Initial revision

Demo/sgi/video/VFile.py

+# VFile -- two classes for Video Files.
+# VinFile -- for video input.
+# VoutFile -- for video output.
+
+import sys
+import gl
+import GL
+
+Error = 'VFile.Error' # Exception
+
+
+# Class VinFile represents a video file used for input.
+#
+# It has the following methods:
+# init(filename)
+# initfp(fp, filename)
+# rewind()
+# getframe()
+# skipframe()
+#
+# The following read-only data members provide public information:
+# version
+# filename
+# width, height
+# packfactor
+# ybits, ibits, qbits, chrompack
+#
+# These writable data members provide additional parametrization:
+# xorigin, yorigin
+
+class VinFile():
+
+	# init() and initfp() raise Error if the header is bad.
+	# init() raises whatever open() raises if the file can't be opened.
+
+	def init(self, filename):
+		if filename = '-':
+			return self.initfp(sys.stdin, filename)
+		return self.initfp(open(filename, 'r'), filename)
+
+	def initfp(self, (fp, filename)):
+		self.colormapinited = 0
+		self.magnify = 1.0
+		self.xorigin = self.yorigin = 0
+		self.fp = fp
+		self.filename = filename
+		#
+		line = self.fp.readline()
+		if line = 'CMIF video 1.0\n':
+			self.version = 1.0
+		elif line = 'CMIF video 2.0\n':
+			self.version = 2.0
+		else:
+			raise Error, self.filename + ': bad video format'
+		#
+		if self.version < 2.0:
+			self.ybits, self.ibits, self.qbits = 8, 0, 0
+			self.chrompack = 0
+		else:
+			line = self.fp.readline()
+			try:
+				self.ybits, self.ibits, self.qbits, \
+					self.chrompack = eval(line[:-1])
+			except:
+				raise Error, self.filename + ': bad color info'
+		#
+		line = self.fp.readline()
+		try:
+			x = eval(line[:-1])
+			if self.version > 1.0 or len(x) = 3:
+				self.width, self.height, self.packfactor = x
+			else:
+				sef.width, self.height = x
+				self.packfactor = 2
+		except:
+			raise Error, self.filename + ': bad (w,h,pf) info'
+		#
+		return self
+
+	# rewind() raises Error if the header is bad (which can only
+	# happen if the file was written to since opened).
+
+	def rewind(self):
+		self.fp.seek(0)
+		x = self.initfp(self.fp, self.filename)
+
+	# getnextframe() raises EOFError (built-in) if there is no next frame,
+	# or if the next frame is broken.
+	# So to getnextframeheader(), getnextframedata() and skipnextframe().
+
+	def getnextframe(self):
+		time, size, chromsize = self.getnextframeheader()
+		data, chromdata = self.getnextframedata(size, chromsize)
+		return time, data, chromdata
+
+	def getnextframedata(self, (size, chromsize)):
+		data = self.fp.read(size)
+		if len(data) <> size: raise EOFError
+		if chromsize:
+			chromdata = self.fp.read(chromsize)
+			if len(chromdata) <> chromsize: raise EOFError
+		else:
+			chromdata = None
+		#
+		return data, chromdata
+
+	def skipnextframe(self):
+		time, size, chromsize = self.getnextframeheader()
+		self.skipnextframedata(size, chromsize)
+		return time
+
+	def skipnextframedata(self, (size, chromsize)):
+		# Note that this won't raise EOFError for a partial frame.
+		try:
+			self.fp.seek(size + chromsize, 1) # Relative seek
+		except:
+			# Assume it's a pipe -- read the data to discard it
+			dummy = self.fp.read(size)
+			dummy = self.fp.read(chromsize)
+
+	def getnextframeheader(self):
+		line = self.fp.readline()
+		if not line:
+			raise EOFError
+		#
+		w, h, pf = self.width, self.height, self.packfactor
+		try:
+			x = eval(line[:-1])
+			if type(x) in (type(0), type(0.0)):
+				time = x
+				if pf = 0:
+					size = w * h * 4
+				else:
+					size = (w/pf) * (h/pf)
+			elif len(x) = 2:
+				time, size = x
+				cp = self.chrompack
+				if cp:
+					cw = (w + cp - 1) / cp
+					ch = (h + cp - 1) / cp
+					chromsize = 2 * cw * ch
+				else:
+					chromsize = 0
+			else:
+				time, size, chromsize = x
+		except:
+			raise Error, self.filename + ': bad frame header'
+		return time, size, chromsize
+
+	def shownextframe(self):
+		time, data, chromdata = self.getnextframe()
+		self.showframe(data, chromdata)
+		return time
+
+	def showframe(self, (data, chromdata)):
+		w, h, pf = self.width, self.height, self.packfactor
+		factor = self.magnify
+		if pf: factor = factor * pf
+		if chromdata:
+			cp = self.chrompack
+			cw = (w+cp-1)/cp
+			ch = (h+cp-1)/cp
+			gl.rectzoom(factor*cp, factor*cp)
+			gl.pixmode(GL.PM_SIZE, 16)
+			gl.writemask(0x7ff - ((1 << self.ybits) - 1))
+			gl.lrectwrite(self.xorigin, self.yorigin, \
+				self.xorigin + cw - 1, self.yorigin + ch - 1, \
+				chromdata)
+		#
+		if pf:
+			if not self.colormapinited:
+				self.initcolormap()
+			gl.writemask((1 << self.ybits) - 1)
+			gl.pixmode(GL.PM_SIZE, 8)
+			gl.rectzoom(factor, factor)
+			w = w/pf
+			h = h/pf
+		gl.lrectwrite(self.xorigin, self.yorigin, \
+			self.xorigin + w - 1, self.yorigin + h - 1, data)
+
+	def initcolormap(self):
+		initcmap(self.ybits, self.ibits, self.qbits, self.chrompack)
+		gl.color(0x800)
+		gl.clear()
+		self.colormapinited = 1
+
+
+def initcmap(ybits, ibits, qbits, chrompack):
+	if ybits+ibits+qbits > 11:
+		raise Error, 'Sorry, 11 bits max'
+	import colorsys
+	maxy = 1 << ybits
+	maxi = 1 << ibits
+	maxq = 1 << qbits
+	for i in range(2048, 4096-256):
+		gl.mapcolor(i, 0, 255, 0)
+	for y in range(maxy):
+		yv = y/float(maxy-1)
+		for i in range(maxi):
+			if maxi = 1:
+				iv = 0
+			else:
+				iv = (i/float(maxi-1))-0.5
+			for q in range(maxq):
+				if maxq = 1:
+					qv = 0
+				else:
+					qv = (q/float(maxq-1))-0.5
+				index = 2048 + y + \
+					(i << ybits) + (q << (ybits+ibits))
+				rv, gv, bv = colorsys.yiq_to_rgb(yv, iv, qv)
+				r, g, b = \
+				    int(rv*255.0), int(gv*255.0), int(bv*255.0)
+				if index < 4096 - 256:
+					gl.mapcolor(index, r, g, b)
+
+
+def test():
+	import sys
+	filename = 'film.video'
+	if sys.argv[1:]: filename = sys.argv[1]
+	vin = VinFile().init(filename)
+	gl.foreground()
+	gl.prefsize(vin.width, vin.height)
+	wid = gl.winopen('VFile.test: ' + filename)
+	try:
+		while 1:
+			t = vin.shownextframe()
+	except EOFError:
+		pass