7821686983e1a95d2cf0b57a427d7f989e585aea
[libav.git] / libavformat / rtpdec_xiph.c
1 /*
2 * Xiph RTP Protocols
3 * Copyright (c) 2009 Colin McQuillian
4 * Copyright (c) 2010 Josh Allmann
5 *
6 * This file is part of Libav.
7 *
8 * Libav is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * Libav is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 /**
24 * @file
25 * @brief Xiph / RTP Code
26 * @author Colin McQuillan <m.niloc@gmail.com>
27 * @author Josh Allmann <joshua.allmann@gmail.com>
28 */
29
30 #include "libavutil/attributes.h"
31 #include "libavutil/avstring.h"
32 #include "libavutil/base64.h"
33 #include "libavcodec/bytestream.h"
34
35 #include <assert.h>
36
37 #include "avio_internal.h"
38 #include "rtpdec.h"
39 #include "rtpdec_formats.h"
40
41 /**
42 * RTP/Xiph specific private data.
43 */
44 struct PayloadContext {
45 unsigned ident; ///< 24-bit stream configuration identifier
46 uint32_t timestamp;
47 AVIOContext* fragment; ///< buffer for split payloads
48 uint8_t *split_buf;
49 int split_pos, split_buf_len, split_buf_size;
50 int split_pkts;
51 };
52
53 static void xiph_close_context(PayloadContext * data)
54 {
55 ffio_free_dyn_buf(&data->fragment);
56 av_free(data->split_buf);
57 }
58
59
60 static int xiph_handle_packet(AVFormatContext *ctx, PayloadContext *data,
61 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
62 const uint8_t *buf, int len, uint16_t seq,
63 int flags)
64 {
65
66 int ident, fragmented, tdt, num_pkts, pkt_len;
67
68 if (!buf) {
69 if (!data->split_buf || data->split_pos + 2 > data->split_buf_len ||
70 data->split_pkts <= 0) {
71 av_log(ctx, AV_LOG_ERROR, "No more data to return\n");
72 return AVERROR_INVALIDDATA;
73 }
74 pkt_len = AV_RB16(data->split_buf + data->split_pos);
75 data->split_pos += 2;
76 if (data->split_pos + pkt_len > data->split_buf_len) {
77 av_log(ctx, AV_LOG_ERROR, "Not enough data to return\n");
78 return AVERROR_INVALIDDATA;
79 }
80 if (av_new_packet(pkt, pkt_len)) {
81 av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
82 return AVERROR(ENOMEM);
83 }
84 pkt->stream_index = st->index;
85 memcpy(pkt->data, data->split_buf + data->split_pos, pkt_len);
86 data->split_pos += pkt_len;
87 data->split_pkts--;
88 return data->split_pkts > 0;
89 }
90
91 if (len < 6) {
92 av_log(ctx, AV_LOG_ERROR, "Invalid %d byte packet\n", len);
93 return AVERROR_INVALIDDATA;
94 }
95
96 // read xiph rtp headers
97 ident = AV_RB24(buf);
98 fragmented = buf[3] >> 6;
99 tdt = (buf[3] >> 4) & 3;
100 num_pkts = buf[3] & 0xf;
101 pkt_len = AV_RB16(buf + 4);
102
103 if (pkt_len > len - 6) {
104 av_log(ctx, AV_LOG_ERROR,
105 "Invalid packet length %d in %d byte packet\n", pkt_len,
106 len);
107 return AVERROR_INVALIDDATA;
108 }
109
110 if (ident != data->ident) {
111 av_log(ctx, AV_LOG_ERROR,
112 "Unimplemented Xiph SDP configuration change detected\n");
113 return AVERROR_PATCHWELCOME;
114 }
115
116 if (tdt) {
117 av_log(ctx, AV_LOG_ERROR,
118 "Unimplemented RTP Xiph packet settings (%d,%d,%d)\n",
119 fragmented, tdt, num_pkts);
120 return AVERROR_PATCHWELCOME;
121 }
122
123 buf += 6; // move past header bits
124 len -= 6;
125
126 if (fragmented == 0) {
127 if (av_new_packet(pkt, pkt_len)) {
128 av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
129 return AVERROR(ENOMEM);
130 }
131 pkt->stream_index = st->index;
132 memcpy(pkt->data, buf, pkt_len);
133 buf += pkt_len;
134 len -= pkt_len;
135 num_pkts--;
136
137 if (num_pkts > 0) {
138 if (len > data->split_buf_size || !data->split_buf) {
139 av_freep(&data->split_buf);
140 data->split_buf_size = 2 * len;
141 data->split_buf = av_malloc(data->split_buf_size);
142 if (!data->split_buf) {
143 av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
