# $Id: rtp.py 23 2006-11-08 15:45:33Z dugsong $
# -*- coding: utf-8 -*-
"""Real-Time Transport Protocol."""
from dpkt import Packet
from decorators import deprecated
# version 1100 0000 0000 0000 ! 0xC000 14
# p 0010 0000 0000 0000 ! 0x2000 13
# x 0001 0000 0000 0000 ! 0x1000 12
# cc 0000 1111 0000 0000 ! 0x0F00 8
# m 0000 0000 1000 0000 ! 0x0080 7
# pt 0000 0000 0111 1111 ! 0x007F 0
#
_VERSION_MASK = 0xC000
_P_MASK = 0x2000
_X_MASK = 0x1000
_CC_MASK = 0x0F00
_M_MASK = 0x0080
_PT_MASK = 0x007F
_VERSION_SHIFT = 14
_P_SHIFT = 13
_X_SHIFT = 12
_CC_SHIFT = 8
_M_SHIFT = 7
_PT_SHIFT = 0
VERSION = 2
[docs]class RTP(Packet):
"""Real-Time Transport Protocol.
TODO: Longer class information....
Attributes:
__hdr__: Header fields of RTP.
TODO.
"""
__hdr__ = (
('_type', 'H', 0x8000),
('seq', 'H', 0),
('ts', 'I', 0),
('ssrc', 'I', 0),
)
csrc = ''
@property
def version(self): return (self._type & _VERSION_MASK) >> _VERSION_SHIFT
@version.setter
def version(self, ver):
self._type = (ver << _VERSION_SHIFT) | (self._type & ~_VERSION_MASK)
@property
def p(self): return (self._type & _P_MASK) >> _P_SHIFT
@p.setter
def p(self, p): self._type = (p << _P_SHIFT) | (self._type & ~_P_MASK)
@property
def x(self): return (self._type & _X_MASK) >> _X_SHIFT
@x.setter
def x(self, x): self._type = (x << _X_SHIFT) | (self._type & ~_X_MASK)
@property
def cc(self): return (self._type & _CC_MASK) >> _CC_SHIFT
@cc.setter
def cc(self, cc): self._type = (cc << _CC_SHIFT) | (self._type & ~_CC_MASK)
@property
def m(self): return (self._type & _M_MASK) >> _M_SHIFT
@m.setter
def m(self, m): self._type = (m << _M_SHIFT) | (self._type & ~_M_MASK)
@property
def pt(self): return (self._type & _PT_MASK) >> _PT_SHIFT
@pt.setter
def pt(self, m): self._type = (m << _PT_SHIFT) | (self._type & ~_PT_MASK)
# Deprecated methods, will be removed in the future
# =================================================
@deprecated('version')
def _get_version(self): return self.version
@deprecated('version')
def _set_version(self, ver): self.version = ver
@deprecated('p')
def _get_p(self): return self.p
@deprecated('p')
def _set_p(self, p): self.p = p
@deprecated('x')
def _get_x(self): return self.x
@deprecated('x')
def _set_x(self, x): self.x = x
@deprecated('cc')
def _get_cc(self): return self.cc
@deprecated('cc')
def _set_cc(self, cc): self.cc = cc
@deprecated('m')
def _get_m(self): return self.m
@deprecated('m')
def _set_m(self, m): self.m = m
@deprecated('pt')
def _get_pt(self): return self.pt
@deprecated('pt')
def _set_pt(self, pt): self.pt = pt
# =================================================
def __len__(self):
return self.__hdr_len__ + len(self.csrc) + len(self.data)
def __str__(self):
return self.pack_hdr() + self.csrc + str(self.data)
[docs] def unpack(self, buf):
super(RTP, self).unpack(buf)
self.csrc = buf[self.__hdr_len__:self.__hdr_len__ + self.cc * 4]
self.data = buf[self.__hdr_len__ + self.cc * 4:]