blackhole

BlackHole is an open-source macOS virtual audio loopback driver developed by Existential Audio. It provides a system-level audio routing solution that allows applications to pass audio to other applications with zero additional latency. Key Features: - Multiple channel configurations: 2, 16, 64, 128, and 256 audio channels - Customizable channel count, latency, and hidden devices - Mirror device support for separate input/output routing - Wide sample rate support: 8kHz to 768kHz - Zero additional driver latency - Compatible with macOS 10.10 Yosemite and newer - Supports both Intel and Apple Silicon architectures - No kernel extensions or system security modifications required Installation: BlackHole can be installed via a downloadable installer from the official website or through Homebrew (brew install blackhole-2ch, blackhole-16ch, or blackhole-64ch). After installation, the driver appears in Audio MIDI Setup and can be used as an input or output device in any audio application. Use Cases: - Recording system audio in DAWs like GarageBand, Logic Pro X, Audacity, and Reaper - Routing audio between applications (e.g., streaming from Logic Pro X to Zoom, Google Meet, Skype, or FaceTime) - Setting up multi-output devices for simultaneous monitoring and recording - Creating custom audio routing configurations for professional audio workflows Developer Customization: The driver is highly customizable through pre-compiler constants that can be specified at build time using xcodebuild. Developers can customize: - Driver name, bundle ID, and icon - Device visibility, input/output capabilities - Channel count, latency frame size, and sample rates - Mirror device configuration for separate input/output devices The project is licensed under GPL-3.0, with commercial licensing available for non-GPLv3 projects. It includes CI/CD integration support for building, signing, and notarizing installers. The project also maintains a wiki with detailed user guides, FAQ, and troubleshooting information for common issues like multi-output device setup, drift correction, and application compatibility.