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
30
31 typedef struct MPJPEGDemuxContext {
32 const AVClass *class;
33 char *boundary;
34 char *searchstr;
35 int searchstr_len;
36 int strict_mime_boundary;
37 } MPJPEGDemuxContext;
38
39
trim_right(char * p)40 static void trim_right(char *p)
41 {
42 char *end;
43
44 if (!p || !*p)
45 return;
46
47 end = p + strlen(p);
48 while (end > p && av_isspace(*(end-1)))
49 *(--end) = '\0';
50 }
51
get_line(AVIOContext * pb,char * line,int line_size)52 static int get_line(AVIOContext *pb, char *line, int line_size)
53 {
54 ff_get_line(pb, line, line_size);
55
56 if (pb->error)
57 return pb->error;
58
59 if (pb->eof_reached)
60 return AVERROR_EOF;
61
62 trim_right(line);
63 return 0;
64 }
65
66
67
split_tag_value(char ** tag,char ** value,char * line)68 static int split_tag_value(char **tag, char **value, char *line)
69 {
70 char *p = line;
71 int foundData = 0;
72
73 *tag = NULL;
74 *value = NULL;
75
76
77 while (*p != '\0' && *p != ':') {
78 if (!av_isspace(*p)) {
79 foundData = 1;
80 }
81 p++;
82 }
83 if (*p != ':')
84 return foundData ? AVERROR_INVALIDDATA : 0;
85
86 *p = '\0';
87 *tag = line;
88 trim_right(*tag);
89
90 p++;
91
92 while (av_isspace(*p))
93 p++;
94
95 *value = p;
96 trim_right(*value);
97
98 return 0;
99 }
100
101 static int parse_multipart_header(AVIOContext *pb,
102 int* size,
103 const char* expected_boundary,
104 void *log_ctx);
105
mpjpeg_read_close(AVFormatContext * s)106 static int mpjpeg_read_close(AVFormatContext *s)
107 {
108 MPJPEGDemuxContext *mpjpeg = s->priv_data;
109 av_freep(&mpjpeg->boundary);
110 av_freep(&mpjpeg->searchstr);
111 return 0;
112 }
113
mpjpeg_read_probe(const AVProbeData * p)114 static int mpjpeg_read_probe(const AVProbeData *p)
115 {
116 AVIOContext pb;
117 int ret = 0;
118 int size = 0;
119
120 if (p->buf_size < 2 || p->buf[0] != '-' || p->buf[1] != '-')
121 return 0;
122
123 ffio_init_context(&pb, p->buf, p->buf_size, 0, NULL, NULL, NULL, NULL);
124
125 ret = (parse_multipart_header(&pb, &size, "--", NULL) >= 0) ? AVPROBE_SCORE_MAX : 0;
126
127 return ret;
128 }
129
mpjpeg_read_header(AVFormatContext * s)130 static int mpjpeg_read_header(AVFormatContext *s)
131 {
132 AVStream *st;
133 char boundary[70 + 2 + 1] = {0};
134 int64_t pos = avio_tell(s->pb);
135 int ret;
136
137 do {
138 ret = get_line(s->pb, boundary, sizeof(boundary));
139 if (ret < 0)
140 return ret;
141 } while (!boundary[0]);
142
143 if (strncmp(boundary, "--", 2))
144 return AVERROR_INVALIDDATA;
145
146 st = avformat_new_stream(s, NULL);
147 if (!st)
148 return AVERROR(ENOMEM);
149
150 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
151 st->codecpar->codec_id = AV_CODEC_ID_MJPEG;
152
153 avpriv_set_pts_info(st, 60, 1, 25);
154
155 avio_seek(s->pb, pos, SEEK_SET);
156
157 return 0;
158 }
159
parse_content_length(const char * value)160 static int parse_content_length(const char *value)
161 {
162 long int val = strtol(value, NULL, 10);
163
164 if (val == LONG_MIN || val == LONG_MAX)
165 return AVERROR(errno);
166 if (val > INT_MAX)
167 return AVERROR(ERANGE);
168 return val;
169 }
170
parse_multipart_header(AVIOContext * pb,int * size,const char * expected_boundary,void * log_ctx)171 static int parse_multipart_header(AVIOContext *pb,
172 int* size,
173 const char* expected_boundary,
174 void *log_ctx)
175 {
176 char line[128];
177 int found_content_type = 0;
178 int ret;
179
180 *size = -1;
181
182 // get the CRLF as empty string
183 ret = get_line(pb, line, sizeof(line));
184 if (ret < 0)
185 return ret;
186
187 /* some implementation do not provide the required
188 * initial CRLF (see rfc1341 7.2.1)
189 */
190 while (!line[0]) {
191 ret = get_line(pb, line, sizeof(line));
192 if (ret < 0)
193 return ret;
194 }
195
196 if (!av_strstart(line, expected_boundary, NULL)) {
197 if (log_ctx)
198 av_log(log_ctx,
199 AV_LOG_ERROR,
200 "Expected boundary '%s' not found, instead found a line of %"SIZE_SPECIFIER" bytes\n",
201 expected_boundary,
202 strlen(line));
203
204 return AVERROR_INVALIDDATA;
205 }
206
207 while (!pb->eof_reached) {
208 char *tag, *value;
209
210 ret = get_line(pb, line, sizeof(line));
211 if (ret < 0) {
212 if (ret == AVERROR_EOF)
213 break;
214 return ret;
215 }
216
217 if (line[0] == '\0')
218 break;
219
220 ret = split_tag_value(&tag, &value, line);
221 if (ret < 0)
222 return ret;
223 if (value==NULL || tag==NULL)
224 break;
225
226 if (!av_strcasecmp(tag, "Content-type")) {
227 if (av_strcasecmp(value, "image/jpeg")) {
