yading@11: /*
yading@11:  * Session Announcement Protocol (RFC 2974) muxer
yading@11:  * Copyright (c) 2010 Martin Storsjo
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "libavutil/parseutils.h"
yading@11: #include "libavutil/random_seed.h"
yading@11: #include "libavutil/avstring.h"
yading@11: #include "libavutil/dict.h"
yading@11: #include "libavutil/intreadwrite.h"
yading@11: #include "libavutil/time.h"
yading@11: #include "libavutil/dict.h"
yading@11: #include "internal.h"
yading@11: #include "network.h"
yading@11: #include "os_support.h"
yading@11: #include "rtpenc_chain.h"
yading@11: #include "url.h"
yading@11: 
yading@11: struct SAPState {
yading@11:     uint8_t    *ann;
yading@11:     int         ann_size;
yading@11:     URLContext *ann_fd;
yading@11:     int64_t     last_time;
yading@11: };
yading@11: 
yading@11: static int sap_write_close(AVFormatContext *s)
yading@11: {
yading@11:     struct SAPState *sap = s->priv_data;
yading@11:     int i;
yading@11: 
yading@11:     for (i = 0; i < s->nb_streams; i++) {
yading@11:         AVFormatContext *rtpctx = s->streams[i]->priv_data;
yading@11:         if (!rtpctx)
yading@11:             continue;
yading@11:         av_write_trailer(rtpctx);
yading@11:         avio_close(rtpctx->pb);
yading@11:         avformat_free_context(rtpctx);
yading@11:         s->streams[i]->priv_data = NULL;
yading@11:     }
yading@11: 
yading@11:     if (sap->last_time && sap->ann && sap->ann_fd) {
yading@11:         sap->ann[0] |= 4; /* Session deletion*/
yading@11:         ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
yading@11:     }
yading@11: 
yading@11:     av_freep(&sap->ann);
yading@11:     if (sap->ann_fd)
yading@11:         ffurl_close(sap->ann_fd);
yading@11:     ff_network_close();
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int sap_write_header(AVFormatContext *s)
yading@11: {
yading@11:     struct SAPState *sap = s->priv_data;
yading@11:     char host[1024], path[1024], url[1024], announce_addr[50] = "";
yading@11:     char *option_list;
yading@11:     int port = 9875, base_port = 5004, i, pos = 0, same_port = 0, ttl = 255;
yading@11:     AVFormatContext **contexts = NULL;
yading@11:     int ret = 0;
yading@11:     struct sockaddr_storage localaddr;
yading@11:     socklen_t addrlen = sizeof(localaddr);
yading@11:     int udp_fd;
yading@11:     AVDictionaryEntry* title = av_dict_get(s->metadata, "title", NULL, 0);
yading@11: 
yading@11:     if (!ff_network_init())
yading@11:         return AVERROR(EIO);
yading@11: 
yading@11:     /* extract hostname and port */
yading@11:     av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &base_port,
yading@11:                  path, sizeof(path), s->filename);
yading@11:     if (base_port < 0)
yading@11:         base_port = 5004;
yading@11: 
yading@11:     /* search for options */
yading@11:     option_list = strrchr(path, '?');
yading@11:     if (option_list) {
yading@11:         char buf[50];
yading@11:         if (av_find_info_tag(buf, sizeof(buf), "announce_port", option_list)) {
yading@11:             port = strtol(buf, NULL, 10);
yading@11:         }
yading@11:         if (av_find_info_tag(buf, sizeof(buf), "same_port", option_list)) {
yading@11:             same_port = strtol(buf, NULL, 10);
yading@11:         }
yading@11:         if (av_find_info_tag(buf, sizeof(buf), "ttl", option_list)) {
yading@11:             ttl = strtol(buf, NULL, 10);
yading@11:         }
yading@11:         if (av_find_info_tag(buf, sizeof(buf), "announce_addr", option_list)) {
yading@11:             av_strlcpy(announce_addr, buf, sizeof(announce_addr));
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     if (!announce_addr[0]) {
yading@11:         struct addrinfo hints = { 0 }, *ai = NULL;
yading@11:         hints.ai_family = AF_UNSPEC;
yading@11:         if (getaddrinfo(host, NULL, &hints, &ai)) {
yading@11:             av_log(s, AV_LOG_ERROR, "Unable to resolve %s\n", host);
yading@11:             ret = AVERROR(EIO);
yading@11:             goto fail;
yading@11:         }
yading@11:         if (ai->ai_family == AF_INET) {
yading@11:             /* Also known as sap.mcast.net */
yading@11:             av_strlcpy(announce_addr, "224.2.127.254", sizeof(announce_addr));
yading@11: #if HAVE_STRUCT_SOCKADDR_IN6
yading@11:         } else if (ai->ai_family == AF_INET6) {
yading@11:             /* With IPv6, you can use the same destination in many different
yading@11:              * multicast subnets, to choose how far you want it routed.
