vfile.py

reduced python source for embedded apps

		# Permanently make the first color index current
		gl.color(self.color0[0])

	# Install the colormap in the window (may be overridden for Glx window)

	def install_colormap(self, map):
		if not self.quiet:
			sys.stderr.write(' Installing ' + `len(map)` + \
				  ' entries...')
		for irgb in map:
			gl.mapcolor(irgb)
		gl.gflush() # send the colormap changes to the X server


# Read a CMIF video file header.
# Return (version, values) where version is 0.0, 1.0, 2.0 or 3.[01],
# and values is ready for setinfo().
# Raise Error if there is an error in the info

def readfileheader(fp, filename):
	#
	# Get identifying header
	#
	line = fp.readline(20)
	if   line == 'CMIF video 0.0\n':
		version = 0.0
	elif line == 'CMIF video 1.0\n':
		version = 1.0
	elif line == 'CMIF video 2.0\n':
		version = 2.0
	elif line == 'CMIF video 3.0\n':
		version = 3.0
	elif line == 'CMIF video 3.1\n':
		version = 3.1
	else:
		# XXX Could be version 0.0 without identifying header
		raise Error, \
			filename + ': Unrecognized file header: ' + `line`[:20]
	compressheader = None
	#
	# Get color encoding info
	# (The format may change to 'rgb' later when packfactor == 0)
	#
	if version <= 1.0:
		format = 'grey'
		c0bits, c1bits, c2bits = 8, 0, 0
		chrompack = 0
		offset = 0
	elif version == 2.0:
		line = fp.readline()
		try:
			c0bits, c1bits, c2bits, chrompack = eval(line[:-1])
		except:
			raise Error, filename + ': Bad 2.0 color info'
		if c1bits or c2bits:
			format = 'yiq'
		else:
			format = 'grey'
		offset = 0
	elif version in (3.0, 3.1):
		line = fp.readline()
		try:
			format, rest = eval(line[:-1])
		except:
			raise Error, filename + ': Bad 3.[01] color info'
		if format in ('rgb', 'jpeg'):
			c0bits = c1bits = c2bits = 0
			chrompack = 0
			offset = 0
		elif format == 'compress':
			c0bits = c1bits = c2bits = 0
			chrompack = 0
			offset = 0
			compressheader = rest
		elif format in ('grey', 'jpeggrey', 'mono', 'grey2', 'grey4'):
			c0bits = rest
			c1bits = c2bits = 0
			chrompack = 0
			offset = 0
		else:
			# XXX ought to check that the format is valid
			try:
			    c0bits, c1bits, c2bits, chrompack, offset = rest
			except:
			    raise Error, filename + ': Bad 3.[01] color info'
	if format == 'xrgb8':
		format = 'rgb8' # rgb8 upside-down, for X
		upside_down = 1
	else:
		upside_down = 0
	#
	# Get frame geometry info
	#
	line = fp.readline()
	try:
		x = eval(line[:-1])
	except:
		raise Error, filename + ': Bad (w,h,pf) info'
	if type(x) <> type(()):
		raise Error, filename + ': Bad (w,h,pf) info'
	if len(x) == 3:
		width, height, packfactor = x
		if packfactor == 0 and version < 3.0:
			format = 'rgb'
			c0bits = 0
	elif len(x) == 2 and version <= 1.0:
		width, height = x
		packfactor = 2
	else:
		raise Error, filename + ': Bad (w,h,pf) info'
	if type(packfactor) is type(0):
		if packfactor == 0: packfactor = 1
		xpf = ypf = packfactor
	else:
		xpf, ypf = packfactor
	if upside_down:
		ypf = -ypf
	packfactor = (xpf, ypf)
	xpf = abs(xpf)
	ypf = abs(ypf)
	width = (width/xpf) * xpf
	height = (height/ypf) * ypf
	#
	# Return (version, values)
	#
	values = (format, width, height, packfactor, \
		  c0bits, c1bits, c2bits, offset, chrompack, compressheader)
	return (version, values)


# Read a *frame* header -- separate functions per version.
# Return (timecode, datasize, chromdatasize).
# Raise EOFError if end of data is reached.
# Raise Error if data is bad.

