Changed the init() interface of LiveVideoOut to read out the window

size automatically -- the video is always centered.  Added
resizevideo() and reshapewindow() interfaces.  Documented all methods.
Changed Vsend/Vreceive to use the new interface.  Allow window
resizing by the user in Vreceive.

Demo/sgi/video/LiveVideoOut.py

@@ -8,7 +8,11 @@ from VFile import Displayer
 
 class LiveVideoOut:
 
-	def init(self, wid, xywh, vw, vh):
+	# Call this to initialize things.  Arguments:
+	# wid:    the window id where the video is to be displayed (centered)
+	# vw, vh: size of the video image to be displayed
+
+	def init(self, wid, vw, vh):
 		##print 'Init', wid, xywh
 		##print 'video', vw, vw
 		self.vw = vw
@@ -20,38 +24,48 @@ class LiveVideoOut:
 		oldwid = gl.winget()
 		gl.winset(wid)
 		self.disp.initcolormap()
-		self.resize(xywh)
+		self.reshapewindow()
 		gl.winset(oldwid)
 		return self
 
-	def resize(self, (x, y, w, h)):
+	# Call this in response to every REDRAW event for the window
+	# or if the window size has changed for other reasons.
+
+	def reshapewindow(self):
 		oldwid = gl.winget()
 		gl.winset(self.wid)
-		##print 'Resize', x, y, w, h
-		gl.winposition(x, x+w-1, y, y+h-1)
 		gl.reshapeviewport()
-		if w < self.vw or h < self.vh:
-			self.toosmall = 1
-		else:
-			self.disp.xorigin = (w-self.vw)/2
-			self.disp.yorigin = (h-self.vh)/2
-			self.toosmall = 0
-			##print 'VIDEO OFFSET:', \
-			##	self.disp.xorigin, self.disp.yorigin
+		w, h = gl.getsize()
+		self.disp.xorigin = (w-self.vw)/2
+		self.disp.yorigin = (h-self.vh)/2
 		self.disp.clear()
 		gl.winset(oldwid)
 
+	# Call this to change the size of the video images being displayed.
+	# Implies reshapewindow().
+
+	def resizevideo(self, vw, vh):
+		self.vw, self.vh = vw, vh
+		self.disp.setsize(vw, vh)
+		self.reshapewindow()
+
+	# Call this to display the next video packet.  Arguments:
+	# pos:  line number where the packet begins
+	# data: image data of the packet
+	# (these correspond directly to the return values from
+	# LiveVideoIn.getnextpacket()).
+
 	def putnextpacket(self, pos, data):
-		if self.toosmall:
+		nline = len(data)/self.vw
+		if nline*self.vw <> len(data):
+			print 'Incorrect-sized video fragment ignored'
 			return
 		oldwid = gl.winget()
 		gl.winset(self.wid)
-		nline = len(data)/self.vw
-		if nline*self.vw <> len(data):
-			print 'Incorrect-sized video fragment'
 		self.disp.showpartframe(data, None, (0, pos, self.vw, nline))
 		gl.winset(oldwid)
 
+	# Call this to close the window.
+
 	def close(self):
-		##print 'Done video out'
 		pass

Demo/sgi/video/Vreceive.py

@@ -19,6 +19,8 @@ import getopt
 from senddefs import *
 
 
+# Print usage message and exit(2).
+
 def usage(msg):
 	print msg
 	print 'usage: Vreceive [-m mcastgrp] [-p port]'
@@ -27,6 +29,8 @@ def usage(msg):
 	sys.exit(2)
 
 
+# Main program: parse options and main loop.
+
 def main():
 
 	sys.stdout = sys.stderr
@@ -55,13 +59,12 @@ def main():
 	gl.foreground()
 	gl.prefsize(width, height)
 	wid = gl.winopen('Vreceive')
+	gl.winconstraints()
 	gl.qdevice(DEVICE.ESCKEY)
 	gl.qdevice(DEVICE.WINSHUT)
 	gl.qdevice(DEVICE.WINQUIT)
 
-	x, y = gl.getorigin()
-	lvo = LiveVideoOut.LiveVideoOut().init(wid, (x, y, width, height), \
-		width, height)
+	lvo = LiveVideoOut.LiveVideoOut().init(wid, width, height)
 
 	ifdlist = [gl.qgetfd(), s.fileno()]
 	ofdlist = []
@@ -77,18 +80,16 @@ def main():
 				DEVICE.WINSHUT, DEVICE.WINQUIT):
 				break
 			if dev == DEVICE.REDRAW:
-				gl.clear()
+				lvo.reshapewindow()
 		elif s.avail():
 			data = s.recv(16*1024)
 			pos, w, h = struct.unpack('hhh', data[:6])
 			if (w, h) <> (width, height):
-				x, y = gl.getorigin()
+				x, y =  gl.getorigin()
 				y = y + height - h
+				gl.winposition(x, x+w-1, y, y+h-1)
 				width, height = w, h
-				lvo.close()
-				lvo = LiveVideoOut.LiveVideoOut() \
-				      .init(wid, (x, y, width, height), \
-				            width, height)
+				lvo.resizevideo(width, height)
 			lvo.putnextpacket(pos, data[6:])
 		else:
 			x = select.select(selectargs)
@@ -103,16 +104,16 @@ def opensocket(group, port):
 	# Create the socket
 	s = socket(AF_INET, SOCK_DGRAM)
 
-	# Bind the port to it
-	s.bind('', port)
-
 	# Allow multiple copies of this program on one machine
 	s.setsockopt(SOL_SOCKET, SO_REUSEPORT, 1) # (Not strictly needed)
 
+	# Bind the port to it
+	s.bind('', port)
+
 	# Look up the group once
 	group = gethostbyname(group)
 
-	# Ugly: construct binary group address
+	# Construct binary group address
 	group_bytes = eval(regsub.gsub('\.', ',', group))
 	grpaddr = 0
 	for byte in group_bytes: grpaddr = (grpaddr << 8) | byte
@@ -126,4 +127,5 @@ def opensocket(group, port):
 
 	return s
 
+
 main()

Demo/sgi/video/Vsend.py

@@ -92,9 +92,7 @@ def main():
 	gl.qdevice(DEVICE.WINTHAW)
 	width, height = gl.getsize()
 
-	x, y = gl.getorigin()
-	lvo = LiveVideoOut.LiveVideoOut().init(wid, (x, y, width, height), \
-		width, height)
+	lvo = LiveVideoOut.LiveVideoOut().init(wid, width, height)
 
 	lvi = LiveVideoIn.LiveVideoIn().init(pktmax, width, height)
 
@@ -124,11 +122,7 @@ def main():
 					width, height = w, h
 					lvi = LiveVideoIn.LiveVideoIn() \
 						.init(pktmax, width, height)
-					lvo.close()
-					lvo = LiveVideoOut.LiveVideoOut() \
-						.init(wid, \
-						      (x, y, width, height), \
-						      width, height)
+					lvo.resizevideo(width, height)
 
 		rv = lvi.getnextpacket()
 		if not rv: