| /* | |
| * Session Announcement Protocol (RFC 2974) demuxer | |
| * Copyright (c) 2010 Martin Storsjo | |
| * | |
| * This file is part of FFmpeg. | |
| * | |
| * FFmpeg is free software; you can redistribute it and/or | |
| * modify it under the terms of the GNU Lesser General Public | |
| * License as published by the Free Software Foundation; either | |
| * version 2.1 of the License, or (at your option) any later version. | |
| * | |
| * FFmpeg is distributed in the hope that it will be useful, | |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| * Lesser General Public License for more details. | |
| * | |
| * You should have received a copy of the GNU Lesser General Public | |
| * License along with FFmpeg; if not, write to the Free Software | |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
| */ | |
| #include "avformat.h" | |
| #include "demux.h" | |
| #include "libavutil/avstring.h" | |
| #include "libavutil/intreadwrite.h" | |
| #include "network.h" | |
| #include "os_support.h" | |
| #include "internal.h" | |
| #include "avio_internal.h" | |
| #include "url.h" | |
| #include "rtpdec.h" | |
| #if HAVE_POLL_H | |
| #include <poll.h> | |
| #endif | |
| struct SAPState { | |
| URLContext *ann_fd; | |
| AVFormatContext *sdp_ctx; | |
| FFIOContext sdp_pb; | |
| uint16_t hash; | |
| char *sdp; | |
| int eof; | |
| }; | |
| static int sap_probe(const AVProbeData *p) | |
| { | |
| if (av_strstart(p->filename, "sap:", NULL)) | |
| return AVPROBE_SCORE_MAX; | |
| return 0; | |
| } | |
| static int sap_read_close(AVFormatContext *s) | |
| { | |
| struct SAPState *sap = s->priv_data; | |
| if (sap->sdp_ctx) | |
| avformat_close_input(&sap->sdp_ctx); | |
| ffurl_closep(&sap->ann_fd); | |
| av_freep(&sap->sdp); | |
| ff_network_close(); | |
| return 0; | |
| } | |
| static int sap_read_header(AVFormatContext *s) | |
| { | |
| struct SAPState *sap = s->priv_data; | |
| char host[1024], path[1024], url[1024]; | |
| uint8_t recvbuf[RTP_MAX_PACKET_LENGTH]; | |
| const AVInputFormat *infmt; | |
| int port; | |
| int ret, i; | |
| if (!ff_network_init()) | |
| return AVERROR(EIO); | |
| av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port, | |
| path, sizeof(path), s->url); | |
| if (port < 0) | |
| port = 9875; | |
| if (!host[0]) { | |
| /* Listen for announcements on sap.mcast.net if no host was specified */ | |
| av_strlcpy(host, "224.2.127.254", sizeof(host)); | |
| } | |
| ff_url_join(url, sizeof(url), "udp", NULL, host, port, "?localport=%d", | |
| port); | |
| ret = ffurl_open_whitelist(&sap->ann_fd, url, AVIO_FLAG_READ, | |
| &s->interrupt_callback, NULL, | |
| s->protocol_whitelist, s->protocol_blacklist, NULL); | |
| if (ret) | |
| goto fail; | |
| while (1) { | |
| int addr_type, auth_len; | |
| int pos; | |
| ret = ffurl_read(sap->ann_fd, recvbuf, sizeof(recvbuf) - 1); | |
| if (ret == AVERROR(EAGAIN)) | |
| continue; | |
| if (ret < 0) | |
| goto fail; | |
| recvbuf[ret] = '\0'; /* Null terminate for easier parsing */ | |
| if (ret < 8) { | |
| av_log(s, AV_LOG_WARNING, "Received too short packet\n"); | |
| continue; | |
| } | |
| if ((recvbuf[0] & 0xe0) != 0x20) { | |
| av_log(s, AV_LOG_WARNING, "Unsupported SAP version packet " | |
| "received\n"); | |
| continue; | |
| } | |
| if (recvbuf[0] & 0x04) { | |
| av_log(s, AV_LOG_WARNING, "Received stream deletion " | |
| "announcement\n"); | |
| continue; | |
| } | |
| addr_type = recvbuf[0] & 0x10; | |
| auth_len = recvbuf[1]; | |
| sap->hash = AV_RB16(&recvbuf[2]); | |
| pos = 4; | |
| if (addr_type) | |
| pos += 16; /* IPv6 */ | |
