Extract duplicate arithmetic decoder to own class
This commit is contained in:
fkaelberer
parent
5c448135cc
commit
7b5b5178ef
1
make.js
1
make.js
@ -309,6 +309,7 @@ target.bundle = function(args) {
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'core/ps_parser.js',
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'core/stream.js',
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'core/worker.js',
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'core/arithmetic_decoder.js',
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'core/jpx.js',
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'core/jbig2.js',
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'core/bidi.js',
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175
src/core/arithmetic_decoder.js
Normal file
175
src/core/arithmetic_decoder.js
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@ -0,0 +1,175 @@
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/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
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/* Copyright 2012 Mozilla Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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'use strict';
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// Annex E. Arithmetic Coding
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var ArithmeticDecoder = (function ArithmeticDecoderClosure() {
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var QeTable = [
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{qe: 0x5601, nmps: 1, nlps: 1, switchFlag: 1},
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{qe: 0x3401, nmps: 2, nlps: 6, switchFlag: 0},
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{qe: 0x1801, nmps: 3, nlps: 9, switchFlag: 0},
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{qe: 0x0AC1, nmps: 4, nlps: 12, switchFlag: 0},
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{qe: 0x0521, nmps: 5, nlps: 29, switchFlag: 0},
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{qe: 0x0221, nmps: 38, nlps: 33, switchFlag: 0},
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{qe: 0x5601, nmps: 7, nlps: 6, switchFlag: 1},
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{qe: 0x5401, nmps: 8, nlps: 14, switchFlag: 0},
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{qe: 0x4801, nmps: 9, nlps: 14, switchFlag: 0},
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{qe: 0x3801, nmps: 10, nlps: 14, switchFlag: 0},
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{qe: 0x3001, nmps: 11, nlps: 17, switchFlag: 0},
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{qe: 0x2401, nmps: 12, nlps: 18, switchFlag: 0},
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{qe: 0x1C01, nmps: 13, nlps: 20, switchFlag: 0},
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{qe: 0x1601, nmps: 29, nlps: 21, switchFlag: 0},
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{qe: 0x5601, nmps: 15, nlps: 14, switchFlag: 1},
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{qe: 0x5401, nmps: 16, nlps: 14, switchFlag: 0},
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{qe: 0x5101, nmps: 17, nlps: 15, switchFlag: 0},
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{qe: 0x4801, nmps: 18, nlps: 16, switchFlag: 0},
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{qe: 0x3801, nmps: 19, nlps: 17, switchFlag: 0},
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{qe: 0x3401, nmps: 20, nlps: 18, switchFlag: 0},
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{qe: 0x3001, nmps: 21, nlps: 19, switchFlag: 0},
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{qe: 0x2801, nmps: 22, nlps: 19, switchFlag: 0},
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{qe: 0x2401, nmps: 23, nlps: 20, switchFlag: 0},
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{qe: 0x2201, nmps: 24, nlps: 21, switchFlag: 0},
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{qe: 0x1C01, nmps: 25, nlps: 22, switchFlag: 0},
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{qe: 0x1801, nmps: 26, nlps: 23, switchFlag: 0},
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{qe: 0x1601, nmps: 27, nlps: 24, switchFlag: 0},
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{qe: 0x1401, nmps: 28, nlps: 25, switchFlag: 0},
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{qe: 0x1201, nmps: 29, nlps: 26, switchFlag: 0},
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{qe: 0x1101, nmps: 30, nlps: 27, switchFlag: 0},
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{qe: 0x0AC1, nmps: 31, nlps: 28, switchFlag: 0},
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{qe: 0x09C1, nmps: 32, nlps: 29, switchFlag: 0},
