Version 4 added IIS live smooth streaming, screen capture improvements and an H.264 encoder based on the MainConcept SDK. Expression Encoder 4.0 SP1 was released in January 2011 and added CUDA-enabled GPU-assisted encoding, HE-AAC, screen captures as a live source, live broadcasting templates, Selective Blend de-interlacing and other features. Service Pack 2 (SP2) with about 300 bugs fixes was released on November 2, 2011 and added new features such GPU-accelerated video encoding and the removal of 10 minutes screen recording limit.