38 lines
1.5 KiB
JavaScript
38 lines
1.5 KiB
JavaScript
import { inflate } from 'pako';
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// @ts-expect-error
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import Lerc from 'lerc';
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import { ZSTDDecoder } from 'zstddec';
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import BaseDecoder from './basedecoder.js';
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import { LercParameters, LercAddCompression } from '../globals.js';
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/**
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* @typedef {import('./basedecoder.js').BaseDecoderParameters & { LercParameters?: any }} LercDecoderParameters
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*/
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export const zstd = new ZSTDDecoder();
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export default class LercDecoder extends BaseDecoder {
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/**
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* @param {ArrayBufferLike} buffer
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* @returns {ArrayBufferLike}
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*/
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decodeBlock(buffer) {
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const params = /** @type {LercDecoderParameters} */ (this.parameters);
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const addCompression = params.LercParameters?.[LercParameters.AddCompression];
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/** @type {ArrayBufferLike} */
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let decoded = buffer;
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switch (addCompression) {
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case LercAddCompression.None:
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break;
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case LercAddCompression.Deflate:
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decoded = inflate(new Uint8Array(decoded)).buffer;
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break;
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case LercAddCompression.Zstandard:
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decoded = zstd.decode(new Uint8Array(decoded)).buffer;
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break;
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default:
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throw new Error(`Unsupported LERC additional compression method identifier: ${addCompression}`);
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}
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const lercResult = Lerc.decode(decoded, { returnPixelInterleavedDims: this.parameters.planarConfiguration === 1 });
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const lercData = lercResult.pixels[0];
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return lercData.buffer;
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}
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}
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//# sourceMappingURL=lerc.js.map
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