FFmpeg
dvbsub.c
Go to the documentation of this file.
1 /*
2  * RAW dvbsub demuxer
3  * Copyright (c) 2015 Michael Niedermayer <michaelni@gmx.at>
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/intreadwrite.h"
23 
24 #include "avformat.h"
25 #include "rawdec.h"
26 
27 
28 static int dvbsub_probe(const AVProbeData *p)
29 {
30  int i, j, k;
31  const uint8_t *end = p->buf + p->buf_size;
32  int type, len;
33  int max_score = 0;
34 
35  for(i=0; i<p->buf_size; i++){
36  if (p->buf[i] == 0x0f) {
37  const uint8_t *ptr = p->buf + i;
38  uint8_t histogram[6] = {0};
39  int min = 255;
40  for(j=0; 6 < end - ptr; j++) {
41  if (*ptr != 0x0f)
42  break;
43  type = ptr[1];
44  //page_id = AV_RB16(ptr + 2);
45  len = AV_RB16(ptr + 4);
46  if (type == 0x80) {
47  ;
48  } else if (type >= 0x10 && type <= 0x14) {
49  histogram[type - 0x10] ++;
50  } else
51  break;
52  if (6 + len > end - ptr)
53  break;
54  ptr += 6 + len;
55  }
56  for (k=0; k < 4; k++) {
57  min = FFMIN(min, histogram[k]);
58  }
59  if (min && j > max_score)
60  max_score = j;
61  }
62  }
63 
64  if (max_score > 5)
66 
67  return 0;
68 }
69 
#define NULL
Definition: coverity.c:32
GLint GLenum type
Definition: opengl_enc.c:104
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:87
uint8_t
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
#define FFMIN(a, b)
Definition: common.h:96
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:468
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:456
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
Main libavformat public API header.
static int dvbsub_probe(const AVProbeData *p)
Definition: dvbsub.c:28
#define FF_DEF_RAWSUB_DEMUXER(shortname, longname, probe, ext, id, flag)
Definition: rawdec.h:97
int len
float min