CCM Multi-Mic Recorder | Parliamentary Owl Consulting

Pre-release. The full pipeline has been tested on simulated receivers and a simulated camera. It has not yet been tested on real DJI Mic 3 receivers or a real webcam. Do a full practice run with it before using it at a contest.

Why it is a download and not a web page

A DJI Mic 3 receiver in Quadraphonic (Q) mode sends each of its four transmitters on its own USB channel. Web browsers read only two channels from any one device. A web page would therefore lose TX3 and TX4. The recorder runs on the laptop and reads all four channels. It opens its screen in your browser, but the screen is served from the laptop itself. Nothing leaves the laptop unless you press Transcribe.

What you need

Microphones

Up to seven DJI Mic 3 transmitters and two DJI Mic 3 receivers. Each receiver carries at most four transmitters: TX1–TX4 on the first and TX1–TX3 on the second.

Webcam

A USB webcam aimed at the members' side of the table. Its video shows who stands. Its built-in mic is recorded as a room reference.

Laptop

Windows 10/11 or a Mac, with Python 3.10 or newer from python.org. You need about 100 MB of free space per minute of recording. Plug both receivers directly into the laptop, not through a hub, and keep the charger plugged in.

Install

Install Python from python.org. On Windows, tick Add python.exe to PATH.
Download the zip above and unzip it to a folder on the laptop (not a cloud-synced folder).
Windows: double-click START_CCM_RECORDER.bat. Mac: double-click start_mac.command and allow microphone and camera access.
The first start downloads its parts and needs internet once. After that it starts offline.
To look around without any hardware, run TRY_DEMO.bat.

Settings for the event

Table 1. DJI Mic 3 and laptop settings for CCM
Setting	Use	Why
Receiver recording mode	Q – Quadraphonic	Each transmitter arrives on its own channel. In S mode with three or four transmitters, the receiver mixes them into two channels.
Noise cancelling	Off (Basic only if HVAC is loud)	Noise gating cuts quiet words.
Adaptive gain control	Off	The recorder compares levels across mics to tell who is speaking. Changing gain breaks that comparison.
Voice tone / lossless audio	Regular / On	Flat, full-quality sound transcribes best.
Transmitter internal recording	On	A backup copy on each transmitter in case of a wireless dropout.
Auto power-off	Off	A mic that sleeps through a long report is a lost line.
Transmitter gain	Set in the app's Sound check	Target speech around −24 dBFS with peaks near −12, which leaves room for a raised voice.
Windows sound settings	Audio enhancements off, 48000 Hz	Windows processing can gate quiet speech.

On contest day

Microphones: press Find devices. Each receiver must show 4 channels. Suggest a layout, check the officer on each transmitter, then press Use these microphones.
Sound check: each officer reads their opening ceremony line. Adjust the gain on the receiver until every line reads Good.
Camera & seats: click each officer's head and drag the gold line just above the seated heads. With everyone seated, press Everyone is seated.
Record: enter the round, team and card motion, watch every meter move, then press Record.
Recordings: press Analyze for the speaking timeline, then Transcribe for a transcript labeled by officer.

What you get

One mono 48 kHz WAV file per officer, plus the webcam mic.
Webcam video on the same clock as the audio.
A timeline of who spoke and who was standing.
A cleaned audio copy of each officer for transcription.
A transcript in text, JSON and WebVTT, with each line labeled by officer and stands marked.

Transcription uses the same Whisper model as the CCM scoring app (@cf/openai/whisper-large-v3-turbo on Cloudflare Workers AI). It needs a Cloudflare account ID and an API token entered in the app's Settings.