisons across engines live in performance.