DisplayVideoIn - Class similar to LiveVideoIn but sends data from

                 screen
Dsend - Main program analogous to Vsend to send data from display

1 files changed, 100 insertions, 0 deletions

diff --git a/Demo/sgi/video/DisplayVideoIn.py b/Demo/sgi/video/DisplayVideoIn.py
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+++ b/Demo/sgi/video/DisplayVideoIn.py
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+# Live video input from display class.
+
+import gl
+import GL
+
+# The live video input class.
+# Only instantiate this if have_video is true!
+
+class DisplayVideoIn:
+
+	# Initialize an instance.  Arguments:
+	# vw, vh: size of the video window data to be captured.
+	# position defaults to 0, 0 but can be set later
+	def init(self, pktmax, vw, vh, type):
+		self.pktmax = pktmax
+		self.realwidth, self.realheight = vw, vh
+		if type <> 'rgb':
+			raise 'Incorrent video data type', type
+		self.type = type
+		self.width = vw
+		self.height = vh
+		#
+		# Open dummy window
+		#
+		gl.foreground()
+		gl.noport()
+		self.wid = gl.winopen('DisplayVideoIn')
+		
+		self.x0 = 0
+		self.x1 = self.x0 + self.width - 1
+		self.y0 = 0
+		self.y1 = self.y0 + self.height - 1
+		# Compute # full lines per packet
+		self.lpp = pktmax / self.linewidth()
+		if self.lpp <= 0:
+			raise 'No lines in packet', self.linewidth()
+		self.pktsize = self.lpp*self.linewidth()
+		self.data = None
+		self.old_data = None
+		self.dataoffset = 0
+		self.lpos = 0
+		self.hints = 0
+		return self
+
+	# Change the size of the video being displayed.
+
+	def resizevideo(self, vw, vh):
+		self.width = vw
+		self.height = vh
+		self.x1 = self.x0 + self.width - 1
+		self.y1 = self.y0 + self.height - 1
+
+	def positionvideo(self, x, y):
+		self.x0 = x
+		self.y0 = y
+		self.x1 = self.x0 + self.width - 1
+		self.y1 = self.y0 + self.height - 1
+
+	# Remove an instance.
+	# This turns off continuous capture.
+
+	def close(self):
+		gl.winclose(self.wid)
+
+	# Get the length in bytes of a video line
+	def linewidth(self):
+		return self.width*4
+
+	# Get the next video packet.
+	# This returns (lpos, data) where:
+	# - lpos is the line position
+	# - data is a piece of data
+	# The dimensions of data are:
+	# - pixel depth = 1 byte
+	# - scan line width = self.width (the vw argument to init())
+	# - number of scan lines = self.lpp (PKTMAX / vw)
+
+	def getnextpacket(self):
+		if not self.data or self.dataoffset >= len(self.data):
+			self.old_data = self.data
+			self.data = gl.readdisplay(self.x0, self.y0, \
+				  self.x1, self.y1, self.hints)
+			self.dataoffset = 0
+			self.lpos = 0
+		data = self.data[self.dataoffset:self.dataoffset+self.pktsize]
+		while self.old_data and \
+			  self.dataoffset+self.pktsize < len(self.data):
+			odata = self.old_data[self.dataoffset: \
+				  self.dataoffset+self.pktsize]
+			if odata <> data:
+				break
+			print 'skip', self.lpos
+			self.lpos = self.lpos + self.lpp
+			self.dataoffset = self.dataoffset + self.pktsize
+			data = self.data[self.dataoffset:\
+				  self.dataoffset+self.pktsize]
+		lpos = self.lpos
+		self.dataoffset = self.dataoffset + self.pktsize
+		self.lpos = self.lpos + self.lpp
+		return lpos, data