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115 lines
3.2 KiB
C
115 lines
3.2 KiB
C
/*
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* Copyright (c) 2014 Tim Walker <tdskywalker@gmail.com>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef AVUTIL_DOWNMIX_INFO_H
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#define AVUTIL_DOWNMIX_INFO_H
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#include "frame.h"
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/**
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* @file
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* audio downmix medatata
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*/
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/**
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* @addtogroup lavu_audio
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* @{
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*/
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/**
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* @defgroup downmix_info Audio downmix metadata
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* @{
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*/
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/**
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* Possible downmix types.
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*/
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enum AVDownmixType {
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AV_DOWNMIX_TYPE_UNKNOWN, /**< Not indicated. */
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AV_DOWNMIX_TYPE_LORO, /**< Lo/Ro 2-channel downmix (Stereo). */
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AV_DOWNMIX_TYPE_LTRT, /**< Lt/Rt 2-channel downmix, Dolby Surround compatible. */
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AV_DOWNMIX_TYPE_DPLII, /**< Lt/Rt 2-channel downmix, Dolby Pro Logic II compatible. */
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AV_DOWNMIX_TYPE_NB /**< Number of downmix types. Not part of ABI. */
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};
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/**
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* This structure describes optional metadata relevant to a downmix procedure.
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*
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* All fields are set by the decoder to the value indicated in the audio
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* bitstream (if present), or to a "sane" default otherwise.
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*/
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typedef struct AVDownmixInfo {
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/**
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* Type of downmix preferred by the mastering engineer.
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*/
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enum AVDownmixType preferred_downmix_type;
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/**
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* Absolute scale factor representing the nominal level of the center
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* channel during a regular downmix.
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*/
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double center_mix_level;
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/**
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* Absolute scale factor representing the nominal level of the center
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* channel during an Lt/Rt compatible downmix.
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*/
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double center_mix_level_ltrt;
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/**
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* Absolute scale factor representing the nominal level of the surround
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* channels during a regular downmix.
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*/
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double surround_mix_level;
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/**
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* Absolute scale factor representing the nominal level of the surround
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* channels during an Lt/Rt compatible downmix.
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*/
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double surround_mix_level_ltrt;
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/**
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* Absolute scale factor representing the level at which the LFE data is
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* mixed into L/R channels during downmixing.
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*/
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double lfe_mix_level;
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} AVDownmixInfo;
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/**
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* Get a frame's AV_FRAME_DATA_DOWNMIX_INFO side data for editing.
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*
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* If the side data is absent, it is created and added to the frame.
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*
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* @param frame the frame for which the side data is to be obtained or created
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*
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* @return the AVDownmixInfo structure to be edited by the caller, or NULL if
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* the structure cannot be allocated.
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*/
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AVDownmixInfo *av_downmix_info_update_side_data(AVFrame *frame);
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/**
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* @}
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*/
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/**
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* @}
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*/
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#endif /* AVUTIL_DOWNMIX_INFO_H */
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