yading@10: /*
yading@10:  * JPEG-LS common code
yading@10:  * Copyright (c) 2003 Michael Niedermayer
yading@10:  * Copyright (c) 2006 Konstantin Shishkov
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * JPEG-LS common code.
yading@10:  */
yading@10: 
yading@10: #ifndef AVCODEC_JPEGLS_H
yading@10: #define AVCODEC_JPEGLS_H
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "libavutil/common.h"
yading@10: 
yading@10: typedef struct JpeglsContext{
yading@10:     AVCodecContext *avctx;
yading@10:     AVFrame picture;
yading@10: }JpeglsContext;
yading@10: 
yading@10: typedef struct JLSState{
yading@10:     int T1, T2, T3;
yading@10:     int A[367], B[367], C[365], N[367];
yading@10:     int limit, reset, bpp, qbpp, maxval, range;
yading@10:     int near, twonear;
yading@10:     int run_index[4];
yading@10: }JLSState;
yading@10: 
yading@10: extern const uint8_t ff_log2_run[32];
yading@10: 
yading@10: /**
yading@10:  * Calculate initial JPEG-LS parameters
yading@10:  */
yading@10: void ff_jpegls_init_state(JLSState *state);
yading@10: 
yading@10: /**
yading@10:  * Calculate quantized gradient value, used for context determination
yading@10:  */
yading@10: static inline int ff_jpegls_quantize(JLSState *s, int v){ //FIXME optimize
yading@10:     if(v==0) return 0;
yading@10:     if(v < 0){
yading@10:         if(v <= -s->T3) return -4;
yading@10:         if(v <= -s->T2) return -3;
yading@10:         if(v <= -s->T1) return -2;
yading@10:         if(v <  -s->near) return -1;
yading@10:         return 0;
yading@10:     }else{
yading@10:         if(v <= s->near) return 0;
yading@10:         if(v <  s->T1) return 1;
yading@10:         if(v <  s->T2) return 2;
yading@10:         if(v <  s->T3) return 3;
yading@10:         return 4;
yading@10:     }
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Calculate JPEG-LS codec values
yading@10:  */
yading@10: void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all);
yading@10: 
yading@10: 
yading@10: static inline void ff_jpegls_downscale_state(JLSState *state, int Q){
yading@10:     if(state->N[Q] == state->reset){
yading@10:         state->A[Q] >>=1;
yading@10:         state->B[Q] >>=1;
yading@10:         state->N[Q] >>=1;
yading@10:     }
yading@10:     state->N[Q]++;
yading@10: }
yading@10: 
yading@10: static inline int ff_jpegls_update_state_regular(JLSState *state, int Q, int err){
yading@10:     if(FFABS(err) > 0xFFFF)
yading@10:         return -0x10000;
yading@10:     state->A[Q] += FFABS(err);
yading@10:     err *= state->twonear;
yading@10:     state->B[Q] += err;
yading@10: 
yading@10:     ff_jpegls_downscale_state(state, Q);
yading@10: 
yading@10:     if(state->B[Q] <= -state->N[Q]) {
yading@10:         state->B[Q]= FFMAX(state->B[Q] + state->N[Q], 1-state->N[Q]);
yading@10:         if(state->C[Q] > -128)
yading@10:             state->C[Q]--;
yading@10:     }else if(state->B[Q] > 0){
yading@10:         state->B[Q]= FFMIN(state->B[Q] - state->N[Q], 0);
yading@10:         if(state->C[Q] < 127)
yading@10:             state->C[Q]++;
yading@10:     }
yading@10: 
yading@10:     return err;
yading@10: }
yading@10: 
yading@10: #define R(a, i   ) (bits == 8 ?  ((uint8_t*)(a))[i]    :  ((uint16_t*)(a))[i]  )
yading@10: #define W(a, i, v) (bits == 8 ? (((uint8_t*)(a))[i]=v) : (((uint16_t*)(a))[i]=v))
yading@10: 
yading@10: #endif /* AVCODEC_JPEGLS_H */