User`s manual

Reference Manual 83
encoding
X 2: Linear filter applied in the horizontal direction before
encoding
v_filter_mode
The mode of pre-filtering in a vertical direction.
X 0: No pre-filtering in the vertical direction before encoding
X 1: Median filter applied in the vertical direction before
encoding
X 2: Linear filter applied in the vertical direction before encod-
ing
filter_nAX
filter_nBX
filter_nCX
The coefficients of linear filter in horizontal direction. Valid only
if the h_filter_mode equals to two.
filter_nAX, filter_nBX, and filter_nCX correspond to precedent
pixel, current pixel, and following pixel respectively. These
three coefficients are all 5-bit values. filter_nBX is an unsigned
value. filter_nAX and filter_nCX are signed values, with the
highest bit indicating the sign and the rest four bits indicating
the absolute value.
Typically, if filter_nAX and filter_nCX are positive, the filter will
be a low-pass filter. Otherwise, if filter_nAX and filter_nCX are
negative, the filter is a high-pass filter. A typical requirement for
the coefficients is:
filter_nAX + filter_nBX + filter_nCX = 16.
filter_nAY
filter_nBY
filter_nCY
The coefficients of linear filter in vertical direction. Valid only if