1 /*
2 * Format register and lookup
3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
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 "config_components.h"
23
24 #include "libavutil/avstring.h"
25 #include "libavutil/bprint.h"
26 #include "libavutil/opt.h"
27 #include "libavutil/thread.h"
28
29 #include "avio_internal.h"
30 #include "avformat.h"
31 #include "id3v2.h"
32 #include "internal.h"
33
34
35 /**
36 * @file
37 * Format register and lookup
38 */
39
av_match_ext(const char * filename,const char * extensions)40 int av_match_ext(const char *filename, const char *extensions)
41 {
42 const char *ext;
43
44 if (!filename)
45 return 0;
46
47 ext = strrchr(filename, '.');
48 if (ext)
49 return av_match_name(ext + 1, extensions);
50 return 0;
51 }
52
av_guess_format(const char * short_name,const char * filename,const char * mime_type)53 const AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
54 const char *mime_type)
55 {
56 const AVOutputFormat *fmt = NULL;
57 const AVOutputFormat *fmt_found = NULL;
58 void *i = 0;
59 int score_max, score;
60
61 /* specific test for image sequences */
62 #if CONFIG_IMAGE2_MUXER
63 if (!short_name && filename &&
64 av_filename_number_test(filename) &&
65 ff_guess_image2_codec(filename) != AV_CODEC_ID_NONE) {
66 return av_guess_format("image2", NULL, NULL);
67 }
68 #endif
69 /* Find the proper file type. */
70 score_max = 0;
71 while ((fmt = av_muxer_iterate(&i))) {
72 score = 0;
73 if (fmt->name && short_name && av_match_name(short_name, fmt->name))
74 score += 100;
75 if (fmt->mime_type && mime_type && !strcmp(fmt->mime_type, mime_type))
76 score += 10;
77 if (filename && fmt->extensions &&
78 av_match_ext(filename, fmt->extensions)) {
79 score += 5;
80 }
81 if (score > score_max) {
82 score_max = score;
83 fmt_found = fmt;
84 }
85 }
86 return fmt_found;
87 }
88
av_guess_codec(const AVOutputFormat * fmt,const char * short_name,const char * filename,const char * mime_type,enum AVMediaType type)89 enum AVCodecID av_guess_codec(const AVOutputFormat *fmt, const char *short_name,
90 const char *filename, const char *mime_type,
91 enum AVMediaType type)
92 {
93 if (av_match_name("segment", fmt->name) || av_match_name("ssegment", fmt->name)) {
94 const AVOutputFormat *fmt2 = av_guess_format(NULL, filename, NULL);
95 if (fmt2)
96 fmt = fmt2;
97 }
98
99 if (type == AVMEDIA_TYPE_VIDEO) {
100 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
101
102 #if CONFIG_IMAGE2_MUXER || CONFIG_IMAGE2PIPE_MUXER
103 if (!strcmp(fmt->name, "image2") || !strcmp(fmt->name, "image2pipe")) {
104 codec_id = ff_guess_image2_codec(filename);
105 }
106 #endif
107 if (codec_id == AV_CODEC_ID_NONE)
108 codec_id = fmt->video_codec;
109 return codec_id;
110 } else if (type == AVMEDIA_TYPE_AUDIO)
111 return fmt->audio_codec;
112 else if (type == AVMEDIA_TYPE_SUBTITLE)
113 return fmt->subtitle_codec;
114 else if (type == AVMEDIA_TYPE_DATA)
115 return fmt->data_codec;
116 else
117 return AV_CODEC_ID_NONE;
118 }
119
av_find_input_format(const char * short_name)120 const AVInputFormat *av_find_input_format(const char *short_name)
121 {
122 const AVInputFormat *fmt = NULL;
123 void *i = 0;
124 while ((fmt = av_demuxer_iterate(&i)))
125 if (av_match_name(short_name, fmt->name))
126 return fmt;
