ffmpeg -i inputmp4 -cv rawvideo -pix_fmt rgba outputrgba

This command uses ffmpeg to convert the input video file "input.mp4" to a rawvideo format with RGBA pixel format, and saves it as "output.rgba".

• "-i input.mp4" specifies the input file.
• "-c:v rawvideo" sets the video codec to rawvideo.
• "-pix_fmt rgba" sets the pixel format to RGBA.

This command can be useful for extracting the raw video data with alpha channel from a video file, which can then be used for further processing or compositing with other video or image files.