RTPPacket Class Reference
[RTP data packets manipulation.]

A base class for both IncomingRTPPkt and OutgoingRTPPkt. More...

#include <rtppkt.h>

Inheritance diagram for RTPPacket:

IncomingRTPPkt OutgoingRTPPkt

List of all members.

Public Member Functions

 RTPPacket (const unsigned char *const block, size_t len, bool duplicate=false)
 Constructor, construct a packet object given the memory zone its content (header and payload) is stored.
 RTPPacket (size_t hdrlen, size_t plen, uint8 paddinglen, CryptoContext *pcc=NULL)
 Construct a packet object without specifying its real content yet.
uint32 getHeaderSize () const
 Get the length of the header, including contributing sources identifiers and header extension, if present.
const uint8 *const getPayload () const
uint32 getPayloadSize () const
PayloadType getPayloadType () const
uint16 getSeqNum () const
uint32 getTimestamp () const
uint8 getProtocolVersion () const
bool isPadded () const
 Ask whether the packet contains padding bytes at the end.
uint8 getPaddingSize () const
 Get the number of octets padding the end of the payload section.
bool isMarked () const
 Ask whether the packet is marked (for isntance, is a new talk spurt in some audio profiles).
bool isExtended () const
 Ask whether the packet contains header extensions.
uint16 getCSRCsCount () const
 Get the number of contributing sources specified in the packet header.
const uint32 * getCSRCs () const
 Get the 32-bit identifiers of the contributing sources for the packet as an array, of length getCSRCsCount().
uint16 getHdrExtUndefined () const
 Get the first 16 bits (in network order) of the header of the RTP header extension.
uint32 getHdrExtSize () const
 Get the length (in octets) of the data contained in the header extension.
const unsigned char * getHdrExtContent () const
 Get the content of the header extension.
const unsigned char *const getRawPacket () const
 Get the raw packet as it will be sent through the network.
uint32 getRawPacketSize () const
 Get the raw packet length, including header, extension, payload and padding.
uint32 getRawPacketSizeSrtp () const
size_t getSizeOfFixedHeader () const
struct RFC2833PayloadgetRaw2833Payload (void)
 Fetch a raw 2833 packet.
uint16 get2833Duration (void)
 Fetch 2833 duration field.
void set2833Duration (uint16 timestamp)
 Set 2833 duration field.

Protected Member Functions

virtual ~RTPPacket ()
 Destructor, free the buffer provided in the constructor.
void endPacket ()
 Free memory allocated for the packet.
RTPFixedHeader * getHeader () const
 Return low level structure for the header of the packet.
void setExtension (bool e)
const RTPHeaderExt * getHeaderExt () const
 Get a pointer to RTPHeaderExt pointing after the RTP header (fixed part plus contributing sources).
uint32 getRawTimestamp () const
 Obtain the absolute timestamp carried in the packet header.
void setbuffer (const void *src, size_t len, size_t pos)

Protected Attributes

uint16 cachedSeqNum
 Packet sequence number in host order.
uint32 cachedTimestamp
 Packet timestamp in host order (includes initial shift).
uint32 srtpDataOffset
 Offset into packet memory pointing to area for SRTP data.
int32 srtpLength
 Lebgth of additional SRTP data.
uint32 total
 total length, including header, payload and padding
uint32 payloadSize
 note: payload (not full packet) size.

Classes

struct  RFC2833Payload
 a structure defining RFC2833 Telephony events. More...
struct  RTPFixedHeader
 RTP fixed header as it is send through the network.
struct  RTPHeaderExt
 Fixed component of the variable-length header extension, appended to the fixed header, after the CSRC list, when X == 1.


Detailed Description

A base class for both IncomingRTPPkt and OutgoingRTPPkt.

Provides common low level header structures and related methods. This class provides an interface that allows for partial and generic manipulation of RTP data packets. Values are returned in host order, except raw structures, which are returned as they are sent through the network.

Author:
David Sugar <dyfet@ostel.com>

Constructor & Destructor Documentation

RTPPacket::RTPPacket ( const unsigned char *const   block,
size_t  len,
bool  duplicate = false 
)

Constructor, construct a packet object given the memory zone its content (header and payload) is stored.

Commonly used to build RTPPacket objects from incoming data.

Parameters:
block whole packet
len total length (header + payload + padding) of the packet
duplicate whether to memcopy the packet. At present, this feature is not used.
Note:
used in IncomingRTPPkt.

RTPPacket::RTPPacket ( size_t  hdrlen,
size_t  plen,
uint8  paddinglen,
CryptoContext pcc = NULL 
)

Construct a packet object without specifying its real content yet.

Commonly used for outgoing packets. Header fields and payload must be filled in by another methods or by a derived constructor.

Parameters:
hdrlen length of the header (including CSRC and extension).
plen payload length.
paddinglen pad packet to a multiple of paddinglen
Note:
used in OutgoingRTPPkt.

virtual RTPPacket::~RTPPacket (  )  [inline, protected, virtual]

Destructor, free the buffer provided in the constructor.


Member Function Documentation

uint32 RTPPacket::getHeaderSize (  )  const [inline]

Get the length of the header, including contributing sources identifiers and header extension, if present.

