93 lines
2.8 KiB
JavaScript
93 lines
2.8 KiB
JavaScript
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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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import { DecodeStream } from './stream';
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import { JpxImage } from './jpx';
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import { shadow } from '../shared/util';
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/**
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* For JPEG 2000's we use a library to decode these images and
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* the stream behaves like all the other DecodeStreams.
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*/
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var JpxStream = (function JpxStreamClosure() {
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function JpxStream(stream, maybeLength, dict, params) {
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this.stream = stream;
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this.maybeLength = maybeLength;
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this.dict = dict;
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this.params = params;
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DecodeStream.call(this, maybeLength);
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}
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JpxStream.prototype = Object.create(DecodeStream.prototype);
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Object.defineProperty(JpxStream.prototype, 'bytes', {
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get: function JpxStream_bytes() {
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// If this.maybeLength is null, we'll get the entire stream.
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return shadow(this, 'bytes', this.stream.getBytes(this.maybeLength));
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},
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configurable: true,
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});
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JpxStream.prototype.ensureBuffer = function JpxStream_ensureBuffer(req) {
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if (this.bufferLength) {
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return;
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}
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var jpxImage = new JpxImage();
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jpxImage.parse(this.bytes);
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var width = jpxImage.width;
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var height = jpxImage.height;
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var componentsCount = jpxImage.componentsCount;
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var tileCount = jpxImage.tiles.length;
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if (tileCount === 1) {
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this.buffer = jpxImage.tiles[0].items;
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} else {
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var data = new Uint8ClampedArray(width * height * componentsCount);
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for (var k = 0; k < tileCount; k++) {
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var tileComponents = jpxImage.tiles[k];
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var tileWidth = tileComponents.width;
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var tileHeight = tileComponents.height;
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var tileLeft = tileComponents.left;
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var tileTop = tileComponents.top;
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var src = tileComponents.items;
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var srcPosition = 0;
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var dataPosition = (width * tileTop + tileLeft) * componentsCount;
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var imgRowSize = width * componentsCount;
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var tileRowSize = tileWidth * componentsCount;
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for (var j = 0; j < tileHeight; j++) {
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var rowBytes = src.subarray(srcPosition, srcPosition + tileRowSize);
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data.set(rowBytes, dataPosition);
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srcPosition += tileRowSize;
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dataPosition += imgRowSize;
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}
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}
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this.buffer = data;
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}
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this.bufferLength = this.buffer.length;
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this.eof = true;
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};
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return JpxStream;
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})();
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export {
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JpxStream,
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};
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