from __future__ import division
from pylab import *
import os, sys, re

try: fn = sys.argv[1]
except:
    print "Syntax: python %s BRAMPnn.LOG" % sys.argv[0]
    raise SystemExit


f = open(fn)

Fs = []
Es = []
Esr = []

Fb = []
Eb = []

F = []
Y = []

e0 = None
ep = 0
while 1:
    l = f.readline()
    if not l: break
    m = re.match("([0-9a-f]+)", l)
    if not m: continue
    file_number = int(m.groups()[0])
    
    m = re.match(".* shutter= *([0-9.]+)s", l)
    if m:
        shutter = float(m.groups()[0])
    else:
        m = re.match(".* shutter= *([0-9]+)ms", l)
        if m:
            shutter = max(int(m.groups()[0]), 1./3)
        else:
            continue

    m = re.match(".* iso= *([0-9]+)", l)
    if not m: continue
    iso = int(m.groups()[0])

    m = re.match(".* y=([\- 0-9]+)", l)
    if not m: continue
    y = int(m.groups()[0].replace(" ", ""))
    
    e = log2(shutter * iso/100)
    if e0 is None: e0 = int(e)

    if shutter < 100 and iso <= 200:
        Fs.append(file_number)
        Es.append(e - e0)
        Esr.append(int((e - e0)*4 + 0.5) / 4)
    else:
        Fb.append(file_number)
        Eb.append(e - e0)
    
    F.append(file_number)
    Y.append(ep - e0 - y/100)
    ep = e

Y[0] = Y[1];

plot(Fs,Es,'r'), grid('on'), hold('on')
plot(Fb,Eb,'b'), grid('on')
plot(F, Y, 'y')
plot(Fs,Esr,'r')
print Y
xlabel('Image number')
ylabel('Exposure value (EV)')
legend(['Regular exposure (1/8 EV flicker)', 'Bulb exposure', 'Estimated scene exposure level'], loc=4)

show()