127 return NULL;
128 }
129
av_probe_input_format3(const AVProbeData * pd,int is_opened,int * score_ret)130 const AVInputFormat *av_probe_input_format3(const AVProbeData *pd,
131 int is_opened, int *score_ret)
132 {
133 AVProbeData lpd = *pd;
134 const AVInputFormat *fmt1 = NULL;
135 const AVInputFormat *fmt = NULL;
136 int score, score_max = 0;
137 void *i = 0;
138 const static uint8_t zerobuffer[AVPROBE_PADDING_SIZE];
139 enum nodat {
140 NO_ID3,
141 ID3_ALMOST_GREATER_PROBE,
142 ID3_GREATER_PROBE,
143 ID3_GREATER_MAX_PROBE,
144 } nodat = NO_ID3;
145
146 if (!lpd.buf)
147 lpd.buf = (unsigned char *) zerobuffer;
148
149 if (lpd.buf_size > 10 && ff_id3v2_match(lpd.buf, ID3v2_DEFAULT_MAGIC)) {
150 int id3len = ff_id3v2_tag_len(lpd.buf);
151 if (lpd.buf_size > id3len + 16) {
152 if (lpd.buf_size < 2LL*id3len + 16)
153 nodat = ID3_ALMOST_GREATER_PROBE;
154 lpd.buf += id3len;
155 lpd.buf_size -= id3len;
156 } else if (id3len >= PROBE_BUF_MAX) {
157 nodat = ID3_GREATER_MAX_PROBE;
158 } else
159 nodat = ID3_GREATER_PROBE;
160 }
161
162 while ((fmt1 = av_demuxer_iterate(&i))) {
163 if (fmt1->flags & AVFMT_EXPERIMENTAL)
164 continue;
165 if (!is_opened == !(fmt1->flags & AVFMT_NOFILE) && strcmp(fmt1->name, "image2"))
166 continue;
167 score = 0;
168 if (fmt1->read_probe) {
169 score = fmt1->read_probe(&lpd);
170 if (score)
171 av_log(NULL, AV_LOG_TRACE, "Probing %s score:%d size:%d\n", fmt1->name, score, lpd.buf_size);
172 if (fmt1->extensions && av_match_ext(lpd.filename, fmt1->extensions)) {
173 switch (nodat) {
174 case NO_ID3:
175 score = FFMAX(score, 1);
176 break;
177 case ID3_GREATER_PROBE:
178 case ID3_ALMOST_GREATER_PROBE:
179 score = FFMAX(score, AVPROBE_SCORE_EXTENSION / 2 - 1);
180 break;
181 case ID3_GREATER_MAX_PROBE:
182 score = FFMAX(score, AVPROBE_SCORE_EXTENSION);
183 break;
184 }
185 }
186 } else if (fmt1->extensions) {
187 if (av_match_ext(lpd.filename, fmt1->extensions))
188 score = AVPROBE_SCORE_EXTENSION;
189 }
190 if (av_match_name(lpd.mime_type, fmt1->mime_type)) {
191 if (AVPROBE_SCORE_MIME > score) {
192 av_log(NULL, AV_LOG_DEBUG, "Probing %s score:%d increased to %d due to MIME type\n", fmt1->name, score, AVPROBE_SCORE_MIME);
193 score = AVPROBE_SCORE_MIME;
194 }
195 }
196 if (score > score_max) {
197 score_max = score;
198 fmt = fmt1;
199 } else if (score == score_max)
200 fmt = NULL;
201 }
202 if (nodat == ID3_GREATER_PROBE)
203 score_max = FFMIN(AVPROBE_SCORE_EXTENSION / 2 - 1, score_max);
204 *score_ret = score_max;
205
206 return fmt;
207 }
208
av_probe_input_format2(const AVProbeData * pd,int is_opened,int * score_max)209 const AVInputFormat *av_probe_input_format2(const AVProbeData *pd,
210 int is_opened, int *score_max)
211 {
212 int score_ret;
213 const AVInputFormat *fmt = av_probe_input_format3(pd, is_opened, &score_ret);
214 if (score_ret > *score_max) {
215 *score_max = score_ret;
216 return fmt;
217 } else
218 return NULL;
219 }
220
av_probe_input_format(const AVProbeData * pd,int is_opened)221 const AVInputFormat *av_probe_input_format(const AVProbeData *pd, int is_opened)
222 {
223 int score = 0;
224 return av_probe_input_format2(pd, is_opened, &score);
225 }
226
av_probe_input_buffer2(AVIOContext * pb,const AVInputFormat ** fmt,const char * filename,void * logctx,unsigned int offset,unsigned int max_probe_size)227 int av_probe_input_buffer2(AVIOContext *pb, const AVInputFormat **fmt,
