probetest.c
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1 /*
2  * copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of Libav.
5  *
6  * Libav is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * Libav is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <stdlib.h>
22 
23 #include "libavformat/avformat.h"
24 #include "libavcodec/put_bits.h"
25 #include "libavutil/lfg.h"
26 
27 static int score_array[1000]; //this must be larger than the number of formats
28 static int failures = 0;
29 
30 static void probe(AVProbeData *pd, int type, int p, int size)
31 {
32  int i = 0;
33  AVInputFormat *fmt = NULL;
34 
35  while ((fmt = av_iformat_next(fmt))) {
36  if (fmt->flags & AVFMT_NOFILE)
37  continue;
38  if (fmt->read_probe) {
39  int score = fmt->read_probe(pd);
40  if (score > score_array[i] && score > AVPROBE_SCORE_MAX / 4) {
41  score_array[i] = score;
42  fprintf(stderr, "Failure of %s probing code with score=%d type=%d p=%X size=%d\n",
43  fmt->name, score, type, p, size);
44  failures++;
45  }
46  }
47  i++;
48  }
49 }
50 
51 int main(void)
52 {
53  unsigned int p, i, type, size, retry;
54  AVProbeData pd;
55  AVLFG state;
56  PutBitContext pb;
57 
60 
61  av_lfg_init(&state, 0xdeadbeef);
62 
63  pd.buf = NULL;
64  for (size = 1; size < 65537; size *= 2) {
65  pd.buf_size = size;
66  pd.buf = av_realloc(pd.buf, size + AVPROBE_PADDING_SIZE);
67  pd.filename = "";
68 
69  fprintf(stderr, "testing size=%d\n", size);
70 
71  for (retry = 0; retry < 4097; retry += FFMAX(size, 32)) {
72  for (type = 0; type < 4; type++) {
73  for (p = 0; p < 4096; p++) {
74  unsigned hist = 0;
75  init_put_bits(&pb, pd.buf, size);
76  switch (type) {
77  case 0:
78  for (i = 0; i < size * 8; i++) {
79  put_bits(&pb, 1, (av_lfg_get(&state) & 0xFFFFFFFF) > p << 20);
80  }
81  break;
82  case 1:
83  for (i = 0; i < size * 8; i++) {
84  unsigned int p2 = hist ? p & 0x3F : (p >> 6);
85  unsigned int v = (av_lfg_get(&state) & 0xFFFFFFFF) > p2 << 26;
86  put_bits(&pb, 1, v);
87  hist = v;
88  }
89  break;
90  case 2:
91  for (i = 0; i < size * 8; i++) {
92  unsigned int p2 = (p >> (hist*3)) & 7;
93  unsigned int v = (av_lfg_get(&state) & 0xFFFFFFFF) > p2 << 29;
94  put_bits(&pb, 1, v);
95  hist = (2*hist + v) & 3;
96  }
97  break;
98  case 3:
99  for (i = 0; i < size; i++) {
100  int c = 0;
101  while (p & 63) {
102  c = (av_lfg_get(&state) & 0xFFFFFFFF) >> 24;
103  if (c >= 'a' && c <= 'z' && (p & 1)) break;
104  else if(c >= 'A' && c <= 'Z' && (p & 2)) break;
105  else if(c >= '0' && c <= '9' && (p & 4)) break;
106  else if(c == ' ' && (p & 8)) break;
107  else if(c == 0 && (p & 16)) break;
108  else if(c == 1 && (p & 32)) break;
109  }
110  pd.buf[i] = c;
111  }
112  }
113  flush_put_bits(&pb);
114  probe(&pd, type, p, size);
115  }
116  }
117  }
118  }
119  return failures;
120 }
Definition: lfg.h:25
void avcodec_register_all(void)
Register all the codecs, parsers and bitstream filters which were enabled at configuration time...
Definition: allcodecs.c:48
int size
const char * filename
Definition: avformat.h:340
#define AVPROBE_PADDING_SIZE
extra allocated bytes at the end of the probe buffer
Definition: avformat.h:346
void * av_realloc(void *ptr, size_t size)
Allocate or reallocate a block of memory.
Definition: mem.c:117
#define v(n)
Definition: regs.h:34
static void probe(AVProbeData *pd, int type, int p, int size)
Definition: probetest.c:30
int flags
Can use flags: AVFMT_NOFILE, AVFMT_NEEDNUMBER, AVFMT_SHOW_IDS, AVFMT_GENERIC_INDEX, AVFMT_TS_DISCONT, AVFMT_NOBINSEARCH, AVFMT_NOGENSEARCH, AVFMT_NO_BYTE_SEEK.
Definition: avformat.h:530
int(* read_probe)(AVProbeData *)
Tell if a given file has a chance of being parsed as this format.
Definition: avformat.h:479
static void put_bits(PutBitContext *s, int n, unsigned int value)
Write up to 31 bits into a bitstream.
Definition: put_bits.h:136
#define FFMAX(a, b)
Definition: common.h:53
static int failures
Definition: probetest.c:28
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:342
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:341
static int score_array[1000]
Definition: probetest.c:27
NULL
Definition: eval.c:50
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:38
This structure contains the data a format has to probe a file.
Definition: avformat.h:339
static uint32_t state
Definition: trasher.c:25
int main(void)
Definition: probetest.c:51
#define AVPROBE_SCORE_MAX
maximum score, half of that is used for file-extension-based detection
Definition: avformat.h:345
Main libavformat public API header.
static void flush_put_bits(PutBitContext *s)
Pad the end of the output stream with zeros.
Definition: put_bits.h:86
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:368
void av_cold av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:30
static void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
Initialize the PutBitContext s.
Definition: put_bits.h:52
AVInputFormat * av_iformat_next(AVInputFormat *f)
If f is NULL, returns the first registered input format, if f is non-NULL, returns the next registere...
Definition: utils.c:127
#define fprintf
Definition: internal.h:153
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:460
void av_register_all(void)
Initialize libavformat and register all the muxers, demuxers and protocols.
Definition: allformats.c:40
bitstream writer API