mpf_rtcp_packet.h

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/*
 * Copyright 2008-2010 Arsen Chaloyan
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * $Id: mpf_rtcp_packet.h 1474 2010-02-07 20:51:47Z achaloyan $
 */

#ifndef MPF_RTCP_PACKET_H
#define MPF_RTCP_PACKET_H

/**
 * @file mpf_rtcp_packet.h
 * @brief RTCP Packet Definition
 */ 

#include "mpf_rtp_stat.h"

APT_BEGIN_EXTERN_C


/** RTCP payload (packet) types */
typedef enum {
        RTCP_SR   = 200,
        RTCP_RR   = 201,
        RTCP_SDES = 202,
        RTCP_BYE  = 203,
        RTCP_APP  = 204
} rtcp_type_e;

/** RTCP SDES types */
typedef enum {
        RTCP_SDES_END   = 0,
        RTCP_SDES_CNAME = 1,
        RTCP_SDES_NAME  = 2,
        RTCP_SDES_EMAIL = 3,
        RTCP_SDES_PHONE = 4,
        RTCP_SDES_LOC   = 5,
        RTCP_SDES_TOOL  = 6,
        RTCP_SDES_NOTE  = 7,
        RTCP_SDES_PRIV  = 8
} rtcp_sdes_type_e;

/** RTCP header declaration */
typedef struct rtcp_header_t rtcp_header_t;
/** RTCP packet declaration */
typedef struct rtcp_packet_t rtcp_packet_t;
/** SDES item declaration*/
typedef struct rtcp_sdes_item_t rtcp_sdes_item_t;


/** RTCP header */
struct rtcp_header_t {
#if (APR_IS_BIGENDIAN == 1)
        /** protocol version */
        unsigned int version: 2;
        /** padding flag */
        unsigned int padding: 1;
        /** varies by packet type */
        unsigned int count:   5;
        /** packet type */
        unsigned int pt:      8;
#else
        /** varies by packet type */
        unsigned int count:   5;
        /** padding flag */
        unsigned int padding: 1;
        /** protocol version */
        unsigned int version: 2;
        /** packet type */
        unsigned int pt:      8;
#endif  
        
        /** packet length in words, w/o this word */
        unsigned int length:  16;
};

/** SDES item */
struct rtcp_sdes_item_t {
        /** type of item (rtcp_sdes_type_t) */
        apr_byte_t type;
        /** length of item (in octets) */
        apr_byte_t length;
        /** text, not null-terminated */
        char       data[1];
};

/** RTCP packet */
struct rtcp_packet_t {
        /** common header */
        rtcp_header_t header;
        /** union of RTCP reports */
        union {
                /** sender report (SR) */
                struct {
                        /** sr stat */
                        rtcp_sr_stat_t sr_stat;
                        /** variable-length list rr stats */
                        rtcp_rr_stat_t rr_stat[1];
                } sr;

                /** reception report (RR) */
                struct {
                        /** receiver generating this report */
                        apr_uint32_t   ssrc;
                        /** variable-length list rr stats */
                        rtcp_rr_stat_t rr_stat[1];
                } rr;

                /** source description (SDES) */
                struct {
                        /** first SSRC/CSRC */
                        apr_uint32_t     ssrc;
                        /** list of SDES items */
                        rtcp_sdes_item_t item[1];
                } sdes;

                /** BYE */
                struct {
                        /** list of sources */
                        apr_uint32_t ssrc[1];
                        /* optional length of reason string (in octets) */
                        apr_byte_t   length;
                        /* optional reason string, not null-terminated */
                        char         data[1];
                } bye;
        } r;
};

/** Initialize RTCP header */
static APR_INLINE void rtcp_header_init(rtcp_header_t *header, rtcp_type_e pt)
{
        header->version = RTP_VERSION;
        header->padding = 0;
        header->count = 0;
        header->pt = pt;
        header->length = 0;
}

static APR_INLINE void rtcp_header_length_set(rtcp_header_t *header, apr_size_t length)
{
        header->length = htons((apr_uint16_t)length / 4 - 1);
}

static APR_INLINE void rtcp_sr_hton(rtcp_sr_stat_t *sr_stat)
{
        sr_stat->ssrc = htonl(sr_stat->ssrc);
        sr_stat->ntp_sec = htonl(sr_stat->ntp_sec);
        sr_stat->ntp_frac = htonl(sr_stat->ntp_frac);
        sr_stat->rtp_ts = htonl(sr_stat->rtp_ts);
        sr_stat->sent_packets = htonl(sr_stat->sent_packets);
        sr_stat->sent_octets = htonl(sr_stat->sent_octets);
}

static APR_INLINE void rtcp_sr_ntoh(rtcp_sr_stat_t *sr_stat)
{
        sr_stat->ssrc = ntohl(sr_stat->ssrc);
        sr_stat->ntp_sec = ntohl(sr_stat->ntp_sec);
        sr_stat->ntp_frac = ntohl(sr_stat->ntp_frac);
        sr_stat->rtp_ts = ntohl(sr_stat->rtp_ts);
        sr_stat->sent_packets = ntohl(sr_stat->sent_packets);
        sr_stat->sent_octets = ntohl(sr_stat->sent_octets);
}

static APR_INLINE void rtcp_rr_hton(rtcp_rr_stat_t *rr_stat)
{
        rr_stat->ssrc = htonl(rr_stat->ssrc);
        rr_stat->last_seq =     htonl(rr_stat->last_seq);
        rr_stat->jitter = htonl(rr_stat->jitter);

#if (APR_IS_BIGENDIAN == 0)
        rr_stat->lost = ((rr_stat->lost >> 16) & 0x000000ff) |
                                                (rr_stat->lost & 0x0000ff00) |
                                                        ((rr_stat->lost << 16) & 0x00ff0000);
#endif
}

static APR_INLINE void rtcp_rr_ntoh(rtcp_rr_stat_t *rr_stat)
{
        rr_stat->ssrc = ntohl(rr_stat->ssrc);
        rr_stat->last_seq =     ntohl(rr_stat->last_seq);
        rr_stat->jitter = ntohl(rr_stat->jitter);

#if (APR_IS_BIGENDIAN == 0)
        rr_stat->lost = ((rr_stat->lost >> 16) & 0x000000ff) |
                                                (rr_stat->lost & 0x0000ff00) |
                                                        ((rr_stat->lost << 16) & 0x00ff0000);
#endif
}

APT_END_EXTERN_C

#endif /* MPF_RTCP_PACKET_H */

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