FFmpeg
mpjpegdec.c
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1 /*
2  * Multipart JPEG format
3  * Copyright (c) 2015 Luca Barbato
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 "libavutil/avstring.h"
23 #include "libavutil/opt.h"
24 
25 #include "avformat.h"
26 #include "internal.h"
27 #include "avio_internal.h"
28 
29 typedef struct MPJPEGDemuxContext {
30  const AVClass *class;
31  char *boundary;
32  char *searchstr;
36 
37 static void trim_right(char *p)
38 {
39  char *end;
40 
41  if (!p || !*p)
42  return;
43 
44  end = p + strlen(p);
45  while (end > p && av_isspace(*(end-1)))
46  *(--end) = '\0';
47 }
48 
49 static int get_line(AVIOContext *pb, char *line, int line_size)
50 {
51  ff_get_line(pb, line, line_size);
52 
53  if (pb->error)
54  return pb->error;
55 
56  if (pb->eof_reached)
57  return AVERROR_EOF;
58 
60  return 0;
61 }
62 
63 static int split_tag_value(char **tag, char **value, char *line)
64 {
65  char *p = line;
66  int foundData = 0;
67 
68  *tag = NULL;
69  *value = NULL;
70 
71  while (*p != '\0' && *p != ':') {
72  if (!av_isspace(*p)) {
73  foundData = 1;
74  }
75  p++;
76  }
77  if (*p != ':')
78  return foundData ? AVERROR_INVALIDDATA : 0;
79 
80  *p = '\0';
81  *tag = line;
82  trim_right(*tag);
83 
84  p++;
85 
86  while (av_isspace(*p))
87  p++;
88 
89  *value = p;
90  trim_right(*value);
91 
92  return 0;
93 }
94 
95 static int parse_multipart_header(AVIOContext *pb,
96  int* size,
97  const char* expected_boundary,
98  void *log_ctx);
99 
101 {
102  MPJPEGDemuxContext *mpjpeg = s->priv_data;
103  av_freep(&mpjpeg->boundary);
104  av_freep(&mpjpeg->searchstr);
105  return 0;
106 }
107 
108 static int mpjpeg_read_probe(const AVProbeData *p)
109 {
110  FFIOContext pb;
111  int ret = 0;
112  int size = 0;
113 
114  if (p->buf_size < 2 || p->buf[0] != '-' || p->buf[1] != '-')
115  return 0;
116 
117  ffio_init_read_context(&pb, p->buf, p->buf_size);
118 
119  ret = (parse_multipart_header(&pb.pub, &size, "--", NULL) >= 0) ? AVPROBE_SCORE_MAX : 0;
120 
121  return ret;
122 }
123 
125 {
126  AVStream *st;
127  char boundary[70 + 2 + 1] = {0};
128  int64_t pos = avio_tell(s->pb);
129  int ret;
130 
131  do {
132  ret = get_line(s->pb, boundary, sizeof(boundary));
133  if (ret < 0)
134  return ret;
135  } while (!boundary[0]);
136 
137  if (strncmp(boundary, "--", 2))
138  return AVERROR_INVALIDDATA;
139 
140  st = avformat_new_stream(s, NULL);
141  if (!st)
142  return AVERROR(ENOMEM);
143 
146 
147  avpriv_set_pts_info(st, 60, 1, 25);
148 
149  avio_seek(s->pb, pos, SEEK_SET);
150 
151  return 0;
152 }
153 
154 static int parse_content_length(const char *value)
155 {
156  long int val = strtol(value, NULL, 10);
157 
158  if (val == LONG_MIN || val == LONG_MAX)
159  return AVERROR(errno);
160  if (val > INT_MAX)
161  return AVERROR(ERANGE);
162  return val;
163 }
164 
166  int* size,
167  const char* expected_boundary,
168  void *log_ctx)
169 {
170  char line[128];
171  int found_content_type = 0;
172  int ret;
173 
174  *size = -1;
175 
176  // get the CRLF as empty string
177  ret = get_line(pb, line, sizeof(line));
178  if (ret < 0)
179  return ret;
180 
181  /* some implementation do not provide the required
182  * initial CRLF (see rfc1341 7.2.1)
183  */
184  while (!line[0]) {
185  ret = get_line(pb, line, sizeof(line));
186  if (ret < 0)
187  return ret;
188  }
189 
190  if (!av_strstart(line, expected_boundary, NULL)) {
191  if (log_ctx)
192  av_log(log_ctx,
193  AV_LOG_ERROR,
194  "Expected boundary '%s' not found, instead found a line of %"SIZE_SPECIFIER" bytes\n",
