FFmpeg
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 
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) {
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
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:141
int codec_ids[5]
Definition: avcodec.h:5272
AVCodecParser ff_tak_parser
Definition: tak_parser.c:121
int duration
Duration of the current frame.
Definition: avcodec.h:5226
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:219
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:234
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is needed
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:312
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
#define s(width, name)
Definition: cbs_vp9.c:257
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:677
ParseContext pc
Definition: tak_parser.c:32
main external API structure.
Definition: avcodec.h:1565
void * buf
Definition: avisynth_c.h:766
int frame_samples
Definition: tak.h:136
TAK (Tom&#39;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:5138
#define TAK_MAX_FRAME_HEADER_BYTES
Definition: tak.h:96
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
int key_frame
Set by parser to 1 for key frames and 0 for non-key frames.
Definition: avcodec.h:5153