FFmpeg
downmix_info.h
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1 /*
2  * Copyright (c) 2014 Tim Walker <tdskywalker@gmail.com>
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 AVUTIL_DOWNMIX_INFO_H
22 #define AVUTIL_DOWNMIX_INFO_H
23 
24 #include "frame.h"
25 
26 /**
27  * @file
28  * audio downmix medatata
29  */
30 
31 /**
32  * @addtogroup lavu_audio
33  * @{
34  */
35 
36 /**
37  * @defgroup downmix_info Audio downmix metadata
38  * @{
39  */
40 
41 /**
42  * Possible downmix types.
43  */
45  AV_DOWNMIX_TYPE_UNKNOWN, /**< Not indicated. */
46  AV_DOWNMIX_TYPE_LORO, /**< Lo/Ro 2-channel downmix (Stereo). */
47  AV_DOWNMIX_TYPE_LTRT, /**< Lt/Rt 2-channel downmix, Dolby Surround compatible. */
48  AV_DOWNMIX_TYPE_DPLII, /**< Lt/Rt 2-channel downmix, Dolby Pro Logic II compatible. */
49  AV_DOWNMIX_TYPE_NB /**< Number of downmix types. Not part of ABI. */
50 };
51 
52 /**
53  * This structure describes optional metadata relevant to a downmix procedure.
54  *
55  * All fields are set by the decoder to the value indicated in the audio
56  * bitstream (if present), or to a "sane" default otherwise.
57  */
58 typedef struct AVDownmixInfo {
59  /**
60  * Type of downmix preferred by the mastering engineer.
61  */
63 
64  /**
65  * Absolute scale factor representing the nominal level of the center
66  * channel during a regular downmix.
67  */
69 
70  /**
71  * Absolute scale factor representing the nominal level of the center
72  * channel during an Lt/Rt compatible downmix.
73  */
75 
76  /**
77  * Absolute scale factor representing the nominal level of the surround
78  * channels during a regular downmix.
79  */
81 
82  /**
83  * Absolute scale factor representing the nominal level of the surround
84  * channels during an Lt/Rt compatible downmix.
85  */
87 
88  /**
89  * Absolute scale factor representing the level at which the LFE data is
90  * mixed into L/R channels during downmixing.
91  */
92  double lfe_mix_level;
94 
95 /**
96  * Get a frame's AV_FRAME_DATA_DOWNMIX_INFO side data for editing.
97  *
98  * If the side data is absent, it is created and added to the frame.
99  *
100  * @param frame the frame for which the side data is to be obtained or created
101  *
102  * @return the AVDownmixInfo structure to be edited by the caller, or NULL if
103  * the structure cannot be allocated.
104  */
106 
107 /**
108  * @}
109  */
110 
111 /**
112  * @}
113  */
114 
115 #endif /* AVUTIL_DOWNMIX_INFO_H */
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:344
AVDownmixInfo::surround_mix_level_ltrt
double surround_mix_level_ltrt
Absolute scale factor representing the nominal level of the surround channels during an Lt/Rt compati...
Definition: downmix_info.h:86
AV_DOWNMIX_TYPE_UNKNOWN
@ AV_DOWNMIX_TYPE_UNKNOWN
Not indicated.
Definition: downmix_info.h:45
AVDownmixInfo
This structure describes optional metadata relevant to a downmix procedure.
Definition: downmix_info.h:58
frame
static AVFrame * frame
Definition: demux_decode.c:54
AVDownmixInfo::surround_mix_level
double surround_mix_level
Absolute scale factor representing the nominal level of the surround channels during a regular downmi...
Definition: downmix_info.h:80
AVDownmixInfo::center_mix_level_ltrt
double center_mix_level_ltrt
Absolute scale factor representing the nominal level of the center channel during an Lt/Rt compatible...
Definition: downmix_info.h:74
frame.h
AVDownmixType
AVDownmixType
Possible downmix types.
Definition: downmix_info.h:44
AVDownmixInfo::lfe_mix_level
double lfe_mix_level
Absolute scale factor representing the level at which the LFE data is mixed into L/R channels during ...
Definition: downmix_info.h:92
AVDownmixInfo::center_mix_level
double center_mix_level
Absolute scale factor representing the nominal level of the center channel during a regular downmix.
Definition: downmix_info.h:68
AVDownmixInfo::preferred_downmix_type
enum AVDownmixType preferred_downmix_type
Type of downmix preferred by the mastering engineer.
Definition: downmix_info.h:62
AV_DOWNMIX_TYPE_LORO
@ AV_DOWNMIX_TYPE_LORO
Lo/Ro 2-channel downmix (Stereo).
Definition: downmix_info.h:46
AV_DOWNMIX_TYPE_NB
@ AV_DOWNMIX_TYPE_NB
Number of downmix types.
Definition: downmix_info.h:49
AV_DOWNMIX_TYPE_DPLII
@ AV_DOWNMIX_TYPE_DPLII
Lt/Rt 2-channel downmix, Dolby Pro Logic II compatible.
Definition: downmix_info.h:48
av_downmix_info_update_side_data
AVDownmixInfo * av_downmix_info_update_side_data(AVFrame *frame)
Get a frame's AV_FRAME_DATA_DOWNMIX_INFO side data for editing.
Definition: downmix_info.c:24
AV_DOWNMIX_TYPE_LTRT
@ AV_DOWNMIX_TYPE_LTRT
Lt/Rt 2-channel downmix, Dolby Surround compatible.
Definition: downmix_info.h:47