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Filename : MpegParser.js
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"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.MpegParser = void 0;
const Token = require("token-types");
const core_1 = require("strtok3/lib/core");
const debug_1 = require("debug");
const common = require("../common/Util");
const AbstractID3Parser_1 = require("../id3v2/AbstractID3Parser");
const XingTag_1 = require("./XingTag");
const debug = (0, debug_1.default)('music-metadata:parser:mpeg');
/**
 * Cache buffer size used for searching synchronization preabmle
 */
const maxPeekLen = 1024;
/**
 * MPEG-4 Audio definitions
 * Ref:  https://wiki.multimedia.cx/index.php/MPEG-4_Audio
 */
const MPEG4 = {
    /**
     * Audio Object Types
     */
    AudioObjectTypes: [
        'AAC Main',
        'AAC LC',
        'AAC SSR',
        'AAC LTP' // Long Term Prediction
    ],
    /**
     * Sampling Frequencies
     * https://wiki.multimedia.cx/index.php/MPEG-4_Audio#Sampling_Frequencies
     */
    SamplingFrequencies: [
        96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000, 7350, undefined, undefined, -1
    ]
    /**
     * Channel Configurations
     */
};
const MPEG4_ChannelConfigurations = [
    undefined,
    ['front-center'],
    ['front-left', 'front-right'],
    ['front-center', 'front-left', 'front-right'],
    ['front-center', 'front-left', 'front-right', 'back-center'],
    ['front-center', 'front-left', 'front-right', 'back-left', 'back-right'],
    ['front-center', 'front-left', 'front-right', 'back-left', 'back-right', 'LFE-channel'],
    ['front-center', 'front-left', 'front-right', 'side-left', 'side-right', 'back-left', 'back-right', 'LFE-channel']
];
/**
 * MPEG Audio Layer I/II/III frame header
 * Ref: https://www.mp3-tech.org/programmer/frame_header.html
 * Bit layout: AAAAAAAA AAABBCCD EEEEFFGH IIJJKLMM
 * Ref: https://wiki.multimedia.cx/index.php/ADTS
 */
class MpegFrameHeader {
    constructor(buf, off) {
        // B(20,19): MPEG Audio versionIndex ID
        this.versionIndex = common.getBitAllignedNumber(buf, off + 1, 3, 2);
        // C(18,17): Layer description
        this.layer = MpegFrameHeader.LayerDescription[common.getBitAllignedNumber(buf, off + 1, 5, 2)];
        if (this.versionIndex > 1 && this.layer === 0) {
            this.parseAdtsHeader(buf, off); // Audio Data Transport Stream (ADTS)
        }
        else {
            this.parseMpegHeader(buf, off); // Conventional MPEG header
        }
        // D(16): Protection bit (if true 16-bit CRC follows header)
        this.isProtectedByCRC = !common.isBitSet(buf, off + 1, 7);
    }
    calcDuration(numFrames) {
        return numFrames * this.calcSamplesPerFrame() / this.samplingRate;
    }
    calcSamplesPerFrame() {
        return MpegFrameHeader.samplesInFrameTable[this.version === 1 ? 0 : 1][this.layer];
    }
    calculateSideInfoLength() {
        if (this.layer !== 3)
            return 2;
        if (this.channelModeIndex === 3) {
            // mono
            if (this.version === 1) {
                return 17;
            }
            else if (this.version === 2 || this.version === 2.5) {
                return 9;
            }
        }
        else {
            if (this.version === 1) {
                return 32;
            }
            else if (this.version === 2 || this.version === 2.5) {
                return 17;
            }
        }
    }
    calcSlotSize() {
        return [null, 4, 1, 1][this.layer];
    }
    parseMpegHeader(buf, off) {
        this.container = 'MPEG';
        // E(15,12): Bitrate index
        this.bitrateIndex = common.getBitAllignedNumber(buf, off + 2, 0, 4);
        // F(11,10): Sampling rate frequency index
        this.sampRateFreqIndex = common.getBitAllignedNumber(buf, off + 2, 4, 2);
        // G(9): Padding bit
        this.padding = common.isBitSet(buf, off + 2, 6);
        // H(8): Private bit
        this.privateBit = common.isBitSet(buf, off + 2, 7);
        // I(7,6): Channel Mode
        this.channelModeIndex = common.getBitAllignedNumber(buf, off + 3, 0, 2);
        // J(5,4): Mode extension (Only used in Joint stereo)
        this.modeExtension = common.getBitAllignedNumber(buf, off + 3, 2, 2);
        // K(3): Copyright
        this.isCopyrighted = common.isBitSet(buf, off + 3, 4);
        // L(2): Original
        this.isOriginalMedia = common.isBitSet(buf, off + 3, 5);
        // M(3): The original bit indicates, if it is set, that the frame is located on its original media.
