Imported Debian version 2.5.0~trusty1.1
[deb_ffmpeg.git] / ffmpeg / libavformat / format.c
CommitLineData
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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/atomic.h"
23#include "libavutil/avstring.h"
24#include "libavutil/bprint.h"
25#include "libavutil/opt.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/** head of registered input format linked list */
38static AVInputFormat *first_iformat = NULL;
39/** head of registered output format linked list */
40static AVOutputFormat *first_oformat = NULL;
41
42static AVInputFormat **last_iformat = &first_iformat;
43static AVOutputFormat **last_oformat = &first_oformat;
44
45AVInputFormat *av_iformat_next(const AVInputFormat *f)
46{
47 if (f)
48 return f->next;
49 else
50 return first_iformat;
51}
52
53AVOutputFormat *av_oformat_next(const AVOutputFormat *f)
54{
55 if (f)
56 return f->next;
57 else
58 return first_oformat;
59}
60
61void av_register_input_format(AVInputFormat *format)
62{
63 AVInputFormat **p = last_iformat;
64
65 format->next = NULL;
66 while(*p || avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format))
67 p = &(*p)->next;
68 last_iformat = &format->next;
69}
70
71void av_register_output_format(AVOutputFormat *format)
72{
73 AVOutputFormat **p = last_oformat;
74
75 format->next = NULL;
76 while(*p || avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format))
77 p = &(*p)->next;
78 last_oformat = &format->next;
79}
80
81int av_match_ext(const char *filename, const char *extensions)
82{
f6fa7814 83 const char *ext;
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84
85 if (!filename)
86 return 0;
87
88 ext = strrchr(filename, '.');
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89 if (ext)
90 return av_match_name(ext + 1, extensions);
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91 return 0;
92}
93
94AVOutputFormat *av_guess_format(const char *short_name, const char *filename,
95 const char *mime_type)
96{
97 AVOutputFormat *fmt = NULL, *fmt_found;
98 int score_max, score;
99
100 /* specific test for image sequences */
101#if CONFIG_IMAGE2_MUXER
102 if (!short_name && filename &&
103 av_filename_number_test(filename) &&
104 ff_guess_image2_codec(filename) != AV_CODEC_ID_NONE) {
105 return av_guess_format("image2", NULL, NULL);
106 }
107#endif
108 /* Find the proper file type. */
109 fmt_found = NULL;
110 score_max = 0;
111 while ((fmt = av_oformat_next(fmt))) {
112 score = 0;
113 if (fmt->name && short_name && av_match_name(short_name, fmt->name))
114 score += 100;
115 if (fmt->mime_type && mime_type && !strcmp(fmt->mime_type, mime_type))
116 score += 10;
117 if (filename && fmt->extensions &&
118 av_match_ext(filename, fmt->extensions)) {
119 score += 5;
120 }
121 if (score > score_max) {
122 score_max = score;
123 fmt_found = fmt;
124 }
125 }
126 return fmt_found;
127}
128
129enum AVCodecID av_guess_codec(AVOutputFormat *fmt, const char *short_name,
130 const char *filename, const char *mime_type,
131 enum AVMediaType type)
132{
133 if (av_match_name("segment", fmt->name) || av_match_name("ssegment", fmt->name)) {
134 AVOutputFormat *fmt2 = av_guess_format(NULL, filename, NULL);
135 if (fmt2)
136 fmt = fmt2;
137 }
138
139 if (type == AVMEDIA_TYPE_VIDEO) {
140 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
141
142#if CONFIG_IMAGE2_MUXER
143 if (!strcmp(fmt->name, "image2") || !strcmp(fmt->name, "image2pipe")) {
144 codec_id = ff_guess_image2_codec(filename);
145 }
146#endif
147 if (codec_id == AV_CODEC_ID_NONE)
148 codec_id = fmt->video_codec;
149 return codec_id;
150 } else if (type == AVMEDIA_TYPE_AUDIO)
151 return fmt->audio_codec;
152 else if (type == AVMEDIA_TYPE_SUBTITLE)
153 return fmt->subtitle_codec;
154 else
155 return AV_CODEC_ID_NONE;
156}
157
158AVInputFormat *av_find_input_format(const char *short_name)
159{
160 AVInputFormat *fmt = NULL;
161 while ((fmt = av_iformat_next(fmt)))
162 if (av_match_name(short_name, fmt->name))
163 return fmt;
164 return NULL;
165}
166
167AVInputFormat *av_probe_input_format3(AVProbeData *pd, int is_opened,
168 int *score_ret)
169{
170 AVProbeData lpd = *pd;
171 AVInputFormat *fmt1 = NULL, *fmt;
172 int score, nodat = 0, score_max = 0;
173 const static uint8_t zerobuffer[AVPROBE_PADDING_SIZE];
174
175 if (!lpd.buf)
176 lpd.buf = zerobuffer;
177
178 if (lpd.buf_size > 10 && ff_id3v2_match(lpd.buf, ID3v2_DEFAULT_MAGIC)) {
179 int id3len = ff_id3v2_tag_len(lpd.buf);
180 if (lpd.buf_size > id3len + 16) {
181 lpd.buf += id3len;
182 lpd.buf_size -= id3len;
183 } else if (id3len >= PROBE_BUF_MAX) {
184 nodat = 2;
185 } else
186 nodat = 1;
187 }
188
189 fmt = NULL;
190 while ((fmt1 = av_iformat_next(fmt1))) {
