Vibelight is a fork of moonlight-stream/moonlight-qt that adds client-side microphone capture and passthrough for use with Vibepollo on the Windows host. Built with AI assistance (Claude Code) by a UX designer — hence the name.

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What Is This?

Moonlight streams games from your PC to your Steam Deck but ignores the Steam Deck microphone. Vibelight fixes that by capturing mic audio on the Steam Deck, encoding it with Opus, and streaming it back to the host PC where it appears as a virtual microphone that Discord, games, and voice chat apps can use normally.

Vibelight is the client side. It pairs with Vibepollo on the Windows host.

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Features

• Mic passthrough — captures Steam Deck mic, Opus-encodes it, streams to host
• Encrypted transport — mic data rides the AES-GCM encrypted control stream. The host refuses unencrypted mic sessions.
• Steam Streaming Microphone host backend — Vibepollo renders decoded audio directly to the Steam Streaming Microphone endpoint (no third-party driver required).
• Opus audio — 64kbps mono, complexity 10, FEC enabled, explicit 20ms frame duration. Optimized for voice quality and packet loss resilience.
• Deadline-based send pacer — sends frames at exactly 20ms intervals with re-sync guard. Eliminates jitter from SDL2 timer irregularities for clean audio.
• 12-frame buffer cap — prevents audio backup during capture irregularities, always dropping oldest frames to keep latency low.
• Device fallback — if a named device fails, automatically falls back to default mic
• Frame spec mismatch detection — detects and logs SDL2 format mismatches without crashing
• All Moonlight features — video streaming, HDR, controller support, and everything from upstream Moonlight

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Requirements

• Steam Deck (SteamOS) — primary supported platform
• Vibepollo running on Windows host

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Installation (Steam Deck)

One command:

curl -sSL https://raw.githubusercontent.com/xenstalker02/Vibelight/master/install.sh | bash

Or clone and install:

git clone https://github.com/xenstalker02/Vibelight.git
cd Vibelight
bash install.sh

The installer builds and installs the Flatpak. Mic capture is opt-in — enable it in Settings → Microphone Capture after installing. Safe to re-run on update — fully idempotent.

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Configuration

Edit the Moonlight config file at: ~/.var/app/com.moonlight_stream.Moonlight/config/Moonlight Game Streaming Project/Moonlight.conf

Option	Default	Description
micCapture	false	Enable mic capture and passthrough. Opt-in — disabled by default. Enable in Settings → Microphone Capture before streaming.
micDevice	(empty)	Specific mic device name. Leave empty to use the default mic (built-in Steam Deck mic). Set to your Bluetooth or USB mic device name to use an external device.
micBitrate	64000	Opus bitrate in bps. Adjustable via the Bitrate slider in Settings (32–128 kbps, default 64 kbps).
absoluteMouseMode	false	Set false for Steam trackpad mouse compatibility
mouseAcceleration	false	Set false for consistent pointer feel

Deck built-in mic gain note: The Steam Deck's built-in microphone runs at high gain by default and will clip on loud input. During installation, PipeWire capture volume is set to 50% to prevent clipping:

pactl set-source-volume @DEFAULT_SOURCE@ 50%

If mic audio sounds distorted, re-run this command.

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Using Bluetooth Headphones

Vibelight supports using Bluetooth headphones (e.g. Nothing Ear (1), Sony WH-1000XM5, or any Bluetooth headset) as the microphone source:

1. Pair your headphones on the Steam Deck in Desktop Mode (Settings → Bluetooth)
2. In SteamOS, the Bluetooth headset mic appears as a PipeWire device
3. Find the device name:

   pactl list sources short | grep -i bluetooth

4. Set micDevice in Moonlight.conf to the device name shown (e.g. bluez_input.XX_XX_XX_XX_XX_XX.0)

If the named device is unavailable at session start, Vibelight automatically falls back to the default microphone.

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Security

Mic audio is sent over the AES-GCM encrypted Moonlight control stream. The host (Vibepollo) refuses to render mic audio from clients that did not negotiate an encrypted session. No plaintext mic audio is ever transmitted.

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How It Works

Steam Deck mic (or USB/Bluetooth mic)
→ SDL2 capture (48kHz, 16-bit, stereo or mono)
→ (L+R)/2 downmix to mono
→ 12-frame ring buffer (jitter smoothing)
→ Opus encode (64kbps mono, FEC, complexity 10, FRAMESIZE_20_MS)
→ 4-byte header prepended (channel/flags)
→ Deadline-based pacer (20ms intervals, re-sync guard)
→ AES-GCM encrypted control stream
→ Vibepollo: jitter buffer (40ms) → Opus decode
→ Steam Streaming Microphone
→ Windows default capture switches to Microphone (Steam Streaming Microphone)
→ Discord/games hear mic automatically

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Platform Support

Platform	Status
Steam Deck (SteamOS)	Supported
Windows	Not supported
macOS	Not supported

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Steam Deck Art

Custom Steam Grid artwork is included in steamgridDB/. Apply it via SGDBoop with Decky Loader, or copy the files manually into your Steam grid directory.

File	Type	Dimensions
capsule.png	Capsule	920×430
wide_capsule.png	Wide Capsule	600×900
hero.png	Hero	3840×1240
logo.png	Logo	512×140
icon.png	Icon	256×256

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Related Projects

Project	Description
Vibepollo	Companion server-side fork
logabell/moonlight-qt-mic	Parallel client mic implementation — not compatible with Vibelight (uses LiSendMicrophoneOpusDataEx on a separate UDP port; Vibelight uses 0x3003 on the encrypted control stream)
moonlight-stream/moonlight-qt	Upstream Moonlight
ClassicOldSong/Apollo	Apollo (server) upstream

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Acknowledgments

Mic passthrough was developed in parallel with logabell/moonlight-qt-mic. We adopted Opus encoder tuning (64kbps mono, FEC, VBR, complexity 10, FRAMESIZE_20_MS) and the deadline-based send pacer from that work after comparing implementations.