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rtpdec_xiph.c
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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  */
44 struct PayloadContext {
45  unsigned ident; ///< 24-bit stream configuration identifier
46  uint32_t timestamp;
47  AVIOContext* fragment; ///< buffer for split payloads
50  int split_pkts;
51 };
52 
54 {
56  av_freep(&data->split_buf);
57 }
58 
59 
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  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  av_assert1(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
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 %"PTRDIFF_SPECIFIER" 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: %d packed headers, %d 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 (%d,%d,%"PTRDIFF_SPECIFIER",%d)\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  if (ff_alloc_extradata(par, extradata_alloc)) {
270  av_log(s, AV_LOG_ERROR, "Out of memory\n");
271  return AVERROR(ENOMEM);
272  }
273  ptr = par->extradata;
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 
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,
365  }
366 
367  return 0;
368 }
369 
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,
378 };
379 
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,
389 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
Bytestream IO Context.
Definition: avio.h:147
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:67
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
RTP/JPEG specific private data.
Definition: rdt.c:83
int index
stream index in AVFormatContext
Definition: avformat.h:882
RTPDynamicProtocolHandler ff_theora_dynamic_handler
Definition: rtpdec_xiph.c:370
static AVPacket pkt
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:87
int avio_open_dyn_buf(AVIOContext **s)
Open a write only memory stream.
Definition: aviobuf.c:1266
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3971
Macro definitions for various function/variable attributes.
Format I/O context.
Definition: avformat.h:1330
static int xiph_parse_sdp_line(AVFormatContext *s, int st_index, PayloadContext *data, const char *line)
Definition: rtpdec_xiph.c:354
uint8_t
static int xiph_parse_fmtp_pair(AVFormatContext *s, AVStream *stream, PayloadContext *xiph_data, const char *attr, const char *value)
Definition: rtpdec_xiph.c:286
#define av_malloc(s)
int width
Video only.
Definition: avcodec.h:4045
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1398
uint8_t * data
Definition: avcodec.h:1600
static void xiph_close_context(PayloadContext *data)
Definition: rtpdec_xiph.c:53
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:204
#define av_log(a,...)
unsigned ident
24-bit stream configuration identifier
Definition: rtpdec_xiph.c:45
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
uint32_t timestamp
current frame timestamp
Definition: rtpdec_ac3.c:31
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define PTRDIFF_SPECIFIER
Definition: internal.h:251
#define AVERROR(e)
Definition: error.h:43
Definition: graph2dot.c:48
simple assert() macros that are a bit more flexible than ISO C assert().
GLsizei GLsizei * length
Definition: opengl_enc.c:115
int extradata_size
Size of the extradata content in bytes.
Definition: avcodec.h:3997
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:66
Only parse headers, do not repack.
Definition: avformat.h:809
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0...
Definition: utils.c:3165
#define av_assert1(cond)
assert() equivalent, that does not lie in speed critical code.
Definition: avassert.h:53
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:109
AVFormatContext * ctx
Definition: movenc.c:48
static int get_base128(const uint8_t **buf, const uint8_t *buf_end)
Length encoding described in RFC5215 section 3.1.1.
Definition: rtpdec_xiph.c:207
int n
Definition: avisynth_c.h:684
void ffio_free_dyn_buf(AVIOContext **s)
Free a dynamic buffer.
Definition: aviobuf.c:1306
Stream structure.
Definition: avformat.h:881
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
AVIOContext * fragment
buffer for split payloads
Definition: rtpdec_ac3.c:32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_RB24
Definition: bytestream.h:87
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:567
void * buf
Definition: avisynth_c.h:690
unsigned int av_xiphlacing(unsigned char *s, unsigned int v)
Encode extradata length to a buffer.
Definition: utils.c:3714
int ff_parse_fmtp(AVFormatContext *s, AVStream *stream, PayloadContext *data, const char *p, int(*parse_fmtp)(AVFormatContext *s, AVStream *stream, PayloadContext *data, const char *attr, const char *value))
Definition: rtpdec.c:861
const char * enc_name
Definition: rtpdec.h:116
static int flags
Definition: cpu.c:47
int av_strstart(const char *str, const char *pfx, const char **ptr)
Return non-zero if pfx is a prefix of str.
Definition: avstring.c:34
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:62
static int xiph_handle_packet(AVFormatContext *ctx, PayloadContext *data, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, uint16_t seq, int flags)
Definition: rtpdec_xiph.c:60
RTPDynamicProtocolHandler ff_vorbis_dynamic_handler
Definition: rtpdec_xiph.c:380
int ff_rtp_finalize_packet(AVPacket *pkt, AVIOContext **dyn_buf, int stream_idx)
Close the dynamic buffer and make a packet from it.
Definition: rtpdec.c:899
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:733
static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index)
Parse a packet, add all split parts to parse_queue.
Definition: utils.c:1368
#define av_free(p)
int len
int av_base64_decode(uint8_t *out, const char *in_str, int out_size)
Decode a base64-encoded string.
Definition: base64.c:79
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3993
#define av_freep(p)
AVCodecParameters * codecpar
Definition: avformat.h:1233
int stream_index
Definition: avcodec.h:1602
static int parse_packed_headers(AVFormatContext *s, const uint8_t *packed_headers, const uint8_t *packed_headers_end, AVCodecParameters *par, PayloadContext *xiph_data)
Based off parse_packed_headers in Vorbis RTP.
Definition: rtpdec_xiph.c:225
This structure stores compressed data.
Definition: avcodec.h:1577