        this.emphasis = common.getBitAllignedNumber(buf, off + 3, 7, 2);
        this.version = MpegFrameHeader.VersionID[this.versionIndex];
        this.channelMode = MpegFrameHeader.ChannelMode[this.channelModeIndex];
        this.codec = `MPEG ${this.version} Layer ${this.layer}`;
        // Calculate bitrate
        const bitrateInKbps = this.calcBitrate();
        if (!bitrateInKbps) {
            throw new Error('Cannot determine bit-rate');
        }
        this.bitrate = bitrateInKbps * 1000;
        // Calculate sampling rate
        this.samplingRate = this.calcSamplingRate();
        if (this.samplingRate == null) {
            throw new Error('Cannot determine sampling-rate');
        }
    }
    parseAdtsHeader(buf, off) {
        debug(`layer=0 => ADTS`);
        this.version = this.versionIndex === 2 ? 4 : 2;
        this.container = 'ADTS/MPEG-' + this.version;
        const profileIndex = common.getBitAllignedNumber(buf, off + 2, 0, 2);
        this.codec = 'AAC';
        this.codecProfile = MPEG4.AudioObjectTypes[profileIndex];
        debug(`MPEG-4 audio-codec=${this.codec}`);
        const samplingFrequencyIndex = common.getBitAllignedNumber(buf, off + 2, 2, 4);
        this.samplingRate = MPEG4.SamplingFrequencies[samplingFrequencyIndex];
        debug(`sampling-rate=${this.samplingRate}`);
        const channelIndex = common.getBitAllignedNumber(buf, off + 2, 7, 3);
        this.mp4ChannelConfig = MPEG4_ChannelConfigurations[channelIndex];
        debug(`channel-config=${this.mp4ChannelConfig.join('+')}`);
        this.frameLength = common.getBitAllignedNumber(buf, off + 3, 6, 2) << 11;
    }
    calcBitrate() {
        if (this.bitrateIndex === 0x00 || // free
            this.bitrateIndex === 0x0F) { // reserved
            return;
        }
        const codecIndex = `${Math.floor(this.version)}${this.layer}`;
        return MpegFrameHeader.bitrate_index[this.bitrateIndex][codecIndex];
    }
    calcSamplingRate() {
        if (this.sampRateFreqIndex === 0x03)
            return null; // 'reserved'
        return MpegFrameHeader.sampling_rate_freq_index[this.version][this.sampRateFreqIndex];
    }
}
MpegFrameHeader.SyncByte1 = 0xFF;
MpegFrameHeader.SyncByte2 = 0xE0;
MpegFrameHeader.VersionID = [2.5, null, 2, 1];
MpegFrameHeader.LayerDescription = [0, 3, 2, 1];
MpegFrameHeader.ChannelMode = ['stereo', 'joint_stereo', 'dual_channel', 'mono'];
MpegFrameHeader.bitrate_index = {
    0x01: { 11: 32, 12: 32, 13: 32, 21: 32, 22: 8, 23: 8 },
    0x02: { 11: 64, 12: 48, 13: 40, 21: 48, 22: 16, 23: 16 },
    0x03: { 11: 96, 12: 56, 13: 48, 21: 56, 22: 24, 23: 24 },
    0x04: { 11: 128, 12: 64, 13: 56, 21: 64, 22: 32, 23: 32 },
    0x05: { 11: 160, 12: 80, 13: 64, 21: 80, 22: 40, 23: 40 },
    0x06: { 11: 192, 12: 96, 13: 80, 21: 96, 22: 48, 23: 48 },
    0x07: { 11: 224, 12: 112, 13: 96, 21: 112, 22: 56, 23: 56 },
    0x08: { 11: 256, 12: 128, 13: 112, 21: 128, 22: 64, 23: 64 },
    0x09: { 11: 288, 12: 160, 13: 128, 21: 144, 22: 80, 23: 80 },
    0x0A: { 11: 320, 12: 192, 13: 160, 21: 160, 22: 96, 23: 96 },
    0x0B: { 11: 352, 12: 224, 13: 192, 21: 176, 22: 112, 23: 112 },
    0x0C: { 11: 384, 12: 256, 13: 224, 21: 192, 22: 128, 23: 128 },
    0x0D: { 11: 416, 12: 320, 13: 256, 21: 224, 22: 144, 23: 144 },
    0x0E: { 11: 448, 12: 384, 13: 320, 21: 256, 22: 160, 23: 160 }
};
MpegFrameHeader.sampling_rate_freq_index = {
    1: { 0x00: 44100, 0x01: 48000, 0x02: 32000 },
    2: { 0x00: 22050, 0x01: 24000, 0x02: 16000 },
    2.5: { 0x00: 11025, 0x01: 12000, 0x02: 8000 }
};
MpegFrameHeader.samplesInFrameTable = [
    /* Layer   I    II   III */
    [0, 384, 1152, 1152],
    [0, 384, 1152, 576] // MPEG-2(.5
];
/**
 * MPEG Audio Layer I/II/III
 */
const FrameHeader = {
    len: 4,
    get: (buf, off) => {
        return new MpegFrameHeader(buf, off);
    }
};
function getVbrCodecProfile(vbrScale) {
    return 'V' + Math.floor((100 - vbrScale) / 10);
}
class MpegParser extends AbstractID3Parser_1.AbstractID3Parser {
    constructor() {
        super(...arguments);
        this.frameCount = 0;
        this.syncFrameCount = -1;
        this.countSkipFrameData = 0;
        this.totalDataLength = 0;
        this.bitrates = [];
        this.calculateEofDuration = false;
        this.buf_frame_header = Buffer.alloc(4);
        this.syncPeek = {
            buf: Buffer.alloc(maxPeekLen),
            len: 0
        };
    }
    /**
