There are two "modes" to the RLE algorithm used in both QGF/QFF:
128 octets
length = marker - 128length number of octets follow directly after the marker octet128
length = markerlength times.Decoder pseudocode:
while !EOF
    marker = READ_OCTET()
    if marker >= 128
        length = marker - 128
        for i = 0 ... length-1
            c = READ_OCTET()
            WRITE_OCTET(c)
    else
        length = marker
        c = READ_OCTET()
        for i = 0 ... length-1
            WRITE_OCTET(c)