Python script to solve traces from 32c3

parse_traces.py

#!/usr/bin/env python

valid = False
fw = None
x = 0
y = 0
# Guess that width is 752 pixels, try some different widths
width = 752
xline = []

def output_val(val):
    global valid
    global x
    global y
    global xline
    """
    First 2 bits are Line valid and Frame valid.
    When both are 1, start writing new image.
    End when both are not 1.
    """
    if (valid == False) and (val[:2] == '11'):
        # line start
        xline = []
        valid = True

    if (valid == True) and (val[:2] == '11'):
        # Write one pixel
        # Convert 10-bit pixeldata to 8-bit
        # by dividing by 4
        if x < width:
            pixel = int(val[2:], 2) // 4
            xline.append(chr(pixel))
            x += 1

    if (valid == True) and (val[:2] != '11'):
        # line end
        while x < width:
            # Append 0:s if line < 752 pixels
            xline.append(chr(0))
            x += 1
        for c in xline:
            fw.write(c)
        x = 0
        valid = False
        y += 1

fd = open('clean.csv', 'r')
fw = open('output.data', 'wb')

old = 10
new = 0
for line in fd:
    l = line.split()
    # Ignore bad lines
    if len(l) < 2:
        continue
    new = float(l[0])
    if new >= 1.5 and old < 1.5:
        # positive flank
        output_val(l[1])
    old = new
    # break after 1024 lines
    if y >= 1024:
        break

fd.close()
fw.close()