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{qe: 0x08A1, nmps: 33, nlps: 30, switchFlag: 0},
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{qe: 0x0521, nmps: 34, nlps: 31, switchFlag: 0},
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{qe: 0x0441, nmps: 35, nlps: 32, switchFlag: 0},
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{qe: 0x02A1, nmps: 36, nlps: 33, switchFlag: 0},
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{qe: 0x0221, nmps: 37, nlps: 34, switchFlag: 0},
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{qe: 0x0141, nmps: 38, nlps: 35, switchFlag: 0},
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{qe: 0x0111, nmps: 39, nlps: 36, switchFlag: 0},
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{qe: 0x0085, nmps: 40, nlps: 37, switchFlag: 0},
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{qe: 0x0049, nmps: 41, nlps: 38, switchFlag: 0},
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{qe: 0x0025, nmps: 42, nlps: 39, switchFlag: 0},
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{qe: 0x0015, nmps: 43, nlps: 40, switchFlag: 0},
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{qe: 0x0009, nmps: 44, nlps: 41, switchFlag: 0},
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{qe: 0x0005, nmps: 45, nlps: 42, switchFlag: 0},
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{qe: 0x0001, nmps: 45, nlps: 43, switchFlag: 0},
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{qe: 0x5601, nmps: 46, nlps: 46, switchFlag: 0}
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];
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function ArithmeticDecoder(data, start, end) {
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this.data = data;
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this.bp = start;
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this.dataEnd = end;
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this.chigh = data[start];
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this.clow = 0;
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this.byteIn();
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this.chigh = ((this.chigh << 7) & 0xFFFF) | ((this.clow >> 9) & 0x7F);
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this.clow = (this.clow << 7) & 0xFFFF;
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this.ct -= 7;
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this.a = 0x8000;
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}
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ArithmeticDecoder.prototype = {
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byteIn: function ArithmeticDecoder_byteIn() {
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var data = this.data;
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var bp = this.bp;
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if (data[bp] == 0xFF) {
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var b1 = data[bp + 1];
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if (b1 > 0x8F) {
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this.clow += 0xFF00;
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this.ct = 8;
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} else {
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bp++;
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this.clow += (data[bp] << 9);
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this.ct = 7;
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this.bp = bp;
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}
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} else {
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bp++;
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this.clow += bp < this.dataEnd ? (data[bp] << 8) : 0xFF00;
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this.ct = 8;
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this.bp = bp;
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}
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if (this.clow > 0xFFFF) {
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this.chigh += (this.clow >> 16);
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this.clow &= 0xFFFF;
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}
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},
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readBit: function ArithmeticDecoder_readBit(contexts, pos) {
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// contexts are packed into 1 byte:
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// highest 7 bits carry cx.index, lowest bit carries cx.mps
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var cx_index = contexts[pos] >> 1, cx_mps = contexts[pos] & 1;
