During their work on the FFmpeg/FFmpeg repository, Niyinghao introduced a type-safe approach to format handling and negotiation within the AVFilter module. By developing and integrating type-safe functions for AVSampleFormat and AVPixelFormat lists, they addressed potential undefined behavior and improved memory safety in audio and video filter processing. Their refactoring of the format negotiation logic in C enhanced code correctness and reduced future maintenance risks. Drawing on skills in C programming, audio processing, and filter development, Niyinghao’s contributions focused on safer memory access and more robust system programming, resulting in a more reliable and extensible filter negotiation framework.