Worked on the ossrs/ffmpeg-webrtc repository to enhance the stability and correctness of the VVC decoder, focusing on the ALF filtering path. Addressed a critical bug by ensuring proper initialization of the alf->ctb_cc_idc variable when ALF is enabled but CC-ALF is not, which prevented uninitialized reads and reduced crash risk in ALF-enabled configurations. This fix improved reliability for downstream applications using WebRTC and FFmpeg. Demonstrated strong debugging skills and deep understanding of codec internals, with careful attention to memory safety and correctness in C. The work centered on bug fixing, codec implementation, and video decoding within complex code paths.