/*
  * 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.
  */
 
 #include "jpegls.h"
 
 void ff_jpegls_init_state(JLSState *state){
     int i;
 
     state->twonear = state->near * 2 + 1;
     state->range = ((state->maxval + state->twonear - 1) / state->twonear) + 1;
 
     // QBPP = ceil(log2(RANGE))
     for(state->qbpp = 0; (1 << state->qbpp) < state->range; state->qbpp++);
 

     state->bpp = FFMAX(av_log2(state->maxval)+1, 2);
     state->limit = 2*(state->bpp + FFMAX(state->bpp, 8)) - state->qbpp;

 
     for(i = 0; i < 367; i++) {
         state->A[i] = FFMAX((state->range + 32) >> 6, 2);
         state->N[i] = 1;
     }
 
 }
 
 /**
  * Custom value clipping function used in T1, T2, T3 calculation
  */
 static inline int iso_clip(int v, int vmin, int vmax){
     if(v > vmax || v < vmin) return vmin;
     else                     return v;
 }
 
 void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all){
     const int basic_t1= 3;
     const int basic_t2= 7;
     const int basic_t3= 21;
     int factor;
 
     if(s->maxval==0 || reset_all) s->maxval= (1 << s->bpp) - 1;
 
     if(s->maxval >=128){
         factor= (FFMIN(s->maxval, 4095) + 128)>>8;
 
         if(s->T1==0     || reset_all)
             s->T1= iso_clip(factor*(basic_t1-2) + 2 + 3*s->near, s->near+1, s->maxval);
         if(s->T2==0     || reset_all)
             s->T2= iso_clip(factor*(basic_t2-3) + 3 + 5*s->near, s->T1, s->maxval);
         if(s->T3==0     || reset_all)
             s->T3= iso_clip(factor*(basic_t3-4) + 4 + 7*s->near, s->T2, s->maxval);
     }else{
         factor= 256 / (s->maxval + 1);
 
         if(s->T1==0     || reset_all)
             s->T1= iso_clip(FFMAX(2, basic_t1/factor + 3*s->near), s->near+1, s->maxval);
         if(s->T2==0     || reset_all)
             s->T2= iso_clip(FFMAX(3, basic_t2/factor + 5*s->near), s->T1, s->maxval);
         if(s->T3==0     || reset_all)

             s->T3= iso_clip(FFMAX(4, basic_t3/factor + 7*s->near), s->T2, s->maxval);

     }
 
     if(s->reset==0  || reset_all) s->reset= 64;

     av_dlog(NULL, "[JPEG-LS RESET] T=%i,%i,%i\n", s->T1, s->T2, s->T3);

 }