FFmpeg  4.0
dvd_nav_parser.c
Go to the documentation of this file.
1 /*
2  * DVD navigation block parser for FFmpeg
3  * Copyright (c) 2013 The FFmpeg Project
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 #include "avcodec.h"
22 #include "get_bits.h"
23 #include "parser.h"
24 
25 #define PCI_SIZE 980
26 #define DSI_SIZE 1018
27 
28 /* parser definition */
29 typedef struct DVDNavParseContext {
30  uint32_t lba;
32  int copied;
34 
36 {
38 
39  pc->lba = 0xFFFFFFFF;
40  pc->copied = 0;
41  return 0;
42 }
43 
45  AVCodecContext *avctx,
46  const uint8_t **poutbuf, int *poutbuf_size,
47  const uint8_t *buf, int buf_size)
48 {
49  DVDNavParseContext *pc1 = s->priv_data;
50  int lastPacket = 0;
51  int valid = 0;
52 
54 
55  avctx->time_base.num = 1;
56  avctx->time_base.den = 90000;
57 
58  if (buf && buf_size) {
59  switch(buf[0]) {
60  case 0x00:
61  if (buf_size == PCI_SIZE) {
62  /* PCI */
63  uint32_t lba = AV_RB32(&buf[0x01]);
64  uint32_t startpts = AV_RB32(&buf[0x0D]);
65  uint32_t endpts = AV_RB32(&buf[0x11]);
66 
67  if (endpts > startpts) {
68  pc1->lba = lba;
69  s->pts = (int64_t)startpts;
70  s->duration = endpts - startpts;
71 
72  memcpy(pc1->buffer, buf, PCI_SIZE);
73  pc1->copied = PCI_SIZE;
74  valid = 1;
75  }
76  }
77  break;
78 
79  case 0x01:
80  if ((buf_size == DSI_SIZE) && (pc1->copied == PCI_SIZE)) {
81  /* DSI */
82  uint32_t lba = AV_RB32(&buf[0x05]);
83 
84  if (lba == pc1->lba) {
85  memcpy(pc1->buffer + pc1->copied, buf, DSI_SIZE);
86  lastPacket = 1;
87  valid = 1;
88  }
89  }
90  break;
91  }
92  }
93 
94  if (!valid || lastPacket) {
95  pc1->copied = 0;
96  pc1->lba = 0xFFFFFFFF;
97  }
98 
99  if (lastPacket) {
100  *poutbuf = pc1->buffer;
101  *poutbuf_size = sizeof(pc1->buffer);
102  } else {
103  *poutbuf = NULL;
104  *poutbuf_size = 0;
105  }
106 
107  return buf_size;
108 }
109 
112  .priv_data_size = sizeof(DVDNavParseContext),
113  .parser_init = dvd_nav_parse_init,
114  .parser_parse = dvd_nav_parse,
115 };
AVCodecParser ff_dvd_nav_parser
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
static int dvd_nav_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
int num
Numerator.
Definition: rational.h:59
int codec_ids[5]
Definition: avcodec.h:5200
int duration
Duration of the current frame.
Definition: avcodec.h:5154
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avcodec.h:1640
Undefined.
Definition: avutil.h:273
uint8_t
#define av_cold
Definition: attributes.h:82
#define AV_RB32
Definition: intreadwrite.h:130
bitstream reader API header.
static av_cold int dvd_nav_parse_init(AVCodecParserContext *s)
#define DSI_SIZE
Libavcodec external API header.
main external API structure.
Definition: avcodec.h:1518
void * buf
Definition: avisynth_c.h:690
int den
Denominator.
Definition: rational.h:60
uint8_t buffer[PCI_SIZE+DSI_SIZE]
#define PCI_SIZE