Kaido Kert | b108943 | 2024-03-18 19:46:49 -0700 | [diff] [blame] | 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 | */ |
| 44 | enum AVDownmixType { |
| 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 | */ |
| 62 | enum AVDownmixType preferred_downmix_type; |
| 63 | |
| 64 | /** |
| 65 | * Absolute scale factor representing the nominal level of the center |
| 66 | * channel during a regular downmix. |
| 67 | */ |
| 68 | double center_mix_level; |
| 69 | |
| 70 | /** |
| 71 | * Absolute scale factor representing the nominal level of the center |
| 72 | * channel during an Lt/Rt compatible downmix. |
| 73 | */ |
| 74 | double center_mix_level_ltrt; |
| 75 | |
| 76 | /** |
| 77 | * Absolute scale factor representing the nominal level of the surround |
| 78 | * channels during a regular downmix. |
| 79 | */ |
| 80 | double surround_mix_level; |
| 81 | |
| 82 | /** |
| 83 | * Absolute scale factor representing the nominal level of the surround |
| 84 | * channels during an Lt/Rt compatible downmix. |
| 85 | */ |
| 86 | double surround_mix_level_ltrt; |
| 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; |
| 93 | } AVDownmixInfo; |
| 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 | */ |
| 105 | AVDownmixInfo *av_downmix_info_update_side_data(AVFrame *frame); |
| 106 | |
| 107 | /** |
| 108 | * @} |
| 109 | */ |
| 110 | |
| 111 | /** |
| 112 | * @} |
| 113 | */ |
| 114 | |
| 115 | #endif /* AVUTIL_DOWNMIX_INFO_H */ |