The FFmpeg version of Nvidia Codec SDK headers which are required to interface with Nvidia's codec APIs. The purpose of these headers is to allow hardware (GPU) encoding with suitable NVidia cards. This version corresponds to Video Codec SDK version 9.1.23 and requires NVidia drivers version 435.21 or newer. There are 3 stages in the history of NVidia GPU encoding with FFmpeg: 1. Pre August 27th 2016 it was necessary to track down your own headers to build nvenc. 2. Post August 27th 2016 the required headers were incorporated as part of the FFmpeg source. 3. Post February 26th 2018 the NVidia headers were removed from the FFmpeg source and a separate git repository was created to hold continuing work with these headers. This nv-codec-headers script is for point 3 where the headers will need to be installed before compiling a recent FFmpeg.