• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 "put_bits.h"
31 
32 typedef struct MPEG4AudioConfig {
33     int object_type;
34     int sampling_index;
35     int sample_rate;
36     int chan_config;
37     int sbr; ///< -1 implicit, 1 presence
38     int ext_object_type;
39     int ext_sampling_index;
40     int ext_sample_rate;
41     int ext_chan_config;
42     int channels;
43     int ps;  ///< -1 implicit, 1 presence
44     int frame_length_short;
45 } MPEG4AudioConfig;
46 
47 extern const int     ff_mpeg4audio_sample_rates[16];
48 extern const uint8_t ff_mpeg4audio_channels[14];
49 
50 /**
51  * Parse MPEG-4 systems extradata from a potentially unaligned GetBitContext to retrieve audio configuration.
52  * @param[in] c        MPEG4AudioConfig structure to fill.
53  * @param[in] gb       Extradata from container.
54  * @param[in] sync_extension look for a sync extension after config if true.
55  * @param[in] logctx opaque struct starting with an AVClass element, used for logging.
56  * @return negative AVERROR code on error, on success AudioSpecificConfig bit index in extradata.
57  */
58 int ff_mpeg4audio_get_config_gb(MPEG4AudioConfig *c, GetBitContext *gb,
59                                 int sync_extension, void *logctx);
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] size     Extradata size in bytes.
66  * @param[in] sync_extension look for a sync extension after config if true.
67  * @param[in] logctx opaque struct starting with an AVClass element, used for logging.
68  * @return negative AVERROR code on error, AudioSpecificConfig bit index in extradata on success.
69  */
70 int avpriv_mpeg4audio_get_config2(MPEG4AudioConfig *c, const uint8_t *buf,
71                                   int size, int sync_extension, void *logctx);
72 
73 enum AudioObjectType {
74     AOT_NULL,
75                                // Support?                Name
76     AOT_AAC_MAIN,              ///< Y                       Main
77     AOT_AAC_LC,                ///< Y                       Low Complexity
78     AOT_AAC_SSR,               ///< N (code in SoC repo)    Scalable Sample Rate
79     AOT_AAC_LTP,               ///< Y                       Long Term Prediction
80     AOT_SBR,                   ///< Y                       Spectral Band Replication
81     AOT_AAC_SCALABLE,          ///< N                       Scalable
82     AOT_TWINVQ,                ///< N                       Twin Vector Quantizer
83     AOT_CELP,                  ///< N                       Code Excited Linear Prediction
84     AOT_HVXC,                  ///< N                       Harmonic Vector eXcitation Coding
85     AOT_TTSI             = 12, ///< N                       Text-To-Speech Interface
86     AOT_MAINSYNTH,             ///< N                       Main Synthesis
87     AOT_WAVESYNTH,             ///< N                       Wavetable Synthesis
88     AOT_MIDI,                  ///< N                       General MIDI
89     AOT_SAFX,                  ///< N                       Algorithmic Synthesis and Audio Effects
90     AOT_ER_AAC_LC,             ///< N                       Error Resilient Low Complexity
91     AOT_ER_AAC_LTP       = 19, ///< N                       Error Resilient Long Term Prediction
92     AOT_ER_AAC_SCALABLE,       ///< N                       Error Resilient Scalable
93     AOT_ER_TWINVQ,             ///< N                       Error Resilient Twin Vector Quantizer
94     AOT_ER_BSAC,               ///< N                       Error Resilient Bit-Sliced Arithmetic Coding
95     AOT_ER_AAC_LD,             ///< N                       Error Resilient Low Delay
96     AOT_ER_CELP,               ///< N                       Error Resilient Code Excited Linear Prediction
97     AOT_ER_HVXC,               ///< N                       Error Resilient Harmonic Vector eXcitation Coding
