micvol

macOS microphone input volume control library.

中文文档

What is "input volume"?

This is not the output volume you adjust with keyboard volume keys. This is the input volume slider in System Settings > Sound > Input.

micvol lets you programmatically control this slider.

Features

• VolumeGuard — maximize input volume, automatically restore on drop
• Device enumeration — list all audio input devices
• Input volume control — get/set volume (0.0–1.0)
• Mute control — get/set mute state

Install

Rust:

[dependencies]
micvol = "0.1"

Swift / ObjC (static library):

./scripts/build_release.sh
# outputs dist/libmicvol.a + dist/micvol.h

CocoaPods:

pod 'Micvol', :git => 'https://github.com/Fengur/micvol.git'

Usage

Rust

let device = micvol::default_input_device()?;
{
    let _guard = micvol::VolumeGuard::maximize(&device.id)?;
    // ... record audio — input volume is maximized ...
}
// guard dropped: input volume automatically restored

C / Swift / ObjC

#include "micvol.h"

uint32_t device_id;
char *name;
micvol_default_input_device(&device_id, &name);

MicvolGuard guard;
micvol_guard_maximize(device_id, &guard);
// ... record audio ...
micvol_guard_restore(guard);

micvol_free_string(name);

API

// Device enumeration
micvol::input_devices() -> Result<Vec<DeviceInfo>>
micvol::default_input_device() -> Result<DeviceInfo>

// Input volume control
micvol::get_volume(&DeviceId) -> Result<Volume>
micvol::set_volume(&DeviceId, Volume) -> Result<()>

// Mute control
micvol::get_mute(&DeviceId) -> Result<MuteState>
micvol::set_mute(&DeviceId, MuteState) -> Result<()>

// VolumeGuard
micvol::VolumeGuard::maximize(&DeviceId) -> Result<VolumeGuard>
micvol::VolumeGuard::with_volume(&DeviceId, Volume) -> Result<VolumeGuard>

Demo App

A SwiftUI demo app is included in demo/MicvolDemo/. To build:

./scripts/build_release.sh
cd demo/MicvolDemo
xcodegen generate
open MicvolDemo.xcodeproj

Technical Details

For implementation principles and technical documentation, please contact the author.

License

MIT