Demo/sgi/video/VGrabber.py

   1 # Class to grab frames from a window.
   2 # (This has fewer user-settable parameters than Displayer.)
   3 # It is the caller's responsibility to initialize the window and to
   4 # ensure that it is current when using grabframe()
   5
   6 import gl, GL
   7 import VFile
   8 import GET
   9 from VFile import Error
  10
  11 class VGrabber(VFile.VideoParams):
  12
  13         # XXX The constructor of VideoParams is just fine, for now
  14
  15         # Grab a frame.
  16         # Return (data, chromdata) just like getnextframe().
  17
  18         def grabframe(self):
  19                 grabber = choose_grabber(self.format)
  20                 return grabber(self.width, self.height, self.packfactor)
  21
  22
  23 # Choose one of the grabber functions below based upon a color system name
  24
  25 def choose_grabber(format):
  26         try:
  27                 return eval('grab_' + format)
  28         except:
  29                 raise Error, 'Unknown color system: ' + `format`
  30
  31
  32 # Routines to grab data, per color system (only a few really supported).
  33 # (These functions are used via eval with a constructed argument!)
  34
  35 def grab_rgb(w, h, pf):
  36         if gl.getdisplaymode() <> GET.DMRGB:
  37                 raise Error, 'Sorry, can only grab rgb in single-buf rgbmode'
  38         if pf <> (1, 1):
  39                 raise Error, 'Sorry, only grab rgb with packfactor (1,1)'
  40         return gl.lrectread(0, 0, w-1, h-1), None
  41
  42 def grab_rgb8(w, h, pf):
  43         if gl.getdisplaymode() <> GET.DMRGB:
  44                 raise Error, 'Sorry, can only grab rgb8 in single-buf rgbmode'
  45         if pf <> (1, 1):
  46                 raise Error, 'Sorry, can only grab rgb8 with packfactor (1,1)'
  47         if not VFile.is_entry_indigo():
  48                 raise Error, 'Sorry, can only grab rgb8 on entry level Indigo'
  49         # XXX Dirty Dirty here.
  50         # XXX Set buffer to cmap mode, grab image and set it back.
  51         gl.cmode()
  52         gl.gconfig()
  53         gl.pixmode(GL.PM_SIZE, 8)
  54         data = gl.lrectread(0, 0, w-1, h-1)
  55         data = data[:w*h]       # BUG FIX for python lrectread
  56         gl.RGBmode()
  57         gl.gconfig()
  58         gl.pixmode(GL.PM_SIZE, 32)
  59         return data, None
  60
  61 def grab_grey(w, h, pf):
  62         raise Error, 'Sorry, grabbing grey not implemented'
  63
  64 def grab_yiq(w, h, pf):
  65         raise Error, 'Sorry, grabbing yiq not implemented'
  66
  67 def grab_hls(w, h, pf):
  68         raise Error, 'Sorry, grabbing hls not implemented'
  69
  70 def grab_hsv(w, h, pf):
  71         raise Error, 'Sorry, grabbing hsv not implemented'
  72
  73 def grab_jpeg(w, h, pf):
  74         data, dummy = grab_rgb(w, h, pf)
  75         import jpeg
  76         data = jpeg.compress(data, w, h, 4)
  77         return data, None
  78
  79 def grab_jpeggrey(w, h, pf):
  80         raise Error, 'sorry, grabbing jpeggrey not implemented'