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 "libavutil/avstring.h"
23 #include "libavutil/bprint.h"
24 #include "libavutil/opt.h"
25 #include "libavutil/thread.h"
26
27 #include "avio_internal.h"
28 #include "avformat.h"
29 #include "id3v2.h"
30 #include "internal.h"
31
32
33 /**
34 * @file
35 * Format register and lookup
36 */
37
av_match_ext(const char * filename,const char * extensions)38 int av_match_ext(const char *filename, const char *extensions)
39 {
40 const char *ext;
41
42 if (!filename)
43 return 0;
44
45 ext = strrchr(filename, '.');
46 if (ext)
47 return av_match_name(ext + 1, extensions);
48 return 0;
49 }
50
av_guess_format(const char * short_name,const char * filename,const char * mime_type)51 ff_const59 AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
52 const char *mime_type)
53 {
54 const AVOutputFormat *fmt = NULL;
55 AVOutputFormat *fmt_found = NULL;
56 void *i = 0;
57 int score_max, score;
58
59 /* specific test for image sequences */
60 #if CONFIG_IMAGE2_MUXER
61 if (!short_name && filename &&
62 av_filename_number_test(filename) &&
63 ff_guess_image2_codec(filename) != AV_CODEC_ID_NONE) {
64 return av_guess_format("image2", NULL, NULL);
65 }
66 #endif
67 /* Find the proper file type. */
68 score_max = 0;
69 while ((fmt = av_muxer_iterate(&i))) {
70 score = 0;
71 if (fmt->name && short_name && av_match_name(short_name, fmt->name))
72 score += 100;
73 if (fmt->mime_type && mime_type && !strcmp(fmt->mime_type, mime_type))
74 score += 10;
75 if (filename && fmt->extensions &&
76 av_match_ext(filename, fmt->extensions)) {
77 score += 5;
78 }
79 if (score > score_max) {
80 score_max = score;
81 fmt_found = (AVOutputFormat*)fmt;
82 }
83 }
84 return fmt_found;
85 }
86
av_guess_codec(ff_const59 AVOutputFormat * fmt,const char * short_name,const char * filename,const char * mime_type,enum AVMediaType type)87 enum AVCodecID av_guess_codec(ff_const59 AVOutputFormat *fmt, const char *short_name,
88 const char *filename, const char *mime_type,
89 enum AVMediaType type)
90 {
91 if (av_match_name("segment", fmt->name) || av_match_name("ssegment", fmt->name)) {
92 ff_const59 AVOutputFormat *fmt2 = av_guess_format(NULL, filename, NULL);
93 if (fmt2)
94 fmt = fmt2;
95 }
96
97 if (type == AVMEDIA_TYPE_VIDEO) {
98 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
99
100 #if CONFIG_IMAGE2_MUXER
101 if (!strcmp(fmt->name, "image2") || !strcmp(fmt->name, "image2pipe")) {
102 codec_id = ff_guess_image2_codec(filename);
103 }
104 #endif
105 if (codec_id == AV_CODEC_ID_NONE)
106 codec_id = fmt->video_codec;
107 return codec_id;
108 } else if (type == AVMEDIA_TYPE_AUDIO)
109 return fmt->audio_codec;
110 else if (type == AVMEDIA_TYPE_SUBTITLE)
111 return fmt->subtitle_codec;
112 else if (type == AVMEDIA_TYPE_DATA)
113 return fmt->data_codec;
114 else
115 return AV_CODEC_ID_NONE;
116 }
117
av_find_input_format(const char * short_name)118 ff_const59 AVInputFormat *av_find_input_format(const char *short_name)
119 {
120 const AVInputFormat *fmt = NULL;
121 void *i = 0;
122 while ((fmt = av_demuxer_iterate(&i)))
123 if (av_match_name(short_name, fmt->name))
124 return (AVInputFormat*)fmt;
125 return NULL;
126 }
127
