Rename var: val -> energy
[FFMpeg-mirror/DVCPRO-HD.git] / libavcodec / jpegls.c
blob8a6f5065c28e360ae9d56c0e50fa25b4bdac12e4
1 /*
2 * JPEG-LS common code
3 * Copyright (c) 2003 Michael Niedermayer
4 * Copyright (c) 2006 Konstantin Shishkov
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 /**
24 * @file jpegls.c
25 * JPEG-LS common code.
28 #include "jpegls.h"
30 const uint8_t ff_log2_run[32]={
31 0, 0, 0, 0, 1, 1, 1, 1,
32 2, 2, 2, 2, 3, 3, 3, 3,
33 4, 4, 5, 5, 6, 6, 7, 7,
34 8, 9,10,11,12,13,14,15
37 void ff_jpegls_init_state(JLSState *state){
38 int i;
40 state->twonear = state->near * 2 + 1;
41 state->range = ((state->maxval + state->twonear - 1) / state->twonear) + 1;
43 // QBPP = ceil(log2(RANGE))
44 for(state->qbpp = 0; (1 << state->qbpp) < state->range; state->qbpp++);
46 if(state->bpp < 8)
47 state->limit = 16 + 2 * state->bpp - state->qbpp;
48 else
49 state->limit = (4 * state->bpp) - state->qbpp;
51 for(i = 0; i < 367; i++) {
52 state->A[i] = FFMAX((state->range + 32) >> 6, 2);
53 state->N[i] = 1;
58 /**
59 * Custom value clipping function used in T1, T2, T3 calculation
61 static inline int iso_clip(int v, int vmin, int vmax){
62 if(v > vmax || v < vmin) return vmin;
63 else return v;
66 void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all){
67 const int basic_t1= 3;
68 const int basic_t2= 7;
69 const int basic_t3= 21;
70 int factor;
72 if(s->maxval==0 || reset_all) s->maxval= (1 << s->bpp) - 1;
74 if(s->maxval >=128){
75 factor= (FFMIN(s->maxval, 4095) + 128)>>8;
77 if(s->T1==0 || reset_all)
78 s->T1= iso_clip(factor*(basic_t1-2) + 2 + 3*s->near, s->near+1, s->maxval);
79 if(s->T2==0 || reset_all)
80 s->T2= iso_clip(factor*(basic_t2-3) + 3 + 5*s->near, s->T1, s->maxval);
81 if(s->T3==0 || reset_all)
82 s->T3= iso_clip(factor*(basic_t3-4) + 4 + 7*s->near, s->T2, s->maxval);
83 }else{
84 factor= 256 / (s->maxval + 1);
86 if(s->T1==0 || reset_all)
87 s->T1= iso_clip(FFMAX(2, basic_t1/factor + 3*s->near), s->near+1, s->maxval);
88 if(s->T2==0 || reset_all)
89 s->T2= iso_clip(FFMAX(3, basic_t2/factor + 5*s->near), s->T1, s->maxval);
90 if(s->T3==0 || reset_all)
91 s->T3= iso_clip(FFMAX(4, basic_t3/factor + 6*s->near), s->T2, s->maxval);
94 if(s->reset==0 || reset_all) s->reset= 64;
95 // av_log(NULL, AV_LOG_DEBUG, "[JPEG-LS RESET] T=%i,%i,%i\n", s->T1, s->T2, s->T3);