aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/sapenc.c
blob: 3098e340ca94a4dae3afd6596cac9f1a0ba4af39 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
/*
 * 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/parseutils.h"
#include "libavutil/random_seed.h"
#include "libavutil/avstring.h"
#include "libavutil/dict.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/time.h"
#include "internal.h"
#include "network.h"
#include "os_support.h"
#include "rtpenc_chain.h"
#include "url.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);
        avio_closep(&rtpctx->pb);
        avformat_free_context(rtpctx);
        s->streams[i]->priv_data = NULL;
    }

    if (sap->last_time && sap->ann && sap->ann_fd) {
        sap->ann[0] |= 4; /* Session deletion*/
        ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
    }

    av_freep(&sap->ann);
    if (sap->ann_fd)
        ffurl_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 = 9875, 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;
    AVDictionaryEntry* title = av_dict_get(s->metadata, "title", NULL, 0);

    if (!ff_network_init())
        return AVERROR(EIO);

    /* extract hostname and port */
    av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &base_port,
                 path, sizeof(path), s->filename);
    if (base_port < 0)
        base_port = 5004;

    /* search for options */
    option_list = strrchr(path, '?');
    if (option_list) {
        char buf[50];
        if (av_find_info_tag(buf, sizeof(buf), "announce_port", option_list)) {
            port = strtol(buf, NULL, 10);
        }
        if (av_find_info_tag(buf, sizeof(buf), "same_port", option_list)) {
            same_port = strtol(buf, NULL, 10);
        }
        if (av_find_info_tag(buf, sizeof(buf), "ttl", option_list)) {
            ttl = strtol(buf, NULL, 10);
        }
        if (av_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 = { 0 }, *ai = NULL;
        hints.ai_family = AF_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));
#if HAVE_STRUCT_SOCKADDR_IN6
        } 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));
#endif
        } 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_array(s->nb_streams, sizeof(AVFormatContext*));
    if (!contexts) {
        ret = AVERROR(ENOMEM);
        goto fail;
    }

    if (s->start_time_realtime == 0  ||  s->start_time_realtime == AV_NOPTS_VALUE)
        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 = ffurl_open_whitelist(&fd, url, AVIO_FLAG_WRITE,
                                   &s->interrupt_callback, NULL,
                                   s->protocol_whitelist, s->protocol_blacklist, NULL);
        if (ret) {
            ret = AVERROR(EIO);
            goto fail;
        }
        ret = ff_rtp_chain_mux_open(&contexts[i], s, s->streams[i], fd, 0, i);
        if (ret < 0)
            goto fail;
        s->streams[i]->priv_data = contexts[i];
        s->streams[i]->time_base = contexts[i]->streams[0]->time_base;
        av_strlcpy(contexts[i]->filename, url, sizeof(contexts[i]->filename));
    }

    if (s->nb_streams > 0 && title)
        av_dict_set(&contexts[0]->metadata, "title", title->value, 0);

    ff_url_join(url, sizeof(url), "udp", NULL, announce_addr, port,
                "?ttl=%d&connect=1", ttl);
    ret = ffurl_open_whitelist(&sap->ann_fd, url, AVIO_FLAG_WRITE,
                               &s->interrupt_callback, NULL,
                               s->protocol_whitelist, s->protocol_blacklist, NULL);
    if (ret) {
        ret = AVERROR(EIO);
        goto fail;
    }

    udp_fd = ffurl_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
#if HAVE_STRUCT_SOCKADDR_IN6
        && localaddr.ss_family != AF_INET6
#endif
        ) {
        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);
#if HAVE_STRUCT_SOCKADDR_IN6
    if (localaddr.ss_family == AF_INET6)
        sap->ann[pos] |= 0x10;
#endif
    pos++;
    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);
#if HAVE_STRUCT_SOCKADDR_IN6
    } else {
        memcpy(&sap->ann[pos], &((struct sockaddr_in6*)&localaddr)->sin6_addr,
               sizeof(struct in6_addr));
        pos += sizeof(struct in6_addr);
#endif
    }

    av_strlcpy(&sap->ann[pos], "application/sdp", sap->ann_size - pos);
    pos += strlen(&sap->ann[pos]) + 1;

    if (av_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 > sap->ann_fd->max_packet_size) {
        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_relative();

    if (!sap->last_time || now - sap->last_time > 5000000) {
        int ret = ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
        /* Don't abort even if we get "Destination unreachable" */
        if (ret < 0 && ret != AVERROR(ECONNREFUSED))
            return ret;
        sap->last_time = now;
    }
    rtpctx = s->streams[pkt->stream_index]->priv_data;
    return ff_write_chained(rtpctx, 0, pkt, s, 0);
}

AVOutputFormat ff_sap_muxer = {
    .name              = "sap",
    .long_name         = NULL_IF_CONFIG_SMALL("SAP output"),
    .priv_data_size    = sizeof(struct SAPState),
    .audio_codec       = AV_CODEC_ID_AAC,
    .video_codec       = AV_CODEC_ID_MPEG4,
    .write_header      = sap_write_header,
    .write_packet      = sap_write_packet,
    .write_trailer     = sap_write_close,
    .flags             = AVFMT_NOFILE | AVFMT_GLOBALHEADER,
};