191 if (!is_opened == !(fmt1->flags & AVFMT_NOFILE) && strcmp(fmt1->name, "image2"))
192 continue;
193 score = 0;
194 if (fmt1->read_probe) {
195 score = fmt1->read_probe(&lpd);
196 if (fmt1->extensions && av_match_ext(lpd.filename, fmt1->extensions)) {
197 if (nodat == 0) score = FFMAX(score, 1);
198 else if (nodat == 1) score = FFMAX(score, AVPROBE_SCORE_EXTENSION / 2 - 1);
199 else score = FFMAX(score, AVPROBE_SCORE_EXTENSION);
200 }
201 } else if (fmt1->extensions) {
202 if (av_match_ext(lpd.filename, fmt1->extensions))
203 score = AVPROBE_SCORE_EXTENSION;
204 }
205 if (av_match_name(lpd.mime_type, fmt1->mime_type))
206 score = FFMAX(score, AVPROBE_SCORE_MIME);
207 if (score > score_max) {
208 score_max = score;
209 fmt = fmt1;
210 } else if (score == score_max)
211 fmt = NULL;
212 }
213 if (nodat == 1)
214 score_max = FFMIN(AVPROBE_SCORE_EXTENSION / 2 - 1, score_max);
215 *score_ret = score_max;
216
217 return fmt;
218}
219
220AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened, int *score_max)
221{
222 int score_ret;
223 AVInputFormat *fmt = av_probe_input_format3(pd, is_opened, &score_ret);
224 if (score_ret > *score_max) {
225 *score_max = score_ret;
226 return fmt;
227 } else
228 return NULL;
229}
230
231AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened)
232{
233 int score = 0;
234 return av_probe_input_format2(pd, is_opened, &score);
235}
236
237int av_probe_input_buffer2(AVIOContext *pb, AVInputFormat **fmt,
238 const char *filename, void *logctx,
239 unsigned int offset, unsigned int max_probe_size)
240{
241 AVProbeData pd = { filename ? filename : "" };
242 uint8_t *buf = NULL;
243 int ret = 0, probe_size, buf_offset = 0;
244 int score = 0;
245 int ret2;
246
247 if (!max_probe_size)
248 max_probe_size = PROBE_BUF_MAX;
249 else if (max_probe_size < PROBE_BUF_MIN) {
250 av_log(logctx, AV_LOG_ERROR,
251 "Specified probe size value %u cannot be < %u\n", max_probe_size, PROBE_BUF_MIN);
252 return AVERROR(EINVAL);
253 }
254
255 if (offset >= max_probe_size)
256 return AVERROR(EINVAL);
257
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258 if (pb->av_class) {
259 uint8_t *mime_type_opt = NULL;
260 av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type_opt);
261 pd.mime_type = (const char *)mime_type_opt;
262 }
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263#if 0
264 if (!*fmt && pb->av_class && av_opt_get(pb, "mime_type", AV_OPT_SEARCH_CHILDREN, &mime_type) >= 0 && mime_type) {
265 if (!av_strcasecmp(mime_type, "audio/aacp")) {
266 *fmt = av_find_input_format("aac");
267 }
268 av_freep(&mime_type);
269 }
270#endif
271
272 for (probe_size = PROBE_BUF_MIN; probe_size <= max_probe_size && !*fmt;
273 probe_size = FFMIN(probe_size << 1,
274 FFMAX(max_probe_size, probe_size + 1))) {
275 score = probe_size < max_probe_size ? AVPROBE_SCORE_RETRY : 0;
276
277 /* Read probe data. */
278 if ((ret = av_reallocp(&buf, probe_size + AVPROBE_PADDING_SIZE)) < 0)
279 goto fail;
280 if ((ret = avio_read(pb, buf + buf_offset,
281 probe_size - buf_offset)) < 0) {
282 /* Fail if error was not end of file, otherwise, lower score. */
283 if (ret != AVERROR_EOF)
284 goto fail;
285
286 score = 0;
287 ret = 0; /* error was end of file, nothing read */
288 }
289 buf_offset += ret;
290 if (buf_offset < offset)
291 continue;
292 pd.buf_size = buf_offset - offset;
293 pd.buf = &buf[offset];
294
295 memset(pd.buf + pd.buf_size, 0, AVPROBE_PADDING_SIZE);
296
297 /* Guess file format. */
298 *fmt = av_probe_input_format2(&pd, 1, &score);
299 if (*fmt) {
300 /* This can only be true in the last iteration. */
301 if (score <= AVPROBE_SCORE_RETRY) {
302 av_log(logctx, AV_LOG_WARNING,
303 "Format %s detected only with low score of %d, "
304 "misdetection possible!\n", (*fmt)->name, score);
305 } else
306 av_log(logctx, AV_LOG_DEBUG,
307 "Format %s probed with size=%d and score=%d\n",
308 (*fmt)->name, probe_size, score);
309#if 0
310 FILE *f = fopen("probestat.tmp", "ab");
311 fprintf(f, "probe_size:%d format:%s score:%d filename:%s\n", probe_size, (*fmt)->name, score, filename);
312 fclose(f);
313#endif
314 }
315 }
316
317 if (!*fmt)
318 ret = AVERROR_INVALIDDATA;
319
320fail:
321 /* Rewind. Reuse probe buffer to avoid seeking. */
322 ret2 = ffio_rewind_with_probe_data(pb, &buf, buf_offset);
323 if (ret >= 0)
324 ret = ret2;
325
f6fa7814 326 av_freep(&pd.mime_type);
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327 return ret < 0 ? ret : score;
328}
329
330int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
331 const char *filename, void *logctx,
332 unsigned int offset, unsigned int max_probe_size)
333{
334 int ret = av_probe_input_buffer2(pb, fmt, filename, logctx, offset, max_probe_size);
335 return ret < 0 ? ret : 0;
336}