64 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			64 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2020 Björn Ottosson
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|  * Copyright (c) 2022 Clément Bœsch <u pkh me>
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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 AVFILTER_PALETTE_H
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| #define AVFILTER_PALETTE_H
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| 
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| #include <math.h>
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| #include <stdint.h>
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| 
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| #include "libavutil/attributes.h"
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| 
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| struct Lab {
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|     int32_t L, a, b;
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| };
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| 
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| /**
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|  * Map sRGB 8-bit color component to a 16-bit linear value (gamma
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|  * expand from electrical to optical value).
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|  */
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| int32_t ff_srgb_u8_to_linear_int(uint8_t x);
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| 
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| /**
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|  * Map a 16-bit linear value to a sRGB 8-bit color component (gamma
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|  * compressed from optical to electrical value).
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|  */
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| uint8_t ff_linear_int_to_srgb_u8(int32_t x);
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| 
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| /**
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|  * sRGB (non-linear) to OkLab conversion
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|  * @see https://bottosson.github.io/posts/oklab/
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|  */
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| struct Lab ff_srgb_u8_to_oklab_int(uint32_t srgb);
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| 
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| /**
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|  * OkLab to sRGB (non-linear) conversion
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|  * @see https://bottosson.github.io/posts/oklab/
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|  */
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| uint32_t ff_oklab_int_to_srgb_u8(struct Lab c);
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| 
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| /*
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|  * lowbias32 hashing from https://nullprogram.com/blog/2018/07/31/
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|  */
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| uint32_t ff_lowbias32(uint32_t x);
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| 
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| #endif /* AVFILTER_PALETTE_H */
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