When writing my filtergraphs, I’ve found the following three “tricks” to be immensely helpful
Use an actual editor. Fish shell has a keybind that opens the current prompt in your $EDITOR, and saving+quitting returns to the editor. Makes multi line ffmpeg filters trivial. Doubly so if your editor has something like TabNine completions
If that’s not enough, write the filter in a dedicated file, and use either editor automation or something like entr to run ffmpeg’s graph2dot command and then graphviz to get a visualization of said graph. Helps ferret out bugs
Build up more complex graphs using either ffplay or mpv. You can add filters at runtime to mpv via the repl (press ~) and the vf add command
When writing my filtergraphs, I’ve found the following three “tricks” to be immensely helpful
$EDITOR, and saving+quitting returns to the editor. Makes multi line ffmpeg filters trivial. Doubly so if your editor has something like TabNine completionsvf addcommand