dnet/pySSTV
1
0
Fork 0
mirror of https://github.com/dnet/pySSTV.git synced 2026-01-11 11:10:09 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity

moved multichannel logic to write_wav

Browse source
This commit is contained in:
András Veres-Szentkirályi 2013-07-01 23:14:28 +02:00
parent 30ec459a22
commit f0a2076a68
1 changed files with 6 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
pysstv/sstv.py
View file

@ -4,7 +4,7 @@ from __future__ import division, with_statement
from math import sin, pi, floor
from random import random
from contextlib import closing
from itertools import imap, izip, cycle
from itertools import imap, izip, cycle, chain
from array import array
import wave
@ -40,6 +40,9 @@ class SSTV(object):
"""writes the whole image to a Microsoft WAV file"""
fmt = self.BITS_TO_STRUCT[self.bits]
data = array(fmt, self.gen_samples())
if self.nchannels != 1:
data = array(fmt, chain.from_iterable(
izip(*([data] * self.nchannels))))
with closing(wave.open(filename, 'wb')) as wav:
wav.setnchannels(self.nchannels)
wav.setsampwidth(self.bits // 8)
@ -57,13 +60,11 @@ class SSTV(object):
amp = max_value // 2
lowest = -amp
highest = amp - 1
chans = range(self.nchannels)
alias_cycle = cycle((alias * (random() - 0.5) for _ in xrange(1024)))
for value, alias_item in izip(self.gen_values(), alias_cycle):
sample = int(round(value * amp + alias_item))
for chan in chans:
yield (lowest if sample <= lowest else
sample if sample <= highest else highest)
yield (lowest if sample <= lowest else
sample if sample <= highest else highest)
def gen_values(self):
"""generates samples between -1 and +1 from gen_freq_bits()