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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4349 | Serge | 1 | /* |
| 2 | * JPEG-LS common code |
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| 3 | * Copyright (c) 2003 Michael Niedermayer |
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| 4 | * Copyright (c) 2006 Konstantin Shishkov |
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| 5 | * |
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| 6 | * This file is part of FFmpeg. |
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| 7 | * |
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| 8 | * FFmpeg is free software; you can redistribute it and/or |
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| 9 | * modify it under the terms of the GNU Lesser General Public |
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| 10 | * License as published by the Free Software Foundation; either |
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| 11 | * version 2.1 of the License, or (at your option) any later version. |
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| 12 | * |
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| 13 | * FFmpeg is distributed in the hope that it will be useful, |
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| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 16 | * Lesser General Public License for more details. |
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| 17 | * |
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| 18 | * You should have received a copy of the GNU Lesser General Public |
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| 19 | * License along with FFmpeg; if not, write to the Free Software |
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| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 21 | */ |
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| 22 | |||
| 23 | /** |
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| 24 | * @file |
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| 25 | * JPEG-LS common code. |
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| 26 | */ |
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| 27 | |||
| 28 | #include "jpegls.h" |
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| 29 | |||
| 30 | void ff_jpegls_init_state(JLSState *state) |
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| 31 | { |
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| 32 | int i; |
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| 33 | |||
| 34 | state->twonear = state->near * 2 + 1; |
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| 35 | state->range = (state->maxval + state->twonear - 1) / state->twonear + 1; |
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| 36 | |||
| 37 | // QBPP = ceil(log2(RANGE)) |
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| 38 | for (state->qbpp = 0; (1 << state->qbpp) < state->range; state->qbpp++) |
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| 39 | ; |
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| 40 | |||
| 41 | state->bpp = FFMAX(av_log2(state->maxval) + 1, 2); |
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| 42 | state->limit = 2*(state->bpp + FFMAX(state->bpp, 8)) - state->qbpp; |
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| 43 | |||
| 44 | for (i = 0; i < 367; i++) { |
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| 45 | state->A[i] = FFMAX(state->range + 32 >> 6, 2); |
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| 46 | state->N[i] = 1; |
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| 47 | } |
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| 48 | } |
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| 49 | |||
| 50 | /** |
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| 51 | * Custom value clipping function used in T1, T2, T3 calculation |
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| 52 | */ |
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| 53 | static inline int iso_clip(int v, int vmin, int vmax) |
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| 54 | { |
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| 55 | if (v > vmax || v < vmin) |
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| 56 | return vmin; |
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| 57 | else |
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| 58 | return v; |
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| 59 | } |
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| 60 | |||
| 61 | void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all) |
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| 62 | { |
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| 63 | const int basic_t1 = 3; |
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| 64 | const int basic_t2 = 7; |
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| 65 | const int basic_t3 = 21; |
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| 66 | int factor; |
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| 67 | |||
| 68 | if (s->maxval == 0 || reset_all) |
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| 69 | s->maxval = (1 << s->bpp) - 1; |
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| 70 | |||
| 71 | if (s->maxval >= 128) { |
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| 72 | factor = FFMIN(s->maxval, 4095) + 128 >> 8; |
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| 73 | |||
| 74 | if (s->T1 == 0 || reset_all) |
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| 75 | s->T1 = iso_clip(factor * (basic_t1 - 2) + 2 + 3 * s->near, |
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| 76 | s->near + 1, s->maxval); |
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| 77 | if (s->T2 == 0 || reset_all) |
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| 78 | s->T2 = iso_clip(factor * (basic_t2 - 3) + 3 + 5 * s->near, |
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| 79 | s->T1, s->maxval); |
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| 80 | if (s->T3 == 0 || reset_all) |
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| 81 | s->T3 = iso_clip(factor * (basic_t3 - 4) + 4 + 7 * s->near, |
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| 82 | s->T2, s->maxval); |
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| 83 | } else { |
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| 84 | factor = 256 / (s->maxval + 1); |
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| 85 | |||
| 86 | if (s->T1 == 0 || reset_all) |
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| 87 | s->T1 = iso_clip(FFMAX(2, basic_t1 / factor + 3 * s->near), |
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| 88 | s->near + 1, s->maxval); |
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| 89 | if (s->T2 == 0 || reset_all) |
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| 90 | s->T2 = iso_clip(FFMAX(3, basic_t2 / factor + 5 * s->near), |
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| 91 | s->T1, s->maxval); |
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| 92 | if (s->T3 == 0 || reset_all) |
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| 93 | s->T3 = iso_clip(FFMAX(4, basic_t3 / factor + 7 * s->near), |
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| 94 | s->T2, s->maxval); |
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| 95 | } |
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| 96 | |||
| 97 | if (s->reset == 0 || reset_all) |
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| 98 | s->reset = 64; |
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| 99 | av_dlog(NULL, "[JPEG-LS RESET] T=%i,%i,%i\n", s->T1, s->T2, s->T3); |
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| 100 | } |