/*
  * 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 "libavutil/common.h"

 #include "avcodec.h"

 #include "internal.h"

 typedef struct JpeglsContext {

     AVCodecContext *avctx;

 } 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[4];

 } JLSState;

 
 /**
  * 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)
 {
     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)
 {

     if(FFABS(err) > 0xFFFF)
         return -0x10000;

     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 */