def readv0frameheader(fp):
	line = fp.readline()
	if not line or line == '\n': raise EOFError
	try:
		t = eval(line[:-1])
	except:
		raise Error, 'Bad 0.0 frame header'
	return (t, 0, 0)

def readv1frameheader(fp):
	line = fp.readline()
	if not line or line == '\n': raise EOFError
	try:
		t, datasize = eval(line[:-1])
	except:
		raise Error, 'Bad 1.0 frame header'
	return (t, datasize, 0)

def readv2frameheader(fp):
	line = fp.readline()
	if not line or line == '\n': raise EOFError
	try:
		t, datasize = eval(line[:-1])
	except:
		raise Error, 'Bad 2.0 frame header'
	return (t, datasize, 0)

def readv3frameheader(fp):
	line = fp.readline()
	if not line or line == '\n': raise EOFError
	try:
		t, datasize, chromdatasize = x = eval(line[:-1])
	except:
		raise Error, 'Bad 3.[01] frame header'
	return x


# Write a CMIF video file header (always version 3.1)

def writefileheader(fp, values):
	(format, width, height, packfactor, \
		c0bits, c1bits, c2bits, offset, chrompack) = values
	#
	# Write identifying header
	#
	fp.write('CMIF video 3.1\n')
	#
	# Write color encoding info
	#
	if format in ('rgb', 'jpeg'):
		data = (format, 0)
	elif format in ('grey', 'jpeggrey', 'mono', 'grey2', 'grey4'):
		data = (format, c0bits)
	else:
		data = (format, (c0bits, c1bits, c2bits, chrompack, offset))
	fp.write(`data`+'\n')
	#
	# Write frame geometry info
	#
	data = (width, height, packfactor)
	fp.write(`data`+'\n')
	
def writecompressfileheader(fp, cheader, values):
	(format, width, height, packfactor, \
		c0bits, c1bits, c2bits, offset, chrompack) = values
	#
	# Write identifying header
	#
	fp.write('CMIF video 3.1\n')
	#
	# Write color encoding info
	#
	data = (format, cheader)
	fp.write(`data`+'\n')
	#
	# Write frame geometry info
	#
	data = (width, height, packfactor)
	fp.write(`data`+'\n')


# Basic class for reading CMIF video files

class BasicVinFile(VideoParams):

	def __init__(self, filename):
		if type(filename) != type(''):
			fp = filename
			filename = '???'
		elif filename == '-':
			fp = sys.stdin
		else:
			fp = open(filename, 'r')
		self.initfp(fp, filename)

	def initfp(self, fp, filename):
		VideoParams.__init__(self)
		self.fp = fp
		self.filename = filename
		self.version, values = readfileheader(fp, filename)
		self.setinfo(values)
		self.freeze()
		if self.version == 0.0:
			w, h, pf = self.width, self.height, self.packfactor
			if pf == 0:
				self._datasize = w*h*4
			else:
				self._datasize = (w/pf) * (h/pf)
			self._readframeheader = self._readv0frameheader
		elif self.version == 1.0:
			self._readframeheader = readv1frameheader
		elif self.version == 2.0:
			self._readframeheader = readv2frameheader
		elif self.version in (3.0, 3.1):
			self._readframeheader = readv3frameheader
		else:
			raise Error, \
				filename + ': Bad version: ' + `self.version`
		self.framecount = 0
		self.atframeheader = 1
		self.eofseen = 0
		self.errorseen = 0
		try:
			self.startpos = self.fp.tell()
			self.canseek = 1
		except IOError:
			self.startpos = -1
			self.canseek = 0

	def _readv0frameheader(self, fp):
		t, ds, cs = readv0frameheader(fp)
		ds = self._datasize
		return (t, ds, cs)

	def close(self):
		self.fp.close()
		del self.fp
		del self._readframeheader

	def rewind(self):
		if not self.canseek:
			raise Error, self.filename + ': can\'t seek'
		self.fp.seek(self.startpos)
		self.framecount = 0
		self.atframeheader = 1
		self.eofseen = 0
		self.errorseen = 0

	def warmcache(self):
		print '[BasicVinFile.warmcache() not implemented]'

	def printinfo(self):
		print 'File:    ', self.filename
		print 'Size:    ', getfilesize(self.filename)
		print 'Version: ', self.version
		VideoParams.printinfo(self)

