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path: root/libavformat/rtpdec_xiph.c (plain)
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1/*
2 * Xiph RTP Protocols
3 * Copyright (c) 2009 Colin McQuillian
4 * Copyright (c) 2010 Josh Allmann
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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/avassert.h"
32#include "libavutil/avstring.h"
33#include "libavutil/base64.h"
34#include "libavcodec/bytestream.h"
35
36#include "avio_internal.h"
37#include "internal.h"
38#include "rtpdec.h"
39#include "rtpdec_formats.h"
40
41/**
42 * RTP/Xiph specific private data.
43 */
44struct 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
53static void xiph_close_context(PayloadContext * data)
54{
55 ffio_free_dyn_buf(&data->fragment);
56 av_freep(&data->split_buf);
57}
58
59
60static 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 (pkt_len > data->split_buf_len - data->split_pos) {
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 || len > INT_MAX/2) {
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 avpriv_report_missing_feature(ctx, "Xiph SDP configuration change");
112 return AVERROR_PATCHWELCOME;
113 }
114
115 if (tdt) {
116 avpriv_report_missing_feature(ctx,
117 "RTP Xiph packet settings (%d,%d,%d)",
118 fragmented, tdt, num_pkts);
119 return AVERROR_PATCHWELCOME;
120 }
121
122 buf += 6; // move past header bits
123 len -= 6;
124
125 if (fragmented == 0) {
126 if (av_new_packet(pkt, pkt_len)) {
127 av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
128 return AVERROR(ENOMEM);
129 }
130 pkt->stream_index = st->index;
131 memcpy(pkt->data, buf, pkt_len);
132 buf += pkt_len;
133 len -= pkt_len;
134 num_pkts--;
135
136 if (num_pkts > 0) {
137 if (len > data->split_buf_size || !data->split_buf) {
138 av_freep(&data->split_buf);
139 data->split_buf_size = 2 * len;
140 data->split_buf = av_malloc(data->split_buf_size);
141 if (!data->split_buf) {
142 av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
143 av_packet_unref(pkt);
144 return AVERROR(ENOMEM);
145 }
146 }
147 memcpy(data->split_buf, buf, len);
148 data->split_buf_len = len;
149 data->split_pos = 0;
150 data->split_pkts = num_pkts;
151 return 1;
152 }
153
154 return 0;
155
156 } else if (fragmented == 1) {
157 // start of xiph data fragment
158 int res;
159
160 // end packet has been lost somewhere, so drop buffered data
161 ffio_free_dyn_buf(&data->fragment);
162
163 if((res = avio_open_dyn_buf(&data->fragment)) < 0)
164 return res;
165
166 avio_write(data->fragment, buf, pkt_len);
167 data->timestamp = *timestamp;
168
169 } else {
170 av_assert1(fragmented < 4);
171 if (data->timestamp != *timestamp) {
172 // skip if fragmented timestamp is incorrect;
173 // a start packet has been lost somewhere
174 ffio_free_dyn_buf(&data->fragment);
175 av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match!\n");
176 return AVERROR_INVALIDDATA;
177 }
178 if (!data->fragment) {
179 av_log(ctx, AV_LOG_WARNING,
180 "Received packet without a start fragment; dropping.\n");
181 return AVERROR(EAGAIN);
182 }
183
184 // copy data to fragment buffer
185 avio_write(data->fragment, buf, pkt_len);
186
187 if (fragmented == 3) {
188 // end of xiph data packet
189 int ret = ff_rtp_finalize_packet(pkt, &data->fragment, st->index);
190 if (ret < 0) {
191 av_log(ctx, AV_LOG_ERROR,
192 "Error occurred when getting fragment buffer.");
193 return ret;
194 }
195
196 return 0;
197 }
198 }
199
200 return AVERROR(EAGAIN);
201}
202
203/**
204 * Length encoding described in RFC5215 section 3.1.1.
205 */
206static int get_base128(const uint8_t ** buf, const uint8_t * buf_end)
207{
208 int n = 0;
209 for (; *buf < buf_end; ++*buf) {
210 n <<= 7;
211 n += **buf & 0x7f;
212 if (!(**buf & 0x80)) {
213 ++*buf;
214 return n;
215 }
216 }
217 return 0;
218}
219
220/**
221 * Based off parse_packed_headers in Vorbis RTP
222 */
223static int
224parse_packed_headers(AVFormatContext *s,
225 const uint8_t * packed_headers,
226 const uint8_t * packed_headers_end,
227 AVCodecParameters *par, PayloadContext * xiph_data)
228{
229
230 unsigned num_packed, num_headers, length, length1, length2, extradata_alloc;
231 uint8_t *ptr;
232
233 if (packed_headers_end - packed_headers < 9) {
234 av_log(s, AV_LOG_ERROR,
235 "Invalid %"PTRDIFF_SPECIFIER" byte packed header.",
236 packed_headers_end - packed_headers);
237 return AVERROR_INVALIDDATA;
238 }
239
240 num_packed = bytestream_get_be32(&packed_headers);
241 xiph_data->ident = bytestream_get_be24(&packed_headers);
242 length = bytestream_get_be16(&packed_headers);
243 num_headers = get_base128(&packed_headers, packed_headers_end);
244 length1 = get_base128(&packed_headers, packed_headers_end);