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var qeTableIcx = QeTable[cx_index];
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var qeIcx = qeTableIcx.qe;
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var nmpsIcx = qeTableIcx.nmps;
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var nlpsIcx = qeTableIcx.nlps;
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var switchIcx = qeTableIcx.switchFlag;
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var d;
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this.a -= qeIcx;
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if (this.chigh < qeIcx) {
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// exchangeLps
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if (this.a < qeIcx) {
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this.a = qeIcx;
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d = cx_mps;
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cx_index = nmpsIcx;
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} else {
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this.a = qeIcx;
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d = 1 - cx_mps;
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if (switchIcx) {
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cx_mps = d;
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}
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cx_index = nlpsIcx;
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}
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} else {
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this.chigh -= qeIcx;
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if ((this.a & 0x8000) !== 0) {
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return cx_mps;
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}
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// exchangeMps
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if (this.a < qeIcx) {
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d = 1 - cx_mps;
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if (switchIcx) {
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cx_mps = d;
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}
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cx_index = nlpsIcx;
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} else {
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d = cx_mps;
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cx_index = nmpsIcx;
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}
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}
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// renormD;
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do {
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if (this.ct === 0) {
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this.byteIn();
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}
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this.a <<= 1;
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this.chigh = ((this.chigh << 1) & 0xFFFF) | ((this.clow >> 15) & 1);
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this.clow = (this.clow << 1) & 0xFFFF;
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this.ct--;
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} while ((this.a & 0x8000) === 0);
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contexts[pos] = cx_index << 1 | cx_mps;
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return d;
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}
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};
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return ArithmeticDecoder;
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})();
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@ -1,6 +1,5 @@
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/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
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/* globals error, shadow */
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/* Copyright 2012 Mozilla Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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@ -15,166 +14,11 @@
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/* globals ArithmeticDecoder, error, shadow */
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'use strict';
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var Jbig2Image = (function Jbig2ImageClosure() {
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// Annex E. Arithmetic Coding
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var ArithmeticDecoder = (function ArithmeticDecoderClosure() {