228 const char *filename, void *logctx,
229 unsigned int offset, unsigned int max_probe_size)
230 {
231 AVProbeData pd = { filename ? filename : "" };
232 uint8_t *buf = NULL;
233 int ret = 0, probe_size, buf_offset = 0;
234 int score = 0;
235 int ret2;
236 int eof = 0;
237
238 if (!max_probe_size)
239 max_probe_size = PROBE_BUF_MAX;
240 else if (max_probe_size < PROBE_BUF_MIN) {
241 av_log(logctx, AV_LOG_ERROR,
242 "Specified probe size value %u cannot be < %u\n", max_probe_size, PROBE_BUF_MIN);
243 return AVERROR(EINVAL);
244 }
245
246 if (offset >= max_probe_size)
247 return AVERROR(EINVAL);
248
249 if (pb->av_class) {
250 uint8_t *mime_type_opt = NULL;
251 char *semi;
252 av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type_opt);
253 pd.mime_type = (const char *)mime_type_opt;
254 semi = pd.mime_type ? strchr(pd.mime_type, ';') : NULL;
255 if (semi) {
256 *semi = '\0';
257 }
258 }
259
260 for (probe_size = PROBE_BUF_MIN; probe_size <= max_probe_size && !*fmt && !eof;
261 probe_size = FFMIN(probe_size << 1,
262 FFMAX(max_probe_size, probe_size + 1))) {
263 score = probe_size < max_probe_size ? AVPROBE_SCORE_RETRY : 0;
264
265 /* Read probe data. */
266 if ((ret = av_reallocp(&buf, probe_size + AVPROBE_PADDING_SIZE)) < 0)
267 goto fail;
268 if ((ret = avio_read(pb, buf + buf_offset,
269 probe_size - buf_offset)) < 0) {
270 /* Fail if error was not end of file, otherwise, lower score. */
271 if (ret != AVERROR_EOF)
272 goto fail;
273
274 score = 0;
275 ret = 0; /* error was end of file, nothing read */
276 eof = 1;
277 }
278 buf_offset += ret;
279 if (buf_offset < offset)
280 continue;
281 pd.buf_size = buf_offset - offset;
282 pd.buf = &buf[offset];
283
284 memset(pd.buf + pd.buf_size, 0, AVPROBE_PADDING_SIZE);
285
286 /* Guess file format. */
287 *fmt = av_probe_input_format2(&pd, 1, &score);
288 if (*fmt) {
289 /* This can only be true in the last iteration. */
290 if (score <= AVPROBE_SCORE_RETRY) {
291 av_log(logctx, AV_LOG_WARNING,
292 "Format %s detected only with low score of %d, "
293 "misdetection possible!\n", (*fmt)->name, score);
294 } else
295 av_log(logctx, AV_LOG_DEBUG,
296 "Format %s probed with size=%d and score=%d\n",
297 (*fmt)->name, probe_size, score);
298 #if 0
299 FILE *f = fopen("probestat.tmp", "ab");
300 fprintf(f, "probe_size:%d format:%s score:%d filename:%s\n", probe_size, (*fmt)->name, score, filename);
301 fclose(f);
302 #endif
303 }
304 }
305
306 if (!*fmt)
307 ret = AVERROR_INVALIDDATA;
308
309 fail:
310 /* Rewind. Reuse probe buffer to avoid seeking. */
311 ret2 = ffio_rewind_with_probe_data(pb, &buf, buf_offset);
312 if (ret >= 0)
313 ret = ret2;
314
315 av_freep(&pd.mime_type);
316 return ret < 0 ? ret : score;
317 }
318
av_probe_input_buffer(AVIOContext * pb,const AVInputFormat ** fmt,const char * filename,void * logctx,unsigned int offset,unsigned int max_probe_size)319 int av_probe_input_buffer(AVIOContext *pb, const AVInputFormat **fmt,
320 const char *filename, void *logctx,
321 unsigned int offset, unsigned int max_probe_size)
322 {
323 int ret = av_probe_input_buffer2(pb, fmt, filename, logctx, offset, max_probe_size);
324 return ret < 0 ? ret : 0;
325 }
326