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libavcodec/jpegls.h

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00001 /*
00002  * JPEG-LS common code
00003  * Copyright (c) 2003 Michael Niedermayer
00004  * Copyright (c) 2006 Konstantin Shishkov
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00028 #ifndef AVCODEC_JPEGLS_H
00029 #define AVCODEC_JPEGLS_H
00030 
00031 #include "avcodec.h"
00032 
00033 typedef struct JpeglsContext{
00034     AVCodecContext *avctx;
00035     AVFrame picture;
00036 }JpeglsContext;
00037 
00038 typedef struct JLSState{
00039     int T1, T2, T3;
00040     int A[367], B[367], C[365], N[367];
00041     int limit, reset, bpp, qbpp, maxval, range;
00042     int near, twonear;
00043     int run_index[3];
00044 }JLSState;
00045 
00046 extern const uint8_t ff_log2_run[32];
00047 
00051 void ff_jpegls_init_state(JLSState *state);
00052 
00056 static inline int ff_jpegls_quantize(JLSState *s, int v){ //FIXME optimize
00057     if(v==0) return 0;
00058     if(v < 0){
00059         if(v <= -s->T3) return -4;
00060         if(v <= -s->T2) return -3;
00061         if(v <= -s->T1) return -2;
00062         if(v <  -s->near) return -1;
00063         return 0;
00064     }else{
00065         if(v <= s->near) return 0;
00066         if(v <  s->T1) return 1;
00067         if(v <  s->T2) return 2;
00068         if(v <  s->T3) return 3;
00069         return 4;
00070     }
00071 }
00072 
00076 void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all);
00077 
00078 
00079 static inline void ff_jpegls_downscale_state(JLSState *state, int Q){
00080     if(state->N[Q] == state->reset){
00081         state->A[Q] >>=1;
00082         state->B[Q] >>=1;
00083         state->N[Q] >>=1;
00084     }
00085     state->N[Q]++;
00086 }
00087 
00088 static inline int ff_jpegls_update_state_regular(JLSState *state, int Q, int err){
00089     state->A[Q] += FFABS(err);
00090     err *= state->twonear;
00091     state->B[Q] += err;
00092 
00093     ff_jpegls_downscale_state(state, Q);
00094 
00095     if(state->B[Q] <= -state->N[Q]) {
00096         state->B[Q]= FFMAX(state->B[Q] + state->N[Q], 1-state->N[Q]);
00097         if(state->C[Q] > -128)
00098             state->C[Q]--;
00099     }else if(state->B[Q] > 0){
00100         state->B[Q]= FFMIN(state->B[Q] - state->N[Q], 0);
00101         if(state->C[Q] < 127)
00102             state->C[Q]++;
00103     }
00104 
00105     return err;
00106 }
00107 
00108 #define R(a, i   ) (bits == 8 ?  ((uint8_t*)(a))[i]    :  ((uint16_t*)(a))[i]  )
00109 #define W(a, i, v) (bits == 8 ? (((uint8_t*)(a))[i]=v) : (((uint16_t*)(a))[i]=v))
00110 
00111 #endif /* AVCODEC_JPEGLS_H */

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