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var QeTable = [
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{qe: 0x5601, nmps: 1, nlps: 1, switchFlag: 1},
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{qe: 0x3401, nmps: 2, nlps: 6, switchFlag: 0},
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{qe: 0x1801, nmps: 3, nlps: 9, switchFlag: 0},
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{qe: 0x0AC1, nmps: 4, nlps: 12, switchFlag: 0},
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{qe: 0x0521, nmps: 5, nlps: 29, switchFlag: 0},
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{qe: 0x0221, nmps: 38, nlps: 33, switchFlag: 0},
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{qe: 0x5601, nmps: 7, nlps: 6, switchFlag: 1},
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{qe: 0x5401, nmps: 8, nlps: 14, switchFlag: 0},
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{qe: 0x4801, nmps: 9, nlps: 14, switchFlag: 0},
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{qe: 0x3801, nmps: 10, nlps: 14, switchFlag: 0},
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{qe: 0x3001, nmps: 11, nlps: 17, switchFlag: 0},
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{qe: 0x2401, nmps: 12, nlps: 18, switchFlag: 0},
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{qe: 0x1C01, nmps: 13, nlps: 20, switchFlag: 0},
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{qe: 0x1601, nmps: 29, nlps: 21, switchFlag: 0},
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{qe: 0x5601, nmps: 15, nlps: 14, switchFlag: 1},
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{qe: 0x5401, nmps: 16, nlps: 14, switchFlag: 0},
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{qe: 0x5101, nmps: 17, nlps: 15, switchFlag: 0},
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{qe: 0x4801, nmps: 18, nlps: 16, switchFlag: 0},
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{qe: 0x3801, nmps: 19, nlps: 17, switchFlag: 0},
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{qe: 0x3401, nmps: 20, nlps: 18, switchFlag: 0},
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{qe: 0x3001, nmps: 21, nlps: 19, switchFlag: 0},
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{qe: 0x2801, nmps: 22, nlps: 19, switchFlag: 0},
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{qe: 0x2401, nmps: 23, nlps: 20, switchFlag: 0},
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{qe: 0x2201, nmps: 24, nlps: 21, switchFlag: 0},
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{qe: 0x1C01, nmps: 25, nlps: 22, switchFlag: 0},
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{qe: 0x1801, nmps: 26, nlps: 23, switchFlag: 0},
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{qe: 0x1601, nmps: 27, nlps: 24, switchFlag: 0},
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{qe: 0x1401, nmps: 28, nlps: 25, switchFlag: 0},
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{qe: 0x1201, nmps: 29, nlps: 26, switchFlag: 0},
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{qe: 0x1101, nmps: 30, nlps: 27, switchFlag: 0},
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{qe: 0x0AC1, nmps: 31, nlps: 28, switchFlag: 0},
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{qe: 0x09C1, nmps: 32, nlps: 29, switchFlag: 0},
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{qe: 0x08A1, nmps: 33, nlps: 30, switchFlag: 0},
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{qe: 0x0521, nmps: 34, nlps: 31, switchFlag: 0},
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{qe: 0x0441, nmps: 35, nlps: 32, switchFlag: 0},
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{qe: 0x02A1, nmps: 36, nlps: 33, switchFlag: 0},
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{qe: 0x0221, nmps: 37, nlps: 34, switchFlag: 0},
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{qe: 0x0141, nmps: 38, nlps: 35, switchFlag: 0},
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{qe: 0x0111, nmps: 39, nlps: 36, switchFlag: 0},
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{qe: 0x0085, nmps: 40, nlps: 37, switchFlag: 0},
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{qe: 0x0049, nmps: 41, nlps: 38, switchFlag: 0},
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{qe: 0x0025, nmps: 42, nlps: 39, switchFlag: 0},
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{qe: 0x0015, nmps: 43, nlps: 40, switchFlag: 0},
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{qe: 0x0009, nmps: 44, nlps: 41, switchFlag: 0},
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{qe: 0x0005, nmps: 45, nlps: 42, switchFlag: 0},
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{qe: 0x0001, nmps: 45, nlps: 43, switchFlag: 0},
