FFmpeg
mpeg4audio.h
Go to the documentation of this file.
1 /*
2  * MPEG-4 Audio common header
3  * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
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 #ifndef AVCODEC_MPEG4AUDIO_H
23 #define AVCODEC_MPEG4AUDIO_H
24 
25 #include <stdint.h>
26 
27 #include "libavutil/attributes.h"
28 
29 #include "get_bits.h"
30 #include "internal.h"
31 #include "put_bits.h"
32 
33 typedef struct MPEG4AudioConfig {
38  int sbr; ///< -1 implicit, 1 presence
43  int channels;
44  int ps; ///< -1 implicit, 1 presence
47 
49 extern const uint8_t ff_mpeg4audio_channels[8];
50 
51 /**
52  * Parse MPEG-4 systems extradata from a potentially unaligned GetBitContext to retrieve audio configuration.
53  * @param[in] c MPEG4AudioConfig structure to fill.
54  * @param[in] gb Extradata from container.
55  * @param[in] sync_extension look for a sync extension after config if true.
56  * @return On error -1 is returned, on success AudioSpecificConfig bit index in extradata.
57  */
59  int sync_extension);
60 
61 /**
62  * Parse MPEG-4 systems extradata from a raw buffer to retrieve audio configuration.
63  * @param[in] c MPEG4AudioConfig structure to fill.
64  * @param[in] buf Extradata from container.
65  * @param[in] bit_size Extradata size in bits.
66  * @param[in] sync_extension look for a sync extension after config if true.
67  * @return On error -1 is returned, on success AudioSpecificConfig bit index in extradata.
68  */
70  int bit_size, int sync_extension);
71 
74  // Support? Name
75  AOT_AAC_MAIN, ///< Y Main
76  AOT_AAC_LC, ///< Y Low Complexity
77  AOT_AAC_SSR, ///< N (code in SoC repo) Scalable Sample Rate
78  AOT_AAC_LTP, ///< Y Long Term Prediction
79  AOT_SBR, ///< Y Spectral Band Replication
80  AOT_AAC_SCALABLE, ///< N Scalable
81  AOT_TWINVQ, ///< N Twin Vector Quantizer
82  AOT_CELP, ///< N Code Excited Linear Prediction
83  AOT_HVXC, ///< N Harmonic Vector eXcitation Coding
84  AOT_TTSI = 12, ///< N Text-To-Speech Interface
85  AOT_MAINSYNTH, ///< N Main Synthesis
86  AOT_WAVESYNTH, ///< N Wavetable Synthesis
87  AOT_MIDI, ///< N General MIDI
88  AOT_SAFX, ///< N Algorithmic Synthesis and Audio Effects
89  AOT_ER_AAC_LC, ///< N Error Resilient Low Complexity
90  AOT_ER_AAC_LTP = 19, ///< N Error Resilient Long Term Prediction
91  AOT_ER_AAC_SCALABLE, ///< N Error Resilient Scalable
92  AOT_ER_TWINVQ, ///< N Error Resilient Twin Vector Quantizer
93  AOT_ER_BSAC, ///< N Error Resilient Bit-Sliced Arithmetic Coding
94  AOT_ER_AAC_LD, ///< N Error Resilient Low Delay
95  AOT_ER_CELP, ///< N Error Resilient Code Excited Linear Prediction
96  AOT_ER_HVXC, ///< N Error Resilient Harmonic Vector eXcitation Coding
97  AOT_ER_HILN, ///< N Error Resilient Harmonic and Individual Lines plus Noise
98  AOT_ER_PARAM, ///< N Error Resilient Parametric
99  AOT_SSC, ///< N SinuSoidal Coding
100  AOT_PS, ///< N Parametric Stereo
101  AOT_SURROUND, ///< N MPEG Surround
102  AOT_ESCAPE, ///< Y Escape Value
103  AOT_L1, ///< Y Layer 1
104  AOT_L2, ///< Y Layer 2
105  AOT_L3, ///< Y Layer 3
106  AOT_DST, ///< N Direct Stream Transfer
107  AOT_ALS, ///< Y Audio LosslesS
