One ffmpeg input declaration.
Accessing an input returns FFix.Stream references that can be used in graphs
or mapped directly to outputs. The access keys mirror common ffmpeg stream
selectors:
input[:input]maps the whole input, like-map 0input[:video]maps/selects the first video stream class, like0:vinput[:audio]maps/selects the first audio stream class, like0:ainput[audio: 1]maps/selects a specific stream class index, like0:a:1input[raw: "s?"]keeps an explicit ffmpeg selector escape hatch
Examples
src = FFix.Command.input("input.mp4", ss: "00:00:03")
logo = FFix.Command.input("logo.png", loop: 1, framerate: 1)
src[:input]
src[:video]
src[:audio]
src[audio: 1]
logo[:video]