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Martin Pulec edited this page Jan 12, 2022 · 22 revisions
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UltraGrid from Laboratory of Advanced Networking Technologies (SITOLA) is a software implementation of high-quality low-latency video and audio transmissions using commodity PC and Mac hardware. UltraGrid uses uncompressed or very low compression-ratio streams to achieve up to 8K resolution with as low as 100ms end-to-end latency. UltraGrid is used, among others in areas like collaborative environments, medical cinematography, broadcasting application and various educational activities.

SITOLA's UltraGrid is based on original UltraGrid developed by Colin Perkins, Ladan Gharai, et al., a research project used to demonstrate the possibilities of 10Gbps networks and to study multi-point data distribution in such environments. Due to recent advances in the field of GPU-accelerated low-latency codecs, we have been able to extend its usability also to Gigabit networks.

UltraGrid is open-source software, distributed under BSD license - we're interested in both research/academic and commercial applications. Our work is supported by CESNET large infrastructure LM2010005. In the past, it was also supported by "Optical Network of National Research and Its New Applications" (MŠM 6383917201) and incorporated research results achieved within by research intent "Parallel and Distributed Systems" (MŠM 0021622419).


  • As low as 83ms end-to-end latency
  • Support for various video standards (PAL/NTSC, HD, 2K, 4K - both tiled and untiled)
  • Runs on macOS, Windows, and various Linux distributions, shipped with a cross-platform GUI
  • OpenGL and SDL software displays
  • CUDA accelerated JPEG compression, low-complexity GPU accelerated DXT compression, support for Comprimato J2K codec
  • FFmpeg-backed compressions (i.a. H.264/HEVC) including HW acceleration, CineForm
  • Syphon, SPOUT, NDI®[1] and SAGE support
  • Support for various SDI and HDMI cards (AJA, BlackMagic, BlueFish444, Deltacast, DVS, XIMEA), generic capture APIs (DirectShow, AVFoundation, V4L2), and computer screen capture
  • Support for system audio, JACK or SDI-embedded sound
  • uncompressed (PCM) or compressed audio transmission - subset of FFmpeg-backed compressions available - i.a. OPUS, FLAC, A/u-law or MP3
  • 3D support, encryption support, 10/12 bit depth video support (including RGB and 4:4:4 subsampling)
  • Flexible RTP-based format for up to 8K video or standard SDP/RTSP source
  • Support for multicast, included packet reflectors for application-level multi-point distribution
  • for list of recent changes in UltraGrid code see here

[1] NDI® is a registered trademark of NewTek, Inc., NDI® is available at