     * Called after ID3 headers have been parsed
     */
    async postId3v2Parse() {
        this.metadata.setFormat('lossless', false);
        try {
            let quit = false;
            while (!quit) {
                await this.sync();
                quit = await this.parseCommonMpegHeader();
            }
        }
        catch (err) {
            if (err instanceof core_1.EndOfStreamError) {
                debug(`End-of-stream`);
                if (this.calculateEofDuration) {
                    const numberOfSamples = this.frameCount * this.samplesPerFrame;
                    this.metadata.setFormat('numberOfSamples', numberOfSamples);
                    const duration = numberOfSamples / this.metadata.format.sampleRate;
                    debug(`Calculate duration at EOF: ${duration} sec.`, duration);
                    this.metadata.setFormat('duration', duration);
                }
            }
            else {
                throw err;
            }
        }
    }
    /**
     * Called after file has been fully parsed, this allows, if present, to exclude the ID3v1.1 header length
     */
    finalize() {
        const format = this.metadata.format;
        const hasID3v1 = this.metadata.native.hasOwnProperty('ID3v1');
        if (format.duration && this.tokenizer.fileInfo.size) {
            const mpegSize = this.tokenizer.fileInfo.size - this.mpegOffset - (hasID3v1 ? 128 : 0);
            if (format.codecProfile && format.codecProfile[0] === 'V') {
                this.metadata.setFormat('bitrate', mpegSize * 8 / format.duration);
            }
        }
        else if (this.tokenizer.fileInfo.size && format.codecProfile === 'CBR') {
            const mpegSize = this.tokenizer.fileInfo.size - this.mpegOffset - (hasID3v1 ? 128 : 0);
            const numberOfSamples = Math.round(mpegSize / this.frame_size) * this.samplesPerFrame;
            this.metadata.setFormat('numberOfSamples', numberOfSamples);
            const duration = numberOfSamples / format.sampleRate;
            debug("Calculate CBR duration based on file size: %s", duration);
            this.metadata.setFormat('duration', duration);
        }
    }
    async sync() {
        let gotFirstSync = false;
        while (true) {
            let bo = 0;
            this.syncPeek.len = await this.tokenizer.peekBuffer(this.syncPeek.buf, { length: maxPeekLen, mayBeLess: true });
            if (this.syncPeek.len <= 163) {
                throw new core_1.EndOfStreamError();
            }
            while (true) {
                if (gotFirstSync && (this.syncPeek.buf[bo] & 0xE0) === 0xE0) {
                    this.buf_frame_header[0] = MpegFrameHeader.SyncByte1;
                    this.buf_frame_header[1] = this.syncPeek.buf[bo];
                    await this.tokenizer.ignore(bo);
                    debug(`Sync at offset=${this.tokenizer.position - 1}, frameCount=${this.frameCount}`);
                    if (this.syncFrameCount === this.frameCount) {
                        debug(`Re-synced MPEG stream, frameCount=${this.frameCount}`);
                        this.frameCount = 0;
                        this.frame_size = 0;
                    }
                    this.syncFrameCount = this.frameCount;
                    return; // sync
                }
                else {
                    gotFirstSync = false;
                    bo = this.syncPeek.buf.indexOf(MpegFrameHeader.SyncByte1, bo);
                    if (bo === -1) {
                        if (this.syncPeek.len < this.syncPeek.buf.length) {
                            throw new core_1.EndOfStreamError();
                        }
                        await this.tokenizer.ignore(this.syncPeek.len);
                        break; // continue with next buffer
                    }
                    else {
                        ++bo;
                        gotFirstSync = true;
                    }
                }
            }
        }
    }
    /**
     * Combined ADTS & MPEG (MP2 & MP3) header handling
     * @return {Promise<boolean>} true if parser should quit
     */
    async parseCommonMpegHeader() {
        if (this.frameCount === 0) {
            this.mpegOffset = this.tokenizer.position - 1;
        }
        await this.tokenizer.peekBuffer(this.buf_frame_header, { offset: 1, length: 3 });
        let header;
        try {
            header = FrameHeader.get(this.buf_frame_header, 0);