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{qe: 0x5601, nmps: 46, nlps: 46, switchFlag: 0}
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];
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function ArithmeticDecoder(data, start, end) {
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this.data = data;
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this.bp = start;
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this.dataEnd = end;
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this.chigh = data[start];
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this.clow = 0;
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this.byteIn();
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this.chigh = ((this.chigh << 7) & 0xFFFF) | ((this.clow >> 9) & 0x7F);
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this.clow = (this.clow << 7) & 0xFFFF;
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this.ct -= 7;
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this.a = 0x8000;
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}
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ArithmeticDecoder.prototype = {
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byteIn: function ArithmeticDecoder_byteIn() {
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var data = this.data;
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var bp = this.bp;
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if (data[bp] == 0xFF) {
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var b1 = data[bp + 1];
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if (b1 > 0x8F) {
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this.clow += 0xFF00;
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this.ct = 8;
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} else {
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bp++;
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this.clow += (data[bp] << 9);
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this.ct = 7;
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this.bp = bp;
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}
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} else {
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bp++;
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this.clow += bp < this.dataEnd ? (data[bp] << 8) : 0xFF00;
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this.ct = 8;
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this.bp = bp;
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}
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if (this.clow > 0xFFFF) {
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this.chigh += (this.clow >> 16);
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this.clow &= 0xFFFF;
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}
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},
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readBit: function ArithmeticDecoder_readBit(contexts, pos) {
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// contexts are packed into 1 byte:
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// highest 7 bits carry cx.index, lowest bit carries cx.mps
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var cx_index = contexts[pos] >> 1, cx_mps = contexts[pos] & 1;
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var qeTableIcx = QeTable[cx_index];
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var qeIcx = qeTableIcx.qe;
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var nmpsIcx = qeTableIcx.nmps;
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var nlpsIcx = qeTableIcx.nlps;
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var switchIcx = qeTableIcx.switchFlag;
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var d;
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this.a -= qeIcx;
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if (this.chigh < qeIcx) {
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// exchangeLps
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if (this.a < qeIcx) {
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this.a = qeIcx;
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d = cx_mps;
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cx_index = nmpsIcx;
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} else {
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this.a = qeIcx;
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d = 1 - cx_mps;
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if (switchIcx) {
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cx_mps = d;
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}