195  expected_boundary,
196  strlen(line));
197 
198  return AVERROR_INVALIDDATA;
199  }
200 
201  while (!pb->eof_reached) {
202  char *tag, *value;
203 
204  ret = get_line(pb, line, sizeof(line));
205  if (ret < 0) {
206  if (ret == AVERROR_EOF)
207  break;
208  return ret;
209  }
210 
211  if (line[0] == '\0')
212  break;
213 
215  if (ret < 0)
216  return ret;
217  if (value==NULL || tag==NULL)
218  break;
219 
220  if (!av_strcasecmp(tag, "Content-type")) {
221  if (av_strcasecmp(value, "image/jpeg")) {
222  if (log_ctx)
223  av_log(log_ctx, AV_LOG_ERROR,
224  "Unexpected %s : %s\n",
225  tag, value);
226  return AVERROR_INVALIDDATA;
227  } else
228  found_content_type = 1;
229  } else if (!av_strcasecmp(tag, "Content-Length")) {
231  if ( *size < 0 )
232  if (log_ctx)
233  av_log(log_ctx, AV_LOG_WARNING,
234  "Invalid Content-Length value : %s\n",
235  value);
236  }
237  }
238 
239  return found_content_type ? 0 : AVERROR_INVALIDDATA;
240 }
241 
243 {
244  uint8_t *mime_type = NULL;
245  const char *start;
246  const char *end;
247  uint8_t *res = NULL;
248  int len;
249 
250  /* get MIME type, and skip to the first parameter */
251  av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type);
252  start = mime_type;
253  while (start != NULL && *start != '\0') {
254  start = strchr(start, ';');
255  if (!start)
256  break;
257 
258  start = start+1;
259 
260  while (av_isspace(*start))
261  start++;
262 
263  if (av_stristart(start, "boundary=", &start)) {
264  end = strchr(start, ';');
265  if (end)
266  len = end - start - 1;
267  else
268  len = strlen(start);
269 
270  /* some endpoints may enclose the boundary
271  in Content-Type in quotes */
272  if ( len>2 && *start == '"' && start[len-1] == '"' ) {
273  start++;
274  len -= 2;
275  }
276  res = av_strndup(start, len);
277  break;
278  }
279  }
280 
281  av_freep(&mime_type);
282  return res;
283 }
284 
286 {
287  int size;
288  int ret;
289 
290  MPJPEGDemuxContext *mpjpeg = s->priv_data;
291  if (mpjpeg->boundary == NULL) {
292  uint8_t* boundary = NULL;
293  if (mpjpeg->strict_mime_boundary) {
294  boundary = mpjpeg_get_boundary(s->pb);
295  }
296  if (boundary != NULL) {
297  mpjpeg->boundary = av_asprintf("--%s", boundary);
298  mpjpeg->searchstr = av_asprintf("\r\n--%s\r\n", boundary);
299  av_freep(&boundary);
300  } else {
301  mpjpeg->boundary = av_strdup("--");
302  mpjpeg->searchstr = av_strdup("\r\n--");
303  }
304  if (!mpjpeg->boundary || !mpjpeg->searchstr) {
305  av_freep(&mpjpeg->boundary);
306  av_freep(&mpjpeg->searchstr);
307  return AVERROR(ENOMEM);
308  }
309  mpjpeg->searchstr_len = strlen(mpjpeg->searchstr);
310  }
311 
312  ret = parse_multipart_header(s->pb, &size, mpjpeg->boundary, s);
313  if (ret < 0)
314  return ret;
315 
316  if (size > 0) {
317  /* size has been provided to us in MIME header */
318  ret = av_get_packet(s->pb, pkt, size);
319  } else {
320  /* no size was given -- we read until the next boundary or end-of-file */
321  int len;
322 
323  const int read_chunk = 2048;
324 
325  pkt->pos = avio_tell(s->pb);
326 
327  while ((ret = ffio_ensure_seekback(s->pb, read_chunk)) >= 0 && /* we may need to return as much as all we've read back to the buffer */
328  (ret = av_append_packet(s->pb, pkt, read_chunk)) >= 0) {
329  /* scan the new data */
330  char *start;
331 
332  len = ret;
333  start = pkt->data + pkt->size - len;
334  do {
335  if (!memcmp(start, mpjpeg->searchstr, mpjpeg->searchstr_len)) {
336  // got the boundary! rewind the stream
337  avio_seek(s->pb, -len, SEEK_CUR);