yading@11:              * This one is intended to be routed globally. */
yading@11:             av_strlcpy(announce_addr, "ff0e::2:7ffe", sizeof(announce_addr));
yading@11: #endif
yading@11:         } else {
yading@11:             freeaddrinfo(ai);
yading@11:             av_log(s, AV_LOG_ERROR, "Host %s resolved to unsupported "
yading@11:                                     "address family\n", host);
yading@11:             ret = AVERROR(EIO);
yading@11:             goto fail;
yading@11:         }
yading@11:         freeaddrinfo(ai);
yading@11:     }
yading@11: 
yading@11:     contexts = av_mallocz(sizeof(AVFormatContext*) * s->nb_streams);
yading@11:     if (!contexts) {
yading@11:         ret = AVERROR(ENOMEM);
yading@11:         goto fail;
yading@11:     }
yading@11: 
yading@11:     s->start_time_realtime = av_gettime();
yading@11:     for (i = 0; i < s->nb_streams; i++) {
yading@11:         URLContext *fd;
yading@11: 
yading@11:         ff_url_join(url, sizeof(url), "rtp", NULL, host, base_port,
yading@11:                     "?ttl=%d", ttl);
yading@11:         if (!same_port)
yading@11:             base_port += 2;
yading@11:         ret = ffurl_open(&fd, url, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
yading@11:         if (ret) {
yading@11:             ret = AVERROR(EIO);
yading@11:             goto fail;
yading@11:         }
yading@11:         ret = ff_rtp_chain_mux_open(&contexts[i], s, s->streams[i], fd, 0, i);
yading@11:         if (ret < 0)
yading@11:             goto fail;
yading@11:         s->streams[i]->priv_data = contexts[i];
yading@11:         av_strlcpy(contexts[i]->filename, url, sizeof(contexts[i]->filename));
yading@11:     }
yading@11: 
yading@11:     if (s->nb_streams > 0 && title)
yading@11:         av_dict_set(&contexts[0]->metadata, "title", title->value, 0);
yading@11: 
yading@11:     ff_url_join(url, sizeof(url), "udp", NULL, announce_addr, port,
yading@11:                 "?ttl=%d&connect=1", ttl);
yading@11:     ret = ffurl_open(&sap->ann_fd, url, AVIO_FLAG_WRITE,
yading@11:                      &s->interrupt_callback, NULL);
yading@11:     if (ret) {
yading@11:         ret = AVERROR(EIO);
yading@11:         goto fail;
yading@11:     }
yading@11: 
yading@11:     udp_fd = ffurl_get_file_handle(sap->ann_fd);
yading@11:     if (getsockname(udp_fd, (struct sockaddr*) &localaddr, &addrlen)) {
yading@11:         ret = AVERROR(EIO);
yading@11:         goto fail;
yading@11:     }
yading@11:     if (localaddr.ss_family != AF_INET
yading@11: #if HAVE_STRUCT_SOCKADDR_IN6
yading@11:         && localaddr.ss_family != AF_INET6
yading@11: #endif
yading@11:         ) {
yading@11:         av_log(s, AV_LOG_ERROR, "Unsupported protocol family\n");
yading@11:         ret = AVERROR(EIO);
yading@11:         goto fail;
yading@11:     }
yading@11:     sap->ann_size = 8192;
yading@11:     sap->ann = av_mallocz(sap->ann_size);
yading@11:     if (!sap->ann) {
yading@11:         ret = AVERROR(EIO);
yading@11:         goto fail;
yading@11:     }
yading@11:     sap->ann[pos] = (1 << 5);
yading@11: #if HAVE_STRUCT_SOCKADDR_IN6
yading@11:     if (localaddr.ss_family == AF_INET6)
