2 * Realmedia RTSP protocol (RDT) support.
3 * Copyright (c) 2007 Ronald S. Bultje
5 * This file is part of FFmpeg.
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.
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.
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
24 * @brief Realmedia RTSP protocol (RDT) support
25 * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
29 #include "libavutil/avstring.h"
30 #include "rtp_internal.h"
32 #include "libavutil/base64.h"
33 #include "libavutil/md5.h"
37 struct RDTDemuxContext {
40 void *dynamic_protocol_context;
41 DynamicPayloadPacketHandlerProc parse_packet;
42 uint32_t prev_sn, prev_ts;
46 ff_rdt_parse_open(AVFormatContext *ic, AVStream *st,
47 void *priv_data, RTPDynamicProtocolHandler *handler)
49 RDTDemuxContext *s = av_mallocz(sizeof(RDTDemuxContext));
57 s->parse_packet = handler->parse_packet;
58 s->dynamic_protocol_context = priv_data;
64 ff_rdt_parse_close(RDTDemuxContext *s)
69 struct PayloadContext {
70 AVFormatContext *rmctx;
72 unsigned int mlti_data_size;
73 char buffer[RTP_MAX_PACKET_LENGTH + FF_INPUT_BUFFER_PADDING_SIZE];
77 ff_rdt_calc_response_and_checksum(char response[41], char chksum[9],
78 const char *challenge)
80 int ch_len = strlen (challenge), i;
81 unsigned char zres[16],
82 buf[64] = { 0xa1, 0xe9, 0x14, 0x9d, 0x0e, 0x6b, 0x3b, 0x59 };
83 #define XOR_TABLE_SIZE 37
84 const unsigned char xor_table[XOR_TABLE_SIZE] = {
85 0x05, 0x18, 0x74, 0xd0, 0x0d, 0x09, 0x02, 0x53,
86 0xc0, 0x01, 0x05, 0x05, 0x67, 0x03, 0x19, 0x70,
87 0x08, 0x27, 0x66, 0x10, 0x10, 0x72, 0x08, 0x09,
88 0x63, 0x11, 0x03, 0x71, 0x08, 0x08, 0x70, 0x02,
89 0x10, 0x57, 0x05, 0x18, 0x54 };
91 /* some (length) checks */
92 if (ch_len == 40) /* what a hack... */
96 memcpy(buf + 8, challenge, ch_len);
98 /* xor challenge bytewise with xor_table */
99 for (i = 0; i < XOR_TABLE_SIZE; i++)
100 buf[8 + i] ^= xor_table[i];
102 av_md5_sum(zres, buf, 64);
103 ff_data_to_hex(response, zres, 16);
104 for (i=0;i<32;i++) response[i] = tolower(response[i]);
107 strcpy (response + 32, "01d0a8e3");
109 /* calculate checksum */
110 for (i = 0; i < 8; i++)
111 chksum[i] = response[i * 4];
116 rdt_load_mdpr (PayloadContext *rdt, AVStream *st, int rule_nr)
123 * Layout of the MLTI chunk:
125 * 2:<number of streams>
126 * Then for each stream ([number_of_streams] times):
128 * 2:<number of mdpr chunks>
129 * Then for each mdpr chunk ([number_of_mdpr_chunks] times):
132 * we skip MDPR chunks until we reach the one of the stream
133 * we're interested in, and forward that ([size]+[data]) to
134 * the RM demuxer to parse the stream-specific header data.
138 url_open_buf(&pb, rdt->mlti_data, rdt->mlti_data_size, URL_RDONLY);
140 if (tag == MKTAG('M', 'L', 'T', 'I')) {
143 /* read index of MDPR chunk numbers */
145 if (rule_nr < 0 || rule_nr >= num)
147 url_fskip(pb, rule_nr * 2);
148 chunk_nr = get_be16(pb);
149 url_fskip(pb, (num - 1 - rule_nr) * 2);
151 /* read MDPR chunks */
156 url_fskip(pb, get_be32(pb));
159 size = rdt->mlti_data_size;
160 url_fseek(pb, 0, SEEK_SET);
163 if (ff_rm_read_mdpr_codecdata(rdt->rmctx, st, size) < 0)
171 * Actual data handling.
