mdx-m3-viewer/dist/cjs/parsers/mpq/adpcm.js

A browser WebGL model viewer. Mainly focused on models of the games Warcraft 3 and Starcraft 2.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const binarystream_1 = require("../../common/binarystream");
const MAX_ADPCM_CHANNEL_COUNT = 2;
const INITIAL_ADPCM_STEP_INDEX = 0x2C;
const NextStepTable = new Int32Array([
    -1, 0, -1, 4, -1, 2, -1, 6,
    -1, 1, -1, 5, -1, 3, -1, 7,
    -1, 1, -1, 5, -1, 3, -1, 7,
    -1, 2, -1, 4, -1, 6, -1, 8,
]);
const StepSizeTable = new Int32Array([
    7, 8, 9, 10, 11, 12, 13, 14,
    16, 17, 19, 21, 23, 25, 28, 31,
    34, 37, 41, 45, 50, 55, 60, 66,
    73, 80, 88, 97, 107, 118, 130, 143,
    157, 173, 190, 209, 230, 253, 279, 307,
    337, 371, 408, 449, 494, 544, 598, 658,
    724, 796, 876, 963, 1060, 1166, 1282, 1411,
    1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024,
    3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484,
    7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899,
    15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794,
    32767,
]);
function GetNextStepIndex(StepIndex, EncodedSample) {
    StepIndex = StepIndex + NextStepTable[EncodedSample & 0x1F];
    if (StepIndex < 0) {
        StepIndex = 0;
    }
    else if (StepIndex > 88) {
        StepIndex = 88;
    }
    return StepIndex;
}
function UpdatePredictedSample(PredictedSample, EncodedSample, Difference) {
    if (EncodedSample & 0x40) {
        PredictedSample -= Difference;
        if (PredictedSample <= -32768) {
            PredictedSample = -32768;
        }
    }
    else {
        PredictedSample += Difference;
        if (PredictedSample >= 32767) {
            PredictedSample = 32767;
        }
    }
    return PredictedSample;
}
function DecodeSample(PredictedSample, EncodedSample, StepSize, Difference) {
    if (EncodedSample & 0x01) {
        Difference += (StepSize >> 0);
    }
    if (EncodedSample & 0x02) {
        Difference += (StepSize >> 1);
    }
    if (EncodedSample & 0x04) {
        Difference += (StepSize >> 2);
    }
    if (EncodedSample & 0x08) {
        Difference += (StepSize >> 3);
    }
    if (EncodedSample & 0x10) {
        Difference += (StepSize >> 4);
    }
    if (EncodedSample & 0x20) {
        Difference += (StepSize >> 5);
    }
    return UpdatePredictedSample(PredictedSample, EncodedSample, Difference);
}
function DecompressADPCM(pvInBuffer, ChannelCount) {
    const is = new binarystream_1.default(pvInBuffer);
    const os = [];
    let EncodedSample;
    const PredictedSamples = new Uint16Array(MAX_ADPCM_CHANNEL_COUNT);
    const StepIndexes = new Uint16Array([INITIAL_ADPCM_STEP_INDEX, INITIAL_ADPCM_STEP_INDEX]);
    let ChannelIndex;
    is.readUint8();
    const BitShift = is.readUint8();
    for (let i = 0; i < ChannelCount; i++) {
        const InitialSample = is.readUint16();
        PredictedSamples[i] = InitialSample;
        os.push(InitialSample);
    }
    ChannelIndex = ChannelCount - 1;
    while (is.remaining) {
        EncodedSample = is.readUint8();
        ChannelIndex = (ChannelIndex + 1) % ChannelCount;
        if (EncodedSample == 0x80) {
            if (StepIndexes[ChannelIndex] != 0) {
                StepIndexes[ChannelIndex]--;
            }
            os.push(PredictedSamples[ChannelIndex]);
        }
        else if (EncodedSample == 0x81) {
            StepIndexes[ChannelIndex] += 8;
            if (StepIndexes[ChannelIndex] > 0x58) {
                StepIndexes[ChannelIndex] = 0x58;
            }
            ChannelIndex = (ChannelIndex + 1) % ChannelCount;
        }
        else {
            const StepIndex = StepIndexes[ChannelIndex];
            const StepSize = StepSizeTable[StepIndex];
            PredictedSamples[ChannelIndex] = DecodeSample(PredictedSamples[ChannelIndex], EncodedSample, StepSize, StepSize >> BitShift);
            os.push(PredictedSamples[ChannelIndex]);
            StepIndexes[ChannelIndex] = GetNextStepIndex(StepIndex, EncodedSample);
        }
    }
    return new Uint8Array(new Uint16Array(os).buffer);
}
exports.default = DecompressADPCM;
//# sourceMappingURL=adpcm.js.map