| /* |
| * 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 "libavutil/avassert.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; |
| AVIOContext sdp_pb; |
| uint16_t hash; |
| char *sdp; |
| int eof; |
| }; |
| |
| static int sap_probe(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); |
| if (sap->ann_fd) |
| ffurl_close(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]; |
| int port; |
| int ret, i; |
| AVInputFormat* infmt; |
| |
| if (!ff_network_init()) |
| return AVERROR(EIO); |
| |
| av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port, |
| path, sizeof(path), s->filename); |
| 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); |
| 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]); |
| break; |
| } |
| |
| av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", sap->sdp); |
| ffio_init_context(&sap->sdp_pb, sap->sdp, strlen(sap->sdp), 0, NULL, NULL, |
| NULL, NULL); |
| |
| 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; |
| sap->sdp_ctx->interrupt_callback = s->interrupt_callback; |
| |
| if ((ret = ff_copy_whitelists(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_copy_context(st->codec, sap->sdp_ctx->streams[i]->codec); |
| 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 (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) { |
| av_packet_unref(pkt); |
| return AVERROR(ENOMEM); |
| } |
| st->id = i; |
| avcodec_copy_context(st->codec, sap->sdp_ctx->streams[i]->codec); |
| st->time_base = sap->sdp_ctx->streams[i]->time_base; |
| } |
| } |
| return ret; |
| } |
| |
| AVInputFormat ff_sap_demuxer = { |
| .name = "sap", |
| .long_name = NULL_IF_CONFIG_SMALL("SAP input"), |
| .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, |
| .flags = AVFMT_NOFILE, |
| }; |