108  AOT_SLS, ///< N Scalable LosslesS
109  AOT_SLS_NON_CORE, ///< N Scalable LosslesS (non core)
110  AOT_ER_AAC_ELD, ///< N Error Resilient Enhanced Low Delay
111  AOT_SMR_SIMPLE, ///< N Symbolic Music Representation Simple
112  AOT_SMR_MAIN, ///< N Symbolic Music Representation Main
113  AOT_USAC_NOSBR, ///< N Unified Speech and Audio Coding (no SBR)
114  AOT_SAOC, ///< N Spatial Audio Object Coding
115  AOT_LD_SURROUND, ///< N Low Delay MPEG Surround
116  AOT_USAC, ///< N Unified Speech and Audio Coding
117 };
118 
119 #define MAX_PCE_SIZE 320 ///<Maximum size of a PCE including the 3-bit ID_PCE
120  ///<marker and the comment
121 
123  GetBitContext *gb,
124  int bits)
125 {
126  unsigned int el = get_bits(gb, bits);
127  put_bits(pb, bits, el);
128  return el;
129 }
130 
131 static inline int ff_copy_pce_data(PutBitContext *pb, GetBitContext *gb)
132 {
133  int five_bit_ch, four_bit_ch, comment_size, bits;
134  int offset = put_bits_count(pb);
135 
136  ff_pce_copy_bits(pb, gb, 10); // Tag, Object Type, Frequency
137  five_bit_ch = ff_pce_copy_bits(pb, gb, 4); // Front
138  five_bit_ch += ff_pce_copy_bits(pb, gb, 4); // Side
139  five_bit_ch += ff_pce_copy_bits(pb, gb, 4); // Back
140  four_bit_ch = ff_pce_copy_bits(pb, gb, 2); // LFE
141  four_bit_ch += ff_pce_copy_bits(pb, gb, 3); // Data
142  five_bit_ch += ff_pce_copy_bits(pb, gb, 4); // Coupling
143  if (ff_pce_copy_bits(pb, gb, 1)) // Mono Mixdown
144  ff_pce_copy_bits(pb, gb, 4);
145  if (ff_pce_copy_bits(pb, gb, 1)) // Stereo Mixdown
146  ff_pce_copy_bits(pb, gb, 4);
147  if (ff_pce_copy_bits(pb, gb, 1)) // Matrix Mixdown
148  ff_pce_copy_bits(pb, gb, 3);
149  for (bits = five_bit_ch*5+four_bit_ch*4; bits > 16; bits -= 16)
150  ff_pce_copy_bits(pb, gb, 16);
151  if (bits)
152  ff_pce_copy_bits(pb, gb, bits);
154  align_get_bits(gb);
155  comment_size = ff_pce_copy_bits(pb, gb, 8);
156  for (; comment_size > 0; comment_size--)
157  ff_pce_copy_bits(pb, gb, 8);
158 
159  return put_bits_count(pb) - offset;
160 }
161 
162 #endif /* AVCODEC_MPEG4AUDIO_H */
N Parametric Stereo.
Definition: mpeg4audio.h:100
Y Layer 1.
Definition: mpeg4audio.h:103
static void put_bits(Jpeg2000EncoderContext *s, int val, int n)
put n times val bit
Definition: j2kenc.c:208
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
void avpriv_align_put_bits(PutBitContext *s)
Pad the bitstream with zeros up to the next byte boundary.
Definition: bitstream.c:48
static av_always_inline unsigned int ff_pce_copy_bits(PutBitContext *pb, GetBitContext *gb, int bits)
Definition: mpeg4audio.h:122
int avpriv_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf, int bit_size, int sync_extension)
Parse MPEG-4 systems extradata from a raw buffer to retrieve audio configuration. ...
Definition: mpeg4audio.c:155
Macro definitions for various function/variable attributes.
const uint8_t ff_mpeg4audio_channels[8]
Definition: mpeg4audio.c:67
N Scalable LosslesS (non core)
Definition: mpeg4audio.h:109
N Code Excited Linear Prediction.
Definition: mpeg4audio.h:82
N Error Resilient Parametric.
Definition: mpeg4audio.h:98
N Error Resilient Long Term Prediction.
