@syncfusion/ej2-pdf/src/pdf/core/compression/jpeg-stream.js

Feature-rich JavaScript PDF library with built-in support for loading and manipulating PDF document.

var __extends = (this && this.__extends) || (function () {
    var extendStatics = function (d, b) {
        extendStatics = Object.setPrototypeOf ||
            ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
            function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
        return extendStatics(d, b);
    };
    return function (d, b) {
        extendStatics(d, b);
        function __() { this.constructor = d; }
        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
    };
})();
import { _PdfDecodeStream } from '../decode-stream';
/**
 * Provides a JPEG stream wrapper that reads JPEG bytes from the underlying base stream.
 *
 * @private
 */
var _PdfJpegStream = /** @class */ (function (_super) {
    __extends(_PdfJpegStream, _super);
    function _PdfJpegStream(stream, maybeLength, params) {
        var _this = _super.call(this, maybeLength) || this;
        /**
         * Byte offset at which the JPEG stream data begins.
         *
         * @private
         */
        _this._jpegStreamStart = 0;
        /**
         * Indicates whether the stream requires reprocessing due to parameters.
         *
         * @private
         */
        _this._needsReprocessing = false;
        _this.stream = stream;
        _this.params = params;
        _this.maybeLength = maybeLength;
        return _this;
    }
    _PdfJpegStream.prototype.readBlock = function () {
        this.decodeImage();
    };
    _PdfJpegStream.prototype.decodeImage = function (bytes) {
        if (this.eof) {
            return this.buffer;
        }
        bytes = this.skipUselessBytes(bytes || this.stream.getBytes(this.maybeLength));
        this.buffer = bytes;
        this.bufferLength = bytes.length;
        this.eof = true;
        return this.buffer;
    };
    _PdfJpegStream.prototype.skipUselessBytes = function (data) {
        for (var i = 0, ii = data.length - 1; i < ii; i++) {
            if (data[i] === 0xff && data[i + 1] === 0xd8) {
                if (i > 0) {
                    data = data.subarray(i);
                }
                break;
            }
        }
        return data;
    };
    return _PdfJpegStream;
}(_PdfDecodeStream));
export { _PdfJpegStream };