felixmandClaude Opus 5
9d04427816
Transcripts came back short, but the log showed the whole clip going up: captured samples matched wall clock and upload duration matched the recording minus exactly the fixed 150 ms head trim. So nothing was being cut in transit — the losses had to be at the edges or inside the audio, and neither was visible. Trim the stream-open click by measurement instead of by the clock: cut only the leading frames that are genuinely louder than the rest of the clip, up to the old cap. Mics that do not click now keep their first syllable. Measure each frame against its own mean so a steady DC bias — or a stream frozen on one value — reads as the silence it is, and report the longest run of digital silence as dead=. A live mic never goes below DEAD_AIR_DBFS, so anything there is input that never arrived, which is what following the system default source invites. Warn on startup when no device is pinned, log the noise floor next to the speech level, and log how much of the clip the output limiter had to clamp. BLURT_SAVE_CAPTURES keeps the raw and uploaded WAVs per clip, so the next short transcript can be checked against what the API actually got. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
3.6 KiB
Blurt
Tray-based push-to-talk voice-to-text for Linux and Windows. Toggle recording with a hotkey, speak, toggle off — Blurt transcribes the clip and copies the text to your clipboard.
If a transcript starts with to my agent, the rest is dispatched as an agent
task instead of copied.
Setup
Requires uv and Python 3.11+.
uv sync
API key
Blurt reads the key for its current model's provider in this order: environment variable → OS keyring → local file.
| Provider | Env var | Keyring (service / user) |
File |
|---|---|---|---|
| OpenAI | OPENAI_API_KEY |
openai-api-key / felixm |
api_key.txt |
| OpenRouter | OPENROUTER_API_KEY |
openrouter-api-key / felixm |
openrouter_key.txt |
Key files and runtime config stay local (gitignored).
Running
Linux — uv run blurt starts the tray icon. Bind a hotkey to
./blurt-toggle, which signals the running instance to start/stop recording.
Windows — launch blurt.vbs (runs Blurt with no console window). The
global hotkey is F20.
Configuration
Set from the tray menu, or via files / env vars:
- Model —
model.txt/BLURT_TRANSCRIPTION_MODEL. For lowest latency useopenai/whisper-large-v3-turbo(OpenRouter, served by Groq). - Language —
language.txt/BLURT_TRANSCRIPTION_LANGUAGE(en,de). - Input device — tray menu (persisted by name in
device.txt/BLURT_INPUT_DEVICE). Pick an explicit mic: PortAudio device indices shift when USB gear comes and goes, and the OS default source can change under you. The menu hides playback endpoints and raw ALSAhw:devices that the sound server already owns;BLURT_INPUT_DEVICEcan still name one directly. Devices that refuse 16 kHz (raw ALSA and PipeWire's JACK endpoints do) are captured at their native rate and resampled.
Every clip is conditioned before upload — the stream-open click is trimmed off the front (only as much of it as is actually there, up to 150 ms), DC bias is filtered out, and the level is normalised towards -20 dBFS. Near-silent clips are refused instead of being sent, since transcription models answer silence with confident hallucinations.
Nothing else is cut: the whole recording is uploaded. If a transcript comes
back missing words, check blurt.log — each clip logs its length, speech level,
noise floor, and dead=, the longest run of digital silence inside it. A
non-zero dead= means the input dropped out mid-clip, which is what following
the system default source invites; pin a device instead. Set
BLURT_SAVE_CAPTURES=1 (or to a directory) to keep the raw and uploaded WAVs
for every clip and hear exactly what the API got.
Checking the microphone
uv run mic_check.py [device] [seconds] records from Blurt's configured input,
prints levels before and after conditioning, saves the WAV it would have
uploaded, and transcribes it with the current model. Use it when transcripts
come back wrong: bad audio shows up as a DC bias, clipping, or a speech level
far below -30 dBFS.
Logs are written to blurt.log in your temp directory (openable from the tray
menu).
Moving to another machine
uv run export.py writes a zip of just the source (no 200 MB+ .venv, no
caches, no key files) to your temp directory. It's pure Python, so it runs the
same on Linux and Windows — no shell needed — and it only reads, so it's safe
while Blurt is recording. Unzip on the other machine and uv sync to rebuild
.venv for that OS. (Or simply git clone the repo fresh.)