#!/bin/env python
#
# convert_yuv.py
#
# Converts a bunch of separate image files into animation sequences that can be used with
# Nokia Series 60 emulator
#
# Dec 7, 2004
# kari.pulli@nokia.com

import sys, os, time
from glob import glob
from array import *
import Image
from optparse import OptionParser

sizes = {
    'sqcif': (128,96),
    'qcif' : (176,144),
    'cif'  : (352,288),
    'qqvga': (160,120),
    'qvga' : (320,240),
    'vga'  : (640,480),
    }

def create_yuv( resolution, files, targetdir ):
    w,h = sizes[ resolution ]
    a = array('B') # array of unsigned bytes
    for f in files:
        print 'Processing', f, 'at size', w, h
        im = Image.open(f)
        im.load()
        # convert to correct size, and from rgb to yuv
        # use the ITU-R BT.601 conversion matrix but with full range RGB
        # this is the same as in JPEG (Jfif specs V1.02) encoding (CCIR 601-256 levels)
        rgb2yuv = [  0.299,     0.587,     0.114,      0,
                    -0.168736, -0.331264,  0.5,      128,
                     0.5,      -0.418688, -0.081312, 128 ]
        data = im.resize( (w,h), Image.BICUBIC ).convert( 'RGB', rgb2yuv ).getdata()
        # save in YUV 422, Nokia's ordering
        for i in range(0, w*h, 2):
            Y1,U1,V1 = data[i]
            Y2,U2,V2 = data[i+1]
            a.append( Y2 )
            a.append( int((V1+V2)*.5) )
            a.append( Y1 )
            a.append( int((U1+U2)*.5) )
    name = os.path.join(targetdir, 'handshake_%s.yuv' % resolution)
    print 'Saving file', name
    a.tofile( file( name, 'wb' ) )


if __name__ == '__main__':

    usage = """usage: %prog [options] filebase

    Converts a bunch of separate image files into animation sequences
    that can be used with Nokia Series 60 emulator (at least 7610)
    If you copy these files into EPOCROOT/epoc32/wins/c, the emulator
    will use these files when emulating video camera (instead of using
    the default underwater sequence).
    
    filebase is the path and base file name, e.g., c:/tmp/blah
    if your files are in c:/tmp/ and the names are blah0001.jpg, etc."""
    
    parser = OptionParser( usage = usage )
    parser.add_option( '-t', '--targetdir', dest = 'targetdir', default = '.',
                       help = 'target directory where to store the files (overwrites old ones)' )
    (options, args) = parser.parse_args()

    if not args:
        parser.print_help()
        sys.exit()

    # read in the images
    files = glob( args[0] + '*' )
    files.sort()
    start = time.clock()
    for resolution in sizes.keys():
        create_yuv( resolution, files, options.targetdir )
    print 'Took', time.clock() - start, 'seconds'