av_probe_input_format3(ff_const59 AVProbeData * pd,int is_opened,int * score_ret)128 ff_const59 AVInputFormat *av_probe_input_format3(ff_const59 AVProbeData *pd, int is_opened,
129 int *score_ret)
130 {
131 AVProbeData lpd = *pd;
132 const AVInputFormat *fmt1 = NULL;
133 ff_const59 AVInputFormat *fmt = NULL;
134 int score, score_max = 0;
135 void *i = 0;
136 const static uint8_t zerobuffer[AVPROBE_PADDING_SIZE];
137 enum nodat {
138 NO_ID3,
139 ID3_ALMOST_GREATER_PROBE,
140 ID3_GREATER_PROBE,
141 ID3_GREATER_MAX_PROBE,
142 } nodat = NO_ID3;
143
144 if (!lpd.buf)
145 lpd.buf = (unsigned char *) zerobuffer;
146
147 if (lpd.buf_size > 10 && ff_id3v2_match(lpd.buf, ID3v2_DEFAULT_MAGIC)) {
148 int id3len = ff_id3v2_tag_len(lpd.buf);
149 if (lpd.buf_size > id3len + 16) {
150 if (lpd.buf_size < 2LL*id3len + 16)
151 nodat = ID3_ALMOST_GREATER_PROBE;
152 lpd.buf += id3len;
153 lpd.buf_size -= id3len;
154 } else if (id3len >= PROBE_BUF_MAX) {
155 nodat = ID3_GREATER_MAX_PROBE;
156 } else
157 nodat = ID3_GREATER_PROBE;
158 }
159
160 while ((fmt1 = av_demuxer_iterate(&i))) {
161 if (!is_opened == !(fmt1->flags & AVFMT_NOFILE) && strcmp(fmt1->name, "image2"))
162 continue;
163 score = 0;
164 if (fmt1->read_probe) {
165 score = fmt1->read_probe(&lpd);
166 if (score)
167 av_log(NULL, AV_LOG_TRACE, "Probing %s score:%d size:%d\n", fmt1->name, score, lpd.buf_size);
168 if (fmt1->extensions && av_match_ext(lpd.filename, fmt1->extensions)) {
169 switch (nodat) {
170 case NO_ID3:
171 score = FFMAX(score, 1);
172 break;
173 case ID3_GREATER_PROBE:
174 case ID3_ALMOST_GREATER_PROBE:
175 score = FFMAX(score, AVPROBE_SCORE_EXTENSION / 2 - 1);
176 break;
177 case ID3_GREATER_MAX_PROBE:
178 score = FFMAX(score, AVPROBE_SCORE_EXTENSION);
179 break;
180 }
181 }
182 } else if (fmt1->extensions) {
183 if (av_match_ext(lpd.filename, fmt1->extensions))
184 score = AVPROBE_SCORE_EXTENSION;
185 }
186 if (av_match_name(lpd.mime_type, fmt1->mime_type)) {
187 if (AVPROBE_SCORE_MIME > score) {
188 av_log(NULL, AV_LOG_DEBUG, "Probing %s score:%d increased to %d due to MIME type\n", fmt1->name, score, AVPROBE_SCORE_MIME);
189 score = AVPROBE_SCORE_MIME;
190 }
191 }
192 if (score > score_max) {
193 score_max = score;
194 fmt = (AVInputFormat*)fmt1;
195 } else if (score == score_max)
196 fmt = NULL;
197 }
198 if (nodat == ID3_GREATER_PROBE)
199 score_max = FFMIN(AVPROBE_SCORE_EXTENSION / 2 - 1, score_max);
200 *score_ret = score_max;
201
202 return fmt;
203 }
204
av_probe_input_format2(ff_const59 AVProbeData * pd,int is_opened,int * score_max)205 ff_const59 AVInputFormat *av_probe_input_format2(ff_const59 AVProbeData *pd, int is_opened, int *score_max)
206 {
207 int score_ret;
208 ff_const59 AVInputFormat *fmt = av_probe_input_format3(pd, is_opened, &score_ret);
209 if (score_ret > *score_max) {
210 *score_max = score_ret;
211 return fmt;
212 } else
213 return NULL;
214 }
215
av_probe_input_format(ff_const59 AVProbeData * pd,int is_opened)216 ff_const59 AVInputFormat *av_probe_input_format(ff_const59 AVProbeData *pd, int is_opened)
217 {
218 int score = 0;
219 return av_probe_input_format2(pd, is_opened, &score);
220 }
221
av_probe_input_buffer2(AVIOContext * pb,ff_const59 AVInputFormat ** fmt,const char * filename,void * logctx,unsigned int offset,unsigned int max_probe_size)222 int av_probe_input_buffer2(AVIOContext *pb, ff_const59 AVInputFormat **fmt,
