Hwang lets you perform "efficient random access" across the video by building a GOP/Segment aware index. This comes in handy in a lot of applications where you want to access particular frame or set of frames but do not wish to decode and store all frames. Most tools such as ffmpeg (command line application not library) are optimized for sequential decode use case.

> Hwang is a library for performing fast decode of frames from h.264 encoded video (most mp4s). Hwang provides both a Python and C++ API. Hwang decodes on the CPU (using ffmpeg) or on the GPU (using the NVIDIA hardware decoder).