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adx_parser.c
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1 /*
2  * Copyright (c) 2011 Justin Ruggles
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * ADX audio parser
24  *
25  * Splits packets into individual blocks.
26  */
27 
28 #include "libavutil/intreadwrite.h"
29 #include "parser.h"
30 #include "adx.h"
31 
32 typedef struct ADXParseContext {
36  int remaining;
38 
40  AVCodecContext *avctx,
41  const uint8_t **poutbuf, int *poutbuf_size,
42  const uint8_t *buf, int buf_size)
43 {
45  ParseContext *pc = &s->pc;
46  int next = END_NOT_FOUND;
47  int i;
48  uint64_t state = pc->state64;
49 
50  if (!s->header_size) {
51  for (i = 0; i < buf_size; i++) {
52  state = (state << 8) | buf[i];
53  /* check for fixed fields in ADX header for possible match */
54  if ((state & 0xFFFF0000FFFFFF00) == 0x8000000003120400ULL) {
55  int channels = state & 0xFF;
56  int header_size = ((state >> 32) & 0xFFFF) + 4;
57  if (channels > 0 && header_size >= 8) {
58  s->header_size = header_size;
59  s->block_size = BLOCK_SIZE * channels;
60  s->remaining = i - 7 + s->header_size + s->block_size;
61  break;
62  }
63  }
64  }
65  pc->state64 = state;
66  }
67 
68  if (s->header_size) {
69  if (!s->remaining)
70  s->remaining = s->block_size;
71  if (s->remaining <= buf_size) {
72  next = s->remaining;
73  s->remaining = 0;
74  } else
75  s->remaining -= buf_size;
76  }
77 
78  if (ff_combine_frame(pc, next, &buf, &buf_size) < 0 || !buf_size) {
79  *poutbuf = NULL;
80  *poutbuf_size = 0;
81  return buf_size;
82  }
83 
84  s1->duration = BLOCK_SAMPLES;
85 
86  *poutbuf = buf;
87  *poutbuf_size = buf_size;
88  return next;
89 }
90 
93  .priv_data_size = sizeof(ADXParseContext),
94  .parser_parse = adx_parse,
95  .parser_close = ff_parse_close,
96 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
AVCodecParser ff_adx_parser
Definition: adx_parser.c:91
ParseContext pc
Definition: adx_parser.c:33
int codec_ids[5]
Definition: avcodec.h:4451
#define BLOCK_SIZE
Definition: adx.h:53
int duration
Duration of the current frame.
Definition: avcodec.h:4405
uint8_t
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:231
void ff_parse_close(AVCodecParserContext *s)
Definition: parser.c:307
static int adx_parse(AVCodecParserContext *s1, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: adx_parser.c:39
#define BLOCK_SAMPLES
Definition: adx.h:54
main external API structure.
Definition: avcodec.h:1252
void * buf
Definition: avisynth_c.h:553
uint64_t state64
contains the last 8 bytes in MSB order
Definition: parser.h:37
#define s1
Definition: regdef.h:38
#define END_NOT_FOUND
Definition: parser.h:40
static uint32_t state
Definition: trasher.c:27
SEGA CRI adx codecs.