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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 #define BITSTREAM_READER_LE
28 #include "parser.h"
29 #include "tak.h"
30 
31 typedef struct TAKParseContext {
34  int index;
36 
38  const uint8_t **poutbuf, int *poutbuf_size,
39  const uint8_t *buf, int buf_size)
40 {
41  TAKParseContext *t = s->priv_data;
42  ParseContext *pc = &t->pc;
43  int next = END_NOT_FOUND;
44  GetBitContext gb;
45  int consumed = 0;
46  int needed = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8;
47  int ret;
48 
50  TAKStreamInfo ti;
51  if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
52  return ret;
53  if (!ff_tak_decode_frame_header(avctx, &gb, &ti, 127))
55  : t->ti.frame_samples;
56  *poutbuf = buf;
57  *poutbuf_size = buf_size;
58  return buf_size;
59  }
60 
61  while (buf_size || t->index + needed <= pc->index) {
62  if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) {
63  int tmp_buf_size = FFMIN(TAK_MAX_FRAME_HEADER_BYTES,
64  buf_size);
65  const uint8_t *tmp_buf = buf;
66 
67  if (ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size) != -1)
68  return AVERROR(ENOMEM);
69  consumed += tmp_buf_size;
70  buf += tmp_buf_size;
71  buf_size -= tmp_buf_size;
72  }
73 
74  for (; t->index + needed <= pc->index; t->index++) {
75  if (pc->buffer[ t->index ] == 0xFF &&
76  pc->buffer[ t->index + 1 ] == 0xA0) {
77  TAKStreamInfo ti;
78 
79  if ((ret = init_get_bits8(&gb, pc->buffer + t->index,
80  pc->index - t->index)) < 0)
81  return ret;
82  if (!ff_tak_decode_frame_header(avctx, &gb,
83  pc->frame_start_found ? &ti : &t->ti, 127) &&
84  !ff_tak_check_crc(pc->buffer + t->index,
85  get_bits_count(&gb) / 8)) {
86  if (!pc->frame_start_found) {
87  pc->frame_start_found = 1;
90  t->ti.frame_samples;
92  } else {
93  pc->frame_start_found = 0;
94  next = t->index - pc->index;
95  t->index = 0;
96  goto found;
97  }
98  }
99  }
100  }
101  }
102 found:
103 
104  if (consumed && !buf_size && next == END_NOT_FOUND ||
105  ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
106  *poutbuf = NULL;
107  *poutbuf_size = 0;
108  return buf_size + consumed;
109  }
110 
111  if (next != END_NOT_FOUND) {
112  next += consumed;
113  pc->overread = FFMAX(0, -next);
114  }
115 
116  *poutbuf = buf;
117  *poutbuf_size = buf_size;
118  return next;
119 }
120 
122  .codec_ids = { AV_CODEC_ID_TAK },
123  .priv_data_size = sizeof(TAKParseContext),
124  .parser_parse = tak_parse,
125  .parser_close = ff_parse_close,
126 };
#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:128
int codec_ids[5]
Definition: avcodec.h:5108
AVCodecParser ff_tak_parser
Definition: tak_parser.c:121
int duration
Duration of the current frame.
Definition: avcodec.h:5062
int frame_start_found
Definition: parser.h:34
TAKStreamInfo ti
Definition: tak_parser.c:33
uint8_t
int flags
Definition: tak.h:129
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:37
int ff_tak_check_crc(const uint8_t *buf, unsigned int buf_size)
Definition: tak.c:77
#define TAK_FRAME_FLAG_HAS_INFO
Definition: tak.h:61
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:199
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:137
#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:437
ParseContext pc
Definition: tak_parser.c:32
main external API structure.
Definition: avcodec.h:1657
void * buf
Definition: avisynth_c.h:553
int index
Definition: gxfenc.c:89
int frame_samples
Definition: tak.h:136
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:4974
#define TAK_MAX_FRAME_HEADER_BYTES
Definition: tak.h:96
int key_frame
Set by parser to 1 for key frames and 0 for non-key frames.
Definition: avcodec.h:4989