| else | |
| pos += 4; /* IPv4 */ | |
| pos += auth_len * 4; | |
| if (pos + 4 >= ret) { | |
| av_log(s, AV_LOG_WARNING, "Received too short packet\n"); | |
| continue; | |
| } | |
| #define MIME "application/sdp" | |
| if (strcmp(&recvbuf[pos], MIME) == 0) { | |
| pos += strlen(MIME) + 1; | |
| } else if (strncmp(&recvbuf[pos], "v=0\r\n", 5) == 0) { | |
| // Direct SDP without a mime type | |
| } else { | |
| av_log(s, AV_LOG_WARNING, "Unsupported mime type %s\n", | |
| &recvbuf[pos]); | |
| continue; | |
| } | |
| sap->sdp = av_strdup(&recvbuf[pos]); | |
| if (!sap->sdp) { | |
| ret = AVERROR(ENOMEM); | |
| goto fail; | |
| } | |
| break; | |
| } | |
| av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", sap->sdp); | |
| ffio_init_read_context(&sap->sdp_pb, sap->sdp, strlen(sap->sdp)); | |
| infmt = av_find_input_format("sdp"); | |
| if (!infmt) | |
| goto fail; | |
| sap->sdp_ctx = avformat_alloc_context(); | |
| if (!sap->sdp_ctx) { | |
| ret = AVERROR(ENOMEM); | |
| goto fail; | |
| } | |
| sap->sdp_ctx->max_delay = s->max_delay; | |
| sap->sdp_ctx->pb = &sap->sdp_pb.pub; | |
| sap->sdp_ctx->interrupt_callback = s->interrupt_callback; | |
| if ((ret = ff_copy_whiteblacklists(sap->sdp_ctx, s)) < 0) | |
| goto fail; | |
| ret = avformat_open_input(&sap->sdp_ctx, "temp.sdp", infmt, NULL); | |
| if (ret < 0) | |
| goto fail; | |
| if (sap->sdp_ctx->ctx_flags & AVFMTCTX_NOHEADER) | |
| s->ctx_flags |= AVFMTCTX_NOHEADER; | |
| for (i = 0; i < sap->sdp_ctx->nb_streams; i++) { | |
| AVStream *st = avformat_new_stream(s, NULL); | |
| if (!st) { | |
| ret = AVERROR(ENOMEM); | |
| goto fail; | |
| } | |
| st->id = i; | |
| avcodec_parameters_copy(st->codecpar, sap->sdp_ctx->streams[i]->codecpar); | |
| st->time_base = sap->sdp_ctx->streams[i]->time_base; | |
| } | |
| return 0; | |
| fail: | |
| sap_read_close(s); | |
| return ret; | |
| } | |
| static int sap_fetch_packet(AVFormatContext *s, AVPacket *pkt) | |
| { | |
| struct SAPState *sap = s->priv_data; | |
| int fd = ffurl_get_file_handle(sap->ann_fd); | |
| int n, ret; | |
| struct pollfd p = {fd, POLLIN, 0}; | |
| uint8_t recvbuf[RTP_MAX_PACKET_LENGTH]; | |
| if (fd < 0) | |
| return fd; | |
| if (sap->eof) | |
| return AVERROR_EOF; | |
| while (1) { | |
| n = poll(&p, 1, 0); | |
| if (n <= 0 || !(p.revents & POLLIN)) | |
| break; | |
| ret = ffurl_read(sap->ann_fd, recvbuf, sizeof(recvbuf)); | |
| if (ret >= 8) { | |
| uint16_t hash = AV_RB16(&recvbuf[2]); | |
| /* Should ideally check the source IP address, too */ | |
| if (recvbuf[0] & 0x04 && hash == sap->hash) { | |
| /* Stream deletion */ | |
| sap->eof = 1; | |
| return AVERROR_EOF; | |
| } | |
| } | |
| } | |
| ret = av_read_frame(sap->sdp_ctx, pkt); | |
| if (ret < 0) | |
| return ret; | |
| if (s->ctx_flags & AVFMTCTX_NOHEADER) { | |
| while (sap->sdp_ctx->nb_streams > s->nb_streams) { | |
| int i = s->nb_streams; | |
| AVStream *st = avformat_new_stream(s, NULL); | |
| if (!st) { | |
| return AVERROR(ENOMEM); | |
| } | |
| st->id = i; | |
| avcodec_parameters_copy(st->codecpar, sap->sdp_ctx->streams[i]->codecpar); | |
| st->time_base = sap->sdp_ctx->streams[i]->time_base; | |
| } | |
| } | |
| return ret; | |
| } | |
| const FFInputFormat ff_sap_demuxer = { | |
| .p.name = "sap", | |
| .p.long_name = NULL_IF_CONFIG_SMALL("SAP input"), | |
| .p.flags = AVFMT_NOFILE, | |
| .priv_data_size = sizeof(struct SAPState), | |
| .read_probe = sap_probe, | |
| .read_header = sap_read_header, | |
| .read_packet = sap_fetch_packet, | |
| .read_close = sap_read_close, | |
| }; |