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The following pseudo code illustrates how to compress a line of data. The data can be a line
of alpha, Y, or C data in an array.
array is an array of 16 bit unsigned values (alpha, Y, or C values)
value, last_value, and count are 16 bit unsigned values
value = first element of array
count = 1
for P = 1 to ((Xsize/2) - 1)
last_value = value
value = next element of array
if (value = last value) then increment count
if (value != last value) or (at end of array) then
if (count = 1) then
output last_value
if (value = 0x0FF1) then output last_value again
if (at end of array) then
output value
if (value = 0x0FF1) then output value again
else
if (count = 2) and (last_value != 0x0FF1) then
output last_value twice
else
output vector (0x0FF1, count, last_value)
end if
if (at end of array) and (value != last_value) then
output value
if (value = 0x0FF1) then output value again
end if
end if
end if
count = 1
next P
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