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cx_index = nlpsIcx;
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}
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} else {
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this.chigh -= qeIcx;
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if ((this.a & 0x8000) !== 0) {
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return cx_mps;
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}
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// exchangeMps
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if (this.a < qeIcx) {
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d = 1 - cx_mps;
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if (switchIcx) {
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cx_mps = d;
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}
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cx_index = nlpsIcx;
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} else {
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d = cx_mps;
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cx_index = nmpsIcx;
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}
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}
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// renormD;
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do {
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if (this.ct === 0) {
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this.byteIn();
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}
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this.a <<= 1;
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this.chigh = ((this.chigh << 1) & 0xFFFF) | ((this.clow >> 15) & 1);
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this.clow = (this.clow << 1) & 0xFFFF;
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this.ct--;
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} while ((this.a & 0x8000) === 0);
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contexts[pos] = cx_index << 1 | cx_mps;
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return d;
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}
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};
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return ArithmeticDecoder;
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})();
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// Utility data structures
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function ContextCache() {}
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214
src/core/jpx.js
214
src/core/jpx.js
@ -14,7 +14,7 @@
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/* globals error, globalScope, warn */
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/* globals ArithmeticDecoder, error, globalScope, warn */
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'use strict';
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@ -1253,172 +1253,10 @@ var JpxImage = (function JpxImageClosure() {
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return InclusionTree;
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})();
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// Implements C.3. Arithmetic decoding procedures
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var ArithmeticDecoder = (function ArithmeticDecoderClosure() {
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var QeTable = [
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{qe: 0x5601, nmps: 1, nlps: 1, switchFlag: 1},
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{qe: 0x3401, nmps: 2, nlps: 6, switchFlag: 0},
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{qe: 0x1801, nmps: 3, nlps: 9, switchFlag: 0},
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{qe: 0x0AC1, nmps: 4, nlps: 12, switchFlag: 0},
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{qe: 0x0521, nmps: 5, nlps: 29, switchFlag: 0},
|
||||
{qe: 0x0221, nmps: 38, nlps: 33, switchFlag: 0},
|
||||
{qe: 0x5601, nmps: 7, nlps: 6, switchFlag: 1},
|
||||
{qe: 0x5401, nmps: 8, nlps: 14, switchFlag: 0},
|
||||
{qe: 0x4801, nmps: 9, nlps: 14, switchFlag: 0},
|
||||
{qe: 0x3801, nmps: 10, nlps: 14, switchFlag: 0},
|
||||
{qe: 0x3001, nmps: 11, nlps: 17, switchFlag: 0},
|
||||
{qe: 0x2401, nmps: 12, nlps: 18, switchFlag: 0},
|
||||
{qe: 0x1C01, nmps: 13, nlps: 20, switchFlag: 0},
|
||||
{qe: 0x1601, nmps: 29, nlps: 21, switchFlag: 0},
|
||||
{qe: 0x5601, nmps: 15, nlps: 14, switchFlag: 1},
|
||||
{qe: 0x5401, nmps: 16, nlps: 14, switchFlag: 0},
|
||||
{qe: 0x5101, nmps: 17, nlps: 15, switchFlag: 0},
|
||||
{qe: 0x4801, nmps: 18, nlps: 16, switchFlag: 0},
|
