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	Reviewed-by: Timothy Gu <timothygu99@gmail.com> Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
		
			
				
	
	
		
			116 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			116 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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| 
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| #ifndef AVUTIL_DOWNMIX_INFO_H
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| #define AVUTIL_DOWNMIX_INFO_H
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| 
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| #include "frame.h"
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| 
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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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| /**
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|  * @addtogroup lavu_audio
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|  * @{
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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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| /**
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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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| /**
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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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|     /**
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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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|     /**
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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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|     /**
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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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|     /**
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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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|     /**
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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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| /**
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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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|  * @}
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|  */
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| 
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| #endif /* AVUTIL_DOWNMIX_INFO_H */
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