Imported Debian version 2.4.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavformat / sapdec.c
CommitLineData
2ba45a60
DM
1/*
2 * Session Announcement Protocol (RFC 2974) demuxer
3 * Copyright (c) 2010 Martin Storsjo
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "avformat.h"
23#include "libavutil/avstring.h"
24#include "libavutil/intreadwrite.h"
25#include "network.h"
26#include "os_support.h"
27#include "internal.h"
28#include "avio_internal.h"
29#include "url.h"
30#include "rtpdec.h"
31#if HAVE_POLL_H
32#include <poll.h>
33#endif
34
35struct SAPState {
36 URLContext *ann_fd;
37 AVFormatContext *sdp_ctx;
38 AVIOContext sdp_pb;
39 uint16_t hash;
40 char *sdp;
41 int eof;
42};
43
44static int sap_probe(AVProbeData *p)
45{
46 if (av_strstart(p->filename, "sap:", NULL))
47 return AVPROBE_SCORE_MAX;
48 return 0;
49}
50
51static int sap_read_close(AVFormatContext *s)
52{
53 struct SAPState *sap = s->priv_data;
54 if (sap->sdp_ctx)
55 avformat_close_input(&sap->sdp_ctx);
56 if (sap->ann_fd)
57 ffurl_close(sap->ann_fd);
58 av_freep(&sap->sdp);
59 ff_network_close();
60 return 0;
61}
62
63static int sap_read_header(AVFormatContext *s)
64{
65 struct SAPState *sap = s->priv_data;
66 char host[1024], path[1024], url[1024];
67 uint8_t recvbuf[RTP_MAX_PACKET_LENGTH];
68 int port;
69 int ret, i;
70 AVInputFormat* infmt;
71
72 if (!ff_network_init())
73 return AVERROR(EIO);
74
75 av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port,
76 path, sizeof(path), s->filename);
77 if (port < 0)
78 port = 9875;
79
80 if (!host[0]) {
81 /* Listen for announcements on sap.mcast.net if no host was specified */
82 av_strlcpy(host, "224.2.127.254", sizeof(host));
83 }
84
85 ff_url_join(url, sizeof(url), "udp", NULL, host, port, "?localport=%d",
86 port);
87 ret = ffurl_open(&sap->ann_fd, url, AVIO_FLAG_READ,
88 &s->interrupt_callback, NULL);
89 if (ret)
90 goto fail;
91
92 while (1) {
93 int addr_type, auth_len;
94 int pos;
95
96 ret = ffurl_read(sap->ann_fd, recvbuf, sizeof(recvbuf) - 1);
97 if (ret == AVERROR(EAGAIN))
98 continue;
99 if (ret < 0)
100 goto fail;
101 recvbuf[ret] = '\0'; /* Null terminate for easier parsing */
102 if (ret < 8) {
103 av_log(s, AV_LOG_WARNING, "Received too short packet\n");
104 continue;
105 }
106
107 if ((recvbuf[0] & 0xe0) != 0x20) {
108 av_log(s, AV_LOG_WARNING, "Unsupported SAP version packet "
109 "received\n");
110 continue;
111 }
112
113 if (recvbuf[0] & 0x04) {
114 av_log(s, AV_LOG_WARNING, "Received stream deletion "
115 "announcement\n");
116 continue;
117 }
118 addr_type = recvbuf[0] & 0x10;
119 auth_len = recvbuf[1];
120 sap->hash = AV_RB16(&recvbuf[2]);
121 pos = 4;
122 if (addr_type)
123 pos += 16; /* IPv6 */
124 else
125 pos += 4; /* IPv4 */
126 pos += auth_len * 4;
127 if (pos + 4 >= ret) {
128 av_log(s, AV_LOG_WARNING, "Received too short packet\n");
129 continue;
130 }
131#define MIME "application/sdp"
132 if (strcmp(&recvbuf[pos], MIME) == 0) {