||||
{qe: 0x3801, nmps: 19, nlps: 17, switchFlag: 0},
|
||||
{qe: 0x3401, nmps: 20, nlps: 18, switchFlag: 0},
|
||||
{qe: 0x3001, nmps: 21, nlps: 19, switchFlag: 0},
|
||||
{qe: 0x2801, nmps: 22, nlps: 19, switchFlag: 0},
|
||||
{qe: 0x2401, nmps: 23, nlps: 20, switchFlag: 0},
|
||||
{qe: 0x2201, nmps: 24, nlps: 21, switchFlag: 0},
|
||||
{qe: 0x1C01, nmps: 25, nlps: 22, switchFlag: 0},
|
||||
{qe: 0x1801, nmps: 26, nlps: 23, switchFlag: 0},
|
||||
{qe: 0x1601, nmps: 27, nlps: 24, switchFlag: 0},
|
||||
{qe: 0x1401, nmps: 28, nlps: 25, switchFlag: 0},
|
||||
{qe: 0x1201, nmps: 29, nlps: 26, switchFlag: 0},
|
||||
{qe: 0x1101, nmps: 30, nlps: 27, switchFlag: 0},
|
||||
{qe: 0x0AC1, nmps: 31, nlps: 28, switchFlag: 0},
|
||||
{qe: 0x09C1, nmps: 32, nlps: 29, switchFlag: 0},
|
||||
{qe: 0x08A1, nmps: 33, nlps: 30, switchFlag: 0},
|
||||
{qe: 0x0521, nmps: 34, nlps: 31, switchFlag: 0},
|
||||
{qe: 0x0441, nmps: 35, nlps: 32, switchFlag: 0},
|
||||
{qe: 0x02A1, nmps: 36, nlps: 33, switchFlag: 0},
|
||||
{qe: 0x0221, nmps: 37, nlps: 34, switchFlag: 0},
|
||||
{qe: 0x0141, nmps: 38, nlps: 35, switchFlag: 0},
|
||||
{qe: 0x0111, nmps: 39, nlps: 36, switchFlag: 0},
|
||||
{qe: 0x0085, nmps: 40, nlps: 37, switchFlag: 0},
|
||||
{qe: 0x0049, nmps: 41, nlps: 38, switchFlag: 0},
|
||||
{qe: 0x0025, nmps: 42, nlps: 39, switchFlag: 0},
|
||||
{qe: 0x0015, nmps: 43, nlps: 40, switchFlag: 0},
|
||||
{qe: 0x0009, nmps: 44, nlps: 41, switchFlag: 0},
|
||||
{qe: 0x0005, nmps: 45, nlps: 42, switchFlag: 0},
|
||||
{qe: 0x0001, nmps: 45, nlps: 43, switchFlag: 0},
|
||||
{qe: 0x5601, nmps: 46, nlps: 46, switchFlag: 0}
|
||||
];
|
||||
|
||||
function ArithmeticDecoder(data, start, end) {
|
||||
this.data = data;
|
||||
this.bp = start;
|
||||
this.dataEnd = end;
|
||||
|
||||
this.chigh = data[start];
|
||||
this.clow = 0;
|
||||
|
||||
this.byteIn();
|
||||
|
||||
this.chigh = ((this.chigh << 7) & 0xFFFF) | ((this.clow >> 9) & 0x7F);
|
||||
this.clow = (this.clow << 7) & 0xFFFF;
|
||||
this.ct -= 7;
|
||||
this.a = 0x8000;
|
||||
}
|
||||
|
||||
ArithmeticDecoder.prototype = {
|
||||
byteIn: function ArithmeticDecoder_byteIn() {
|
||||
var data = this.data;
|
||||
var bp = this.bp;
|
||||
if (data[bp] == 0xFF) {
|
||||
var b1 = data[bp + 1];
|
||||
if (b1 > 0x8F) {
|
||||
this.clow += 0xFF00;
|
||||
this.ct = 8;
|
||||
} else {
|
||||
bp++;
|
||||
this.clow += (data[bp] << 9);
|
||||
this.ct = 7;
|
||||
this.bp = bp;
|
||||
}
|
||||
} else {
|
||||
bp++;
|
||||
this.clow += bp < this.dataEnd ? (data[bp] << 8) : 0xFF00;
|
||||
this.ct = 8;
|
||||
this.bp = bp;
|
||||
}
|
||||
if (this.clow > 0xFFFF) {
|
||||
this.chigh += (this.clow >> 16);
|
||||
this.clow &= 0xFFFF;
|
||||
}
|
||||
},
|
||||
readBit: function ArithmeticDecoder_readBit(cx) {
|
||||
var qeIcx = QeTable[cx.index].qe;
|
||||
this.a -= qeIcx;
|
||||
|
||||
if (this.chigh < qeIcx) {
|
||||
var d = this.exchangeLps(cx);
|
||||
this.renormD();
|
||||
return d;
|
||||
} else {
|
||||
this.chigh -= qeIcx;
|
||||
if ((this.a & 0x8000) === 0) {
|
||||
var d = this.exchangeMps(cx);
|
||||
this.renormD();
|
||||
return d;
|
||||
} else {
|
||||
return cx.mps;
|
||||
}
|
||||
}
|
||||
},
|
||||
renormD: function ArithmeticDecoder_renormD() {
|
||||
do {
|
||||
if (this.ct === 0) {
|
||||
this.byteIn();
|
||||
}
|
||||
|
||||
this.a <<= 1;
|
||||
this.chigh = ((this.chigh << 1) & 0xFFFF) | ((this.clow >> 15) & 1);
|
||||
this.clow = (this.clow << 1) & 0xFFFF;
|
||||
this.ct--;
|
||||
} while ((this.a & 0x8000) === 0);
|
||||
},
|
||||
exchangeMps: function ArithmeticDecoder_exchangeMps(cx) {
|
||||
var d;
|
||||
var qeTableIcx = QeTable[cx.index];
|
||||
if (this.a < qeTableIcx.qe) {
|
||||
d = 1 - cx.mps;
|
||||
|
||||
if (qeTableIcx.switchFlag == 1) {
|
||||
cx.mps = 1 - cx.mps;
|
||||
}
|
||||
cx.index = qeTableIcx.nlps;
|
||||
} else {
|
||||
d = cx.mps;
|
||||
cx.index = qeTableIcx.nmps;
|
||||
}
|
||||
return d;
|
||||
},
|
||||
exchangeLps: function ArithmeticDecoder_exchangeLps(cx) {
|
||||
var d;
|
||||
var qeTableIcx = QeTable[cx.index];
|
||||
if (this.a < qeTableIcx.qe) {
|
||||
this.a = qeTableIcx.qe;
|
||||
d = cx.mps;
|
||||
cx.index = qeTableIcx.nmps;
|
||||
} else {
|
||||
this.a = qeTableIcx.qe;
|
||||
d = 1 - cx.mps;
|
||||
|
||||
if (qeTableIcx.switchFlag == 1) {
|
||||
cx.mps = 1 - cx.mps;
|
||||
}
|
||||
cx.index = qeTableIcx.nlps;
|
||||
}
|
||||
return d;
|
||||
}
|
||||
};
|
||||
|
||||
return ArithmeticDecoder;
|
||||
})();
|
||||
|
||||
// Section D. Coefficient bit modeling
|
||||
var BitModel = (function BitModelClosure() {
|
||||
var UNIFORM_CONTEXT = 17;
|
||||
var RUNLENGTH_CONTEXT = 18;
|
||||
// Table D-1
|
||||
// The index is binary presentation: 0dddvvhh, ddd - sum of Di (0..4),
|
||||