        }
        catch (err) {
            await this.tokenizer.ignore(1);
            this.metadata.addWarning('Parse error: ' + err.message);
            return false; // sync
        }
        await this.tokenizer.ignore(3);
        this.metadata.setFormat('container', header.container);
        this.metadata.setFormat('codec', header.codec);
        this.metadata.setFormat('lossless', false);
        this.metadata.setFormat('sampleRate', header.samplingRate);
        this.frameCount++;
        return header.version >= 2 && header.layer === 0 ? this.parseAdts(header) : this.parseAudioFrameHeader(header);
    }
    /**
     * @return {Promise<boolean>} true if parser should quit
     */
    async parseAudioFrameHeader(header) {
        this.metadata.setFormat('numberOfChannels', header.channelMode === 'mono' ? 1 : 2);
        this.metadata.setFormat('bitrate', header.bitrate);
        if (this.frameCount < 20 * 10000) {
            debug('offset=%s MP%s bitrate=%s sample-rate=%s', this.tokenizer.position - 4, header.layer, header.bitrate, header.samplingRate);
        }
        const slot_size = header.calcSlotSize();
        if (slot_size === null) {
            throw new Error('invalid slot_size');
        }
        const samples_per_frame = header.calcSamplesPerFrame();
        debug(`samples_per_frame=${samples_per_frame}`);
        const bps = samples_per_frame / 8.0;
        const fsize = (bps * header.bitrate / header.samplingRate) +
            ((header.padding) ? slot_size : 0);
        this.frame_size = Math.floor(fsize);
        this.audioFrameHeader = header;
        this.bitrates.push(header.bitrate);
        // xtra header only exists in first frame
        if (this.frameCount === 1) {
            this.offset = FrameHeader.len;
            await this.skipSideInformation();
            return false;
        }
        if (this.frameCount === 3) {
            // the stream is CBR if the first 3 frame bitrates are the same
            if (this.areAllSame(this.bitrates)) {
                // Actual calculation will be done in finalize
                this.samplesPerFrame = samples_per_frame;
                this.metadata.setFormat('codecProfile', 'CBR');
                if (this.tokenizer.fileInfo.size)
                    return true; // Will calculate duration based on the file size
            }
            else if (this.metadata.format.duration) {
                return true; // We already got the duration, stop processing MPEG stream any further
            }
            if (!this.options.duration) {
                return true; // Enforce duration not enabled, stop processing entire stream
            }
        }
        // once we know the file is VBR attach listener to end of
        // stream so we can do the duration calculation when we
        // have counted all the frames
        if (this.options.duration && this.frameCount === 4) {
            this.samplesPerFrame = samples_per_frame;
            this.calculateEofDuration = true;
        }
        this.offset = 4;
        if (header.isProtectedByCRC) {
            await this.parseCrc();
            return false;
        }
        else {
            await this.skipSideInformation();
            return false;
        }
    }
    async parseAdts(header) {
        const buf = Buffer.alloc(3);
        await this.tokenizer.readBuffer(buf);
        header.frameLength += common.getBitAllignedNumber(buf, 0, 0, 11);
        this.totalDataLength += header.frameLength;
        this.samplesPerFrame = 1024;
        const framesPerSec = header.samplingRate / this.samplesPerFrame;
        const bytesPerFrame = this.frameCount === 0 ? 0 : this.totalDataLength / this.frameCount;
        const bitrate = 8 * bytesPerFrame * framesPerSec + 0.5;
        this.metadata.setFormat('bitrate', bitrate);
        debug(`frame-count=${this.frameCount}, size=${header.frameLength} bytes, bit-rate=${bitrate}`);
        await this.tokenizer.ignore(header.frameLength > 7 ? header.frameLength - 7 : 1);
        // Consume remaining header and frame data
        if (this.frameCount === 3) {
            this.metadata.setFormat('codecProfile', header.codecProfile);
            if (header.mp4ChannelConfig) {
                this.metadata.setFormat('numberOfChannels', header.mp4ChannelConfig.length);
            }
            if (this.options.duration) {
