ffmpeg No such filter woes

/opt/local/bin/ffmpeg -i one.flv -i two.flv -i one.jpg -i two.jpg -filter_complex "
    [0:0] pad='max(240\,iw):max(180\,ih):0:0', scale='240:180', pad='480:180:0:0' [left_video];
    [1:0] pad='max(240\,iw):max(180\,ih):0:0', scale='240:180', pad='480:180:240:0' [right_video];
    [left_video] [right_video] overlay [videos];

    [2:0] pad='max(240\,iw):max(180\,ih):0:0:0x00000000', scale='240:180', pad='480:180:0:0' [left_avatar];
    [3:0] pad='max(240\,iw):max(180\,ih):0:0:0x00000000', scale='240:180', pad='480:180:240:0' [right_avatar];
    [left_avatar] [right_avatar] overlay [avatars];

    [avatars] [videos] overlay [video];

    [0:1] [1:1] amerge;
    " -acodec libfaac -ac 2 -vcodec libx264 -r 15 "$5"