98     AOT_ER_HILN,               ///< N                       Error Resilient Harmonic and Individual Lines plus Noise
99     AOT_ER_PARAM,              ///< N                       Error Resilient Parametric
100     AOT_SSC,                   ///< N                       SinuSoidal Coding
101     AOT_PS,                    ///< N                       Parametric Stereo
102     AOT_SURROUND,              ///< N                       MPEG Surround
103     AOT_ESCAPE,                ///< Y                       Escape Value
104     AOT_L1,                    ///< Y                       Layer 1
105     AOT_L2,                    ///< Y                       Layer 2
106     AOT_L3,                    ///< Y                       Layer 3
107     AOT_DST,                   ///< N                       Direct Stream Transfer
108     AOT_ALS,                   ///< Y                       Audio LosslesS
109     AOT_SLS,                   ///< N                       Scalable LosslesS
110     AOT_SLS_NON_CORE,          ///< N                       Scalable LosslesS (non core)
111     AOT_ER_AAC_ELD,            ///< N                       Error Resilient Enhanced Low Delay
112     AOT_SMR_SIMPLE,            ///< N                       Symbolic Music Representation Simple
113     AOT_SMR_MAIN,              ///< N                       Symbolic Music Representation Main
114     AOT_USAC_NOSBR,            ///< N                       Unified Speech and Audio Coding (no SBR)
115     AOT_SAOC,                  ///< N                       Spatial Audio Object Coding
116     AOT_LD_SURROUND,           ///< N                       Low Delay MPEG Surround
117     AOT_USAC,                  ///< N                       Unified Speech and Audio Coding
118 };
119 
120 #define MAX_PCE_SIZE 320 ///<Maximum size of a PCE including the 3-bit ID_PCE
121                          ///<marker and the comment
122 
ff_pce_copy_bits(PutBitContext * pb,GetBitContext * gb,int bits)123 static av_always_inline unsigned int ff_pce_copy_bits(PutBitContext *pb,
124                                                       GetBitContext *gb,
125                                                       int bits)
126 {
127     unsigned int el = get_bits(gb, bits);
128     put_bits(pb, bits, el);
129     return el;
130 }
131 
ff_copy_pce_data(PutBitContext * pb,GetBitContext * gb)132 static inline int ff_copy_pce_data(PutBitContext *pb, GetBitContext *gb)
133 {
134     int five_bit_ch, four_bit_ch, comment_size, bits;
135     int offset = put_bits_count(pb);
136 
137     ff_pce_copy_bits(pb, gb, 10);               // Tag, Object Type, Frequency
138     five_bit_ch  = ff_pce_copy_bits(pb, gb, 4); // Front
139     five_bit_ch += ff_pce_copy_bits(pb, gb, 4); // Side
140     five_bit_ch += ff_pce_copy_bits(pb, gb, 4); // Back
141     four_bit_ch  = ff_pce_copy_bits(pb, gb, 2); // LFE
142     four_bit_ch += ff_pce_copy_bits(pb, gb, 3); // Data
143     five_bit_ch += ff_pce_copy_bits(pb, gb, 4); // Coupling
144     if (ff_pce_copy_bits(pb, gb, 1))            // Mono Mixdown
145         ff_pce_copy_bits(pb, gb, 4);
146     if (ff_pce_copy_bits(pb, gb, 1))            // Stereo Mixdown
147         ff_pce_copy_bits(pb, gb, 4);
148     if (ff_pce_copy_bits(pb, gb, 1))            // Matrix Mixdown
149         ff_pce_copy_bits(pb, gb, 3);
150     for (bits = five_bit_ch*5+four_bit_ch*4; bits > 16; bits -= 16)
151         ff_pce_copy_bits(pb, gb, 16);
152     if (bits)
153         ff_pce_copy_bits(pb, gb, bits);
154     align_put_bits(pb);
155     align_get_bits(gb);
156     comment_size = ff_pce_copy_bits(pb, gb, 8);
157     for (; comment_size > 0; comment_size--)
158         ff_pce_copy_bits(pb, gb, 8);
159 
160     return put_bits_count(pb) - offset;
161 }
162 
163 #endif /* AVCODEC_MPEG4AUDIO_H */
164