                this.calculateEofDuration = true;
            }
            else {
                return true; // Stop parsing after the third frame
            }
        }
        return false;
    }
    async parseCrc() {
        this.crc = await this.tokenizer.readNumber(Token.INT16_BE);
        this.offset += 2;
        return this.skipSideInformation();
    }
    async skipSideInformation() {
        const sideinfo_length = this.audioFrameHeader.calculateSideInfoLength();
        // side information
        await this.tokenizer.readToken(new Token.Uint8ArrayType(sideinfo_length));
        this.offset += sideinfo_length;
        await this.readXtraInfoHeader();
        return;
    }
    async readXtraInfoHeader() {
        const headerTag = await this.tokenizer.readToken(XingTag_1.InfoTagHeaderTag);
        this.offset += XingTag_1.InfoTagHeaderTag.len; // 12
        switch (headerTag) {
            case 'Info':
                this.metadata.setFormat('codecProfile', 'CBR');
                return this.readXingInfoHeader();
            case 'Xing':
                const infoTag = await this.readXingInfoHeader();
                const codecProfile = getVbrCodecProfile(infoTag.vbrScale);
                this.metadata.setFormat('codecProfile', codecProfile);
                return null;
            case 'Xtra':
                // ToDo: ???
                break;
            case 'LAME':
                const version = await this.tokenizer.readToken(XingTag_1.LameEncoderVersion);
                if (this.frame_size >= this.offset + XingTag_1.LameEncoderVersion.len) {
                    this.offset += XingTag_1.LameEncoderVersion.len;
                    this.metadata.setFormat('tool', 'LAME ' + version);
                    await this.skipFrameData(this.frame_size - this.offset);
                    return null;
                }
                else {
                    this.metadata.addWarning('Corrupt LAME header');
                    break;
                }
            // ToDo: ???
        }
        // ToDo: promise duration???
        const frameDataLeft = this.frame_size - this.offset;
        if (frameDataLeft < 0) {
            this.metadata.addWarning('Frame ' + this.frameCount + 'corrupt: negative frameDataLeft');
        }
        else {
            await this.skipFrameData(frameDataLeft);
        }
        return null;
    }
    /**
     * Ref: http://gabriel.mp3-tech.org/mp3infotag.html
     * @returns {Promise<string>}
     */
    async readXingInfoHeader() {
        const offset = this.tokenizer.position;
        const infoTag = await (0, XingTag_1.readXingHeader)(this.tokenizer);
        this.offset += this.tokenizer.position - offset;
        if (infoTag.lame) {
            this.metadata.setFormat('tool', 'LAME ' + common.stripNulls(infoTag.lame.version));
            if (infoTag.lame.extended) {
                // this.metadata.setFormat('trackGain', infoTag.lame.extended.track_gain);
                this.metadata.setFormat('trackPeakLevel', infoTag.lame.extended.track_peak);
                if (infoTag.lame.extended.track_gain) {
                    this.metadata.setFormat('trackGain', infoTag.lame.extended.track_gain.adjustment);
                }
                if (infoTag.lame.extended.album_gain) {
                    this.metadata.setFormat('albumGain', infoTag.lame.extended.album_gain.adjustment);
                }
                this.metadata.setFormat('duration', infoTag.lame.extended.music_length / 1000);
            }
        }
        if (infoTag.streamSize) {
            const duration = this.audioFrameHeader.calcDuration(infoTag.numFrames);
            this.metadata.setFormat('duration', duration);
            debug('Get duration from Xing header: %s', this.metadata.format.duration);
            return infoTag;
        }
        // frames field is not present
        const frameDataLeft = this.frame_size - this.offset;
        await this.skipFrameData(frameDataLeft);
        return infoTag;
    }
    async skipFrameData(frameDataLeft) {
        if (frameDataLeft < 0)
            throw new Error('frame-data-left cannot be negative');
        await this.tokenizer.ignore(frameDataLeft);
        this.countSkipFrameData += frameDataLeft;
    }
    areAllSame(array) {
        const first = array[0];
        return array.every(element => {
            return element === first;
        });
    }
}
exports.MpegParser = MpegParser;