rtp.c

基于h323协议的软phone

    retVal = rtpRead(hRTP, buf, len, p);

    if (s->hRTCP  &&  retVal >= 0)
    {
        /* Informs the RTCP session about a packet that was received in the corresponding
           RTP session.*/
        rtcpRTPPacketRecv(s->hRTCP, p->sSrc, timestamp,  p->timestamp, p->sequenceNumber);
    }

    return retVal;
}


/************************************************************************************
 * rtpGetPort
 * description: Returns the current port of the RTP session.
 * input: hRTP - Handle of the RTP session.
 * output: none.
 * return value: If no error occurs, the function returns the current port value.
 *               Otherwise, it returns a negative value.
 ***********************************************************************************/
RVAPI
RvUint16 RVCALLCONV rtpGetPort(
        IN HRTPSESSION  hRTP)   /* RTP Session Opaque Handle */
{
    rtpSession* s = (rtpSession *)hRTP;
    RvAddress localAddress;
    RvUint16 sockPort = 0;
    RvStatus res;

    res = RvSocketGetLocalAddress(&s->socket, &localAddress);

    if (res == RV_OK)
    {
        sockPort = RvAddressGetIpPort(&localAddress);

        RvAddressDestruct(&localAddress);
    }

    return sockPort;
}

/************************************************************************************
 * rtpGetVersion
 * description:  Returns the RTP version of the installed RTP Stack.
 * input:  none.
 * output: none.
 * return value: If no error occurs, the function returns the current version value.
 *               Otherwise, it returns a negative value.
 ***********************************************************************************/
RVAPI
char * RVCALLCONV rtpGetVersion(void)
{
    return (char*)VERSION_STR;
}

/************************************************************************************
 * rtpGetVersionNum
 * description:  Returns the RTP version of the installed RTP Stack.
 * input:  none.
 * output: none.
 * return value: If no error occurs, the function returns the current version value.
 *               Otherwise, it returns a negative value.
 ***********************************************************************************/
RVAPI
RvUint32 RVCALLCONV rtpGetVersionNum(void)
{
    return VERSION_NUM;
}


                    /* == ENDS: Basic RTP Functions == */



                     /* == Accessory RTP Functions == */

/************************************************************************************
 * rtpGetRTCPSession
 * description:  Returns the RTCP session.
 * input:  hRTP - Handle of RTP session.
 * output: none.
 * return value: hRTCP - Handle of RTCP session.
 ***********************************************************************************/
RVAPI
HRTCPSESSION RVCALLCONV rtpGetRTCPSession(
        IN  HRTPSESSION  hRTP)
{
    rtpSession *s = (rtpSession *)hRTP;

    return (s->hRTCP);
}

/************************************************************************************
 * rtpSetRTCPSession
 * description:  set the RTCP session.
 * input:  hRTP  - Handle of RTP session.
 *         hRTCP - Handle of RTCP session.
 * output: none.
 * return value:return 0.
 ***********************************************************************************/
RVAPI
RvInt32 RVCALLCONV rtpSetRTCPSession(
        IN  HRTPSESSION   hRTP,
        IN  HRTCPSESSION  hRTCP)
{
    rtpSession *s = (rtpSession *)hRTP;

    s->hRTCP = hRTCP;

    return RV_OK;
}

/************************************************************************************
 * rtpGetHeaderLength
 * description:  return the header of RTP message.
 * input:  none.
 * output: none.
 * return value:The return value is twelve.
 ***********************************************************************************/
RVAPI
RvInt32 RVCALLCONV rtpGetHeaderLength(void)
{
    return 12;
}

/************************************************************************************
 * rtpRegenSSRC
 * description:  Generates a new synchronization source value for the RTP session.
 *               This function, in conjunction with rtpGetSSRC() may be used to
 *               change the SSRC value when an SSRC collision is detected.
 * input:  hRTP  - Handle of RTP session.
 * output: none.
 * return value: ssrc - If an error occurs, the function returns a negative value.
 *               If no error occurs, the function returns a non-negative value.
 ***********************************************************************************/
RVAPI
RvUint32 RVCALLCONV rtpRegenSSRC(
        IN  HRTPSESSION  hRTP)
{
    rtpSession *s = (rtpSession *)hRTP;
    RvRandom randomValue;

