Add a SAP (Session Announcement Protocol, RFC 2974) muxer

Originally committed as revision 25413 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -1363,6 +1363,7 @@ ogg_demuxer_select="golomb"
 psp_muxer_select="mov_muxer"
 rtsp_demuxer_select="http_protocol sdp_demuxer"
 rtsp_muxer_select="rtp_muxer http_protocol sdp_demuxer"
+sap_muxer_select="rtp_muxer"
 sdp_demuxer_select="asf_demuxer rm_demuxer rtp_protocol mpegts_demuxer mov_demuxer"
 spdif_muxer_select="aac_parser"
 tg2_muxer_select="mov_muxer"

doc/general.texi

@@ -217,6 +217,7 @@ library:
     @tab Output is performed by publishing stream to RTMP server
 @item RTP                       @tab X @tab
 @item RTSP                      @tab X @tab X
+@item SAP                       @tab X @tab
 @item SDP                       @tab   @tab X
 @item Sega FILM/CPK             @tab   @tab X
     @tab Used in many Sega Saturn console games.

libavformat/Makefile

@@ -229,6 +229,7 @@ OBJS-$(CONFIG_RTP_MUXER)                 += rtp.o         \
                                             avc.o
 OBJS-$(CONFIG_RTSP_DEMUXER)              += rtsp.o httpauth.o
 OBJS-$(CONFIG_RTSP_MUXER)                += rtsp.o rtspenc.o httpauth.o
+OBJS-$(CONFIG_SAP_MUXER)                 += sapenc.o rtpenc_chain.o
 OBJS-$(CONFIG_SDP_DEMUXER)               += rtsp.o        \
                                             rdt.o         \
                                             rtp.o         \

libavformat/allformats.c

@@ -181,6 +181,7 @@ void av_register_all(void)
     REGISTER_MUXDEMUX (RSO, rso);
     REGISTER_MUXER    (RTP, rtp);
     REGISTER_MUXDEMUX (RTSP, rtsp);
+    REGISTER_MUXER    (SAP, sap);
     REGISTER_DEMUXER  (SDP, sdp);
 #if CONFIG_SDP_DEMUXER
     av_register_rtp_dynamic_payload_handlers();

