Parameters exist in 3 layers: ffmpeg, codec, and an interface layer. You can apply parameters to each layer. The top 2 layers are accessed with the Kind popup menu. The ffmpeg layer is topmost, and is selected as Kind: ffmpeg. It can specify many of the more common parameters, such as the bitrate, quality, and so on. The middle layer is selected as Kind: codec. These options can specialize your choices, and frequently includes presets and profiles useful for coding well known parameter sets, like \textit{profile=high422}, \textit{preset=medium}, or \textit{tune=film}, etc. The interface layer may or may not be available. It is usually accessible only by an \textit{opts} parameter, like \texttt{x264-params key=value:key=value}:\dots These options are passed directly to the low level codec library.
Parameters exist in 3 layers: ffmpeg, codec, and an interface layer. You can apply parameters to each layer. The top 2 layers are accessed with the Kind popup menu. The ffmpeg layer is topmost, and is selected as Kind: ffmpeg. It can specify many of the more common parameters, such as the bitrate, quality, and so on. The middle layer is selected as Kind: codec. These options can specialize your choices, and frequently includes presets and profiles useful for coding well known parameter sets, like \textit{profile=high422}, \textit{preset=medium}, or \textit{tune=film}, etc. The interface layer may or may not be available. It is usually accessible only by an \textit{opts} parameter, like \texttt{x264-params key=value:key=value}:\dots These options are passed directly to the low level codec library.