def dump(x):
c = palette[x]
out.write(
strtoio(
pack([
(getbit(c, 5) * 2 + getbit(c, 2)) * 85,
(getbit(c, 4) * 2 + getbit(c, 1)) * 85,
(getbit(c, 3) * 2 + getbit(c, 0)) * 85,
])))
def test_getbit(self):
self.assertEqual(getbit(33, 0), 1)
self.assertEqual(getbit(32, 0), 0)
self.assertEqual(getbit(128, 7), 1)
self.assertEqual(getbit(128, 0), 0)
def convert(
input_image_stream,
output_image_stream,
arte,
newsroom,
cols,
rows,
skip,
ignore_header_errors,
):
def clip(v):
return 255 if v > 255 else (0 if v < 0 else v)
# imitate +I and -I colours using Coco palette
br2 = [
pack(x)
for x in [[0, 0, 0], [255, 85, 0], [0, 170, 255], [255, 255, 255]]
]
# take names "blue" and "red" too literally like many "patched for Coco3"
# programs
br3 = [
pack(x) for x in [[0, 0, 0], [255, 0, 0], [0, 0, 255], [255, 255, 255]]
]
# probably not exact...
semig = [
pack(x) for x in [
[0, 0, 0],
[0, 255, 0],
[255, 255, 0],
[0, 0, 255],
[255, 0, 0],
[255, 255, 255],
[0, 211, 170],
[204, 0, 255],
[255, 128, 0],
]
]
f = input_image_stream
out = output_image_stream
if skip:
f.read(skip)
if newsroom:
head = iotostr(f.read(2))
cols = ord(head[0]) * 8
rows = ord(head[1])
else:
head = iotostr(f.read(5))
if ord(head[0]) != 0:
sys.stderr.write("bad first byte in header\n")
if not ignore_header_errors:
return False
if not rows:
size = ord(head[1]) * 256 + ord(head[2])
rows = 8 * size // cols
if cols * rows // 8 != size:
sys.stderr.write(
"data length {} in header would be closest to {}x{} but "
"that would be {} bytes\n".format(size, cols, rows,
cols * rows // 8))
if not ignore_header_errors:
return False
out.write(strtoio("P6\n{} {}\n255\n".format(cols, rows)))
for jj in range(rows):
row = iotostr(f.read(cols >> 3))
oy = r2 = g2 = b2 = 0
for vv in row:
v = ord(vv)
if arte == PIXEL_MODE_BW:
for k in range(8):
out.write(strtoio(br2[getbit(v, 7 - k) * 3]))
elif (arte == PIXEL_MODE_BR) or (arte == PIXEL_MODE_RB):
