From 7b5b5178efec7068d5c926e2c0057e2a59a670e2 Mon Sep 17 00:00:00 2001
From: fkaelberer <o_0_o@gmx.de>
Date: Mon, 10 Mar 2014 16:56:00 +0100
Subject: [PATCH] Extract duplicate arithmetic decoder to own class
---
make.js | 1 +
src/core/arithmetic_decoder.js | 175 +++++++++++++++++++++++++++
src/core/jbig2.js | 158 +-----------------------
src/core/jpx.js | 214 ++++-----------------------------
src/worker_loader.js | 1 +
5 files changed, 204 insertions(+), 345 deletions(-)
create mode 100644 src/core/arithmetic_decoder.js
diff --git a/make.js b/make.js
index 4d680a523..8a1a0487e 100644
--- a/make.js
+++ b/make.js
@@ -309,6 +309,7 @@ target.bundle = function(args) {
'core/ps_parser.js',
'core/stream.js',
'core/worker.js',
+ 'core/arithmetic_decoder.js',
'core/jpx.js',
'core/jbig2.js',
'core/bidi.js',
diff --git a/src/core/arithmetic_decoder.js b/src/core/arithmetic_decoder.js
new file mode 100644
index 000000000..e47547d84
--- /dev/null
+++ b/src/core/arithmetic_decoder.js
@@ -0,0 +1,175 @@
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
+/* Copyright 2012 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+'use strict';
+
+// Annex E. Arithmetic Coding
+var ArithmeticDecoder = (function ArithmeticDecoderClosure() {
+ var QeTable = [
+ {qe: 0x5601, nmps: 1, nlps: 1, switchFlag: 1},
+ {qe: 0x3401, nmps: 2, nlps: 6, switchFlag: 0},
+ {qe: 0x1801, nmps: 3, nlps: 9, switchFlag: 0},
+ {qe: 0x0AC1, nmps: 4, nlps: 12, switchFlag: 0},
+ {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(contexts, pos) {
+ // contexts are packed into 1 byte:
+ // highest 7 bits carry cx.index, lowest bit carries cx.mps
+ var cx_index = contexts[pos] >> 1, cx_mps = contexts[pos] & 1;
+ var qeTableIcx = QeTable[cx_index];
+ var qeIcx = qeTableIcx.qe;
+ var nmpsIcx = qeTableIcx.nmps;
+ var nlpsIcx = qeTableIcx.nlps;
+ var switchIcx = qeTableIcx.switchFlag;
+ var d;
+ this.a -= qeIcx;
+
+ if (this.chigh < qeIcx) {
+ // exchangeLps
+ if (this.a < qeIcx) {
+ this.a = qeIcx;
+ d = cx_mps;
+ cx_index = nmpsIcx;
+ } else {
+ this.a = qeIcx;
+ d = 1 - cx_mps;
+ if (switchIcx) {
+ cx_mps = d;
+ }
+ cx_index = nlpsIcx;
+ }
+ } else {
+ this.chigh -= qeIcx;
+ if ((this.a & 0x8000) !== 0) {
+ return cx_mps;
+ }
+ // exchangeMps
+ if (this.a < qeIcx) {
+ d = 1 - cx_mps;
+ if (switchIcx) {
+ cx_mps = d;
+ }
+ cx_index = nlpsIcx;
+ } else {
+ d = cx_mps;
+ cx_index = nmpsIcx;
+ }
+ }
+ // 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);
+
+ contexts[pos] = cx_index << 1 | cx_mps;
+ return d;
+ }
+ };
+
+ return ArithmeticDecoder;
+})();
diff --git a/src/core/jbig2.js b/src/core/jbig2.js
index c4d9d74e3..22d8c91a1 100755
--- a/src/core/jbig2.js
+++ b/src/core/jbig2.js
@@ -1,6 +1,5 @@
/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
-/* globals error, shadow */
/* Copyright 2012 Mozilla Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
@@ -15,166 +14,11 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
+/* globals ArithmeticDecoder, error, shadow */
'use strict';
var Jbig2Image = (function Jbig2ImageClosure() {
- // Annex E. Arithmetic Coding
- var ArithmeticDecoder = (function ArithmeticDecoderClosure() {
- var QeTable = [
- {qe: 0x5601, nmps: 1, nlps: 1, switchFlag: 1},
- {qe: 0x3401, nmps: 2, nlps: 6, switchFlag: 0},
- {qe: 0x1801, nmps: 3, nlps: 9, switchFlag: 0},
- {qe: 0x0AC1, nmps: 4, nlps: 12, switchFlag: 0},
- {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(contexts, pos) {
- // contexts are packed into 1 byte:
- // highest 7 bits carry cx.index, lowest bit carries cx.mps
- var cx_index = contexts[pos] >> 1, cx_mps = contexts[pos] & 1;
- var qeTableIcx = QeTable[cx_index];
- var qeIcx = qeTableIcx.qe;
- var nmpsIcx = qeTableIcx.nmps;
- var nlpsIcx = qeTableIcx.nlps;
- var switchIcx = qeTableIcx.switchFlag;
- var d;
- this.a -= qeIcx;
-
- if (this.chigh < qeIcx) {
- // exchangeLps
- if (this.a < qeIcx) {
- this.a = qeIcx;
- d = cx_mps;
- cx_index = nmpsIcx;
- } else {
- this.a = qeIcx;
- d = 1 - cx_mps;
- if (switchIcx) {
- cx_mps = d;
- }
- cx_index = nlpsIcx;
- }
- } else {
- this.chigh -= qeIcx;
- if ((this.a & 0x8000) !== 0) {
- return cx_mps;
- }
- // exchangeMps
- if (this.a < qeIcx) {
- d = 1 - cx_mps;
- if (switchIcx) {
- cx_mps = d;
- }
- cx_index = nlpsIcx;
- } else {
- d = cx_mps;
- cx_index = nmpsIcx;
- }
- }
- // 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);
-
- contexts[pos] = cx_index << 1 | cx_mps;
- return d;
- }
- };
-
- return ArithmeticDecoder;
- })();
-
// Utility data structures
function ContextCache() {}
diff --git a/src/core/jpx.js b/src/core/jpx.js
index 27f4e4076..55d40783d 100644
--- a/src/core/jpx.js
+++ b/src/core/jpx.js
@@ -14,7 +14,7 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
-/* globals error, globalScope, warn */
+/* globals ArithmeticDecoder, error, globalScope, warn */
'use strict';
@@ -1253,172 +1253,10 @@ var JpxImage = (function JpxImageClosure() {
return InclusionTree;
})();
- // Implements C.3. Arithmetic decoding procedures
- var ArithmeticDecoder = (function ArithmeticDecoderClosure() {
- var QeTable = [
- {qe: 0x5601, nmps: 1, nlps: 1, switchFlag: 1},
- {qe: 0x3401, nmps: 2, nlps: 6, switchFlag: 0},
- {qe: 0x1801, nmps: 3, nlps: 9, switchFlag: 0},
- {qe: 0x0AC1, nmps: 4, nlps: 12, switchFlag: 0},
- {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';
}
diff --git a/src/worker_loader.js b/src/worker_loader.js
index 1cdd1b93c..3333c3009 100644
--- a/src/worker_loader.js
+++ b/src/worker_loader.js
@@ -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',