fasjitter

Fasjitter is a cross-platform software library and framework designed to measure, model, and mitigate timing jitter in real-time systems. It provides tools to estimate jitter, adapt pacing, and compensate delays in networks and processing pipelines. The library is intended for use in audio, video, and data streams to improve quality of service and predictability.

Originating as an open-source effort in the early 2020s, fasjitter was developed by a community of developers focusing on low-latency media and time-sensitive data pipelines. The project name reflects its goal of fast adaptive jitter management and has been adopted by several small-scale and embedded deployments.

Architecture and features include a modular design with a jitter estimator, a pacing controller, and a transport adapter. The estimator supports models such as exponentially weighted moving average and Kalman filtering. The pacing controller adapts event scheduling to maintain target deadlines and reduce observed variance. Transport adapters provide interfaces for UDP/TCP, RTP, and custom pipelines, while the library emphasizes thread safety and low-overhead timers. It offers configurable delay budgets and jitter tolerance levels to fit diverse requirements.

Implementation notes indicate reliance on high-resolution timers and robust clock sources, with an explicit aim to minimize added jitter. Fasjitter is designed to be lightweight, with pluggable components and platform-specific optimizations for Linux, Windows, macOS, and certain RTOS environments.

Applications and limitations: fasjitter is used in VoIP, live streaming, online gaming, and industrial automation to improve timing stability. It is not a universal solution; effectiveness depends on reliable clock sources, kernel timer resolution, and system load. See also jitter buffer, time synchronization, real-time transport protocol, and delay management.