Definition: mpeg4audio.h:90
N MPEG Surround.
Definition: mpeg4audio.h:101
uint8_t
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
N Error Resilient Low Delay.
Definition: mpeg4audio.h:94
int ff_mpeg4audio_get_config_gb(MPEG4AudioConfig *c, GetBitContext *gb, int sync_extension)
Parse MPEG-4 systems extradata from a potentially unaligned GetBitContext to retrieve audio configura...
Definition: mpeg4audio.c:86
N Algorithmic Synthesis and Audio Effects.
Definition: mpeg4audio.h:88
N Scalable LosslesS.
Definition: mpeg4audio.h:108
N General MIDI.
Definition: mpeg4audio.h:87
N Error Resilient Harmonic and Individual Lines plus Noise.
Definition: mpeg4audio.h:97
bitstream reader API header.
Y Escape Value.
Definition: mpeg4audio.h:102
N Error Resilient Low Complexity.
Definition: mpeg4audio.h:89
N Unified Speech and Audio Coding (no SBR)
Definition: mpeg4audio.h:113
N Symbolic Music Representation Main.
Definition: mpeg4audio.h:112
#define av_export_avcodec
Definition: internal.h:431
N Error Resilient Twin Vector Quantizer.
Definition: mpeg4audio.h:92
uint8_t bits
Definition: vp3data.h:202
N Text-To-Speech Interface.
Definition: mpeg4audio.h:84
N Low Delay MPEG Surround.
Definition: mpeg4audio.h:115
av_export_avcodec const int avpriv_mpeg4audio_sample_rates[16]
Definition: mpeg4audio.c:62
static int put_bits_count(PutBitContext *s)
Definition: put_bits.h:85
N Error Resilient Scalable.
Definition: mpeg4audio.h:91
AudioObjectType
Definition: mpeg4audio.h:72
N Unified Speech and Audio Coding.
Definition: mpeg4audio.h:116
N Harmonic Vector eXcitation Coding.
Definition: mpeg4audio.h:83
N Error Resilient Harmonic Vector eXcitation Coding.
Definition: mpeg4audio.h:96
Y Main.
Definition: mpeg4audio.h:75
N Main Synthesis.
Definition: mpeg4audio.h:85
N (code in SoC repo) Scalable Sample Rate.
Definition: mpeg4audio.h:77
N Scalable.
Definition: mpeg4audio.h:80
N Direct Stream Transfer.
Definition: mpeg4audio.h:106
N Wavetable Synthesis.
Definition: mpeg4audio.h:86
N Error Resilient Code Excited Linear Prediction.
Definition: mpeg4audio.h:95
Y Layer 2.
Definition: mpeg4audio.h:104
void * buf
Definition: avisynth_c.h:766
static int ff_copy_pce_data(PutBitContext *pb, GetBitContext *gb)
Definition: mpeg4audio.h:131
N Error Resilient Bit-Sliced Arithmetic Coding.
Definition: mpeg4audio.h:93
int frame_length_short
Definition: mpeg4audio.h:45
N Error Resilient Enhanced Low Delay.
Definition: mpeg4audio.h:110
N Twin Vector Quantizer.
Definition: mpeg4audio.h:81
Y Spectral Band Replication.
Definition: mpeg4audio.h:79
common internal api header.
N SinuSoidal Coding.
Definition: mpeg4audio.h:99
Y Audio LosslesS.
Definition: mpeg4audio.h:107
Y Layer 3.
Definition: mpeg4audio.h:105
Y Long Term Prediction.
Definition: mpeg4audio.h:78
static const uint8_t * align_get_bits(GetBitContext *s)
Definition: get_bits.h:693
N Symbolic Music Representation Simple.
Definition: mpeg4audio.h:111
int sbr
-1 implicit, 1 presence
Definition: mpeg4audio.h:38
#define av_always_inline
Definition: attributes.h:39
int ext_sampling_index
Definition: mpeg4audio.h:40
int ps
-1 implicit, 1 presence
Definition: mpeg4audio.h:44
N Spatial Audio Object Coding.
Definition: mpeg4audio.h:114
Y Low Complexity.
Definition: mpeg4audio.h:76
bitstream writer API