/* * rtp.h -- RTP header file (RFC 1890) */ #include #include "sysdep.h" #define RTP_SVM_RAW 40 /* * The type definitions below are valid for 32-bit architectures and * may have to be adjusted for 16- or 64-bit architectures. */ typedef unsigned char u_int8; typedef unsigned short u_int16; typedef unsigned int u_int32; typedef short int16; /* * Current protocol version. */ #define RTP_VERSION 2 #define RTP_SEQ_MOD (1<<16) #define RTP_MAX_SDES 255 /* maximum text length for SDES */ typedef enum { RTCP_SR = 200, RTCP_RR = 201, RTCP_SDES = 202, RTCP_BYE = 203, RTCP_APP = 204 } rtcp_type_t; 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_t; /* * Largest (user-level) packet size generated by our rtp applications. * Individual video formats may use smaller mtu's. */ #define PACKET_SIZE 1024 #define RTP_MTU 1024 #define MAXHDR 24 #define RTP_HDR_SZ 12 #define TOTHDR 20 /* * * * The RTP header has the following format: * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * |V=2|P|X| CC |M| PT | sequence number | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | timestamp | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | synchronization source (SSRC) identifier | * +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ * | contributing source (CSRC) identifiers | * | .... | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * RTP data header */ typedef struct { #if RTP_BIG_ENDIAN unsigned int version:2; /* protocol version */ unsigned int p:1; /* padding flag */ unsigned int x:1; /* header extension flag */ unsigned int cc:4; /* CSRC count */ unsigned int m:1; /* marker bit */ unsigned int pt:7; /* payload type */ #elif RTP_LITTLE_ENDIAN unsigned int cc:4; /* CSRC count */ unsigned int x:1; /* header extension flag */ unsigned int p:1; /* padding flag */ unsigned int version:2; /* protocol version */ unsigned int pt:7; /* payload type */ unsigned int m:1; /* marker bit */ #else #error Define one of RTP_LITTLE_ENDIAN or RTP_BIG_ENDIAN #endif unsigned int seq:16; /* sequence number */ u_int32 ts; /* timestamp */ u_int32 ssrc; /* synchronization source */ } rtp_hdr_t; /* * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * |V=2|P| RC | PT=SR=200 | length | header * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * * RTCP common header word */ typedef struct { #if RTP_BIG_ENDIAN unsigned int version:2; /* protocol version */ unsigned int p:1; /* padding flag */ unsigned int count:5; /* varies by packet type */ unsigned int pt:8; /* RTCP packet type */ #elif RTP_LITTLE_ENDIAN unsigned int count:5; unsigned int p:1; unsigned int version:2; unsigned int pt:8; #else #error Define one of RTP_LITTLE_ENDIAN or RTP_BIG_ENDIAN #endif u_int16 length; /* pkt len in words, w/o this word */ } rtcp_common_t; /* * Reception report block */ typedef struct { u_int32 ssrc; /* data source being reported */ unsigned int fraction:8; /* fraction lost since last SR/RR */ int lost:24; /* cumul. no. pkts lost (signed!) */ u_int32 last_seq; /* extended last seq. no. received */ u_int32 jitter; /* interarrival jitter */ u_int32 lsr; /* last SR packet from this source */ u_int32 dlsr; /* delay since last SR packet */ } rtcp_rr_t; /* * SDES item */ typedef struct { u_int8 type; /* type of item (rtcp_sdes_type_t) */ u_int8 length; /* length of item (in octets) */ char data[1]; /* text, not null-terminated */ } rtcp_sdes_item_t; /* * One RTCP packet */ typedef struct { rtcp_common_t common; /* common header */ union { /* sender report (SR) */ struct { u_int32 ssrc; /* sender generating this report */ u_int32 ntp_sec; /* NTP timestamp */ u_int32 ntp_frac; u_int32 rtp_ts; /* RTP timestamp */ u_int32 psent; /* packets sent */ u_int32 osent; /* octets sent */ rtcp_rr_t rr[1]; /* variable-length list */ } sr; /* reception report (RR) */ struct { u_int32 ssrc; /* receiver generating this report */ rtcp_rr_t rr[1]; /* variable-length list */ } rr; /* source description (SDES) */ struct rtcp_sdes { u_int32 src; /* first SSRC/CSRC */ rtcp_sdes_item_t item[1]; /* list of SDES items */ } sdes; /* BYE */ struct { u_int32 src[1]; /* list of sources */ /* can't express trailing text for reason */ } bye; } r; } rtcp_t; typedef struct rtcp_sdes rtcp_sdes_t; /* * Per-source state information */ typedef struct { u_int16 max_seq; /* highest seq. number seen */ u_int32 cycles; /* shifted count of seq. number cycles */ u_int32 base_seq; /* base seq number */ u_int32 bad_seq; /* last 'bad' seq number + 1 */ u_int32 probation; /* sequ. packets till source is valid */ u_int32 received; /* packets received */ u_int32 expected_prior; /* packet expected at last interval */ u_int32 received_prior; /* packet received at last interval */ u_int32 transit; /* relative trans time for prev pkt */ u_int32 jitter; /* estimated jitter */ /* ... */ } source; /* * * * Motion JPEG encapsulation. * * 0 1 2 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | frag offset | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * | x | y | Width | Height | * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ * * Type = Index into a table of predefined JPEG parameters * Width = Width of input in 8-pixel blocks * Height = Height of input in 8-pixel blocks * Q = Quality factor (0-100 = std, >100 = custom) * Frag offset = The byte offset into the frame for the data in * this packet */ struct jpeghdr { // unsigned int type:8; // int off:24; u_int32 off; u_int8 x; u_int8 y; u_int8 width; u_int8 height; /* cells */ };