144 av_packet_unref(pkt);
145 return AVERROR(ENOMEM);
146 }
147 }
148 memcpy(data->split_buf, buf, len);
149 data->split_buf_len = len;
150 data->split_pos = 0;
151 data->split_pkts = num_pkts;
152 return 1;
153 }
154
155 return 0;
156
157 } else if (fragmented == 1) {
158 // start of xiph data fragment
159 int res;
160
161 // end packet has been lost somewhere, so drop buffered data
162 ffio_free_dyn_buf(&data->fragment);
163
164 if((res = avio_open_dyn_buf(&data->fragment)) < 0)
165 return res;
166
167 avio_write(data->fragment, buf, pkt_len);
168 data->timestamp = *timestamp;
169
170 } else {
171 assert(fragmented < 4);
172 if (data->timestamp != *timestamp) {
173 // skip if fragmented timestamp is incorrect;
174 // a start packet has been lost somewhere
175 ffio_free_dyn_buf(&data->fragment);
176 av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match!\n");
177 return AVERROR_INVALIDDATA;
178 }
179 if (!data->fragment) {
180 av_log(ctx, AV_LOG_WARNING,
181 "Received packet without a start fragment; dropping.\n");
182 return AVERROR(EAGAIN);
183 }
184
185 // copy data to fragment buffer
186 avio_write(data->fragment, buf, pkt_len);
187
188 if (fragmented == 3) {
189 // end of xiph data packet
190 int ret = ff_rtp_finalize_packet(pkt, &data->fragment, st->index);
191 if (ret < 0) {
192 av_log(ctx, AV_LOG_ERROR,
193 "Error occurred when getting fragment buffer.");
194 return ret;
195 }
196
197 return 0;
198 }
199 }
200
201 return AVERROR(EAGAIN);
202 }
203
204 /**
205 * Length encoding described in RFC5215 section 3.1.1.
206 */
207 static int get_base128(const uint8_t ** buf, const uint8_t * buf_end)
208 {
209 int n = 0;
210 for (; *buf < buf_end; ++*buf) {
211 n <<= 7;
212 n += **buf & 0x7f;
213 if (!(**buf & 0x80)) {
214 ++*buf;
215 return n;
216 }
217 }
218 return 0;
219 }
220
221 /**
222 * Based off parse_packed_headers in Vorbis RTP
223 */
224 static int
225 parse_packed_headers(AVFormatContext *s,
226 const uint8_t * packed_headers,
227 const uint8_t * packed_headers_end,
228 AVCodecParameters *par, PayloadContext * xiph_data)
229 {
230
231 unsigned num_packed, num_headers, length, length1, length2, extradata_alloc;
232 uint8_t *ptr;
233
234 if (packed_headers_end - packed_headers < 9) {
235 av_log(s, AV_LOG_ERROR,
236 "Invalid %td byte packed header.",
237 packed_headers_end - packed_headers);
238 return AVERROR_INVALIDDATA;
239 }
240
241 num_packed = bytestream_get_be32(&packed_headers);
242 xiph_data->ident = bytestream_get_be24(&packed_headers);
243 length = bytestream_get_be16(&packed_headers);
244 num_headers = get_base128(&packed_headers, packed_headers_end);
245 length1 = get_base128(&packed_headers, packed_headers_end);
246 length2 = get_base128(&packed_headers, packed_headers_end);
247
248 if (num_packed != 1 || num_headers > 3) {
249 av_log(s, AV_LOG_ERROR,
250 "Unimplemented number of headers: %u packed headers, %u headers\n",
251 num_packed, num_headers);
252 return AVERROR_PATCHWELCOME;
253 }
254
255 if (packed_headers_end - packed_headers != length ||
256 length1 > length || length2 > length - length1) {
257 av_log(s, AV_LOG_ERROR,
258 "Bad packed header lengths (%u,%u,%td,%u)\n", length1,
259 length2, packed_headers_end - packed_headers, length);
260 return AVERROR_INVALIDDATA;
261 }
262
263 /* allocate extra space:
264 * -- length/255 +2 for xiphlacing
265 * -- one for the '2' marker
266 * -- AV_INPUT_BUFFER_PADDING_SIZE required */
267 extradata_alloc = length + length/255 + 3 + AV_INPUT_BUFFER_PADDING_SIZE;
268
269 ptr = par->extradata = av_malloc(extradata_alloc);
270 if (!ptr) {
271 av_log(s, AV_LOG_ERROR, "Out of memory\n");
272 return AVERROR(ENOMEM);
273 }