yading@11:         sap->ann[pos] |= 0x10;
yading@11: #endif
yading@11:     pos++;
yading@11:     sap->ann[pos++] = 0; /* Authentication length */
yading@11:     AV_WB16(&sap->ann[pos], av_get_random_seed());
yading@11:     pos += 2;
yading@11:     if (localaddr.ss_family == AF_INET) {
yading@11:         memcpy(&sap->ann[pos], &((struct sockaddr_in*)&localaddr)->sin_addr,
yading@11:                sizeof(struct in_addr));
yading@11:         pos += sizeof(struct in_addr);
yading@11: #if HAVE_STRUCT_SOCKADDR_IN6
yading@11:     } else {
yading@11:         memcpy(&sap->ann[pos], &((struct sockaddr_in6*)&localaddr)->sin6_addr,
yading@11:                sizeof(struct in6_addr));
yading@11:         pos += sizeof(struct in6_addr);
yading@11: #endif
yading@11:     }
yading@11: 
yading@11:     av_strlcpy(&sap->ann[pos], "application/sdp", sap->ann_size - pos);
yading@11:     pos += strlen(&sap->ann[pos]) + 1;
yading@11: 
yading@11:     if (av_sdp_create(contexts, s->nb_streams, &sap->ann[pos],
yading@11:                       sap->ann_size - pos)) {
yading@11:         ret = AVERROR_INVALIDDATA;
yading@11:         goto fail;
yading@11:     }
yading@11:     av_freep(&contexts);
yading@11:     av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", &sap->ann[pos]);
yading@11:     pos += strlen(&sap->ann[pos]);
yading@11:     sap->ann_size = pos;
yading@11: 
yading@11:     if (sap->ann_size > sap->ann_fd->max_packet_size) {
yading@11:         av_log(s, AV_LOG_ERROR, "Announcement too large to send in one "
yading@11:                                 "packet\n");
yading@11:         goto fail;
yading@11:     }
yading@11: 
yading@11:     return 0;
yading@11: 
yading@11: fail:
yading@11:     av_free(contexts);
yading@11:     sap_write_close(s);
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: static int sap_write_packet(AVFormatContext *s, AVPacket *pkt)
yading@11: {
yading@11:     AVFormatContext *rtpctx;
yading@11:     struct SAPState *sap = s->priv_data;
yading@11:     int64_t now = av_gettime();
yading@11: 
yading@11:     if (!sap->last_time || now - sap->last_time > 5000000) {
yading@11:         int ret = ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
yading@11:         /* Don't abort even if we get "Destination unreachable" */
yading@11:         if (ret < 0 && ret != AVERROR(ECONNREFUSED))
yading@11:             return ret;
yading@11:         sap->last_time = now;
yading@11:     }
yading@11:     rtpctx = s->streams[pkt->stream_index]->priv_data;
yading@11:     return ff_write_chained(rtpctx, 0, pkt, s);
yading@11: }
yading@11: 
yading@11: AVOutputFormat ff_sap_muxer = {
yading@11:     .name              = "sap",
yading@11:     .long_name         = NULL_IF_CONFIG_SMALL("SAP output"),
yading@11:     .priv_data_size    = sizeof(struct SAPState),
yading@11:     .audio_codec       = AV_CODEC_ID_AAC,
yading@11:     .video_codec       = AV_CODEC_ID_MPEG4,
yading@11:     .write_header      = sap_write_header,
yading@11:     .write_packet      = sap_write_packet,
yading@11:     .write_trailer     = sap_write_close,
yading@11:     .flags             = AVFMT_NOFILE | AVFMT_GLOBALHEADER,
yading@11: };