* feat(asr): add Parakeet engine via sherpa-onnx
Adds a "parakeet" engine backed by sherpa-onnx, running NVIDIA Parakeet
TDT 0.6B int8 models on CPU: v3 (25 European languages, auto-detected)
and v2 (English). Output is punctuated and capitalized.
On an Intel Core Ultra 7 155H it decodes at about 12x realtime on CPU
(RTF 0.08), roughly 8x faster than whisper.cpp large-v3-turbo over the
same clips with its Vulkan GPU backend (RTF 0.59). Being a transducer it
also has no 30s window to pad, so a short push-to-talk utterance returns
in ~0.3s instead of ~2.4s.
Follows the existing engine layout: utils/parakeet_model_info.py holds
the catalog and the get_model_path / is_model_downloaded /
list_downloaded_models / delete_model helpers, while _init_parakeet /
_transcribe_with_parakeet / _download_parakeet_model follow the same shape as their
whisper.cpp counterparts and reuse _stream_model_download for progress
and cancellation.
Registered in the engine dispatch, the settings engine/model/language
pickers, the model info card, the download prompts, the unused-downloads
list and install.sh.
Models download to <models_dir>/parakeet/<model>/ via temp files renamed
on success; is_model_downloaded requires all four files, so an
interrupted download is retried rather than loaded.
Requires the new "parakeet" extra (sherpa-onnx).
* fix(install): write only the engine key for parakeet
The parakeet branch duplicated a full default config.json. ConfigManager
deep-merges DEFAULT_CONFIG on load, so every other key was redundant:
a config holding only "engine": "parakeet" still resolves
parakeet_model_size to v3-european along with the VAD, shortcut and
text-injection defaults.
* fix(install): keep push-to-talk defaults and switch existing configs
Writing only the engine key left config.json without a shortcuts
section, which _migrate_shortcuts_config reads as a pre-push-to-talk
upgrade and pins back to ctrl+ctrl/toggle - contradicting the
installer's own "Hold Right Alt while you speak" message. Seed that
section too.
Point the config at parakeet with set_configured_engine rather than only
on first create, so --engine=parakeet also switches a machine that
already has a config.json, and give print_welcome_message a parakeet arm
so the summary is not blank.
The interactive picker overwrites SELECTED_ENGINE, so document the flag
combination that reaches this branch.
* fix(asr): pin Parakeet bundles and report one progress bar
Pin each bundle to a Hugging Face commit instead of resolve/main, so a
file replaced upstream cannot change what an install downloads. This is
the same approach whispercpp_model_info takes with its pinned revision.
Remap each file's progress into its slice of the bundle. The four files
were reported through the single-file downloader independently, so the
fraction ran to 1.0 and restarted four times; it now advances once and
names the file being fetched.
* fix(asr): reject a truncated Parakeet download
_stream_model_download only rejects an empty body, so a truncated but
nonempty response was renamed into the model directory and then reported
as installed, because is_model_downloaded checks existence.
Record the byte size of each file at the pinned revision and check it
before the rename, the same order whisper.cpp verifies its digest in. A
short file is a truncated transfer rather than an upstream change, since
the revision is pinned, so it raises and the temp file is removed.
* style(asr): annotate the Parakeet model catalog
mypy inferred the catalog values as object, so reading file_sizes out of
an entry raised attr-defined and no-any-return under `just typecheck`.
* fix(asr): pin Parakeet digests in model_checksums.txt
AGENTS.md requires every speech model to be verified against a pinned
digest before install, failing closed on an unpinned one. Parakeet was
checking only the byte size.
Teach scripts/generate-model-checksums.py to emit Parakeet entries: the
ONNX files are LFS so Hugging Face publishes their sha256, and tokens.txt
is hashed from the downloaded bytes the way VOSK archives are. Several
bundles ship the same file names, so a key carries the model name.
_download_parakeet_model now calls verify_model_file before the rename
and catches ChecksumError alongside the other download failures, matching
the whisper.cpp downloader.
* fix(asr): verify on-disk Parakeet models before load
Existing bundle files were trusted by path alone, so a leftover or
copied-in tree could reach sherpa-onnx unchecked. Hash each file against
its pin on download skip and on init, and cover the Parakeet pins in CI.
* fix(ui): hide Parakeet language picker that ignores the setting
Parakeet language coverage is the model choice, not a catalog language.
Hide the picker and persist auto so Settings does not write a lying value.
* fix(asr): normalize Parakeet language to auto at startup
CLI --language and stale saved languages still reached SpeechRecognitionManager
even though Parakeet ignores catalog language. Force auto on the shared helper
used by main and the manager so stored settings stay honest.
* fix(ui): restore language after leaving Parakeet
Remember the prior Whisper/cpp language across a Parakeet visit so switching
back does not leave recognition stuck on auto. Keep Parakeet forced to auto
and the picker hidden. Also satisfy black on the startup normalizer path.
* fix(ui): keep language memory across Vosk fallback
Vosk's unsupported-language en-us coercion was writing into
_last_non_parakeet_language, so Whisper→Parakeet→Vosk→Whisper restored
en-us instead of the user's Greek (or other) preference. Remember the
pre-coercion catalog language and prefer it when leaving Vosk.
* fix(ui): keep language memory when entering Parakeet from Vosk
Vosk's coerced en-us fallback was still written into
_last_non_parakeet_language on Parakeet entry, so Vosk→Parakeet→Whisper
restored en-us instead of the pre-coercion preference (Greek or auto).
Share one coerced-fallback predicate across entry, leave-Vosk, and language
sync, and cover those paths with regression tests.
* fix(tests): set initializing flags false on language-change stubs
Plain Mock attributes are truthy and were short-circuiting the handler.
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Co-authored-by: Alex Thunder <AlexThunder@gmail.com>
