FreeCalypso > hg > themwi-system-sw
view sip-manual-out/rtp_tx.c @ 208:f0b90591f67c
doc/RTP-TRAUlike-format: osmo_{fr,efr}_sid_classify() merged
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sun, 16 Apr 2023 17:54:42 -0800 |
parents | f3164f732b84 |
children | fbfa72b114e8 |
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/* * In this module we implement outgoing RTP stream generation. */ #include <sys/types.h> #include <sys/socket.h> #include <sys/time.h> #include <netinet/in.h> #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include <unistd.h> #include "../include/tmgw_const.h" #include "../include/rtp_defs.h" #include "../libutil/osmo_bits.h" extern struct sockaddr_in rtp_local_addr, rtp_remote_addr; extern int rtp_udp_fd, rtcp_udp_fd, pcma_selected; extern struct timeval cur_event_time; static uint32_t rtp_ssrc; static uint32_t rtp_out_ts; static uint16_t rtp_out_seq; static uint16_t tfo_fill_buf[9], tfo_req_buf[7]; static uint16_t *is_out_ptr; static unsigned is_out_count; static int tfo_stop_req; void assign_rtpout_ssrc() { rtp_ssrc = cur_event_time.tv_sec ^ cur_event_time.tv_usec ^ getpid(); } void prepare_tfo_fill() { tfo_fill_buf[0] = 0x15A; tfo_fill_buf[1] = 0x1A9; tfo_fill_buf[2] = 0x129; tfo_fill_buf[3] = 0x15A; tfo_fill_buf[4] = 0x1A9; tfo_fill_buf[5] = 0x129; tfo_fill_buf[6] = 0x15A; tfo_fill_buf[7] = 0x1A9; tfo_fill_buf[8] = 0x129; } static void insert_is_msg(payload, word) uint8_t *payload; uint16_t word; { ubit_t is_bits[10]; uint8_t *bytep; unsigned n; uint16_to_bits(word, is_bits, 10); for (n = 0; n < 10; n++) { bytep = payload + n * 16; *bytep &= 0xFE; *bytep |= is_bits[n]; } } void generate_rtp_packet() { struct rtp_packet pkt; socklen_t addrlen; pkt.v_p_x_cc = 0x80; pkt.m_pt = pcma_selected ? PSTN_CODEC_PCMA : PSTN_CODEC_PCMU; pkt.seq = htons(rtp_out_seq++); pkt.tstamp = htonl(rtp_out_ts); rtp_out_ts += 160; pkt.ssrc = rtp_ssrc; memset(pkt.payload, pcma_selected ? 0xD5 : 0xFF, RTP_MAX_PAYLOAD); if (is_out_count) { insert_is_msg(pkt.payload, *is_out_ptr++); is_out_count--; if (!is_out_count && !tfo_stop_req) { is_out_ptr = tfo_req_buf; is_out_count = 7; } } addrlen = sizeof(struct sockaddr_in); sendto(rtp_udp_fd, &pkt, RTP_PACKET_SIZE_PSTN, 0, (struct sockaddr *) &rtp_remote_addr, addrlen); } void send_tfo_req(sig, codec) unsigned sig, codec; { tfo_req_buf[0] = 0x15A; tfo_req_buf[1] = 0x1A9; tfo_req_buf[2] = 0x05D; tfo_req_buf[3] = 0x14E; tfo_req_buf[4] = 0x14B; encode_tfo_ext_words(sig, codec, 0, tfo_req_buf + 5); is_out_ptr = tfo_fill_buf; is_out_count = 9; tfo_stop_req = 0; } void stop_tfo_out() { tfo_stop_req = 1; }