/*
  * 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

  * JPEG-LS common code.
  */
 

 #ifndef AVCODEC_JPEGLS_H
 #define AVCODEC_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 /* AVCODEC_JPEGLS_H */