223 const char *filename, void *logctx,
224 unsigned int offset, unsigned int max_probe_size)
225 {
226 AVProbeData pd = { filename ? filename : "" };
227 uint8_t *buf = NULL;
228 int ret = 0, probe_size, buf_offset = 0;
229 int score = 0;
230 int ret2;
231
232 if (!max_probe_size)
233 max_probe_size = PROBE_BUF_MAX;
234 else if (max_probe_size < PROBE_BUF_MIN) {
235 av_log(logctx, AV_LOG_ERROR,
236 "Specified probe size value %u cannot be < %u\n", max_probe_size, PROBE_BUF_MIN);
237 return AVERROR(EINVAL);
238 }
239
240 if (offset >= max_probe_size)
241 return AVERROR(EINVAL);
242
243 if (pb->av_class) {
244 uint8_t *mime_type_opt = NULL;
245 char *semi;
246 av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type_opt);
247 pd.mime_type = (const char *)mime_type_opt;
248 semi = pd.mime_type ? strchr(pd.mime_type, ';') : NULL;
249 if (semi) {
250 *semi = '\0';
251 }
252 }
253
254 for (probe_size = PROBE_BUF_MIN; probe_size <= max_probe_size && !*fmt;
255 probe_size = FFMIN(probe_size << 1,
256 FFMAX(max_probe_size, probe_size + 1))) {
257 score = probe_size < max_probe_size ? AVPROBE_SCORE_RETRY : 0;
258
259 /* Read probe data. */
260 if ((ret = av_reallocp(&buf, probe_size + AVPROBE_PADDING_SIZE)) < 0)
261 goto fail;
262 if ((ret = avio_read(pb, buf + buf_offset,
263 probe_size - buf_offset)) < 0) {
264 /* Fail if error was not end of file, otherwise, lower score. */
265 if (ret != AVERROR_EOF)
266 goto fail;
267
268 score = 0;
269 ret = 0; /* error was end of file, nothing read */
270 }
271 buf_offset += ret;
272 if (buf_offset < offset)
273 continue;
274 pd.buf_size = buf_offset - offset;
275 pd.buf = &buf[offset];
276
277 memset(pd.buf + pd.buf_size, 0, AVPROBE_PADDING_SIZE);
278
279 /* Guess file format. */
280 *fmt = av_probe_input_format2(&pd, 1, &score);
281 if (*fmt) {
282 /* This can only be true in the last iteration. */
283 if (score <= AVPROBE_SCORE_RETRY) {
284 av_log(logctx, AV_LOG_WARNING,
285 "Format %s detected only with low score of %d, "
286 "misdetection possible!\n", (*fmt)->name, score);
287 } else
288 av_log(logctx, AV_LOG_DEBUG,
289 "Format %s probed with size=%d and score=%d\n",
290 (*fmt)->name, probe_size, score);
291 #if 0
292 FILE *f = fopen("probestat.tmp", "ab");
293 fprintf(f, "probe_size:%d format:%s score:%d filename:%s\n", probe_size, (*fmt)->name, score, filename);
294 fclose(f);
295 #endif
296 }
297 }
298
299 if (!*fmt)
300 ret = AVERROR_INVALIDDATA;
301
302 fail:
303 /* Rewind. Reuse probe buffer to avoid seeking. */
304 ret2 = ffio_rewind_with_probe_data(pb, &buf, buf_offset);
305 if (ret >= 0)
306 ret = ret2;
307
308 av_freep(&pd.mime_type);
309 return ret < 0 ? ret : score;
310 }
311
av_probe_input_buffer(AVIOContext * pb,ff_const59 AVInputFormat ** fmt,const char * filename,void * logctx,unsigned int offset,unsigned int max_probe_size)312 int av_probe_input_buffer(AVIOContext *pb, ff_const59 AVInputFormat **fmt,
313 const char *filename, void *logctx,
314 unsigned int offset, unsigned int max_probe_size)
315 {
316 int ret = av_probe_input_buffer2(pb, fmt, filename, logctx, offset, max_probe_size);
317 return ret < 0 ? ret : 0;
318 }
319