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tak_parser.c
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1 /*
2  * TAK parser
3  * Copyright (c) 2012 Michael Niedermayer
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 /**
23  * @file
24  * TAK parser
25  **/
26 
27 #include "tak.h"
28 #include "parser.h"
29 
30 typedef struct TAKParseContext {
33  int index;
35 
37  const uint8_t **poutbuf, int *poutbuf_size,
38  const uint8_t *buf, int buf_size)
39 {
40  TAKParseContext *t = s->priv_data;
41  ParseContext *pc = &t->pc;
42  int next = END_NOT_FOUND;
43  GetBitContext gb;
44  int consumed = 0;
45  int needed = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8;
46  int ret;
47 
49  TAKStreamInfo ti;
50  if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
51  return ret;
52  if (!ff_tak_decode_frame_header(avctx, &gb, &ti, 127))
54  : t->ti.frame_samples;
55  *poutbuf = buf;
56  *poutbuf_size = buf_size;
57  return buf_size;
58  }
59 
60  while (buf_size || t->index + needed <= pc->index) {
61  if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) {
62  int tmp_buf_size = FFMIN(TAK_MAX_FRAME_HEADER_BYTES,
63  buf_size);
64  const uint8_t *tmp_buf = buf;
65 
66  if (ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size) != -1)
67  return AVERROR(ENOMEM);
68  consumed += tmp_buf_size;
69  buf += tmp_buf_size;
70  buf_size -= tmp_buf_size;
71  }
72 
73  for (; t->index + needed <= pc->index; t->index++) {
74  if (pc->buffer[ t->index ] == 0xFF &&
75  pc->buffer[ t->index + 1 ] == 0xA0) {
76  TAKStreamInfo ti;
77 
78  if ((ret = init_get_bits8(&gb, pc->buffer + t->index,
79  pc->index - t->index)) < 0)
80  return ret;
81  if (!ff_tak_decode_frame_header(avctx, &gb,
82  pc->frame_start_found ? &ti : &t->ti, 127) &&
83  !ff_tak_check_crc(pc->buffer + t->index,
84  get_bits_count(&gb) / 8)) {
85  if (!pc->frame_start_found) {
86  pc->frame_start_found = 1;
89  t->ti.frame_samples;
91  } else {
92  pc->frame_start_found = 0;
93  next = t->index - pc->index;
94  t->index = 0;
95  goto found;
96  }
97  }
98  }
99  }
100  }
101 found:
102 
103  if (consumed && !buf_size && next == END_NOT_FOUND ||
104  ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
105  *poutbuf = NULL;
106  *poutbuf_size = 0;
107  return buf_size + consumed;
108  }
109 
110  if (next != END_NOT_FOUND) {
111  next += consumed;
112  pc->overread = FFMAX(0, -next);
113  }
114 
115  *poutbuf = buf;
116  *poutbuf_size = buf_size;
117  return next;
118 }
119 
121  .codec_ids = { AV_CODEC_ID_TAK },
122  .priv_data_size = sizeof(TAKParseContext),
123  .parser_parse = tak_parse,
124  .parser_close = ff_parse_close,
125 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
int ff_tak_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb, TAKStreamInfo *ti, int log_level_offset)
Validate and decode a frame header.
Definition: tak.c:126
int codec_ids[5]
Definition: avcodec.h:5071
AVCodecParser ff_tak_parser
Definition: tak_parser.c:120
int duration
Duration of the current frame.
Definition: avcodec.h:5025
int frame_start_found
Definition: parser.h:34
TAKStreamInfo ti
Definition: tak_parser.c:32
uint8_t
int flags
Definition: tak.h:130
static int tak_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: tak_parser.c:36
int ff_tak_check_crc(const uint8_t *buf, unsigned int buf_size)
Definition: tak.c:75
#define TAK_FRAME_FLAG_HAS_INFO
Definition: tak.h:62
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:212
int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
Combine the (truncated) bitstream to a complete frame.
Definition: parser.c:245
#define AVERROR(e)
Definition: error.h:43
int last_frame_samples
Definition: tak.h:138
#define FFMAX(a, b)
Definition: common.h:94
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:321
int overread
the number of bytes which where irreversibly read from the next frame
Definition: parser.h:35
#define FFMIN(a, b)
Definition: common.h:96
uint8_t * buffer
Definition: parser.h:29
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:449
ParseContext pc
Definition: tak_parser.c:31
main external API structure.
Definition: avcodec.h:1639
void * buf
Definition: avisynth_c.h:553
int index
Definition: gxfenc.c:89
int frame_samples
Definition: tak.h:137
TAK (Tom's lossless Audio Kompressor) decoder/demuxer common functions.
#define END_NOT_FOUND
Definition: parser.h:40
int index
Definition: parser.h:30
#define PARSER_FLAG_COMPLETE_FRAMES
Definition: avcodec.h:4937
#define TAK_MAX_FRAME_HEADER_BYTES
Definition: tak.h:97
int key_frame
Set by parser to 1 for key frames and 0 for non-key frames.
Definition: avcodec.h:4952