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extracted classes GrayscaleSSTV and Robot8BW, reduced shitfs

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András Veres-Szentkirályi 2013-05-23 14:04:21 +02:00
parent 3a10ec83f0
commit 8690249bcc
1 changed files with 23 additions and 14 deletions
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37
sstv.py
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@ -17,12 +17,6 @@ MSEC_VIS_START = 300
MSEC_VIS_SYNC = 10 MSEC_VIS_SYNC = 10
MSEC_VIS_BIT = 30 MSEC_VIS_BIT = 30
ROBOT_BW_8_WIDTH = 160
ROBOT_BW_8_HEIGHT = 120
ROBOT_BW_8_SYNC = 10
ROBOT_BW_8_SCAN = 56
ROBOT_BW_8_VIS = 0x02
class SSTV(object): class SSTV(object):
def __init__(self, image, samples_per_sec, bits): def __init__(self, image, samples_per_sec, bits):
self.image = image self.image = image
@ -77,29 +71,44 @@ class SSTV(object):
yield FREQ_SYNC, MSEC_VIS_SYNC yield FREQ_SYNC, MSEC_VIS_SYNC
yield FREQ_VIS_START, MSEC_VIS_START yield FREQ_VIS_START, MSEC_VIS_START
yield FREQ_SYNC, MSEC_VIS_BIT # start bit yield FREQ_SYNC, MSEC_VIS_BIT # start bit
vis_code = ROBOT_BW_8_VIS vis = self.VIS_CODE
num_ones = 0 num_ones = 0
for bitnum in xrange(7): for _ in xrange(7):
bit = (vis_code >> bitnum) & 1 bit = vis & 1
vis >>= 1
num_ones += bit num_ones += bit
bit_freq = FREQ_VIS_BIT1 if bit == 1 else FREQ_VIS_BIT0 bit_freq = FREQ_VIS_BIT1 if bit == 1 else FREQ_VIS_BIT0
yield bit_freq, MSEC_VIS_BIT yield bit_freq, MSEC_VIS_BIT
parity_freq = FREQ_VIS_BIT1 if num_ones % 2 == 1 else FREQ_VIS_BIT0 parity_freq = FREQ_VIS_BIT1 if num_ones % 2 == 1 else FREQ_VIS_BIT0
yield parity_freq, MSEC_VIS_BIT yield parity_freq, MSEC_VIS_BIT
yield FREQ_SYNC, MSEC_VIS_BIT # stop bit yield FREQ_SYNC, MSEC_VIS_BIT # stop bit
msec_pixel = ROBOT_BW_8_SCAN / ROBOT_BW_8_WIDTH
class GrayscaleSSTV(SSTV):
def gen_freq_bits(self):
for item in SSTV.gen_freq_bits(self):
yield item
msec_pixel = self.SCAN / self.WIDTH
image = self.image image = self.image
for line in xrange(ROBOT_BW_8_HEIGHT): for line in xrange(self.HEIGHT):
yield FREQ_SYNC, ROBOT_BW_8_SYNC yield FREQ_SYNC, self.SYNC
for col in xrange(ROBOT_BW_8_WIDTH): for col in xrange(self.WIDTH):
pixel = image.getpixel((col, line)) pixel = image.getpixel((col, line))
value = sum(pixel) / len(pixel) value = sum(pixel) / len(pixel)
freq_pixel = FREQ_BLACK + FREQ_RANGE * value / 256 freq_pixel = FREQ_BLACK + FREQ_RANGE * value / 256
yield freq_pixel, msec_pixel yield freq_pixel, msec_pixel
class Robot8BW(GrayscaleSSTV):
VIS_CODE = 0x02
WIDTH = 160
HEIGHT = 120
SYNC = 10
SCAN = 56
if __name__ == '__main__': if __name__ == '__main__':
from PIL import Image from PIL import Image
image = Image.open('160x120bw.png') image = Image.open('160x120bw.png')
s = SSTV(image, 48000, 16) s = Robot8BW(image, 48000, 16)
s.write_wav('test.wav') s.write_wav('test.wav')