    /* those line is to prevent collision.*/
    RvRandomGeneratorGetValue(&rvRtpInstance.randomGenerator, &randomValue);
    s->sSrc = (RvUint32)randomValue * (RvUint32)(RvTimestampGet() >> 16);
    s->sSrc &= ~s->sSrcMask;
    s->sSrc |= s->sSrcPattern;

    return s->sSrc;
}

/************************************************************************************
 * rtpSetGroupAddress
 * description:  Defines a multicast IP for the RTP session.
 * input:  hRTP  - Handle of RTP session.
 *         ip    - Multicast IP address for the RTP session.
 * output: none.
 * return value: return 0.
 ***********************************************************************************/
RVAPI
RvInt32 RVCALLCONV rtpSetGroupAddress(
        IN HRTPSESSION hRTP,    /* RTP Session Opaque Handle */
        IN RvUint32     ip)
{
    rtpSession *s = (rtpSession *)hRTP;
    RvAddress addresses[2];
    RvStatus res;

    RvAddressConstructIpv4(&addresses[0], ip, RV_ADDRESS_IPV4_ANYPORT);
    RvAddressConstructIpv4(&addresses[1], rvRtpInstance.localIp, RV_ADDRESS_IPV4_ANYPORT);

    /* This function adds the specified address (in network format) to the specified
       Multicast interface for the specified socket.*/
    res = RvSocketJoinMulticastGroup(&s->socket, addresses, addresses+1);

    RvAddressDestruct(&addresses[0]);
    RvAddressDestruct(&addresses[1]);

    return res;
}

/************************************************************************************
 * rtpResume
 * description:  Causes a blocked rtpRead() or rtpReadEx() function running in
 *               another thread to fail.
 * input:  hRTP  - Handle of RTP session.
 * output: none.
 * return value: If an error occurs, the function returns a negative value.
 *               If no error occurs, the function returns a non-negative value.
 ***********************************************************************************/
RVAPI
RvInt32 RVCALLCONV rtpResume(
        IN  HRTPSESSION hRTP)
{
    rtpSession *s = (rtpSession *)hRTP;
    RvAddress localAddress;
    RvAddressIpv4* localIpV4;
    RvStatus status;

    status = RvSocketGetLocalAddress(&s->socket, &localAddress);

    if (status == RV_OK)
    {
        localIpV4 = (RvAddressIpv4 *)RvAddressGetIpv4(&localAddress);
        if (RvAddressIpv4GetIp(localIpV4) == RV_ADDRESS_IPV4_ANYADDRESS)
        {
            /* No specific IP on this socket - use our default one */
            if (rvRtpInstance.localIp != RV_ADDRESS_IPV4_ANYADDRESS)
                RvAddressIpv4SetIp(localIpV4, rvRtpInstance.localIp);
            else
                RvAddressIpv4SetIp(localIpV4, rvRtpInstance.hostIPs[0]);
        }

        /* We send a dummy buffer to get this connection released from its blocking mode */
        RvSocketSendBuffer(&s->socket, (RvUint8*)"", 1, &localAddress, NULL);

        RvAddressDestruct(&localAddress);
    }

    return status;
}

/************************************************************************************
 * rtpUseSequenceNumber
 * description:  Forces the Stack to accept user input for the sequence number of
 *               the RTP packet. The RTP Stack usually determines the sequence number.
 *               However, the application can force its own sequence number.
 *               Call rtpUseSequenceNumber() at the beginning of the RTP session and
 *               then specify the sequence number in the rtpParam structure of the
 *               rtpWrite() function.
 * input:  hRTP  - Handle of RTP session.
 * output: none.
 * return value: return 0.
 ***********************************************************************************/
RVAPI
RvInt32 RVCALLCONV rtpUseSequenceNumber(
                IN HRTPSESSION  hRTP)
{
    rtpSession *s = (rtpSession *)hRTP;

