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	987903826b
	
	
	
		
			
			Consistently apply this rule: the guard name is obtained from the filename by stripping the leading "lib", converting '/' and '.' to '_' and uppercasing the resulting name. Guard names in the root directory have to be prefixed by "FFMPEG_". Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk
		
			
				
	
	
		
			112 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			112 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * JPEG-LS common code
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|  * Copyright (c) 2003 Michael Niedermayer
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|  * Copyright (c) 2006 Konstantin Shishkov
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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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| /**
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|  * @file jpegls.h
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|  * JPEG-LS common code.
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|  */
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| 
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| #ifndef AVCODEC_JPEGLS_H
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| #define AVCODEC_JPEGLS_H
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| 
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| #include "avcodec.h"
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| 
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| typedef struct JpeglsContext{
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|     AVCodecContext *avctx;
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|     AVFrame picture;
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| }JpeglsContext;
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| 
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| typedef struct JLSState{
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|     int T1, T2, T3;
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|     int A[367], B[367], C[365], N[367];
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|     int limit, reset, bpp, qbpp, maxval, range;
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|     int near, twonear;
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|     int run_index[3];
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| }JLSState;
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| 
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| extern const uint8_t ff_log2_run[32];
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| 
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| /**
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|  * Calculate initial JPEG-LS parameters
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|  */
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| void ff_jpegls_init_state(JLSState *state);
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| 
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| /**
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|  * Calculate quantized gradient value, used for context determination
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|  */
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| static inline int ff_jpegls_quantize(JLSState *s, int v){ //FIXME optimize
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|     if(v==0) return 0;
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|     if(v < 0){
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|         if(v <= -s->T3) return -4;
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|         if(v <= -s->T2) return -3;
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|         if(v <= -s->T1) return -2;
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|         if(v <  -s->near) return -1;
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|         return 0;
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|     }else{
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|         if(v <= s->near) return 0;
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|         if(v <  s->T1) return 1;
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|         if(v <  s->T2) return 2;
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|         if(v <  s->T3) return 3;
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|         return 4;
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|     }
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| }
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| 
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| /**
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|  * Calculate JPEG-LS codec values
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|  */
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| void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all);
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| 
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| 
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| static inline void ff_jpegls_downscale_state(JLSState *state, int Q){
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|     if(state->N[Q] == state->reset){
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|         state->A[Q] >>=1;
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|         state->B[Q] >>=1;
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|         state->N[Q] >>=1;
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|     }
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|     state->N[Q]++;
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| }
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| 
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| static inline int ff_jpegls_update_state_regular(JLSState *state, int Q, int err){
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|     state->A[Q] += FFABS(err);
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|     err *= state->twonear;
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|     state->B[Q] += err;
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| 
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|     ff_jpegls_downscale_state(state, Q);
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| 
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|     if(state->B[Q] <= -state->N[Q]) {
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|         state->B[Q]= FFMAX(state->B[Q] + state->N[Q], 1-state->N[Q]);
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|         if(state->C[Q] > -128)
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|             state->C[Q]--;
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|     }else if(state->B[Q] > 0){
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|         state->B[Q]= FFMIN(state->B[Q] - state->N[Q], 0);
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|         if(state->C[Q] < 127)
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|             state->C[Q]++;
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|     }
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| 
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|     return err;
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| }
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| 
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| #define R(a, i   ) (bits == 8 ?  ((uint8_t*)(a))[i]    :  ((uint16_t*)(a))[i]  )
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| #define W(a, i, v) (bits == 8 ? (((uint8_t*)(a))[i]=v) : (((uint16_t*)(a))[i]=v))
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| 
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| #endif /* AVCODEC_JPEGLS_H */
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