Returns:
number of octets.

const uint8* const RTPPacket::getPayload (  )  const [inline]

Returns:
pointer to the payload section of the packet.

uint32 RTPPacket::getPayloadSize (  )  const [inline]

Returns:
length of the payload section, in octets.

PayloadType RTPPacket::getPayloadType (  )  const [inline]

Returns:
value of the PT header field.

uint16 RTPPacket::getSeqNum (  )  const [inline]

Returns:
value of the sequence number header field, in host order.

uint32 RTPPacket::getTimestamp (  )  const [inline]

Returns:
packet timestamp in host order.

uint8 RTPPacket::getProtocolVersion (  )  const [inline]

Returns:
RTP protocol version of packet.

bool RTPPacket::isPadded (  )  const [inline]

Ask whether the packet contains padding bytes at the end.

Returns:
true if the header padding bit is 1.

uint8 RTPPacket::getPaddingSize (  )  const [inline]

Get the number of octets padding the end of the payload section.

Returns:
Padding length in octets.

bool RTPPacket::isMarked (  )  const [inline]

Ask whether the packet is marked (for isntance, is a new talk spurt in some audio profiles).

Returns:
true is the header marker bit is 1.

bool RTPPacket::isExtended (  )  const [inline]

Ask whether the packet contains header extensions.

Returns:
true if the header extension bit is 1.

uint16 RTPPacket::getCSRCsCount (  )  const [inline]

Get the number of contributing sources specified in the packet header.

const uint32* RTPPacket::getCSRCs (  )  const [inline]

Get the 32-bit identifiers of the contributing sources for the packet as an array, of length getCSRCsCount().

Returns:
An array of CSRC identifiers as they are in the packet (in network order).

uint16 RTPPacket::getHdrExtUndefined (  )  const [inline]

Get the first 16 bits (in network order) of the header of the RTP header extension.

Its meaning is undefined at this level.

Returns:
0 if the packet has no header extension, otherwise the first 16 bits of the header extension, in network order.
Note:
0 could be a valid value for the first 16 bits, in that case RTPPacket::isExtended() should be use.

uint32 RTPPacket::getHdrExtSize (  )  const [inline]

Get the length (in octets) of the data contained in the header extension.

Note that this length does not include the four octets at the beginning of the header extension.

Returns:
0 if the packet has no header extension, otherwise the length.
Note:
0 is a valid value for this field, so RTPPacket::isExtended() should be used.

const unsigned char* RTPPacket::getHdrExtContent (  )  const [inline]

Get the content of the header extension.

Returns:
NULL if the packet has no header extension, otherwise a pointer to the packet header extension content.

const unsigned char* const RTPPacket::getRawPacket (  )  const [inline]

Get the raw packet as it will be sent through the network.

Returns:
memory zone where the raw packet structure is stored in.

uint32 RTPPacket::getRawPacketSize (  )  const [inline]

Get the raw packet length, including header, extension, payload and padding.

Returns:
size of the raw packet structure.

uint32 RTPPacket::getRawPacketSizeSrtp (  )  const [inline]

size_t RTPPacket::getSizeOfFixedHeader (  )  const [inline]

void RTPPacket::endPacket (  )  [protected]

Free memory allocated for the packet.

RTPFixedHeader* RTPPacket::getHeader (  )  const [inline, protected]

Return low level structure for the header of the packet.

Returns:
RTPFixedHeader pointer to the header of the packet.

void RTPPacket::setExtension ( bool  e  )  [inline, protected]

const RTPHeaderExt* RTPPacket::getHeaderExt (  )  const [inline, protected]

Get a pointer to RTPHeaderExt pointing after the RTP header (fixed part plus contributing sources).

No check for for the X bit is done.

Returns:
header extension if present, garbage if not.

uint32 RTPPacket::getRawTimestamp (  )  const [inline, protected]

Obtain the absolute timestamp carried in the packet header.

Returns:
32-bit timestamp in host order.

void RTPPacket::setbuffer ( const void *  src,
size_t  len,
size_t  pos 
) [inline, protected]

struct RFC2833Payload* RTPPacket::getRaw2833Payload ( void   )  [inline, read]

Fetch a raw 2833 packet.

Returns:
low level 2833 data structure.

uint16 RTPPacket::get2833Duration ( void   )  [inline]

Fetch 2833 duration field.

Returns:
2833 duration in native host machine byte order.

void RTPPacket::set2833Duration ( uint16  timestamp  )  [inline]

Set 2833 duration field.

Parameters:
timestamp to use, native host machine byte order.


Member Data Documentation

uint16 RTPPacket::cachedSeqNum [protected]

Packet sequence number in host order.

uint32 RTPPacket::cachedTimestamp [protected]

Packet timestamp in host order (includes initial shift).

uint32 RTPPacket::srtpDataOffset [protected]

Offset into packet memory pointing to area for SRTP data.

This offset points to the memory where the SRTP protect will store the authentication and MKI data.

int32 RTPPacket::srtpLength [protected]

Lebgth of additional SRTP data.

Covers the SRTP authentication and MKI data.

uint32 RTPPacket::total [protected]

total length, including header, payload and padding

uint32 RTPPacket::payloadSize [protected]

note: payload (not full packet) size.


The documentation for this class was generated from the following file:

Generated on Tue Jun 17 07:33:18 2008 for ccRTP by  doxygen 1.5.5