glcs is an ALSA & OpenGL capture and real-time streaming tool for Linux, a fork of glc . Beside code quality improvement, the problem that glcs attempt to resolve over the original is that the glc file format is not adequate to store HD stream on disk. As an example, to capture an opengl window at a 1080P resolution at 30fps, this represents about 2 million pixels of 24 bits or roughly 6MB per frame or 180 MB per second. glc offer general lossless compression but the result is not good enough to consider long session of HD capture. glcs propose a new flexible option allowing to pipe directly the raw audio video streams to a more specialised tool. for instance, ffmpeg. This allows to apply any video codec on the stream for a better compression ratio and also by leveraging the capability of the specialised tool, this open up new possibilities for glcs users such as live stream of a video game session on youtube.