Open Broadcaster Software is free and open source software for video recording and live streaming. Supported features include:
- Encoding using H264 (x264) and AAC.
- Support for Intel Quick Sync Video (QSV) and NVENC.
- Unlimited number of scenes and sources.
- Live RTMP streaming to Twitch, YouTube, DailyMotion, Hitbox and more.
- File output to MP4 or FLV.
- GPU-based game capture for high performance game streaming.
- DirectShow capture device support (webcams, capture cards, etc).
- Windows 8 high speed monitor capture support.
- Bilinear or lanczos3 resampling.
OBS Multiplatform is available as a package for several Linux distributions, and can be compiled from source.
You can download the Linux version here : https://obsproject.com/download#linux