133 pos += strlen(MIME) + 1;
134 } else if (strncmp(&recvbuf[pos], "v=0\r\n", 5) == 0) {
135 // Direct SDP without a mime type
136 } else {
137 av_log(s, AV_LOG_WARNING, "Unsupported mime type %s\n",
138 &recvbuf[pos]);
139 continue;
140 }
141
142 sap->sdp = av_strdup(&recvbuf[pos]);
143 break;
144 }
145
146 av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", sap->sdp);
147 ffio_init_context(&sap->sdp_pb, sap->sdp, strlen(sap->sdp), 0, NULL, NULL,
148 NULL, NULL);
149
150 infmt = av_find_input_format("sdp");
151 if (!infmt)
152 goto fail;
153 sap->sdp_ctx = avformat_alloc_context();
154 if (!sap->sdp_ctx) {
155 ret = AVERROR(ENOMEM);
156 goto fail;
157 }
158 sap->sdp_ctx->max_delay = s->max_delay;
159 sap->sdp_ctx->pb = &sap->sdp_pb;
160 sap->sdp_ctx->interrupt_callback = s->interrupt_callback;
161 ret = avformat_open_input(&sap->sdp_ctx, "temp.sdp", infmt, NULL);
162 if (ret < 0)
163 goto fail;
164 if (sap->sdp_ctx->ctx_flags & AVFMTCTX_NOHEADER)
165 s->ctx_flags |= AVFMTCTX_NOHEADER;
166 for (i = 0; i < sap->sdp_ctx->nb_streams; i++) {
167 AVStream *st = avformat_new_stream(s, NULL);
168 if (!st) {
169 ret = AVERROR(ENOMEM);
170 goto fail;
171 }
172 st->id = i;
173 avcodec_copy_context(st->codec, sap->sdp_ctx->streams[i]->codec);
174 st->time_base = sap->sdp_ctx->streams[i]->time_base;
175 }
176
177 return 0;
178
179fail:
180 sap_read_close(s);
181 return ret;
182}
183
184static int sap_fetch_packet(AVFormatContext *s, AVPacket *pkt)
185{
186 struct SAPState *sap = s->priv_data;
187 int fd = ffurl_get_file_handle(sap->ann_fd);
188 int n, ret;
189 struct pollfd p = {fd, POLLIN, 0};
190 uint8_t recvbuf[RTP_MAX_PACKET_LENGTH];
191
192 if (sap->eof)
193 return AVERROR_EOF;
194
195 while (1) {
196 n = poll(&p, 1, 0);
197 if (n <= 0 || !(p.revents & POLLIN))
198 break;
199 ret = ffurl_read(sap->ann_fd, recvbuf, sizeof(recvbuf));
200 if (ret >= 8) {
201 uint16_t hash = AV_RB16(&recvbuf[2]);
202 /* Should ideally check the source IP address, too */
203 if (recvbuf[0] & 0x04 && hash == sap->hash) {
204 /* Stream deletion */
205 sap->eof = 1;
206 return AVERROR_EOF;
207 }
208 }
209 }
210 ret = av_read_frame(sap->sdp_ctx, pkt);
211 if (ret < 0)
212 return ret;
213 if (s->ctx_flags & AVFMTCTX_NOHEADER) {
214 while (sap->sdp_ctx->nb_streams > s->nb_streams) {
215 int i = s->nb_streams;
216 AVStream *st = avformat_new_stream(s, NULL);
217 if (!st) {
218 av_free_packet(pkt);
219 return AVERROR(ENOMEM);
220 }
221 st->id = i;
222 avcodec_copy_context(st->codec, sap->sdp_ctx->streams[i]->codec);
223 st->time_base = sap->sdp_ctx->streams[i]->time_base;
224 }
225 }
226 return ret;
227}
228
229AVInputFormat ff_sap_demuxer = {
230 .name = "sap",
231 .long_name = NULL_IF_CONFIG_SMALL("SAP input"),
232 .priv_data_size = sizeof(struct SAPState),
233 .read_probe = sap_probe,
234 .read_header = sap_read_header,
235 .read_packet = sap_fetch_packet,
236 .read_close = sap_read_close,
237 .flags = AVFMT_NOFILE,
238};