274 *ptr++ = 2;
275 ptr += av_xiphlacing(ptr, length1);
276 ptr += av_xiphlacing(ptr, length2);
277 memcpy(ptr, packed_headers, length);
278 ptr += length;
279 par->extradata_size = ptr - par->extradata;
280 // clear out remaining parts of the buffer
281 memset(ptr, 0, extradata_alloc - par->extradata_size);
282
283 return 0;
284 }
285
286 static int xiph_parse_fmtp_pair(AVFormatContext *s,
287 AVStream* stream,
288 PayloadContext *xiph_data,
289 const char *attr, const char *value)
290 {
291 AVCodecParameters *par = stream->codecpar;
292 int result = 0;
293
294 if (!strcmp(attr, "sampling")) {
295 if (!strcmp(value, "YCbCr-4:2:0")) {
296 par->format = AV_PIX_FMT_YUV420P;
297 } else if (!strcmp(value, "YCbCr-4:4:2")) {
298 par->format = AV_PIX_FMT_YUV422P;
299 } else if (!strcmp(value, "YCbCr-4:4:4")) {
300 par->format = AV_PIX_FMT_YUV444P;
301 } else {
302 av_log(s, AV_LOG_ERROR,
303 "Unsupported pixel format %s\n", attr);
304 return AVERROR_INVALIDDATA;
305 }
306 } else if (!strcmp(attr, "width")) {
307 /* This is an integer between 1 and 1048561
308 * and MUST be in multiples of 16. */
309 par->width = atoi(value);
310 return 0;
311 } else if (!strcmp(attr, "height")) {
312 /* This is an integer between 1 and 1048561
313 * and MUST be in multiples of 16. */
314 par->height = atoi(value);
315 return 0;
316 } else if (!strcmp(attr, "delivery-method")) {
317 /* Possible values are: inline, in_band, out_band/specific_name. */
318 return AVERROR_PATCHWELCOME;
319 } else if (!strcmp(attr, "configuration-uri")) {
320 /* NOTE: configuration-uri is supported only under 2 conditions:
321 *--after the delivery-method tag
322 * --with a delivery-method value of out_band */
323 return AVERROR_PATCHWELCOME;
324 } else if (!strcmp(attr, "configuration")) {
325 /* NOTE: configuration is supported only AFTER the delivery-method tag
326 * The configuration value is a base64 encoded packed header */
327 uint8_t *decoded_packet = NULL;
328 int packet_size;
329 size_t decoded_alloc = strlen(value) / 4 * 3 + 4;
330
331 if (decoded_alloc <= INT_MAX) {
332 decoded_packet = av_malloc(decoded_alloc);
333 if (decoded_packet) {
334 packet_size =
335 av_base64_decode(decoded_packet, value, decoded_alloc);
336
337 result = parse_packed_headers
338 (s, decoded_packet, decoded_packet + packet_size, par,
339 xiph_data);
340 } else {
341 av_log(s, AV_LOG_ERROR,
342 "Out of memory while decoding SDP configuration.\n");
343 result = AVERROR(ENOMEM);
344 }
345 } else {
346 av_log(s, AV_LOG_ERROR, "Packet too large\n");
347 result = AVERROR_INVALIDDATA;
348 }
349 av_free(decoded_packet);
350 }
351 return result;
352 }
353
354 static int xiph_parse_sdp_line(AVFormatContext *s, int st_index,
355 PayloadContext *data, const char *line)
356 {
357 const char *p;
358
359 if (st_index < 0)
360 return 0;
361
362 if (av_strstart(line, "fmtp:", &p)) {
363 return ff_parse_fmtp(s, s->streams[st_index], data, p,
364 xiph_parse_fmtp_pair);
365 }
366
367 return 0;
368 }
369
370 RTPDynamicProtocolHandler ff_theora_dynamic_handler = {
371 .enc_name = "theora",
372 .codec_type = AVMEDIA_TYPE_VIDEO,
373 .codec_id = AV_CODEC_ID_THEORA,
374 .priv_data_size = sizeof(PayloadContext),
375 .parse_sdp_a_line = xiph_parse_sdp_line,
376 .close = xiph_close_context,
377 .parse_packet = xiph_handle_packet,
378 };
379
380 RTPDynamicProtocolHandler ff_vorbis_dynamic_handler = {
381 .enc_name = "vorbis",
382 .codec_type = AVMEDIA_TYPE_AUDIO,
383 .codec_id = AV_CODEC_ID_VORBIS,
384 .need_parsing = AVSTREAM_PARSE_HEADERS,
385 .priv_data_size = sizeof(PayloadContext),
386 .parse_sdp_a_line = xiph_parse_sdp_line,
387 .close = xiph_close_context,
388 .parse_packet = xiph_handle_packet,
389 };