x = -100 if arte == PIXEL_MODE_BR else 100
# this is using the exact YIQ-to-RGB formula, but the rest is
# just trial-and-error of what looks ok, without actually using
# the spec of NTSC and/or VDG/GIME. more pixel options could
# be added to allow variants on : brightness/contrast ;
# saturation ; double-resolution for greater detail in
# emulation ; different smoothing and horiz phase ; and
# replacing ±I colours by ±V colours (green-purple of PAL and
# of SECAM).
for k in range(8):
ny = getbit(v, 7 - k) * 255
y = (oy + ny + (ny >> 2)) >> 1
i = (x * (y - oy)) >> 7
r = clip(int((y + 0.9563 * i)))
g = clip(int((y - 0.2721 * i)))
b = clip(int((y - 1.1070 * i)))
out.write(
strtoio(
pack([(r + r2) >> 1, (g + g2) >> 1,
(b + b2) >> 1])))
oy = ny
x = -x
r2 = r
g2 = g
b2 = b
elif arte == PIXEL_MODE_BR2:
for k in range(4):
out.write(
strtoio(br2[getbit(v, 7 - k - k) * 2 +
getbit(v, 6 - k - k)] * 2))
elif arte == PIXEL_MODE_RB2:
for k in range(4):
out.write(
strtoio(br2[getbit(v, 7 - k - k) +
getbit(v, 6 - k - k) * 2] * 2))
elif arte == PIXEL_MODE_BR3:
for k in range(4):
out.write(
strtoio(br3[getbit(v, 7 - k - k) * 2 +
getbit(v, 6 - k - k)] * 2))
elif arte == PIXEL_MODE_RB3:
for k in range(4):
out.write(
strtoio(br3[getbit(v, 7 - k - k) +
getbit(v, 6 - k - k) * 2] * 2))
elif arte == PIXEL_MODE_S10:
for k in range(4):
out.write(
strtoio(semig[1 + getbit(v, 7 - k - k) +
getbit(v, 6 - k - k) * 2] * 2))
elif arte == PIXEL_MODE_S11:
for k in range(4):
out.write(
strtoio(semig[5 + getbit(v, 7 - k - k) +
getbit(v, 6 - k - k) * 2] * 2))
return True
def convert(input_image_stream, output_image_stream):
def debug(x):
sys.stderr.write("{}\n".format(x))
def dump(x):
c = palette[x]
out.write(
strtoio(
pack([
(getbit(c, 5) * 2 + getbit(c, 2)) * 85,
(getbit(c, 4) * 2 + getbit(c, 1)) * 85,
(getbit(c, 3) * 2 + getbit(c, 0)) * 85,
])))
# Read basic structure
# - is is a 192 or 384 row image?
# - motifs - patterns used for filling shapes stored in the image file
f = input_image_stream
cols = 320
pictyp = ord(iotostr(f.read(1)))
rows = (getbit(pictyp, 7) + 1) * 192
sans_motifs = getbit(pictyp, 0) != 0
debug("{}x{}, 16 couleurs, sans_motifs={}".format(cols, rows, sans_motifs))
# Get palette information
palette = [ord(iotostr(f.read(1))) for ii in range(16)]
anirat = ord(iotostr(f.read(1)))
cycrat = ord(iotostr(f.read(1)))
cm3cyc = [ord(iotostr(f.read(1))) for ii in range(8)]
aniflg = ord(iotostr(f.read(1))) & 0x80 != 0
cycflg = ord(iotostr(f.read(1))) & 0x80 != 0
debug("palette={}".format(palette))
debug("cm3cyc={} cycrat={} cycflg={} anirat={} aniflg={}".format(
cm3cyc, cycrat, cycflg, anirat, aniflg))
if not sans_motifs:
iotostr(f.read(243))
linbuf = [0] * 160
buff1 = [0] * 20
buff2 = []
# Start outputting image
out = output_image_stream
out.write(strtoio("P6\n{} {}\n255\n".format(cols, rows)))
for ii in range(getbit(pictyp, 7) + 1):
lines = ord(iotostr(f.read(1)))
for jj in range(lines):
u = 0
y = 0
bitu = 7
bity = 7
x = 0
a = None
contr = ord(iotostr(f.read(1)))
if contr < 128:
for kk in range(20):
buff1[kk] = ord(iotostr(f.read(1)))
buff2 = []
for kk in range(contr):
buff2.append(ord(iotostr(f.read(1))))
for kk in range(160):
if contr >= 128:
a = ord(iotostr(f.read(1)))
else:
cc = getbit(buff1[u], bitu)
bitu = bitu - 1
if bitu < 0:
bitu = 7
u = u + 1
if cc == 0:
a = linbuf[(x - 1) % 160]
else:
cc = getbit(buff2[y], bity)
bity = bity - 1
if bity < 0:
bity = 7
y = y + 1
if cc == 0:
a = linbuf[x]
else:
a = ord(iotostr(f.read(1)))
linbuf[x] = a
dump(a >> 4)
dump(a & 15)
x = x + 1
# Look for extra junk at the end of the file
extra = 0
while iotostr(f.read(1)) != "":
extra = extra + 1
pass
if extra > 0:
debug("{} octets de trop".format(extra))