ccitt_stream.js 2.0 KB

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  1. /**
  2. * @licstart The following is the entire license notice for the
  3. * Javascript code in this page
  4. *
  5. * Copyright 2022 Mozilla Foundation
  6. *
  7. * Licensed under the Apache License, Version 2.0 (the "License");
  8. * you may not use this file except in compliance with the License.
  9. * You may obtain a copy of the License at
  10. *
  11. * http://www.apache.org/licenses/LICENSE-2.0
  12. *
  13. * Unless required by applicable law or agreed to in writing, software
  14. * distributed under the License is distributed on an "AS IS" BASIS,
  15. * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16. * See the License for the specific language governing permissions and
  17. * limitations under the License.
  18. *
  19. * @licend The above is the entire license notice for the
  20. * Javascript code in this page
  21. */
  22. "use strict";
  23. Object.defineProperty(exports, "__esModule", {
  24. value: true
  25. });
  26. exports.CCITTFaxStream = void 0;
  27. var _ccitt = require("./ccitt.js");
  28. var _decode_stream = require("./decode_stream.js");
  29. var _primitives = require("./primitives.js");
  30. class CCITTFaxStream extends _decode_stream.DecodeStream {
  31. constructor(str, maybeLength, params) {
  32. super(maybeLength);
  33. this.str = str;
  34. this.dict = str.dict;
  35. if (!(params instanceof _primitives.Dict)) {
  36. params = _primitives.Dict.empty;
  37. }
  38. const source = {
  39. next() {
  40. return str.getByte();
  41. }
  42. };
  43. this.ccittFaxDecoder = new _ccitt.CCITTFaxDecoder(source, {
  44. K: params.get("K"),
  45. EndOfLine: params.get("EndOfLine"),
  46. EncodedByteAlign: params.get("EncodedByteAlign"),
  47. Columns: params.get("Columns"),
  48. Rows: params.get("Rows"),
  49. EndOfBlock: params.get("EndOfBlock"),
  50. BlackIs1: params.get("BlackIs1")
  51. });
  52. }
  53. readBlock() {
  54. while (!this.eof) {
  55. const c = this.ccittFaxDecoder.readNextChar();
  56. if (c === -1) {
  57. this.eof = true;
  58. return;
  59. }
  60. this.ensureBuffer(this.bufferLength + 1);
  61. this.buffer[this.bufferLength++] = c;
  62. }
  63. }
  64. }
  65. exports.CCITTFaxStream = CCITTFaxStream;