FFmpeg h264 Hard-coded Nvenc

Recent projects need to record video taken by the camera, using H264 encoding. The test found that H264 encoded 2k (1980x1080) video was smooth, but encoded 4k (3840x4120) video showed noticeable lag phenomenon. Therefore consider using H264 Nvenc hardware encoding.
The original code

    Avcodec *codec = Avcodec_find_encoder (av_codec_id_h264);

Switch

    Avcodec * codec = Avcodec_find_encoder_by_name ("nvenc_h264");

You can implement H264 Nvenc hardware encoding.
Compared to CPU coding, H264 NVENC hardware encoded 4k video significantly smoother, dropped frame phenomenon significantly reduced.