245 length2 = get_base128(&packed_headers, packed_headers_end);
246
247 if (num_packed != 1 || num_headers > 3) {
248 avpriv_report_missing_feature(s, "%u packed headers, %u headers",
249 num_packed, num_headers);
250 return AVERROR_PATCHWELCOME;
251 }
252
253 if (packed_headers_end - packed_headers != length ||
254 length1 > length || length2 > length - length1) {
255 av_log(s, AV_LOG_ERROR,
256 "Bad packed header lengths (%d,%d,%"PTRDIFF_SPECIFIER",%u)\n", length1,
257 length2, packed_headers_end - packed_headers, length);
258 return AVERROR_INVALIDDATA;
259 }
260
261 /* allocate extra space:
262 * -- length/255 +2 for xiphlacing
263 * -- one for the '2' marker
264 * -- AV_INPUT_BUFFER_PADDING_SIZE required */
265 extradata_alloc = length + length/255 + 3 + AV_INPUT_BUFFER_PADDING_SIZE;
266
267 if (ff_alloc_extradata(par, extradata_alloc)) {
268 av_log(s, AV_LOG_ERROR, "Out of memory\n");
269 return AVERROR(ENOMEM);
270 }
271 ptr = par->extradata;
272 *ptr++ = 2;
273 ptr += av_xiphlacing(ptr, length1);
274 ptr += av_xiphlacing(ptr, length2);
275 memcpy(ptr, packed_headers, length);
276 ptr += length;
277 par->extradata_size = ptr - par->extradata;
278 // clear out remaining parts of the buffer
279 memset(ptr, 0, extradata_alloc - par->extradata_size);
280
281 return 0;
282}
283
284static int xiph_parse_fmtp_pair(AVFormatContext *s,
285 AVStream* stream,
286 PayloadContext *xiph_data,
287 const char *attr, const char *value)
288{
289 AVCodecParameters *par = stream->codecpar;
290 int result = 0;
291
292 if (!strcmp(attr, "sampling")) {
293 if (!strcmp(value, "YCbCr-4:2:0")) {
294 par->format = AV_PIX_FMT_YUV420P;
295 } else if (!strcmp(value, "YCbCr-4:4:2")) {
296 par->format = AV_PIX_FMT_YUV422P;
297 } else if (!strcmp(value, "YCbCr-4:4:4")) {
298 par->format = AV_PIX_FMT_YUV444P;
299 } else {
300 av_log(s, AV_LOG_ERROR,
301 "Unsupported pixel format %s\n", attr);
302 return AVERROR_INVALIDDATA;
303 }
304 } else if (!strcmp(attr, "width")) {
305 /* This is an integer between 1 and 1048561
306 * and MUST be in multiples of 16. */
307 par->width = atoi(value);
308 return 0;
309 } else if (!strcmp(attr, "height")) {
310 /* This is an integer between 1 and 1048561
311 * and MUST be in multiples of 16. */
312 par->height = atoi(value);
313 return 0;
314 } else if (!strcmp(attr, "delivery-method")) {
315 /* Possible values are: inline, in_band, out_band/specific_name. */
316 return AVERROR_PATCHWELCOME;
317 } else if (!strcmp(attr, "configuration-uri")) {
318 /* NOTE: configuration-uri is supported only under 2 conditions:
319 *--after the delivery-method tag
320 * --with a delivery-method value of out_band */
321 return AVERROR_PATCHWELCOME;
322 } else if (!strcmp(attr, "configuration")) {
323 /* NOTE: configuration is supported only AFTER the delivery-method tag
324 * The configuration value is a base64 encoded packed header */
325 uint8_t *decoded_packet = NULL;
326 int packet_size;
327 size_t decoded_alloc = strlen(value) / 4 * 3 + 4;
328
329 if (decoded_alloc <= INT_MAX) {
330 decoded_packet = av_malloc(decoded_alloc);
331 if (decoded_packet) {
332 packet_size =
333 av_base64_decode(decoded_packet, value, decoded_alloc);
334
335 result = parse_packed_headers
336 (s, decoded_packet, decoded_packet + packet_size, par,
337 xiph_data);
338 } else {
339 av_log(s, AV_LOG_ERROR,
340 "Out of memory while decoding SDP configuration.\n");
341 result = AVERROR(ENOMEM);
342 }
343 } else {
344 av_log(s, AV_LOG_ERROR, "Packet too large\n");
345 result = AVERROR_INVALIDDATA;
346 }
347 av_free(decoded_packet);
348 }
349 return result;
350}
351
352static int xiph_parse_sdp_line(AVFormatContext *s, int st_index,
353 PayloadContext *data, const char *line)
354{
355 const char *p;
356
357 if (st_index < 0)
358 return 0;
359
360 if (av_strstart(line, "fmtp:", &p)) {
361 return ff_parse_fmtp(s, s->streams[st_index], data, p,
362 xiph_parse_fmtp_pair);
363 }
364
365 return 0;
366}
367
368RTPDynamicProtocolHandler ff_theora_dynamic_handler = {
369 .enc_name = "theora",
370 .codec_type = AVMEDIA_TYPE_VIDEO,
371 .codec_id = AV_CODEC_ID_THEORA,
372 .priv_data_size = sizeof(PayloadContext),
373 .parse_sdp_a_line = xiph_parse_sdp_line,
374 .close = xiph_close_context,
375 .parse_packet = xiph_handle_packet,
376};
377
378RTPDynamicProtocolHandler ff_vorbis_dynamic_handler = {
379 .enc_name = "vorbis",
380 .codec_type = AVMEDIA_TYPE_AUDIO,
381 .codec_id = AV_CODEC_ID_VORBIS,
382 .need_parsing = AVSTREAM_PARSE_HEADERS,
383 .priv_data_size = sizeof(PayloadContext),
384 .parse_sdp_a_line = xiph_parse_sdp_line,
385 .close = xiph_close_context,
386 .parse_packet = xiph_handle_packet,
387};
388
generated by cgit at 2024-05-17 03:17:41 (GMT)