From 01c8d258da5db97e67ac89af493ffb9bc2f82d2d Mon Sep 17 00:00:00 2001 From: Martin Storsjö Date: Wed, 13 Oct 2010 09:06:59 +0000 Subject: Add a SAP demuxer Originally committed as revision 25463 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavformat/sapdec.c | 238 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 238 insertions(+) create mode 100644 libavformat/sapdec.c (limited to 'libavformat/sapdec.c') diff --git a/libavformat/sapdec.c b/libavformat/sapdec.c new file mode 100644 index 0000000000..19d524314a --- /dev/null +++ b/libavformat/sapdec.c @@ -0,0 +1,238 @@ +/* + * 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/avstring.h" +#include "libavutil/intreadwrite.h" +#include "network.h" +#include "os_support.h" +#include "internal.h" +#if HAVE_SYS_SELECT_H +#include +#endif + +struct SAPState { + URLContext *ann_fd; + AVFormatContext *sdp_ctx; + ByteIOContext 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) + av_close_input_stream(sap->sdp_ctx); + if (sap->ann_fd) + url_close(sap->ann_fd); + av_freep(&sap->sdp); + ff_network_close(); + return 0; +} + +static int sap_read_header(AVFormatContext *s, + AVFormatParameters *ap) +{ + struct SAPState *sap = s->priv_data; + char host[1024], path[1024], url[1024]; + uint8_t recvbuf[1500]; + 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 = url_open(&sap->ann_fd, url, URL_RDONLY); + if (ret) + goto fail; + + while (1) { + int addr_type, auth_len; + int pos; + + ret = url_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); + init_put_byte(&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; + ap->prealloced_context = 1; + ret = av_open_input_stream(&sap->sdp_ctx, &sap->sdp_pb, "temp.sdp", + infmt, ap); + 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 = av_new_stream(s, i); + if (!st) { + ret = AVERROR(ENOMEM); + goto fail; + } + 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 = url_get_file_handle(sap->ann_fd); + int n, ret; + fd_set rfds; + struct timeval tv; + uint8_t recvbuf[1500]; + + if (sap->eof) + return AVERROR_EOF; + + while (1) { + FD_ZERO(&rfds); + FD_SET(fd, &rfds); + tv.tv_sec = tv.tv_usec = 0; + n = select(fd + 1, &rfds, NULL, NULL, &tv); + if (n <= 0 || !FD_ISSET(fd, &rfds)) + break; + ret = url_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 = av_new_stream(s, i); + if (!st) { + av_free_packet(pkt); + return AVERROR(ENOMEM); + } + avcodec_copy_context(st->codec, sap->sdp_ctx->streams[i]->codec); + st->time_base = sap->sdp_ctx->streams[i]->time_base; + } + } + return ret; +} + +AVInputFormat sap_demuxer = { + "sap", + NULL_IF_CONFIG_SMALL("SAP input format"), + sizeof(struct SAPState), + sap_probe, + sap_read_header, + sap_fetch_packet, + sap_read_close, + .flags = AVFMT_NOFILE, +}; + -- cgit v1.2.3