Audio Splitter

中文说明

A lightweight Rust + WASAPI tool for Windows that duplicates system playback audio to an extra output line (for example CABLE Input), while keeping your original speaker/headphone playback.

Demo

Features

• WASAPI loopback capture from system playback
• Duplicate to selected output endpoint (virtual cable, hardware line, etc.)
• Minimal GUI: refresh device list, choose output, start/stop
• Real-time level visualization for input/output flow

What This Project Is Useful For

• Redirecting media player audio into a microphone-like input
• Live speech transcription pipelines
• Meeting note capture workflows
• Call recording / conversation archival workflows
• Routing audio into other software lines or processing tools

Requirements

• Windows 10/11
• Rust toolchain (for building from source)
• A virtual audio cable driver if you want apps to receive this as microphone input

VB-Audio Virtual Cable Recommendation

VB-Audio Virtual Cable is a third-party driver and must be installed manually (it is not built into Windows).

Recommended setup:

1. Install VB-CABLE and reboot if requested.
2. Keep your normal headphone/speaker as Windows default playback device.
3. In this app, select CABLE Input as the output target, then click Start.
4. In your voice/meeting software, set microphone/input to CABLE Output.
5. In that software, disable options similar to "Mute while speaking" / "Mute during voice input".

Build & Run

cargo run --release

Routing Notes

• This app does not create virtual devices by itself. It uses devices already present in Windows.
• If you lose headphone playback, you likely switched system default playback to CABLE Input. Set default playback back to your headphone/speaker.
• For stability, keep sample-rate settings aligned at 48 kHz where possible.

License

MIT