code.delx.au - refind/blob - images/mkegemb.py

   1 #!/usr/bin/env python
   2
   3 import sys, os.path
   4 import Image
   5
   6 def enc_backbuffer(backbuffer):
   7     """Helper function for RLE compression, encodes a string of uncompressable data."""
   8     compdata = []
   9     if len(backbuffer) == 0:
  10         return compdata
  11     while len(backbuffer) > 128:
  12         compdata.append(127)
  13         compdata.extend(backbuffer[0:128])
  14         backbuffer = backbuffer[128:]
  15     compdata.append(len(backbuffer)-1)
  16     compdata.extend(backbuffer)
  17     return compdata
  18
  19 def compress_rle(rawdata):
  20     """Compresses the string using a RLE scheme."""
  21     compdata = []
  22     backbuffer = []
  23
  24     while len(rawdata) >= 3:
  25         c = rawdata[0]
  26         if rawdata[1] == c and rawdata[2] == c:
  27             runlength = 3
  28             while runlength < 130 and len(rawdata) > runlength:
  29                 if rawdata[runlength] == c:
  30                     runlength = runlength + 1
  31                 else:
  32                     break
  33             compdata.extend(enc_backbuffer(backbuffer))
  34             backbuffer = []
  35             compdata.append(runlength + 125)
  36             compdata.append(c)
  37             rawdata = rawdata[runlength:]
  38
  39         else:
  40             backbuffer.append(c)
  41             rawdata = rawdata[1:]
  42
  43     backbuffer.extend(rawdata)
  44     compdata.extend(enc_backbuffer(backbuffer))
  45
  46     return compdata
  47
  48 def encode_plane(rawdata, planename):
  49     """Encodes the data of a single plane."""
  50
  51     rawlen = len(rawdata)
  52     compdata = compress_rle(rawdata)
  53     complen = len(compdata)
  54     print "  plane %s: compressed %d to %d (%.1f%%)" % (planename, rawlen, complen, float(complen) / float(rawlen) * 100.0)
  55
  56     return compdata
  57
  58
  59 ### main loop
  60
  61 print "mkegemb 0.1, Copyright (c) 2006 Christoph Pfisterer"
  62
  63 planenames = ( "blue", "green", "red", "alpha", "grey" )
  64
  65 for filename in sys.argv[1:]:
  66
  67     origimage = Image.open(filename)
  68
  69     (width, height) = origimage.size
  70     mode = origimage.mode
  71     data = origimage.getdata()
  72
  73     print "%s: %d x %d %s" % (filename, width, height, mode)
  74
  75     (basename, extension) = os.path.splitext(filename)
  76     identname = basename.replace("-", "_")
  77
  78     # extract image data from PIL object
  79
  80     planes = [ [], [], [], [] ]
  81
  82     if mode == "RGB":
  83         for pixcount in range(0, width*height):
  84             pixeldata = data[pixcount]
  85             planes[0].append(pixeldata[0])
  86             planes[1].append(pixeldata[1])
  87             planes[2].append(pixeldata[2])
  88
  89     elif mode == "RGBA":
  90         for pixcount in range(0, width*height):
  91             pixeldata = data[pixcount]
  92             planes[0].append(pixeldata[0])
  93             planes[1].append(pixeldata[1])
  94             planes[2].append(pixeldata[2])
  95             planes[3].append(pixeldata[3])
  96
  97     elif mode == "L":
  98         for pixcount in range(0, width*height):
  99             pixeldata = data[pixcount]
 100             planes[0].append(pixeldata)
 101             planes[1].append(pixeldata)
 102             planes[2].append(pixeldata)
 103
 104     else:
 105         print " Error: Mode not supported!"
 106         continue
 107
 108     # special treatment for fonts
 109
 110     if basename[0:4] == "font":
 111         if planes[0] != planes[1] or planes[0] != planes[2]:
 112             print " Error: Font detected, but it is not greyscale!"
 113             continue
 114         print " font detected, encoding as alpha-only"
 115         # invert greyscale values for use as alpha
 116         planes[3] = map(lambda x: 255-x, planes[0])
 117         planes[0] = []
 118         planes[1] = []
 119         planes[2] = []
 120
 121     # encode planes
 122
 123     imagedata = []
 124     pixelformat = "EG_EIPIXELMODE"
 125
 126     if len(planes[0]) > 0 and planes[0] == planes[1] and planes[0] == planes[2]:
 127         print " encoding as greyscale"
 128         imagedata.extend(encode_plane(planes[0], planenames[4]))
 129         pixelformat = pixelformat + "_GRAY"
 130
 131     elif len(planes[0]) > 0:
 132         print " encoding as true color"
 133         imagedata.extend(encode_plane(planes[0], planenames[0]))
 134         imagedata.extend(encode_plane(planes[1], planenames[1]))
 135         imagedata.extend(encode_plane(planes[2], planenames[2]))
 136         pixelformat = pixelformat + "_COLOR"
 137
 138     if len(planes[3]) > 0:
 139         if reduce(lambda x,y: x+y, planes[3]) == 0:
 140             print " skipping alpha plane because it is empty"
 141         else:
 142             imagedata.extend(encode_plane(planes[3], planenames[3]))
 143             pixelformat = pixelformat + "_ALPHA"
 144
 145     # generate compilable header file
 146
 147     output = "static const UINT8 egemb_%s_data[%d] = {\n" % (identname, len(imagedata))
 148     for i in range(0, len(imagedata)):
 149         output = output + " 0x%02x," % imagedata[i]
 150         if (i % 12) == 11:
 151             output = output + "\n"
 152     output = output + "\n};\n"
 153     output = output + "static EG_EMBEDDED_IMAGE egemb_%s = { %d, %d, %s, EG_EICOMPMODE_RLE, egemb_%s_data, %d };\n" % (identname, width, height, pixelformat, identname, len(imagedata))
 154
 155     f = file("egemb_%s.h" % identname, "w")
 156     f.write(output)
 157     f.close()
 158
 159 print "Done!"