	def getnextframe(self):
		t, ds, cs = self.getnextframeheader()
		data, cdata = self.getnextframedata(ds, cs)
		return (t, data, cdata)

	def skipnextframe(self):
		t, ds, cs = self.getnextframeheader()
		self.skipnextframedata(ds, cs)
		return t

	def getnextframeheader(self):
		if self.eofseen: raise EOFError
		if self.errorseen: raise CallError
		if not self.atframeheader: raise CallError
		self.atframeheader = 0
		try:
			return self._readframeheader(self.fp)
		except Error, msg:
			self.errorseen = 1
			# Patch up the error message
			raise Error, self.filename + ': ' + msg
		except EOFError:
			self.eofseen = 1
			raise EOFError

	def getnextframedata(self, ds, cs):
		if self.eofseen: raise EOFError
		if self.errorseen: raise CallError
		if self.atframeheader: raise CallError
		if ds:
			data = self.fp.read(ds)
			if len(data) < ds:
				self.eofseen = 1
				raise EOFError
		else:
			data = ''
		if cs:
			cdata = self.fp.read(cs)
			if len(cdata) < cs:
				self.eofseen = 1
				raise EOFError
		else:
			cdata = ''
		self.atframeheader = 1
		self.framecount = self.framecount + 1
		return (data, cdata)

	def skipnextframedata(self, ds, cs):
		if self.eofseen: raise EOFError
		if self.errorseen: raise CallError
		if self.atframeheader: raise CallError
		# Note that this won't raise EOFError for a partial frame
		# since there is no easy way to tell whether a seek
		# ended up beyond the end of the file
		if self.canseek:
			self.fp.seek(ds + cs, 1) # Relative seek
		else:
			dummy = self.fp.read(ds + cs)
			del dummy
		self.atframeheader = 1
		self.framecount = self.framecount + 1


# Subroutine to return a file's size in bytes

def getfilesize(filename):
	import os, stat
	try:
		st = os.stat(filename)
		return st[stat.ST_SIZE]
	except os.error:
		return 0


# Derived class implementing random access and index cached in the file

class RandomVinFile(BasicVinFile):

	def initfp(self, fp, filename):
		BasicVinFile.initfp(self, fp, filename)
		self.index = []

	def warmcache(self):
		if len(self.index) == 0:
			try:
				self.readcache()
			except Error:
				self.buildcache()
		else:
			print '[RandomVinFile.warmcache(): too late]'
			self.rewind()

	def buildcache(self):
		self.index = []
		self.rewind()
		while 1:
			try: dummy = self.skipnextframe()
			except EOFError: break
		self.rewind()

	def writecache(self):
		# Raises IOerror if the file is not seekable & writable!
		import marshal
		if len(self.index) == 0:
			self.buildcache()
			if len(self.index) == 0:
				raise Error, self.filename + ': No frames'
		self.fp.seek(0, 2)
		self.fp.write('\n/////CMIF/////\n')
		pos = self.fp.tell()
		data = `pos`
		data = '\n-*-*-CMIF-*-*-\n' + data + ' '*(15-len(data)) + '\n'
		try:
			marshal.dump(self.index, self.fp)
			self.fp.write(data)
			self.fp.flush()
		finally:
			self.rewind()

	def readcache(self):
		# Raises Error if there is no cache in the file
		import marshal
		if len(self.index) <> 0:
			raise CallError
		self.fp.seek(-32, 2)
		data = self.fp.read()
		if data[:16] <> '\n-*-*-CMIF-*-*-\n' or data[-1:] <> '\n':
			self.rewind()
			raise Error, self.filename + ': No cache'
		pos = eval(data[16:-1])
		self.fp.seek(pos)
		try:
			self.index = marshal.load(self.fp)
		except TypeError:
			self.rewind()
			raise Error, self.filename + ': Bad cache'
		self.rewind()

	def getnextframeheader(self):
		if self.framecount < len(self.index):
			return self._getindexframeheader(self.framecount)
		if self.framecount > len(self.index):
			raise AssertError, \
				'managed to bypass index?!?'
		rv = BasicVinFile.getnextframeheader(self)
		if self.canseek:
			pos = self.fp.tell()
			self.index.append((rv, pos))
		return rv