338  pkt->size -= len;
339  return pkt->size;
340  }
341  len--;
342  start++;
343  } while (len >= mpjpeg->searchstr_len);
344  avio_seek(s->pb, -len, SEEK_CUR);
345  pkt->size -= len;
346  }
347 
348  /* error or EOF occurred */
349  if (ret == AVERROR_EOF) {
350  ret = pkt->size > 0 ? pkt->size : AVERROR_EOF;
351  }
352  }
353 
354  return ret;
355 }
356 
357 #define OFFSET(x) offsetof(MPJPEGDemuxContext, x)
358 #define DEC AV_OPT_FLAG_DECODING_PARAM
359 static const AVOption mpjpeg_options[] = {
360  { "strict_mime_boundary", "require MIME boundaries match", OFFSET(strict_mime_boundary), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
361  { NULL }
362 };
363 
365  .class_name = "MPJPEG demuxer",
366  .item_name = av_default_item_name,
367  .option = mpjpeg_options,
368  .version = LIBAVUTIL_VERSION_INT,
369 };
370 
372  .name = "mpjpeg",
373  .long_name = NULL_IF_CONFIG_SMALL("MIME multipart JPEG"),
374  .mime_type = "multipart/x-mixed-replace",
375  .extensions = "mjpg",
376  .priv_data_size = sizeof(MPJPEGDemuxContext),
381  .priv_class = &mpjpeg_demuxer_class,
383 };
AV_OPT_SEARCH_CHILDREN
#define AV_OPT_SEARCH_CHILDREN
Search in possible children of the given object first.
Definition: opt.h:459
MPJPEGDemuxContext::boundary
char * boundary
Definition: mpjpegdec.c:31
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
AVFMT_NOTIMESTAMPS
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:480
av_asprintf
char * av_asprintf(const char *fmt,...)
Definition: avstring.c:115
av_strcasecmp
int av_strcasecmp(const char *a, const char *b)
Locale-independent case-insensitive compare.
Definition: avstring.c:207
av_isspace
static av_const int av_isspace(int c)
Locale-independent conversion of ASCII isspace.
Definition: avstring.h:218
AVPacket::data
uint8_t * data
Definition: packet.h:522
AVOption
AVOption.
Definition: opt.h:294
AVIOContext::error
int error
contains the error code or 0 if no error happened
Definition: avio.h:249
ffio_init_read_context
void ffio_init_read_context(FFIOContext *s, const uint8_t *buffer, int buffer_size)
Wrap a buffer in an AVIOContext for reading.
Definition: aviobuf.c:134
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:455
FFIOContext
Definition: avio_internal.h:28
DEC
#define DEC
Definition: mpjpegdec.c:358
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:464
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:843
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:143
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:513
val
static double val(void *priv, double ch)
Definition: aeval.c:78
OFFSET
#define OFFSET(x)
Definition: mpjpegdec.c:357
get_line
static int get_line(AVIOContext *pb, char *line, int line_size)
Definition: mpjpegdec.c:49
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
AVInputFormat
Definition: avformat.h:549
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_read_callback.c:41
mpjpeg_get_boundary
static char * mpjpeg_get_boundary(AVIOContext *pb)
Definition: mpjpegdec.c:242
s
#define s(width, name)
Definition: cbs_vp9.c:198
trim_right
static void trim_right(char *p)
Definition: mpjpegdec.c:37
ff_mpjpeg_demuxer
const AVInputFormat ff_mpjpeg_demuxer
Definition: mpjpegdec.c:371
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:554
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:454
read_chunk
static int read_chunk(AVFormatContext *s)
Definition: dhav.c:170
av_stristart
int av_stristart(const char *str, const char *pfx, const char **ptr)
Return non-zero if pfx is a prefix of str independent of case.