// vv - sum of Vi (0..2), and hh - sum of Hi (0..2)
|
||||
@ -1493,13 +1331,15 @@ var JpxImage = (function JpxImageClosure() {
|
||||
this.decoder = decoder;
|
||||
},
|
||||
reset: function BitModel_reset() {
|
||||
this.uniformContext = {index: 46, mps: 0};
|
||||
this.runLengthContext = {index: 3, mps: 0};
|
||||
this.contexts = [];
|
||||
this.contexts.push({index: 4, mps: 0});
|
||||
for (var i = 1; i <= 16; i++) {
|
||||
this.contexts.push({index: 0, mps: 0});
|
||||
}
|
||||
// We have 17 contexts that are accessed via context labels,
|
||||
// plus the uniform and runlength context.
|
||||
this.contexts = new Int8Array(19);
|
||||
|
||||
// Contexts are packed into 1 byte:
|
||||
// highest 7 bits carry the index, lowest bit carries mps
|
||||
this.contexts[0] = (4 << 1) | 0;
|
||||
this.contexts[UNIFORM_CONTEXT] = (46 << 1) | 0;
|
||||
this.contexts[RUNLENGTH_CONTEXT] = (3 << 1) | 0;
|
||||
},
|
||||
setNeighborsSignificance:
|
||||
function BitModel_setNeighborsSignificance(row, column) {
|
||||
@ -1567,8 +1407,7 @@ var JpxImage = (function JpxImageClosure() {
|
||||
}
|
||||
|
||||
var contextLabel = labels[neighborsSignificance[index]];
|
||||
var cx = contexts[contextLabel];
|
||||
var decision = decoder.readBit(cx);
|
||||
var decision = decoder.readBit(contexts, contextLabel);
|
||||
if (decision) {
|
||||
var sign = this.decodeSignBit(i, j);
|
||||
coefficentsSign[index] = sign;
|
||||
@ -1601,8 +1440,7 @@ var JpxImage = (function JpxImageClosure() {
|
||||
var contextLabelAndXor = SignContextLabels[
|
||||
3 * (1 - horizontalContribution) + (1 - verticalContribution)];
|
||||
var contextLabel = contextLabelAndXor.contextLabel;
|
||||
var cx = this.contexts[contextLabel];
|
||||
var decoded = this.decoder.readBit(cx);
|
||||
var decoded = this.decoder.readBit(this.contexts, contextLabel);
|
||||
return decoded ^ contextLabelAndXor.xorBit;
|
||||
},
|
||||
runMagnitudeRefinementPass:
|
||||
@ -1641,8 +1479,7 @@ var JpxImage = (function JpxImageClosure() {
|
||||
contextLabel = sumOfSignificance >= 1 ? 15 : 14;
|
||||
}
|
||||
|
||||
var cx = contexts[contextLabel];
|
||||
var bit = decoder.readBit(cx);
|
||||
var bit = decoder.readBit(contexts, contextLabel);
|
||||
coefficentsMagnitude[index] =
|
||||
(coefficentsMagnitude[index] << 1) | bit;
|
||||
bitsDecoded[index]++;
|
||||
@ -1682,10 +1519,10 @@ var JpxImage = (function JpxImageClosure() {
|
||||
neighborsSignificance[index0 + twoRowsDown] === 0 &&
|
||||
neighborsSignificance[index0 + threeRowsDown] === 0);
|
||||
var i1 = 0, index = index0;
|
||||
var cx, i;
|
||||
var i;
|
||||
if (allEmpty) {
|
||||
cx = this.runLengthContext;
|
||||
var hasSignificantCoefficent = decoder.readBit(cx);
|
||||
var hasSignificantCoefficent =
|
||||
decoder.readBit(contexts, RUNLENGTH_CONTEXT);
|
||||
if (!hasSignificantCoefficent) {
|
||||
bitsDecoded[index0]++;
|
||||
bitsDecoded[index0 + oneRowDown]++;
|
||||
@ -1693,8 +1530,8 @@ var JpxImage = (function JpxImageClosure() {
|
||||
bitsDecoded[index0 + threeRowsDown]++;
|
||||
continue; // next column
|
||||
}
|
||||
cx = this.uniformContext;
|
||||
i1 = (decoder.readBit(cx) << 1) | decoder.readBit(cx);
|
||||
i1 = (decoder.readBit(contexts, UNIFORM_CONTEXT) << 1) |
|
||||
decoder.readBit(contexts, UNIFORM_CONTEXT);
|
||||
i = i0 + i1;
|
||||
index += i1 * width;
|
||||
|
||||
@ -1723,8 +1560,7 @@ var JpxImage = (function JpxImageClosure() {
|
||||
}
|
||||
|
||||
var contextLabel = labels[neighborsSignificance[index]];
|
||||
cx = contexts[contextLabel];
|
||||
var decision = decoder.readBit(cx);
|
||||
var decision = decoder.readBit(contexts, contextLabel);
|
||||
if (decision == 1) {
|
||||
var sign = this.decodeSignBit(i, j);
|
||||
coefficentsSign[index] = sign;
|
||||
@ -1739,9 +1575,11 @@ var JpxImage = (function JpxImageClosure() {
|
||||
},
|
||||
checkSegmentationSymbol: function BitModel_checkSegmentationSymbol() {
|
||||
var decoder = this.decoder;
|
||||
var cx = this.uniformContext;
|
||||
var symbol = (decoder.readBit(cx) << 3) | (decoder.readBit(cx) << 2) |
|
||||
(decoder.readBit(cx) << 1) | decoder.readBit(cx);
|
||||
var contexts = this.contexts;
|
||||
var symbol = (decoder.readBit(contexts, UNIFORM_CONTEXT) << 3) |
|
||||
(decoder.readBit(contexts, UNIFORM_CONTEXT) << 2) |
|
||||
(decoder.readBit(contexts, UNIFORM_CONTEXT) << 1) |
|
||||
decoder.readBit(contexts, UNIFORM_CONTEXT);
|
||||
if (symbol != 0xA) {
|
||||
throw 'Invalid segmentation symbol';
|
||||
}
|
||||
|
||||
@ -48,6 +48,7 @@ var otherFiles = [
|
||||
'core/ps_parser.js',
|
||||
'core/stream.js',
|
||||
'core/worker.js',
|
||||
'core/arithmetic_decoder.js',
|
||||
'core/jpx.js',
|
||||
'core/jbig2.js',
|
||||
'core/bidi.js',
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user