mirror of
https://github.com/ultravideo/uvg266.git
synced 2024-11-23 18:14:06 +00:00
81b51f17d8
New implementation uses precalculated tables to look up number of reference pixels available in coded CUs. Otherwise it works just like the previous version. - NxN mostly works. Prediction appears to be almost correct but there is a slight error in the exact values, probably related to filtering.
122 lines
3.3 KiB
Python
122 lines
3.3 KiB
Python
"""This is a script that generates tables for Kvazaar HEVC encoder.
|
|
|
|
This script is provided as reference, in case we ever need to change the tables
|
|
or generate more similar tables.
|
|
|
|
Because the CUs are coded in Z-order a particular index in the LCU will always
|
|
have the same number of coded reference pixels, except if the PU is on the very
|
|
top or left edge of the LCU.
|
|
|
|
"""
|
|
|
|
import numpy
|
|
|
|
|
|
def make_z_order_table(width, coord = None, zid=0, min_width=4, result=None):
|
|
"""Return a table with the quadtree z-order.
|
|
|
|
Args:
|
|
width: width of the area (LCU)
|
|
coord: numpy.array with index 0 as x and 1 as y
|
|
min_width: width at which the recursion is stopped
|
|
result: numpy.array with the current table
|
|
|
|
Returns: numpy.array with the quadtree z-order.
|
|
"""
|
|
if coord is None:
|
|
coord = numpy.array([0, 0])
|
|
|
|
if result is None:
|
|
num_pu = width / min_width
|
|
result = numpy.zeros((num_pu, num_pu), numpy.int16)
|
|
offset = width / 2
|
|
|
|
if offset >= min_width:
|
|
# Recurse in quadtree z-order.
|
|
offsets = map(numpy.array, [[0,0],[1,0],[0,1],[1,1]])
|
|
for num, os in enumerate(offsets):
|
|
num_pu = offset**2 / min_width**2
|
|
result = make_z_order_table(offset, coord + os * offset,
|
|
zid + num * num_pu, min_width, result)
|
|
else:
|
|
pu = coord / min_width
|
|
result[pu[1]][pu[0]] = zid
|
|
|
|
return result
|
|
|
|
|
|
def num_lessed_zid_on_left(table, x, y):
|
|
"""Z-order table + coord -> number of ref PUs on the left."""
|
|
i = 0
|
|
while True:
|
|
if x == 0:
|
|
return 16
|
|
if y + i >= 16 or table[y + i][x - 1] > table[y][x]:
|
|
return i
|
|
i = i + 1
|
|
|
|
|
|
def num_lessed_zid_on_top(table, x, y):
|
|
"""Z-order table + coord -> number of ref PUs on the top."""
|
|
i = 0
|
|
while True:
|
|
if y == 0:
|
|
return 16
|
|
if x + i >= 16 or table[y - 1][x + i] > table[y][x]:
|
|
return i
|
|
i = i + 1
|
|
|
|
|
|
def matrix_to_initializer_list(table):
|
|
"""Output a list of lists as an initializer list in C syntax.
|
|
|
|
Args:
|
|
table: list(list(int)) representing 2d array
|
|
Returns:
|
|
str
|
|
"""
|
|
# Convert the numbers into strings and pad them to be 2-chars wide to make
|
|
# the table look nicer.
|
|
str_nums = (("{0: >2}".format(x) for x in line) for line in table)
|
|
|
|
# Get the lines with all the numbers divided by commas.
|
|
lines = (", ".join(line) for line in str_nums)
|
|
|
|
# Join the lines with commas and newlines in between.
|
|
result = "{ %s }" % (" },\n{ ".join(lines))
|
|
|
|
return result
|
|
|
|
|
|
def main():
|
|
zid_table = make_z_order_table(64)
|
|
|
|
num_pu = 16
|
|
left_table = numpy.zeros((num_pu, num_pu), numpy.int16)
|
|
top_table = numpy.zeros((num_pu, num_pu), numpy.int16)
|
|
|
|
for y in range(16):
|
|
for x in range(16):
|
|
left_table[y][x] = num_lessed_zid_on_left(zid_table, x, y)
|
|
top_table[y][x] = num_lessed_zid_on_top(zid_table, x, y)
|
|
|
|
print zid_table
|
|
print left_table
|
|
print top_table
|
|
|
|
# Multiply by number of pixels in a PU
|
|
left_table = left_table * 4
|
|
top_table = top_table * 4
|
|
|
|
print
|
|
print "left"
|
|
print matrix_to_initializer_list(left_table)
|
|
print
|
|
print "top"
|
|
print matrix_to_initializer_list(top_table)
|
|
print
|
|
|
|
|
|
if __name__ == '__main__':
|
|
main()
|