Definition: avstring.c:47
parse_multipart_header
static int parse_multipart_header(AVIOContext *pb, int *size, const char *expected_boundary, void *log_ctx)
Definition: mpjpegdec.c:165
MPJPEGDemuxContext::searchstr
char * searchstr
Definition: mpjpegdec.c:32
AVFormatContext
Format I/O context.
Definition: avformat.h:1363
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:864
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:550
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
MPJPEGDemuxContext::searchstr_len
int searchstr_len
Definition: mpjpegdec.c:33
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:452
mpjpeg_demuxer_class
static const AVClass mpjpeg_demuxer_class
Definition: mpjpegdec.c:364
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
AVPacket::size
int size
Definition: packet.h:523
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:106
MPJPEGDemuxContext::strict_mime_boundary
int strict_mime_boundary
Definition: mpjpegdec.c:34
FFIOContext::pub
AVIOContext pub
Definition: avio_internal.h:29
size
int size
Definition: twinvq_data.h:10344
ffio_ensure_seekback
int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size)
Ensures that the requested seekback buffer size will be available.
Definition: aviobuf.c:1135
mpjpeg_read_probe
static int mpjpeg_read_probe(const AVProbeData *p)
Definition: mpjpegdec.c:108
line
Definition: graph2dot.c:48
mpjpeg_read_close
static int mpjpeg_read_close(AVFormatContext *s)
Definition: mpjpegdec.c:100
mpjpeg_read_packet
static int mpjpeg_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mpjpegdec.c:285
mpjpeg_options
static const AVOption mpjpeg_options[]
Definition: mpjpegdec.c:359
av_strstart
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:36
MPJPEGDemuxContext
Definition: mpjpegdec.c:29
AV_CODEC_ID_MJPEG
@ AV_CODEC_ID_MJPEG
Definition: codec_id.h:59
avio_internal.h
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
ff_get_line
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:816
len
int len
Definition: vorbis_enc_data.h:426
split_tag_value
static int split_tag_value(char **tag, char **value, char *line)
Definition: mpjpegdec.c:63
parse_content_length
static int parse_content_length(const char *value)
Definition: mpjpegdec.c:154
av_get_packet
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:103
tag
uint32_t tag
Definition: movenc.c:1786
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:841
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:278
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
av_append_packet
int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
Read data and append it to the current content of the AVPacket.
Definition: utils.c:119
pos
unsigned int pos
Definition: spdifenc.c:413
avformat.h
SIZE_SPECIFIER
#define SIZE_SPECIFIER
Definition: internal.h:141
AVIOContext::eof_reached
int eof_reached
true if was unable to read due to error or eof
Definition: avio.h:248
mpjpeg_read_header
static int mpjpeg_read_header(AVFormatContext *s)
Definition: mpjpegdec.c:124
av_strdup
char * av_strdup(const char *s)
Duplicate a string.
Definition: mem.c:270
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
read_probe
static int read_probe(const AVProbeData *p)
Definition: cdg.c:29
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:499
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Definition: opt.h:244
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:542
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
av_opt_get
int av_opt_get(void *obj, const char *name, int search_flags, uint8_t **out_val)
Definition: opt.c:847
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
avstring.h
av_strndup
char * av_strndup(const char *s, size_t len)
Duplicate a substring of a string.
Definition: mem.c:282
line
The official guide to swscale for confused that consecutive non overlapping rectangles of slice_bottom special converter These generally are unscaled converters of common like for each output line the vertical scaler pulls lines from a ring buffer When the ring buffer does not contain the wanted line
Definition: swscale.txt:40