228 if (log_ctx)
229 av_log(log_ctx, AV_LOG_ERROR,
230 "Unexpected %s : %s\n",
231 tag, value);
232 return AVERROR_INVALIDDATA;
233 } else
234 found_content_type = 1;
235 } else if (!av_strcasecmp(tag, "Content-Length")) {
236 *size = parse_content_length(value);
237 if ( *size < 0 )
238 if (log_ctx)
239 av_log(log_ctx, AV_LOG_WARNING,
240 "Invalid Content-Length value : %s\n",
241 value);
242 }
243 }
244
245 return found_content_type ? 0 : AVERROR_INVALIDDATA;
246 }
247
248
mpjpeg_get_boundary(AVIOContext * pb)249 static char* mpjpeg_get_boundary(AVIOContext* pb)
250 {
251 uint8_t *mime_type = NULL;
252 const char *start;
253 const char *end;
254 uint8_t *res = NULL;
255 int len;
256
257 /* get MIME type, and skip to the first parameter */
258 av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type);
259 start = mime_type;
260 while (start != NULL && *start != '\0') {
261 start = strchr(start, ';');
262 if (!start)
263 break;
264
265 start = start+1;
266
267 while (av_isspace(*start))
268 start++;
269
270 if (av_stristart(start, "boundary=", &start)) {
271 end = strchr(start, ';');
272 if (end)
273 len = end - start - 1;
274 else
275 len = strlen(start);
276
277 /* some endpoints may enclose the boundary
278 in Content-Type in quotes */
279 if ( len>2 && *start == '"' && start[len-1] == '"' ) {
280 start++;
281 len -= 2;
282 }
283 res = av_strndup(start, len);
284 break;
285 }
286 }
287
288 av_freep(&mime_type);
289 return res;
290 }
291
292
mpjpeg_read_packet(AVFormatContext * s,AVPacket * pkt)293 static int mpjpeg_read_packet(AVFormatContext *s, AVPacket *pkt)
294 {
295 int size;
296 int ret;
297
298 MPJPEGDemuxContext *mpjpeg = s->priv_data;
299 if (mpjpeg->boundary == NULL) {
300 uint8_t* boundary = NULL;
301 if (mpjpeg->strict_mime_boundary) {
302 boundary = mpjpeg_get_boundary(s->pb);
303 }
304 if (boundary != NULL) {
305 mpjpeg->boundary = av_asprintf("--%s", boundary);
306 mpjpeg->searchstr = av_asprintf("\r\n--%s\r\n", boundary);
307 av_freep(&boundary);
308 } else {
309 mpjpeg->boundary = av_strdup("--");
310 mpjpeg->searchstr = av_strdup("\r\n--");
311 }
312 if (!mpjpeg->boundary || !mpjpeg->searchstr) {
313 av_freep(&mpjpeg->boundary);
314 av_freep(&mpjpeg->searchstr);
315 return AVERROR(ENOMEM);
316 }
317 mpjpeg->searchstr_len = strlen(mpjpeg->searchstr);
318 }
319
320 ret = parse_multipart_header(s->pb, &size, mpjpeg->boundary, s);
321
322
323 if (ret < 0)
324 return ret;
325
326 if (size > 0) {
327 /* size has been provided to us in MIME header */
328 ret = av_get_packet(s->pb, pkt, size);
329 } else {
330 /* no size was given -- we read until the next boundary or end-of-file */
331 int len;
332
333 const int read_chunk = 2048;
334
335 pkt->pos = avio_tell(s->pb);
336
337 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 */
338 (ret = av_append_packet(s->pb, pkt, read_chunk)) >= 0) {
339 /* scan the new data */
340 char *start;
341
342 len = ret;
343 start = pkt->data + pkt->size - len;
344 do {
345 if (!memcmp(start, mpjpeg->searchstr, mpjpeg->searchstr_len)) {
346 // got the boundary! rewind the stream
347 avio_seek(s->pb, -len, SEEK_CUR);
348 pkt->size -= len;
349 return pkt->size;
350 }
351 len--;
352 start++;
353 } while (len >= mpjpeg->searchstr_len);
354 avio_seek(s->pb, -len, SEEK_CUR);
355 pkt->size -= len;
356 }
357
358 /* error or EOF occurred */
359 if (ret == AVERROR_EOF) {
360 ret = pkt->size > 0 ? pkt->size : AVERROR_EOF;
361 }
362 }
363
364 return ret;
365 }
366
367 #define OFFSET(x) offsetof(MPJPEGDemuxContext, x)
368
369 #define DEC AV_OPT_FLAG_DECODING_PARAM
370 static const AVOption mpjpeg_options[] = {
371 { "strict_mime_boundary", "require MIME boundaries match", OFFSET(strict_mime_boundary), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
372 { NULL }
373 };
374
375
376 static const AVClass mpjpeg_demuxer_class = {
377 .class_name = "MPJPEG demuxer",
378 .item_name = av_default_item_name,
379 .option = mpjpeg_options,
380 .version = LIBAVUTIL_VERSION_INT,
381 };
382
383 AVInputFormat ff_mpjpeg_demuxer = {
384 .name = "mpjpeg",
385 .long_name = NULL_IF_CONFIG_SMALL("MIME multipart JPEG"),
386 .mime_type = "multipart/x-mixed-replace",
387 .extensions = "mjpg",
388 .priv_data_size = sizeof(MPJPEGDemuxContext),
389 .read_probe = mpjpeg_read_probe,
390 .read_header = mpjpeg_read_header,
391 .read_packet = mpjpeg_read_packet,
392 .read_close = mpjpeg_read_close,
393 .priv_class = &mpjpeg_demuxer_class,
394 .flags = AVFMT_NOTIMESTAMPS,
395 };
396
397
398