x264enc: Allow maximum quantizer value of 63 instead of 51
QP_MAX_SPEC in x264 is set to 63 nowadays and in theory it allows even up to 81 (QP_MAX) but that seems to be outside the spec.
QP_MAX_SPEC in x264 is set to 63 nowadays and in theory it allows even up to 81 (QP_MAX) but that seems to be outside the spec.