Website and downloads: https://nicholaswm.github.io/emeetctl/
Open source Linux control for the EMEET SmartCam S600L webcam (USB 328f:00ef): the ring light (RGB + fill light), the image controls and the microphones (the camera's built-in one and any other USB mic on the desk, e.g. a Blue Yeti Nano), with a GUI, a CLI and an MCP server so AI agents can drive the camera too.
The vendor app (EMEET Studio) only exists for Windows and macOS. The light protocol was reverse engineered from a passive USB capture of EMEET Studio 2.0.4 (firmware 1.0.19), with no decompilation; see Protocol.
Not affiliated with or endorsed by EMEET. "EMEET" is used only to name the supported hardware. The UI and messages are in Brazilian Portuguese for now.
| GUI | CLI | MCP | |
|---|---|---|---|
| Fill light on/off | ✔ | emeetctl on/off fill |
set_light_power |
| RGB ring on/off | ✔ | emeetctl on/off rgb |
set_light_power |
| Modes: cool, warm, balanced, ambient, rainbow | ✔ | emeetctl mode … / rainbow |
set_light_mode |
| Any RGB color (the vendor app has 6 presets) | ✔ | emeetctl color ff0000 |
set_light_color |
| Light brightness | ✔ | emeetctl brightness 40 |
set_light_brightness |
| Image: brightness, contrast, saturation, hue, gamma, gain, sharpness, white balance, exposure, focus, zoom, anti-flicker, backlight | ✔ | emeetctl image list/get/set/reset |
list_image_controls, set_image_control, reset_image_controls |
| Microphones (camera mic, Yeti Nano, any USB mic): gain, mute, live level meter, make it the default input, who is recording from it | ✔ | emeetctl mic [-d nano] list/status/gain/mute/unmute/default/level |
list_microphones, get_mic_status, set_mic_gain, set_mic_mute, set_mic_default |
| Clean microphone: a new input " (limpo)" with WebRTC noise suppression, high-pass and speaker echo cancellation, as a user service (no PipeWire restart) | ✔ | emeetctl mic -d nano clean on --default / off |
set_clean_mic |
| Headphone output of the mic (Yeti Nano): volume, mute | ✔ | emeetctl mic -d nano headphones -12 |
set_headphones |
| Recording to a file: video (camera + any mic, MP4/MKV/WebM) or audio only (WAV/FLAC/MP3/Opus/M4A). With the virtual camera on, it records from a free output, so Meet and the preview keep working | ✔ | emeetctl record -f mkv -m limpo |
start_recording, stop_recording, get_recording |
Recording the PC: what the computer plays (call, video) and the mic in separate tracks (MKA), plus the whole screen with --video (MKV, NVENC on NVIDIA, x264 otherwise). X11 only for the screen |
✔ | emeetctl pc / emeetctl pc --video |
start_pc_recording, stop_recording |
Local transcription (Whisper via whisper-ctranslate2, GPU with CPU fallback): each track on its own, interleaved by time with the track name (Microfone / Sistema), .txt + .srt next to the file |
✔ | emeetctl transcribe file.mka (automatic after emeetctl pc) |
transcribe_recording |
| Live camera preview (MJPEG 1280×720, YUYV fallback; released when paused) | ✔ | ||
| Device info (serial, firmware) | ✔ | emeetctl info |
get_status |
Firmware update is deliberately not supported. The vendor HID channel may carry firmware commands, so emeetctl refuses to send any opcode that was not observed in the capture.
Requires Rust 1.81+ and the ALSA headers (sudo apt install libasound2-dev). The microphone status and meter use PipeWire (pw-dump, pw-record, wpctl); gain and mute work with plain ALSA. Recording needs ffmpeg (sudo apt install ffmpeg); transcription needs whisper-ctranslate2 (uv tool install whisper-ctranslate2).
cargo install --path crates/emeetctl-cli # emeetctl
cargo install --path crates/emeetctl-gui # emeetctl-gui
cargo install --path crates/emeetctl-mcp # emeetctl-mcpThe light uses /dev/hidrawN, which is root-only by default. Install the udev rule once:
sudo cp udev/70-emeetctl.rules /etc/udev/rules.d/
sudo udevadm control --reload
sudo udevadm trigger --subsystem-match=hidraw --action=changeThe image controls use /dev/videoN and work for users in the video group (or the logged-in seat).