	def getrandomframe(self, i):
		t, ds, cs = self.getrandomframeheader(i)
		data, cdata = self.getnextframedata(ds, cs)
		return t, data, cdata

	def getrandomframeheader(self, i):
		if i < 0: raise ValueError, 'negative frame index'
		if not self.canseek:
			raise Error, self.filename + ': can\'t seek'
		if i < len(self.index):
			return self._getindexframeheader(i)
		if len(self.index) > 0:
			rv = self.getrandomframeheader(len(self.index)-1)
		else:
			self.rewind()
			rv = self.getnextframeheader()
		while i > self.framecount:
			self.skipnextframedata()
			rv = self.getnextframeheader()
		return rv

	def _getindexframeheader(self, i):
		(rv, pos) = self.index[i]
		self.fp.seek(pos)
		self.framecount = i
		self.atframeheader = 0
		self.eofseen = 0
		self.errorseen = 0
		return rv


# Basic class for writing CMIF video files

class BasicVoutFile(VideoParams):

	def __init__(self, filename):
		if type(filename) != type(''):
			fp = filename
			filename = '???'
		elif filename == '-':
			fp = sys.stdout
		else:
			fp = open(filename, 'w')
		self.initfp(fp, filename)

	def initfp(self, fp, filename):
		VideoParams.__init__(self)
		self.fp = fp
		self.filename = filename
		self.version = 3.1 # In case anyone inquries

	def flush(self):
		self.fp.flush()

	def close(self):
		self.fp.close()
		del self.fp

	def prealloc(self, nframes):
		if not self.frozen: raise CallError
		data = '\xff' * (self.calcframesize() + 64)
		pos = self.fp.tell()
		for i in range(nframes):
			self.fp.write(data)
		self.fp.seek(pos)

	def writeheader(self):
		if self.frozen: raise CallError
		if self.format == 'compress':
			writecompressfileheader(self.fp, self.compressheader, \
				  self.getinfo())
		else:
			writefileheader(self.fp, self.getinfo())
		self.freeze()
		self.atheader = 1
		self.framecount = 0

	def rewind(self):
		self.fp.seek(0)
		self.unfreeze()
		self.atheader = 1
		self.framecount = 0

	def printinfo(self):
		print 'File:    ', self.filename
		VideoParams.printinfo(self)

	def writeframe(self, t, data, cdata):
		if data: ds = len(data)
		else: ds = 0
		if cdata: cs = len(cdata)
		else: cs = 0
		self.writeframeheader(t, ds, cs)
		self.writeframedata(data, cdata)

	def writeframeheader(self, t, ds, cs):
		if not self.frozen: self.writeheader()
		if not self.atheader: raise CallError
		data = `(t, ds, cs)`
		n = len(data)
		if n < 63: data = data + ' '*(63-n)
		self.fp.write(data + '\n')
		self.atheader = 0

	def writeframedata(self, data, cdata):
		if not self.frozen or self.atheader: raise CallError
		if data: self.fp.write(data)
		if cdata: self.fp.write(cdata)
		self.atheader = 1
		self.framecount = self.framecount + 1


# Classes that combine files with displayers:

class VinFile(RandomVinFile, Displayer):

	def initfp(self, fp, filename):
		Displayer.__init__(self)
		RandomVinFile.initfp(self, fp, filename)

	def shownextframe(self):
		t, data, cdata = self.getnextframe()
		self.showframe(data, cdata)
		return t


class VoutFile(BasicVoutFile, Displayer):

	def initfp(self, fp, filename):
		Displayer.__init__(self)
##		Grabber.__init__(self) # XXX not needed
		BasicVoutFile.initfp(self, fp, filename)


# Simple test program (VinFile only)

def test():
	import time
	if sys.argv[1:]: filename = sys.argv[1]
	else: filename = 'film.video'
	vin = VinFile(filename)
	vin.printinfo()
	gl.foreground()
	gl.prefsize(vin.getsize())
	wid = gl.winopen(filename)
	vin.initcolormap()
	t0 = time.time()
	while 1:
		try: t, data, cdata = vin.getnextframe()
		except EOFError: break
		dt = t0 + t - time.time()
		if dt > 0: time.time(dt)
		vin.showframe(data, cdata)
	time.sleep(2)