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22 | "use strict";
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23 |
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24 | Object.defineProperty(exports, "__esModule", {
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25 | value: true
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26 | });
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27 | exports.JpegStream = void 0;
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28 |
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29 | var _decode_stream = require("./decode_stream.js");
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30 |
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31 | var _primitives = require("./primitives.js");
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32 |
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33 | var _jpg = require("./jpg.js");
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34 |
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35 | var _util = require("../shared/util.js");
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36 |
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37 | class JpegStream extends _decode_stream.DecodeStream {
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38 | constructor(stream, maybeLength, params) {
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39 | let ch;
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40 |
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41 | while ((ch = stream.getByte()) !== -1) {
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42 | if (ch === 0xff) {
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43 | stream.skip(-1);
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44 | break;
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45 | }
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46 | }
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47 |
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48 | super(maybeLength);
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49 | this.stream = stream;
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50 | this.dict = stream.dict;
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51 | this.maybeLength = maybeLength;
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52 | this.params = params;
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53 | }
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54 |
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55 | get bytes() {
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56 | return (0, _util.shadow)(this, "bytes", this.stream.getBytes(this.maybeLength));
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57 | }
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58 |
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59 | ensureBuffer(requested) {}
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60 |
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61 | readBlock() {
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62 | if (this.eof) {
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63 | return;
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64 | }
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65 |
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66 | const jpegOptions = {
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67 | decodeTransform: undefined,
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68 | colorTransform: undefined
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69 | };
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70 | const decodeArr = this.dict.getArray("D", "Decode");
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71 |
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72 | if (this.forceRGB && Array.isArray(decodeArr)) {
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73 | const bitsPerComponent = this.dict.get("BPC", "BitsPerComponent") || 8;
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74 | const decodeArrLength = decodeArr.length;
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75 | const transform = new Int32Array(decodeArrLength);
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76 | let transformNeeded = false;
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77 | const maxValue = (1 << bitsPerComponent) - 1;
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78 |
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79 | for (let i = 0; i < decodeArrLength; i += 2) {
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80 | transform[i] = (decodeArr[i + 1] - decodeArr[i]) * 256 | 0;
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81 | transform[i + 1] = decodeArr[i] * maxValue | 0;
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82 |
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83 | if (transform[i] !== 256 || transform[i + 1] !== 0) {
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84 | transformNeeded = true;
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85 | }
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86 | }
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87 |
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88 | if (transformNeeded) {
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89 | jpegOptions.decodeTransform = transform;
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90 | }
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91 | }
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92 |
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93 | if (this.params instanceof _primitives.Dict) {
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94 | const colorTransform = this.params.get("ColorTransform");
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95 |
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96 | if (Number.isInteger(colorTransform)) {
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97 | jpegOptions.colorTransform = colorTransform;
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98 | }
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99 | }
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100 |
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101 | const jpegImage = new _jpg.JpegImage(jpegOptions);
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102 | jpegImage.parse(this.bytes);
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103 | const data = jpegImage.getData({
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104 | width: this.drawWidth,
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105 | height: this.drawHeight,
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106 | forceRGB: this.forceRGB,
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107 | isSourcePDF: true
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108 | });
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109 | this.buffer = data;
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110 | this.bufferLength = data.length;
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111 | this.eof = true;
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112 | }
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113 |
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114 | }
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115 |
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116 | exports.JpegStream = JpegStream; |
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