175 ff_rdt_parse_header(const uint8_t *buf, int len,
176 int *sn, int *seq, int *rn, uint32_t *ts)
180 if (len > 0 && (buf[0] < 0x40 || buf[0] > 0x42)) {
187 if (sn) *sn = (buf[0]>>1) & 0x1f;
188 if (seq) *seq = AV_RB16(buf+1);
189 if (ts) *ts = AV_RB32(buf+4);
190 if (rn) *rn = buf[3] & 0x3f;
195 /**< return 0 on packet, no more left, 1 on packet, 1 on partial packet... */
197 rdt_parse_packet (PayloadContext *rdt, AVStream *st,
198 AVPacket *pkt, uint32_t *timestamp,
199 const uint8_t *buf, int len, int flags)
202 ByteIOContext *pb = rdt->rmctx->pb;
203 RMContext *rm = rdt->rmctx->priv_data;
205 if (rm->audio_pkt_cnt == 0) {
208 url_open_buf (&pb, buf, len, URL_RDONLY);
209 flags = (flags & PKT_FLAG_KEY) ? 2 : 0;
211 res = ff_rm_parse_packet (rdt->rmctx, st, len, pkt,
212 &seq, &flags, timestamp);
217 if (rm->audio_pkt_cnt > 0 &&
218 st->codec->codec_id == CODEC_ID_AAC) {
219 memcpy (rdt->buffer, buf + pos, len - pos);
220 url_open_buf (&pb, rdt->buffer, len - pos, URL_RDONLY);
224 ff_rm_retrieve_cache (rdt->rmctx, st, pkt);
225 if (rm->audio_pkt_cnt == 0 &&
226 st->codec->codec_id == CODEC_ID_AAC)
229 pkt->stream_index = st->index;
230 pkt->pts = *timestamp;
232 return rm->audio_pkt_cnt > 0;
236 ff_rdt_parse_packet(RDTDemuxContext *s, AVPacket *pkt,
237 const uint8_t *buf, int len)
239 int seq, flags = 0, rule, sn;
243 if (!s->parse_packet)
247 /* return the next packets, if any */
248 timestamp= 0; ///< Should not be used if buf is NULL, but should be set to the timestamp of the packet returned....
249 rv= s->parse_packet(s->dynamic_protocol_context,
250 s->st, pkt, ×tamp, NULL, 0, flags);
256 rv = ff_rdt_parse_header(buf, len, &sn, &seq, &rule, ×tamp);
259 if (!(rule & 1) && (sn != s->prev_sn || timestamp != s->prev_ts)) {
260 flags |= PKT_FLAG_KEY;
262 s->prev_ts = timestamp;
267 rv = s->parse_packet(s->dynamic_protocol_context,
268 s->st, pkt, ×tamp, buf, len, flags);
274 ff_rdt_subscribe_rule (char *cmd, int size,
275 int stream_nr, int rule_nr)
277 av_strlcatf(cmd, size, "stream=%d;rule=%d,stream=%d;rule=%d",
278 stream_nr, rule_nr * 2, stream_nr, rule_nr * 2 + 1);
282 ff_rdt_subscribe_rule2 (RDTDemuxContext *s, char *cmd, int size,
283 int stream_nr, int rule_nr)
285 PayloadContext *rdt = s->dynamic_protocol_context;
287 rdt_load_mdpr(rdt, s->st, rule_nr * 2);
290 static unsigned char *
291 rdt_parse_b64buf (unsigned int *target_len, const char *p)
293 unsigned char *target;
297 len -= 2; /* skip embracing " at start/end */
299 *target_len = len * 3 / 4;
300 target = av_mallocz(*target_len + FF_INPUT_BUFFER_PADDING_SIZE);
301 av_base64_decode(target, p, *target_len);
306 rdt_parse_sdp_line (AVStream *stream, PayloadContext *rdt, const char *line)
308 const char *p = line;
310 if (av_strstart(p, "OpaqueData:buffer;", &p)) {
311 rdt->mlti_data = rdt_parse_b64buf(&rdt->mlti_data_size, p);
312 } else if (av_strstart(p, "StartTime:integer;", &p))
313 stream->first_dts = atoi(p);
318 static PayloadContext *
319 rdt_new_extradata (void)
321 PayloadContext *rdt = av_mallocz(sizeof(PayloadContext));
323 av_open_input_stream(&rdt->rmctx, NULL, "", &rdt_demuxer, NULL);
329 rdt_free_extradata (PayloadContext *rdt)
332 av_close_input_stream(rdt->rmctx);
333 av_freep(&rdt->mlti_data);
337 #define RDT_HANDLER(n, s, t) \
338 static RTPDynamicProtocolHandler ff_rdt_ ## n ## _handler = { \
342 rdt_parse_sdp_line, \
344 rdt_free_extradata, \
348 RDT_HANDLER(live_video, "x-pn-multirate-realvideo-live", CODEC_TYPE_VIDEO);
349 RDT_HANDLER(live_audio, "x-pn-multirate-realaudio-live", CODEC_TYPE_AUDIO);
350 RDT_HANDLER(video, "x-pn-realvideo", CODEC_TYPE_VIDEO);
351 RDT_HANDLER(audio, "x-pn-realaudio", CODEC_TYPE_AUDIO);
353 void av_register_rdt_dynamic_payload_handlers(void)
355 ff_register_dynamic_payload_handler(&ff_rdt_video_handler);
356 ff_register_dynamic_payload_handler(&ff_rdt_audio_handler);
357 ff_register_dynamic_payload_handler(&ff_rdt_live_video_handler);
358 ff_register_dynamic_payload_handler(&ff_rdt_live_audio_handler);