    s->useSequenceNumber = 1;

    return RV_OK;
}

/************************************************************************************
 * rtpSetReceiveBufferSize
 * description:  Changes the RTP session receive buffer size.
 * input:  hRTP  - Handle of RTP session.
 * output: none.
 * return value: return 0.
 ***********************************************************************************/
RVAPI
RvInt32 RVCALLCONV rtpSetReceiveBufferSize(
        IN HRTPSESSION  hRTP,
        IN int size)
{
    rtpSession* s = (rtpSession *)hRTP;

    /* This function sets the size of the read/write buffers of a socket*/
    return RvSocketSetBuffers(&s->socket, -1, size);
}

/************************************************************************************
 * rtpSetTransmitBufferSize
 * description:  Changes the RTP session transmit buffer size.
 * input:  hRTP - Handle of RTP session.
 *         size - The new transmit buffer size.
 * output: none.
 * return value: return 0.
 ***********************************************************************************/
RVAPI
RvInt32 RVCALLCONV rtpSetTransmitBufferSize(
                IN HRTPSESSION  hRTP,
                IN int size)
{
    rtpSession* s = (rtpSession *)hRTP;

    /* This function sets the size of the read/write buffers of a socket*/
    return RvSocketSetBuffers(&s->socket, size, -1);
}

/************************************************************************************
 * rtpSetTrasmitBufferSize
 * description:  Changes the RTP session transmit buffer size.
 * input:  hRTP - Handle of RTP session.
 *         size - The new transmit buffer size.
 * output: none.
 * return value: return 0.
 * comment     : obsolete function provided for compatibility with prev. version
 ***********************************************************************************/
RVAPI
RvInt32 RVCALLCONV rtpSetTrasmitBufferSize(
                IN HRTPSESSION  hRTP,
                IN int size)
{
  return rtpSetTransmitBufferSize(hRTP, size);
}


/************************************************************************************
 * rtpGetAvailableBytes
 * description:  Gets the number of bytes available for reading in the RTP session.
 * input:  hRTP - Handle of RTP session.
 * output: none.
 * return value: If an error occurs, the function returns a negative value.
 *               If no error occurs, the function returns a non-negative value.
 ***********************************************************************************/
RVAPI
RvInt32 RVCALLCONV rtpGetAvailableBytes(
                IN HRTPSESSION  hRTP)
{
    rtpSession *s = (rtpSession *)hRTP;
    RvSize_t bytes;
    RvStatus ret;

    /* This function returns the number of bytes in the specified socket that are
       available for reading.*/

    ret = RvSocketGetBytesAvailable(&s->socket, &bytes);

    if (ret != RV_OK)
        return ret;

    return (RvInt32)bytes;
}

                  /* == ENDS: Accessory RTP Functions == */



                     /* == Internal RTP Functions == */

static void rtpEvent(
        IN RvSelectEngine*  selectEngine,
        IN RvSelectFd*      fd,
        IN RvSelectEvents   selectEvent,
        IN RvBool           error)
{
    rtpSession* s;

    RV_UNUSED_ARG(selectEngine);
    RV_UNUSED_ARG(selectEvent);
    RV_UNUSED_ARG(error);

    s = RV_GET_STRUCT(rtpSession, selectFd, fd);

    if (s->eventHandler)
    {
        s->eventHandler((HRTPSESSION)s, s->context);
    }
}


static RvBool isMyIP(RvUint32 ip)
{
    RvUint32 i;

    for (i = 0; (i < RV_RTP_MAXIPS) && (rvRtpInstance.hostIPs[i]); i++)
    {
        if (ip == rvRtpInstance.hostIPs[i])
            return RV_TRUE;
    }

    return RV_FALSE;
}

                  /* == ENDS: Internal RTP Functions == */




#ifdef __cplusplus
}
#endif