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flac.h
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1 /*
2  * FLAC (Free Lossless Audio Codec) decoder/demuxer common functions
3  * Copyright (c) 2008 Justin Ruggles
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  * FLAC (Free Lossless Audio Codec) decoder/demuxer common functions
25  */
26 
27 #ifndef AVCODEC_FLAC_H
28 #define AVCODEC_FLAC_H
29 
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "get_bits.h"
33 
34 #define FLAC_STREAMINFO_SIZE 34
35 #define FLAC_MAX_CHANNELS 8
36 #define FLAC_MIN_BLOCKSIZE 16
37 #define FLAC_MAX_BLOCKSIZE 65535
38 #define FLAC_MIN_FRAME_SIZE 11
39 
40 enum {
45 };
46 
47 enum {
56 };
57 
61 };
62 
63 #define FLACCOMMONINFO \
64  int samplerate; /**< sample rate */\
65  int channels; /**< number of channels */\
66  int bps; /**< bits-per-sample */\
67 
68 /**
69  * Data needed from the Streaminfo header for use by the raw FLAC demuxer
70  * and/or the FLAC decoder.
71  */
72 #define FLACSTREAMINFO \
73  FLACCOMMONINFO \
74  int max_blocksize; /**< maximum block size, in samples */\
75  int max_framesize; /**< maximum frame size, in bytes */\
76  int64_t samples; /**< total number of samples */\
77 
78 typedef struct FLACStreaminfo {
81 
82 typedef struct FLACFrameInfo {
84  int blocksize; /**< block size of the frame */
85  int ch_mode; /**< channel decorrelation mode */
86  int64_t frame_or_sample_num; /**< frame number or sample number */
87  int is_var_size; /**< specifies if the stream uses variable
88  block sizes or a fixed block size;
89  also determines the meaning of
90  frame_or_sample_num */
92 
93 /**
94  * Parse the Streaminfo metadata block
95  * @param[out] avctx codec context to set basic stream parameters
96  * @param[out] s where parsed information is stored
97  * @param[in] buffer pointer to start of 34-byte streaminfo data
98  */
100  const uint8_t *buffer);
101 
102 /**
103  * Validate the FLAC extradata.
104  * @param[in] avctx codec context containing the extradata.
105  * @param[out] format extradata format.
106  * @param[out] streaminfo_start pointer to start of 34-byte STREAMINFO data.
107  * @return 1 if valid, 0 if not valid.
108  */
111  uint8_t **streaminfo_start);
112 
113 /**
114  * Calculate an estimate for the maximum frame size based on verbatim mode.
115  * @param blocksize block size, in samples
116  * @param ch number of channels
117  * @param bps bits-per-sample
118  */
119 int ff_flac_get_max_frame_size(int blocksize, int ch, int bps);
120 
121 /**
122  * Validate and decode a frame header.
123  * @param avctx AVCodecContext to use as av_log() context
124  * @param gb GetBitContext from which to read frame header
125  * @param[out] fi frame information
126  * @param log_level_offset log level offset. can be used to silence error messages.
127  * @return non-zero on error, 0 if ok
128  */
130  FLACFrameInfo *fi, int log_level_offset);
131 
133 
134 /**
135  * Parse the metadata block parameters from the header.
136  * @param[in] block_header header data, at least 4 bytes
137  * @param[out] last indicator for last metadata block
138  * @param[out] type metadata block type
139  * @param[out] size metadata block size
140  */
141 static av_always_inline void flac_parse_block_header(const uint8_t *block_header,
142  int *last, int *type, int *size)
143 {
144  int tmp = bytestream_get_byte(&block_header);
145  if (last)
146  *last = tmp & 0x80;
147  if (type)
148  *type = tmp & 0x7F;
149  if (size)
150  *size = bytestream_get_be24(&block_header);
151 }
152 
153 #endif /* AVCODEC_FLAC_H */
const char * s
Definition: avisynth_c.h:631
int64_t frame_or_sample_num
frame number or sample number
Definition: flac.h:88
int ff_flac_is_extradata_valid(AVCodecContext *avctx, enum FLACExtradataFormat *format, uint8_t **streaminfo_start)
Validate the FLAC extradata.
Definition: flac.c:169
FLACCOMMONINFO int blocksize
block size of the frame
Definition: flac.h:86
int ff_flac_get_max_frame_size(int blocksize, int ch, int bps)
Calculate an estimate for the maximum frame size based on verbatim mode.
Definition: flac.c:148
uint8_t
void ff_flac_set_channel_layout(AVCodecContext *avctx)
Definition: flac.c:196
bitstream reader API header.
int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb, FLACFrameInfo *fi, int log_level_offset)
Validate and decode a frame header.
Definition: flac.c:50
ptrdiff_t size
Definition: opengl_enc.c:101
FLACExtradataFormat
Definition: flac.h:58
AVS_FilterInfo ** fi
Definition: avisynth_c.h:594
int ch_mode
channel decorrelation mode
Definition: flac.h:87
#define FLACCOMMONINFO
bits-per-sample
Definition: flac.h:63
#define FLACSTREAMINFO
Data needed from the Streaminfo header for use by the raw FLAC demuxer and/or the FLAC decoder...
Definition: flac.h:73
void ff_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s, const uint8_t *buffer)
Parse the Streaminfo metadata block.
Definition: flac.c:204
Libavcodec external API header.
main external API structure.
Definition: avcodec.h:1639
static const char * format
Definition: movenc-test.c:47
GLint GLenum type
Definition: opengl_enc.c:105
static av_always_inline void flac_parse_block_header(const uint8_t *block_header, int *last, int *type, int *size)
Parse the metadata block parameters from the header.
Definition: flac.h:143
unsigned bps
Definition: movenc.c:1354
int is_var_size
specifies if the stream uses variable block sizes or a fixed block size; also determines the meaning ...
Definition: flac.h:89
#define av_always_inline
Definition: attributes.h:39
GLuint buffer
Definition: opengl_enc.c:102