1 /*
2  * Common AC-3 definitions
3  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
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_AC3DEFS_H
23 #define AVCODEC_AC3DEFS_H
24 
25 #define EAC3_MAX_CHANNELS 16          /**< maximum number of channels in EAC3 */
26 #define AC3_MAX_CHANNELS 7            /**< maximum number of channels, including coupling channel */
27 #define CPL_CH 0                      /**< coupling channel index */
28 
29 #define AC3_MAX_COEFS   256
30 #define AC3_BLOCK_SIZE  256
31 #define AC3_MAX_BLOCKS    6
32 #define AC3_FRAME_SIZE (AC3_MAX_BLOCKS * 256)
33 #define AC3_WINDOW_SIZE (AC3_BLOCK_SIZE * 2)
34 #define AC3_CRITICAL_BANDS 50
35 #define AC3_MAX_CPL_BANDS  18
36 
37 /* exponent encoding strategy */
38 #define EXP_REUSE 0
39 #define EXP_NEW   1
40 
41 #define EXP_D15   1
42 #define EXP_D25   2
43 #define EXP_D45   3
44 
45 /** Delta bit allocation strategy */
46 typedef enum {
47     DBA_REUSE = 0,
48     DBA_NEW,
49     DBA_NONE,
50     DBA_RESERVED
51 } AC3DeltaStrategy;
52 
53 /** Channel mode (audio coding mode) */
54 typedef enum {
55     AC3_CHMODE_DUALMONO = 0,
56     AC3_CHMODE_MONO,
57     AC3_CHMODE_STEREO,
58     AC3_CHMODE_3F,
59     AC3_CHMODE_2F1R,
60     AC3_CHMODE_3F1R,
61     AC3_CHMODE_2F2R,
62     AC3_CHMODE_3F2R
63 } AC3ChannelMode;
64 
65 /** Dolby Surround mode */
66 typedef enum AC3DolbySurroundMode {
67     AC3_DSURMOD_NOTINDICATED = 0,
68     AC3_DSURMOD_OFF,
69     AC3_DSURMOD_ON,
70     AC3_DSURMOD_RESERVED
71 } AC3DolbySurroundMode;
72 
73 /** Dolby Surround EX mode */
74 typedef enum AC3DolbySurroundEXMode {
75     AC3_DSUREXMOD_NOTINDICATED = 0,
76     AC3_DSUREXMOD_OFF,
77     AC3_DSUREXMOD_ON,
78     AC3_DSUREXMOD_PLIIZ
79 } AC3DolbySurroundEXMode;
80 
81 /** Dolby Headphone mode */
82 typedef enum AC3DolbyHeadphoneMode {
83     AC3_DHEADPHONMOD_NOTINDICATED = 0,
84     AC3_DHEADPHONMOD_OFF,
85     AC3_DHEADPHONMOD_ON,
86     AC3_DHEADPHONMOD_RESERVED
87 } AC3DolbyHeadphoneMode;
88 
89 /** Preferred Stereo Downmix mode */
90 typedef enum AC3PreferredStereoDownmixMode {
91     AC3_DMIXMOD_NOTINDICATED = 0,
92     AC3_DMIXMOD_LTRT,
93     AC3_DMIXMOD_LORO,
94     AC3_DMIXMOD_DPLII // reserved value in A/52, but used by encoders to indicate DPL2
95 } AC3PreferredStereoDownmixMode;
96 
97 typedef enum {
98     EAC3_FRAME_TYPE_INDEPENDENT = 0,
99     EAC3_FRAME_TYPE_DEPENDENT,
100     EAC3_FRAME_TYPE_AC3_CONVERT,
101     EAC3_FRAME_TYPE_RESERVED
102 } EAC3FrameType;
103 
104 #endif /* AVCODEC_AC3DEFS_H */
105