libavformat/sapenc.c

+/*
+ * Session Announcement Protocol (RFC 2974) muxer
+ * 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/random_seed.h"
+#include "libavutil/avstring.h"
+#include "libavutil/intreadwrite.h"
+#include "internal.h"
+#include "network.h"
+#include "rtpenc_chain.h"
+
+struct SAPState {
+    uint8_t    *ann;
+    int         ann_size;
+    URLContext *ann_fd;
+    int64_t     last_time;
+};
+
+static int sap_write_close(AVFormatContext *s)
+{
+    struct SAPState *sap = s->priv_data;
+    int i;
+
+    for (i = 0; i < s->nb_streams; i++) {
+        AVFormatContext *rtpctx = s->streams[i]->priv_data;
+        if (!rtpctx)
+            continue;
+        av_write_trailer(rtpctx);
+        url_fclose(rtpctx->pb);
+        av_metadata_free(&rtpctx->streams[0]->metadata);
+        av_metadata_free(&rtpctx->metadata);
+        av_free(rtpctx->streams[0]);
+        av_free(rtpctx);
+        s->streams[i]->priv_data = NULL;
+    }
+
+    if (sap->last_time && sap->ann && sap->ann_fd) {
+        sap->ann[0] |= 4; /* Session deletion*/
+        url_write(sap->ann_fd, sap->ann, sap->ann_size);
+    }
+
+    av_freep(&sap->ann);
+    if (sap->ann_fd)
+        url_close(sap->ann_fd);
+    ff_network_close();
+    return 0;
+}
+
+static int sap_write_header(AVFormatContext *s)
+{
+    struct SAPState *sap = s->priv_data;
+    char host[1024], path[1024], url[1024], announce_addr[50] = "";
+    char *option_list;
+    int port, base_port = 5004, i, pos = 0, same_port = 0, ttl = 255;
+    AVFormatContext **contexts = NULL;
+    int ret = 0;
+    struct sockaddr_storage localaddr;
+    socklen_t addrlen = sizeof(localaddr);
+    int udp_fd;
+
+    if (!ff_network_init())
+        return AVERROR(EIO);
+
+    /* extract hostname and port */
+    av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port,
+                 path, sizeof(path), s->filename);
+    if (port < 0)
+        port = 9875;
+
+    /* search for options */
+    option_list = strrchr(path, '?');
+    if (option_list) {
+        char buf[50];
+        if (find_info_tag(buf, sizeof(buf), "base_port", option_list)) {
+            base_port = strtol(buf, NULL, 10);
+        }
+        if (find_info_tag(buf, sizeof(buf), "same_port", option_list)) {
+            same_port = strtol(buf, NULL, 10);
+        }
+        if (find_info_tag(buf, sizeof(buf), "ttl", option_list)) {
+            ttl = strtol(buf, NULL, 10);
+        }
+        if (find_info_tag(buf, sizeof(buf), "announce_addr", option_list)) {
+            av_strlcpy(announce_addr, buf, sizeof(announce_addr));
+        }
+    }
+
+    if (!announce_addr[0]) {
+        struct addrinfo hints, *ai = NULL;
+        memset(&hints, 0, sizeof(hints));
+        hints.ai_family = PF_UNSPEC;
+        if (getaddrinfo(host, NULL, &hints, &ai)) {
+            av_log(s, AV_LOG_ERROR, "Unable to resolve %s\n", host);
+            ret = AVERROR(EIO);
+            goto fail;
+        }
+        if (ai->ai_family == AF_INET) {
+            /* Also known as sap.mcast.net */
+            av_strlcpy(announce_addr, "224.2.127.254", sizeof(announce_addr));
+        } else if (ai->ai_family == AF_INET6) {
+            /* With IPv6, you can use the same destination in many different
+             * multicast subnets, to choose how far you want it routed.
+             * This one is intended to be routed globally. */
+            av_strlcpy(announce_addr, "ff0e::2:7ffe", sizeof(announce_addr));
+        } else {
+            freeaddrinfo(ai);
+            av_log(s, AV_LOG_ERROR, "Host %s resolved to unsupported "
+                                    "address family\n", host);
+            ret = AVERROR(EIO);
+            goto fail;
+        }
+        freeaddrinfo(ai);
+    }
+
+    contexts = av_mallocz(sizeof(AVFormatContext*) * s->nb_streams);
+    if (!contexts) {
+        ret = AVERROR(ENOMEM);
+        goto fail;
+    }
+
+    s->start_time_realtime = av_gettime();
+    for (i = 0; i < s->nb_streams; i++) {
+        URLContext *fd;
+
+        ff_url_join(url, sizeof(url), "rtp", NULL, host, base_port,
+                    "?ttl=%d", ttl);
+        if (!same_port)
+            base_port += 2;
+        ret = url_open(&fd, url, URL_WRONLY);
+        if (ret) {
+            ret = AVERROR(EIO);
+            goto fail;
+        }
+        s->streams[i]->priv_data = contexts[i] =
+            ff_rtp_chain_mux_open(s, s->streams[i], fd, 0);
+        av_strlcpy(contexts[i]->filename, url, sizeof(contexts[i]->filename));
+    }
+
+    ff_url_join(url, sizeof(url), "udp", NULL, announce_addr, port,
+                "?ttl=%d&connect=1", ttl);
+    ret = url_open(&sap->ann_fd, url, URL_WRONLY);
+    if (ret) {
+        ret = AVERROR(EIO);
+        goto fail;
+    }
+
+    udp_fd = url_get_file_handle(sap->ann_fd);
+    if (getsockname(udp_fd, (struct sockaddr*) &localaddr, &addrlen)) {
+        ret = AVERROR(EIO);
+        goto fail;
+    }
+    if (localaddr.ss_family != AF_INET && localaddr.ss_family != AF_INET6) {
+        av_log(s, AV_LOG_ERROR, "Unsupported protocol family\n");
+        ret = AVERROR(EIO);
+        goto fail;
+    }
+    sap->ann_size = 8192;
+    sap->ann = av_mallocz(sap->ann_size);
+    if (!sap->ann) {
+        ret = AVERROR(EIO);
+        goto fail;
+    }
+    sap->ann[pos++] = (1 << 5) | ((localaddr.ss_family == AF_INET6) << 4);
+    sap->ann[pos++] = 0; /* Authentication length */
+    AV_WB16(&sap->ann[pos], av_get_random_seed());
+    pos += 2;
+    if (localaddr.ss_family == AF_INET) {
+        memcpy(&sap->ann[pos], &((struct sockaddr_in*)&localaddr)->sin_addr,
+               sizeof(struct in_addr));
+        pos += sizeof(struct in_addr);
+    } else {
+        memcpy(&sap->ann[pos], &((struct sockaddr_in6*)&localaddr)->sin6_addr,
+               sizeof(struct in6_addr));
+        pos += sizeof(struct in6_addr);
+    }
+
+    av_strlcpy(&sap->ann[pos], "application/sdp", sap->ann_size - pos);
+    pos += strlen(&sap->ann[pos]) + 1;
+
+    if (avf_sdp_create(contexts, s->nb_streams, &sap->ann[pos],
+                       sap->ann_size - pos)) {
+        ret = AVERROR_INVALIDDATA;
+        goto fail;
+    }
+    av_freep(&contexts);
+    av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", &sap->ann[pos]);
+    pos += strlen(&sap->ann[pos]);
+    sap->ann_size = pos;
+
+    if (sap->ann_size > url_get_max_packet_size(sap->ann_fd)) {
+        av_log(s, AV_LOG_ERROR, "Announcement too large to send in one "
+                                "packet\n");
+        goto fail;
+    }
+
+    return 0;
+
+fail:
+    av_free(contexts);
+    sap_write_close(s);
+    return ret;
+}
+
+static int sap_write_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVFormatContext *rtpctx;
+    struct SAPState *sap = s->priv_data;
+    int64_t now = av_gettime();
+
+    if (!sap->last_time || now - sap->last_time > 5000000) {
+        int ret = url_write(sap->ann_fd, sap->ann, sap->ann_size);
+        /* Don't abort even if we get "Destination unreachable" */
+        if (ret < 0 && ret != FF_NETERROR(ECONNREFUSED))
+            return ret;
+        sap->last_time = now;
+    }
+    rtpctx = s->streams[pkt->stream_index]->priv_data;
+    return ff_write_chained(rtpctx, 0, pkt, s);
+}
+
+AVOutputFormat sap_muxer = {
+    "sap",
+    NULL_IF_CONFIG_SMALL("SAP output format"),
+    NULL,
+    NULL,
+    sizeof(struct SAPState),
+    CODEC_ID_AAC,
+    CODEC_ID_MPEG4,
+    sap_write_header,
+    sap_write_packet,
+    sap_write_close,
+    .flags = AVFMT_NOFILE | AVFMT_GLOBALHEADER,
+};
+