aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/sdp.c
blob: 1062c8d3e2ec8a0fe14fb841957ddbcda07dacf0 (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
/*
 * copyright (c) 2007 Luca Abeni
 *
 * 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 "avstring.h"
#include "avformat.h"

#ifdef CONFIG_RTP_MUXER
#define MAX_EXTRADATA_SIZE ((INT_MAX - 10) / 2)

struct sdp_session_level {
    int sdp_version;      /**< protocol version (currently 0) */
    int id;               /**< session id */
    int version;          /**< session version */
    int start_time;       /**< session start time (NTP time, in seconds),
                             or 0 in case of permanent session */
    int end_time;         /**< session end time (NTP time, in seconds),
                               or 0 if the session is not bounded */
    int ttl;              /**< TTL, in case of multicast stream */
    const char *user;     /**< username of the session's creator */
    const char *src_addr; /**< IP address of the machine from which the session was created */
    const char *dst_addr; /**< destination IP address (can be multicast) */
    const char *name;     /**< session name (can be an empty string) */
};

static void dest_write(char *buff, int size, const char *dest_addr, int ttl)
{
    if (dest_addr) {
        if (ttl > 0) {
            av_strlcatf(buff, size, "c=IN IP4 %s/%d\r\n", dest_addr, ttl);
        } else {
            av_strlcatf(buff, size, "c=IN IP4 %s\r\n", dest_addr);
        }
    }
}

static void sdp_write_header(char *buff, int size, struct sdp_session_level *s)
{
    av_strlcatf(buff, size, "v=%d\r\n"
                            "o=- %d %d IN IPV4 %s\r\n"
                            "t=%d %d\r\n"
                            "s=%s\r\n"
                            "a=tool:libavformat\r\n",
                            s->sdp_version,
                            s->id, s->version, s->src_addr,
                            s->start_time, s->end_time,
                            s->name[0] ? s->name : "No Name");
    dest_write(buff, size, s->dst_addr, s->ttl);
}

static int get_address(char *dest_addr, int size, int *ttl, const char *url)
{
    int port;
    const char *p;

    url_split(NULL, 0, NULL, 0, dest_addr, size, &port, NULL, 0, url);

    *ttl = 0;
    p = strchr(url, '?');
    if (p) {
        char buff[64];
        int is_multicast = find_info_tag(buff, sizeof(buff), "multicast", p);

        if (is_multicast) {
            if (find_info_tag(buff, sizeof(buff), "ttl", p)) {
                *ttl = strtol(buff, NULL, 10);
            } else {
                *ttl = 5;
            }
        }
    }

    return port;
}

static void digit_to_char(char *dst, uint8_t src)
{
    if (src < 10) {
        *dst = '0' + src;
    } else {
        *dst = 'A' + src - 10;
    }
}

static char *data_to_hex(char *buff, const uint8_t *src, int s)
{
    int i;

    for(i = 0; i < s; i++) {
        digit_to_char(buff + 2 * i, src[i] >> 4);
        digit_to_char(buff + 2 * i + 1, src[i] & 0xF);
    }

    return buff;
}

static char *sdp_media_attributes(char *buff, int size, AVCodecContext *c, int payload_type)
{
    char *config = NULL;

    switch (c->codec_id) {
        case CODEC_ID_MPEG4:
            if (c->flags & CODEC_FLAG_GLOBAL_HEADER) {
                if (c->extradata_size > MAX_EXTRADATA_SIZE) {
                    av_log(NULL, AV_LOG_ERROR, "Too many extra data!\n");

                    return NULL;
                }
                config = av_malloc(10 + c->extradata_size * 2);
                if (config == NULL) {
                    av_log(NULL, AV_LOG_ERROR, "Cannot allocate memory for the config info\n");
                    return NULL;
                }
                memcpy(config, "; config=", 9);
                data_to_hex(config + 9, c->extradata, c->extradata_size);
                config[9 + c->extradata_size * 2] = 0;
            }
            av_strlcatf(buff, size, "a=rtpmap:%d MP4V-ES/90000\r\n"
                                    "a=fmtp:%d profile-level-id=1%s\r\n",
                                     payload_type,
                                     payload_type, config ? config : "");
            break;
        default:
            /* Nothing special to do, here... */
            break;
    }

    av_free(config);

    return buff;
}

static void sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, int port, int ttl)
{
    const char *type;
    int payload_type;

    payload_type = rtp_get_payload_type(c);
    if (payload_type < 0) {
        payload_type = 96;  /* FIXME: how to assign a private pt? rtp.c is broken too */
    }

    switch (c->codec_type) {
        case CODEC_TYPE_VIDEO   : type = "video"      ; break;
        case CODEC_TYPE_AUDIO   : type = "audio"      ; break;
        case CODEC_TYPE_SUBTITLE: type = "text"       ; break;
        default                 : type = "application"; break;
    }

    av_strlcatf(buff, size, "m=%s %d RTP/AVP %d\r\n", type, port, payload_type);
    dest_write(buff, size, dest_addr, ttl);

    sdp_media_attributes(buff, size, c, payload_type);
}

int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)
{
    struct sdp_session_level s;
    int i, j, port, ttl;
    char dst[32];

    memset(&s, 0, sizeof(struct sdp_session_level));
    s.user = "-";
    s.src_addr = "127.0.0.1";    /* FIXME: Properly set this */
    s.name = ac[0]->title;

    port = 0;
    ttl = 0;
    if (n_files == 1) {
        port = get_address(dst, sizeof(dst), &ttl, ac[0]->filename);
        if (port > 0) {
            s.dst_addr = dst;
            s.ttl = ttl;
        }
    }
    sdp_write_header(buff, size, &s);

    dst[0] = 0;
    for (i = 0; i < n_files; i++) {
        if (n_files != 1) {
            port = get_address(dst, sizeof(dst), &ttl, ac[i]->filename);
        }
        for (j = 0; j < ac[i]->nb_streams; j++) {
            sdp_write_media(buff, size,
                                  ac[i]->streams[j]->codec, dst[0] ? dst : NULL,
                                  (port > 0) ? port + j * 2 : 0, ttl);
            if (port <= 0) {
                av_strlcatf(buff, size,
                                   "a=control:streamid=%d\r\n", i + j);
            }
        }
    }

    return 0;
}
#else
int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)
{
    return AVERROR(ENOSYS);
}
#endif