Discord Mic Streaming Bot (Windows)

A low-latency Discord bot for streaming live microphone audio into a voice channel on Windows using FFmpeg (DirectShow) and @discordjs/voice. The bot supports listing microphones, selecting by index, hot-swapping devices while streaming, and start/stop controls—all without additional audio routing software.

Note: Desktop/system audio streaming is not included in this version. This bot streams microphone input only via DirectShow.

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Features

• 🎙️ Live microphone streaming to Discord voice channels
• 🔁 Hot-swap microphones while streaming (no reconnect required)
• 📋 List all DirectShow audio devices with indices
• ⚡ Low-latency FFmpeg capture tuned for Windows
• 🧠 Safe start/stop lifecycle (no orphan FFmpeg processes)

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Requirements

• Windows 10/11
• Node.js v18+ (tested with Node 22)
• FFmpeg with DirectShow support (in PATH)
• Discord Bot Token

Required npm packages

• discord.js
• @discordjs/voice
• @discordjs/opus
• prism-media

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Installation

npm init -y
npm install discord.js @discordjs/voice @discordjs/opus prism-media

Ensure ffmpeg.exe is accessible:

ffmpeg -version

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Configuration

1. Set your Discord bot token

Temporary (current terminal only):

$env:DISCORD_TOKEN="YOUR_BOT_TOKEN_HERE"

Permanent (recommended):

• System Properties → Environment Variables
• Add User Variable:
  • Name: DISCORD_TOKEN
  • Value: your bot token

Restart your terminal after setting permanently.

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2. (Optional) Set a default microphone

Edit this line in index.js to match one of your DirectShow mic names:

let selectedMic = "Microphone (3- USB Audio CODEC )";

You can always change it at runtime with commands.

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Running the Bot

From the project directory:

node index.js

You should see:

Logged in as YourBotName#1234

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Discord Commands

!mics

Lists all available DirectShow microphone devices with indices.

Example output:

0: Microphone (USB Audio CODEC)
1: Microphone (HyperX Cloud Flight Wireless)
2: Microphone (NVIDIA Broadcast)

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!mic <index>

Selects a microphone by index.

• If not streaming: sets the mic for next start
• If already streaming: hot-swaps the mic live

Example:

!mic 2

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!micstart

Joins the voice channel you are currently in and starts streaming the selected microphone.

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!micstop

Stops the microphone stream and leaves the voice channel.

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!micstatus

Shows whether the mic stream is currently running and which device is selected.

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FFmpeg Device Verification

To verify FFmpeg can see your microphones:

ffmpeg -list_devices true -f dshow -i dummy

Look for entries marked (audio) and ensure the device name matches exactly.

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Latency Tuning

The FFmpeg pipeline is already optimized for low latency using:

• -fflags nobuffer
• -flags low_delay
• -probesize 32
• -analyzeduration 0
• -rtbufsize 16M

Typical end-to-end latency is sub-second on most systems.

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Known Limitations

• Microphone audio only (no system/desktop audio in this version)
• Windows-only (uses DirectShow)
• One active voice stream per bot instance

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Security & Privacy

• Only stream audio you have permission to broadcast
• Inform users in the voice channel when live audio is being relayed
• The bot does not record or store audio

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Troubleshooting

Bot joins but no audio

• Ensure Windows microphone permissions allow desktop apps
• Check the mic is not in exclusive mode
• Verify the device name exactly matches FFmpeg output

Opus errors on startup

Ensure @discordjs/opus is installed:

npm install @discordjs/opus

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License

MIT — use, modify, and distribute freely.

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If you want to extend this project with desktop audio, mixing, push-to-talk, or per-role permissions, this codebase is a solid foundation to build on.