"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.mapAudioObjectTypeToCodecString = exports.parseAacCodecPrivate = exports.createAacCodecPrivate = exports.getSampleRateFromSampleFrequencyIndex = void 0;
const getSampleRateFromSampleFrequencyIndex = (samplingFrequencyIndex) => {
    switch (samplingFrequencyIndex) {
        case 0:
            return 96000;
        case 1:
            return 88200;
        case 2:
            return 64000;
        case 3:
            return 48000;
        case 4:
            return 44100;
        case 5:
            return 32000;
        case 6:
            return 24000;
        case 7:
            return 22050;
        case 8:
            return 16000;
        case 9:
            return 12000;
        case 10:
            return 11025;
        case 11:
            return 8000;
        case 12:
            return 7350;
        default:
            throw new Error(`Unexpected sampling frequency index ${samplingFrequencyIndex}`);
    }
};
exports.getSampleRateFromSampleFrequencyIndex = getSampleRateFromSampleFrequencyIndex;
// codec private, for example [17, 144]
// audioObjectType = 2 = 'AAC LC'
// samplingFrequencyIndex = 3 = '48000 Hz'
// channelConfiguration = 2 = '2 channels'
/**
 * bytes 17,144: 00010 001 | 1 0010 000
                 ^^^^^ ^^^   ^ ^^^^ ^
                 |     |       |    | padding
                 |     |       |
                 |     |       +-- channelConfiguration (2)
                 |     +-- samplingFrequencyIndex (3)
                 +-- audioConfigType (2)
  */
// https://wiki.multimedia.cx/index.php/MPEG-4_Audio#Channel_Configurations
const getConfigForSampleRate = (sampleRate) => {
    if (sampleRate === 96000) {
        return 0;
    }
    if (sampleRate === 88200) {
        return 1;
    }
    if (sampleRate === 64000) {
        return 2;
    }
    if (sampleRate === 48000) {
        return 3;
    }
    if (sampleRate === 44100) {
        return 4;
    }
    if (sampleRate === 32000) {
        return 5;
    }
    if (sampleRate === 24000) {
        return 6;
    }
    if (sampleRate === 22050) {
        return 7;
    }
    if (sampleRate === 16000) {
        return 8;
    }
    if (sampleRate === 12000) {
        return 9;
    }
    if (sampleRate === 11025) {
        return 10;
    }
    if (sampleRate === 8000) {
        return 11;
    }
    if (sampleRate === 7350) {
        return 12;
    }
    throw new Error(`Unexpected sample rate ${sampleRate}`);
};
const createAacCodecPrivate = ({ audioObjectType, sampleRate, channelConfiguration, codecPrivate, }) => {
    if (codecPrivate !== null && codecPrivate.length > 2) {
        // Video submitted
        // submitted by Yossi Elkrief
        // TOOD: Check if we are now parsing correctly
        return codecPrivate;
    }
    const bits = `${audioObjectType.toString(2).padStart(5, '0')}${getConfigForSampleRate(sampleRate).toString(2).padStart(4, '0')}${channelConfiguration.toString(2).padStart(4, '0')}000`;
    if (bits.length !== 16) {
        throw new Error('Invalid AAC codec private ' + bits.length);
    }
    if (channelConfiguration === 0 || channelConfiguration > 7) {
        throw new Error('Invalid channel configuration ' + channelConfiguration);
    }
    const firstByte = parseInt(bits.slice(0, 8), 2);
    const secondByte = parseInt(bits.slice(8, 16), 2);
    return new Uint8Array([firstByte, secondByte]);
};
exports.createAacCodecPrivate = createAacCodecPrivate;
const parseAacCodecPrivate = (bytes) => {
    if (bytes.length < 2) {
        throw new Error('Invalid AAC codec private length');
    }
    const bits = [...bytes].map((b) => b.toString(2).padStart(8, '0')).join('');
    let offset = 0;
    const audioObjectType = parseInt(bits.slice(offset, offset + 5), 2);
    offset += 5;
    const samplingFrequencyIndex = parseInt(bits.slice(offset, offset + 4), 2);
    offset += 4;
    if (samplingFrequencyIndex === 0xf) {
        offset += 24;
    }
    const channelConfiguration = parseInt(bits.slice(offset, offset + 4), 2);
    offset += 4;
    if (audioObjectType === 5) {
        const extensionSamplingFrequencyIndex = parseInt(bits.slice(offset, offset + 4), 2);
        offset += 4;
        const newAudioObjectType = parseInt(bits.slice(offset, offset + 5), 2);
        offset += 5;
        return {
            audioObjectType: newAudioObjectType,
            sampleRate: (0, exports.getSampleRateFromSampleFrequencyIndex)(extensionSamplingFrequencyIndex),
            channelConfiguration,
        };
    }
    const sampleRate = (0, exports.getSampleRateFromSampleFrequencyIndex)(samplingFrequencyIndex);
    return {
        audioObjectType,
        sampleRate,
        channelConfiguration,
    };
};
exports.parseAacCodecPrivate = parseAacCodecPrivate;
const mapAudioObjectTypeToCodecString = (audioObjectType) => {
    /**
 * 	1.	1 - mp4a.40.2: MPEG-4 AAC LC (Low Complexity)
    2.	2 - mp4a.40.5: MPEG-4 AAC HE (High Efficiency)
    3.	3 - mp4a.40.29: MPEG-4 AAC HEv2 (High Efficiency v2)
    4.	4 - mp4a.40.1: MPEG-4 AAC Main
    5.	5 - mp4a.40.3: MPEG-4 AAC SSR (Scalable Sample Rate)
    6.	6 - mp4a.40.4: MPEG-4 AAC LTP (Long Term Prediction)
    7.	17 - mp4a.40.17: MPEG-4 AAC LD (Low Delay)
    8.	23 - mp4a.40.23: MPEG-4 AAC ELD (Enhanced Low Delay)
 */
    switch (audioObjectType) {
        case 1:
            return 'mp4a.40.2';
        case 2:
            return 'mp4a.40.5';
        case 3:
            return 'mp4a.40.29';
        case 4:
            return 'mp4a.40.1';
        case 5:
            return 'mp4a.40.3';
        case 6:
            return 'mp4a.40.4';
        case 17:
            return 'mp4a.40.17';
        case 23:
            return 'mp4a.40.23';
        default:
            throw new Error(`Unexpected audio object type ${audioObjectType}`);
    }
};
exports.mapAudioObjectTypeToCodecString = mapAudioObjectTypeToCodecString;