Optional launcher: cp emeetctl.desktop ~/.local/share/applications/.
emeetctl status # light state
emeetctl color 123456 # any color; puts the ring in fixed-color mode
emeetctl rainbow
emeetctl mode warm # cool | warm | balanced | ambient
emeetctl brightness 30 # % of the current mode's range (--raw 0xNN for the raw value)
emeetctl off rgb # rgb (ring) | fill (whole fill light)
emeetctl image list
emeetctl image set focus_automatic_continuous off
emeetctl image set focus_absolute 420
emeetctl image set zoom_absolute 200
emeetctl image reset
emeetctl mic list # USB microphones (camera = s600l, Yeti Nano = nano)
emeetctl mic -d s600l gain 13 # microphone gain in dB; without -d, the system default input
emeetctl mic level # live level meter (Ctrl+C to stop)
emeetctl record # MP4 in ~/Videos until Ctrl+C (camera + default input)
emeetctl record -f opus -m nano --seconds 60 # audio only, from the Yeti Nano, 1 minute
emeetctl record -f webm -m nenhum -o demo.webm # video without sound
emeetctl pc # PC audio (system + mic) to ~/Music, transcribed on Ctrl+C
emeetctl pc --video --lang en # plus the screen, to ~/Videos; English speech
emeetctl transcribe call.mka --model medium # transcribe an existing recording
emeetctl --json status # machine-readable outputemeetctl-mcp speaks MCP over stdio. Example for Claude Code:
claude mcp add emeetctl -- emeetctl-mcpTools: get_status, set_light_power, set_light_color, set_light_mode, set_light_brightness, list_image_controls, set_image_control, reset_image_controls, list_microphones, get_mic_status, set_mic_gain, set_mic_mute, set_mic_default, set_headphones, set_clean_mic, start_recording, start_pc_recording, stop_recording, get_recording, transcribe_recording (mic tools take an optional device). Each call opens the device, acts and closes it, so the camera can be unplugged between calls.
32-byte HID reports on the vendor interface (interface 4, interrupt OUT 0x01 / IN 0x84):
09 02 02 OP LL LL LL LL <data> 00… LL = data length (u16 big-endian, repeated). No checksum.
| op | meaning | data |
|---|---|---|
00 / 01 |
power set / get | ff 0X 00 00 fill light · 03 01 01 01 / 03 00 00 00 RGB ring |
02 / 03 |
ring color set / get | 00 RR GG BB |
04 / 05 |
brightness set / get | MM BB (MM = mode; rainbow uses the ambient key 03) |
06 / 07 |
mode set / get | 00 MM with 0 cool, 1 warm, 2 balanced, 3 ambient, 4 rainbow |
Every SET is acknowledged with a single 20 byte. The camera also pushes state frames on its own when the mode changes, so replies are matched by opcode.
Brightness ranges seen in the vendor slider: ambient/rainbow 0x14–0xff, cool 0x37–0x64. Warm and balanced were not measured (assumed equal to cool).
- Digital zoom only applies in MJPEG below 1080p. Measured frame by frame: zoom works in MJPEG 2560×1440, 1280×960, 1280×720, 1024×576, 960×720, 800×600, 640×480 and 640×360, and is ignored in MJPEG 1920×1080, 3840×2160 and every YUYV mode (EMEET's FAQ also says the field of view is fixed in 4K and 1080p). If zoom "does nothing", check the resolution/format your video app is using.
- Switching the ring to a color or mode may turn the fill light flag on by itself.
The UVC Extension Unit {46394292-0cd0-4ae3-8783-3133f9eaaa3b} (10 controls) is still unknown. Candidates from public docs: image flip/mirror, factory reset, microphone noise reduction, boot light behaviour. Contributions with USB captures are welcome.
Blue Yeti Nano (b58e:0005): only the standard USB audio controls are used (mic gain 0–33 dB, headphone volume, mutes). Polar pattern and monitor mix live on a vendor HID report that is not mapped yet (capture plan in notes/capture-yeti-nano.md). The front mute button is invisible to the host: the mic just sends zeros, so the level meter warns on digital silence.
crates/emeetctl-core device discovery (sysfs), HID light protocol, V4L2 controls, mics, recording
crates/emeetctl-cli `emeetctl`
crates/emeetctl-gui `emeetctl-gui` (egui)
crates/emeetctl-mcp `emeetctl-mcp` (MCP over stdio)
udev/ hidraw permission rule
MIT OR Apache-2.0.