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/*
* JPEG-LS common code
* Copyright (c) 2003 Michael Niedermayer
* Copyright (c) 2006 Konstantin Shishkov
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file jpegls.h
* JPEG-LS common code.
*/
#ifndef FFMPEG_JPEGLS_H
#define FFMPEG_JPEGLS_H
#include "avcodec.h"
typedef struct JpeglsContext{
AVCodecContext *avctx;
AVFrame picture;
}JpeglsContext;
typedef struct JLSState{
int T1, T2, T3;
int A[367], B[367], C[365], N[367];
int limit, reset, bpp, qbpp, maxval, range;
int near, twonear;
int run_index[3];
}JLSState;
extern const uint8_t ff_log2_run[32];
/**
* Calculate initial JPEG-LS parameters
*/
void ff_jpegls_init_state(JLSState *state);
/**
* Calculate quantized gradient value, used for context determination
*/
static inline int ff_jpegls_quantize(JLSState *s, int v){ //FIXME optimize
if(v==0) return 0;
if(v < 0){
if(v <= -s->T3) return -4;
if(v <= -s->T2) return -3;
if(v <= -s->T1) return -2;
if(v < -s->near) return -1;
return 0;
}else{
if(v <= s->near) return 0;
if(v < s->T1) return 1;
if(v < s->T2) return 2;
if(v < s->T3) return 3;
return 4;
}
}
/**
* Calculate JPEG-LS codec values
*/
void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all);
static inline void ff_jpegls_downscale_state(JLSState *state, int Q){
if(state->N[Q] == state->reset){
state->A[Q] >>=1;
state->B[Q] >>=1;
state->N[Q] >>=1;
}
state->N[Q]++;
}
static inline int ff_jpegls_update_state_regular(JLSState *state, int Q, int err){
state->A[Q] += FFABS(err);
err *= state->twonear;
state->B[Q] += err;
ff_jpegls_downscale_state(state, Q);
if(state->B[Q] <= -state->N[Q]) {
state->B[Q]= FFMAX(state->B[Q] + state->N[Q], 1-state->N[Q]);
if(state->C[Q] > -128)
state->C[Q]--;
}else if(state->B[Q] > 0){
state->B[Q]= FFMIN(state->B[Q] - state->N[Q], 0);
if(state->C[Q] < 127)
state->C[Q]++;
}
return err;
}
#define R(a, i ) (bits == 8 ? ((uint8_t*)(a))[i] : ((uint16_t*)(a))[i] )
#define W(a, i, v) (bits == 8 ? (((uint8_t*)(a))[i]=v) : (((uint16_t*)(a))[i]=v))
#endif /* FFMPEG_JPEGLS_H */
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