FFmpeg
ac3_parser_internal.h
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1 /*
2  * AC-3 parser internal code
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 #ifndef AVCODEC_AC3_PARSER_INTERNAL_H
22 #define AVCODEC_AC3_PARSER_INTERNAL_H
23 
24 #include <stddef.h>
25 #include <stdint.h>
26 
27 #include "ac3defs.h"
28 #include "get_bits.h"
29 
30 /**
31  * @struct AC3HeaderInfo
32  * Coded AC-3 header values up to the lfeon element, plus derived values.
33  */
34 typedef struct AC3HeaderInfo {
35  /** @name Coded elements
36  * @{
37  */
38  uint16_t sync_word;
39  uint16_t crc1;
40  uint8_t sr_code;
41  uint8_t bitstream_id;
42  uint8_t bitstream_mode;
43  uint8_t channel_mode;
44  uint8_t lfe_on;
45  uint8_t frame_type;
46  int substreamid; ///< substream identification
47  int center_mix_level; ///< Center mix level index
48  int surround_mix_level; ///< Surround mix level index
49  uint16_t channel_map;
50  int num_blocks; ///< number of audio blocks
52  /** @} */
53 
54  /** @name Derived values
55  * @{
56  */
57  uint8_t sr_shift;
58  uint16_t sample_rate;
59  uint32_t bit_rate;
60  uint8_t channels;
61  uint16_t frame_size;
62  uint64_t channel_layout;
63  /** @} */
65 
66 /**
67  * Parse AC-3 frame header.
68  * Parse the header up to the lfeon element, which is the first 52 or 54 bits
69  * depending on the audio coding mode.
70  * @param[in] gbc BitContext containing the first 54 bits of the frame.
71  * @param[out] hdr Pointer to struct where header info is written.
72  * @return Returns 0 on success, -1 if there is a sync word mismatch,
73  * -2 if the bsid (version) element is invalid, -3 if the fscod (sample rate)
74  * element is invalid, or -4 if the frmsizecod (bit rate) element is invalid.
75  */
77 
78 int avpriv_ac3_parse_header(AC3HeaderInfo **hdr, const uint8_t *buf,
79  size_t size);
80 
81 #endif /* AVCODEC_AC3_PARSER_INTERNAL_H */
AC3HeaderInfo::center_mix_level
int center_mix_level
Center mix level index.
Definition: ac3_parser_internal.h:47
AC3HeaderInfo::frame_type
uint8_t frame_type
Definition: ac3_parser_internal.h:45
AC3HeaderInfo::dolby_surround_mode
int dolby_surround_mode
Definition: ac3_parser_internal.h:51
AC3HeaderInfo::channel_layout
uint64_t channel_layout
Definition: ac3_parser_internal.h:62
GetBitContext
Definition: get_bits.h:62
AC3HeaderInfo
Definition: ac3_parser_internal.h:34
AC3HeaderInfo::frame_size
uint16_t frame_size
Definition: ac3_parser_internal.h:61
AC3HeaderInfo::channel_mode
uint8_t channel_mode
Definition: ac3_parser_internal.h:43
AC3HeaderInfo::sync_word
uint16_t sync_word
Definition: ac3_parser_internal.h:38
AC3HeaderInfo::crc1
uint16_t crc1
Definition: ac3_parser_internal.h:39
get_bits.h
AC3HeaderInfo::sample_rate
uint16_t sample_rate
Definition: ac3_parser_internal.h:58
ac3defs.h
AC3HeaderInfo::substreamid
int substreamid
substream identification
Definition: ac3_parser_internal.h:46
AC3HeaderInfo::num_blocks
int num_blocks
number of audio blocks
Definition: ac3_parser_internal.h:50
AC3HeaderInfo::channels
uint8_t channels
Definition: ac3_parser_internal.h:60
AC3HeaderInfo::lfe_on
uint8_t lfe_on
Definition: ac3_parser_internal.h:44
size
int size
Definition: twinvq_data.h:10344
AC3HeaderInfo::bitstream_mode
uint8_t bitstream_mode
Definition: ac3_parser_internal.h:42
AC3HeaderInfo::channel_map
uint16_t channel_map
Definition: ac3_parser_internal.h:49
ff_ac3_parse_header
int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr)
Parse AC-3 frame header.
avpriv_ac3_parse_header
int avpriv_ac3_parse_header(AC3HeaderInfo **hdr, const uint8_t *buf, size_t size)
Definition: ac3_parser.c:256
AC3HeaderInfo::bitstream_id
uint8_t bitstream_id
Definition: ac3_parser_internal.h:41
AC3HeaderInfo::sr_shift
uint8_t sr_shift
Definition: ac3_parser_internal.h:57
AC3HeaderInfo::sr_code
uint8_t sr_code
Definition: ac3_parser_internal.h:40
AC3HeaderInfo::bit_rate
uint32_t bit_rate
Definition: ac3_parser_internal.h:59
AC3HeaderInfo::surround_mix_level
int surround_mix_level
Surround mix level index.
Definition: ac3_parser_internal.h:48