diff options
Diffstat (limited to 'ffmpeg1/libavcodec/jpegls.c')
| -rw-r--r-- | ffmpeg1/libavcodec/jpegls.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/ffmpeg1/libavcodec/jpegls.c b/ffmpeg1/libavcodec/jpegls.c new file mode 100644 index 0000000..dc5c9cf --- /dev/null +++ b/ffmpeg1/libavcodec/jpegls.c @@ -0,0 +1,87 @@ +/* + * 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); +} |
