FFmpeg Filter Grammar

gistfile1.txt

// Work in progress! Does not handle escapes within filter arguments.

FilterGraph =
	head: FilterChain
    tail:(";" @FilterChain)*
    { return [head, ...tail]; }

FilterChain =
	head: Filter
    tail:("," @Filter)*
    {
    	return {
	    	"filters": [head, ...tail],
	   	}
    }

Name = [a-zA-Z_0-9:]+

FilterLabel =
	_ "[" _ name:Name _ "]" _
    { return name.join(""); }

FilterArg =
	arg:[a-zA-Z1-9=]+
    { return arg.join(""); }

FilterArgs =
	head: FilterArg
    tail:(":" @FilterArg)*
    { return [head, ...tail]; }

Filter =
	inLabels:FilterLabel*
    name:Name("@"Name)? // TODO capture ID
    args:(
    	"="
	    FilterArgs
    )?
    outLabels:FilterLabel*
    {
    	return {
        	"inLabels": inLabels,
	    	"name": name.join(""),
            "args": args === null ? [] : args[1],
        	"outLabels": inLabels,
        };
    }

_ "whitespace"
  = [ \t\n\r]*