Borewit / music-metadata / 10325900009

import * as Token from 'token-types';

import { EndOfStreamError } from 'strtok3';

import initDebug from 'debug';

import * as common from '../common/Util.js';

import { AbstractID3Parser } from '../id3v2/AbstractID3Parser.js';

import { InfoTagHeaderTag, type IXingInfoTag, LameEncoderVersion, readXingHeader } from './XingTag.js';

const debug = initDebug('music-metadata:parser:mpeg');

/**

 * Cache buffer size used for searching synchronization preabmle

 */

const maxPeekLen = 1024;

type MPEG4Channel = 'front-center' | 'front-left' | 'front-right' | 'side-left' | 'side-right' | 'back-left' | 'back-right' | 'back-center' | 'LFE-channel';

type MPEG4ChannelConfiguration = MPEG4Channel[] | undefined;

/**

 * MPEG-4 Audio definitions

 * Ref:  https://wiki.multimedia.cx/index.php/MPEG-4_Audio

 */

const MPEG4 = {

  /**

   * Audio Object Types

   */

  AudioObjectTypes: [

    'AAC Main',

    'AAC LC', // Low Complexity

    'AAC SSR', // Scalable Sample Rate

    '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, null, null, -1]

  /**

   * Channel Configurations

   */

};

const MPEG4_ChannelConfigurations: MPEG4ChannelConfiguration[] = [

  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 {

  public static SyncByte1 = 0xFF;

  public static SyncByte2 = 0xE0;

  public static VersionID = [2.5, null, 2, 1];

  public static LayerDescription = [0, 3, 2, 1];

  public static ChannelMode = ['stereo', 'joint_stereo', 'dual_channel', 'mono'];

  private static bitrate_index: { [bitrate_index: number]: { [codec_index: number]: number; }; } = {

    1: {11: 32, 12: 32, 13: 32, 21: 32, 22: 8, 23: 8},

    2: {11: 64, 12: 48, 13: 40, 21: 48, 22: 16, 23: 16},

    3: {11: 96, 12: 56, 13: 48, 21: 56, 22: 24, 23: 24},

    4: {11: 128, 12: 64, 13: 56, 21: 64, 22: 32, 23: 32},

    5: {11: 160, 12: 80, 13: 64, 21: 80, 22: 40, 23: 40},

    6: {11: 192, 12: 96, 13: 80, 21: 96, 22: 48, 23: 48},

    7: {11: 224, 12: 112, 13: 96, 21: 112, 22: 56, 23: 56},

    8: {11: 256, 12: 128, 13: 112, 21: 128, 22: 64, 23: 64},

    9: {11: 288, 12: 160, 13: 128, 21: 144, 22: 80, 23: 80},

    10: {11: 320, 12: 192, 13: 160, 21: 160, 22: 96, 23: 96},

    11: {11: 352, 12: 224, 13: 192, 21: 176, 22: 112, 23: 112},

    12: {11: 384, 12: 256, 13: 224, 21: 192, 22: 128, 23: 128},

    13: {11: 416, 12: 320, 13: 256, 21: 224, 22: 144, 23: 144},

    14: {11: 448, 12: 384, 13: 320, 21: 256, 22: 160, 23: 160}

  };

  private static sampling_rate_freq_index: { [sample_rate_index: number]: { [index: number]: number; }; } = {

    1: {0: 44100, 1: 48000, 2: 32000},

    2: {0: 22050, 1: 24000, 2: 16000},

    2.5: {0: 11025, 1: 12000, 2: 8000}

  };

  private static samplesInFrameTable = [

    /* Layer   I    II   III */

    [0, 384, 1152, 1152], // MPEG-1

    [0, 384, 1152, 576] // MPEG-2(.5

  ];

  // B(20,19): MPEG Audio versionIndex ID

  public versionIndex: number;

  // C(18,17): Layer description

  public layer: number;

  // D(16): Protection bit

  public isProtectedByCRC: boolean;

  // E(15,12): Bitrate index

  public bitrateIndex: number | null = null;

  // F(11,10): Sampling rate frequency index

  public sampRateFreqIndex: number | null = null;

  // G(9): Padding bit

  public padding: boolean | null = null;

  // H(8): Private bit

  public privateBit: boolean | null = null;

  // I(7,6): Channel Mode

  public channelModeIndex?: number | null = null;

  // J(5,4): Mode extension (Only used in Joint stereo)

  public modeExtension: number | null = null;

  // K(3): Copyright

  public isCopyrighted?: boolean;

  // L(2): Original

  public isOriginalMedia: boolean | null = null;

  // M(3): The original bit indicates, if it is set, that the frame is located on its original media.

  public emphasis?: number;

  public version: number | null = null;

  public channelMode?: string;

  public bitrate: number | null = null;

  public samplingRate: number | null = null;

  public container?: string;

  public codec?: string;

  public codecProfile?: string;

  public frameLength = 0;

  public mp4ChannelConfig: MPEG4ChannelConfiguration;

  public constructor(buf: Uint8Array, off: number) {

    // 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);

  }

  public calcDuration(numFrames: number): number | null {

  }

  public calcSamplesPerFrame(): number {

    return MpegFrameHeader.samplesInFrameTable[this.version === 1 ? 0 : 1][this.layer];

  }

  public calculateSideInfoLength(): number | null {

    if (this.layer !== 3) return 2;

    if (this.channelModeIndex === 3) {

      // mono

      if (this.version === 1) {

        return 17;

      }if (this.version === 2 || this.version === 2.5) {

        return 9;

      }

    } else {

      if (this.version === 1) {

        return 32;

      }if (this.version === 2 || this.version === 2.5) {

        return 17;

      }

    }

  public calcSlotSize(): number | null {

    return [null, 4, 1, 1][this.layer];

  }

  private parseMpegHeader(buf: Uint8Array, off: number): void {

    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');

    }

  }

  private parseAdtsHeader(buf: Uint8Array, off: number): void {

    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 ? this.mp4ChannelConfig.join('+') : '?'}`);

    this.frameLength = common.getBitAllignedNumber(buf, off + 3, 6, 2) << 11;

  }

  private calcBitrate(): number | null {

    if (this.bitrateIndex === 0x00 || // free

      this.bitrateIndex === 0x0F) { // reserved

      return null;

    }

    if (this.version && this.bitrateIndex) {

      const codecIndex = 10 * Math.floor(this.version) + this.layer;

      return MpegFrameHeader.bitrate_index[this.bitrateIndex][codecIndex];

    }

  private calcSamplingRate(): number | null {

    if (this.sampRateFreqIndex === 0x03 || this.version === null || this.sampRateFreqIndex == null) return null; // 'reserved'

    return MpegFrameHeader.sampling_rate_freq_index[this.version][this.sampRateFreqIndex];

  }

}

/**

 * MPEG Audio Layer I/II/III

 */

const FrameHeader = {

  len: 4,

  get: (buf: Uint8Array, off: number): MpegFrameHeader => {

    return new MpegFrameHeader(buf, off);

  }

};

function getVbrCodecProfile(vbrScale: number): string {

  return `V${Math.floor((100 - vbrScale) / 10)}`;

}

export class MpegParser extends AbstractID3Parser {

  private frameCount = 0;

  private syncFrameCount = -1;

  private countSkipFrameData = 0;

  private totalDataLength = 0;

  private audioFrameHeader? : MpegFrameHeader;

  private bitrates: number[] = [];

  private offset = 0;

  private frame_size: number | null = null;

  private crc: number | null = null;

  private calculateEofDuration = false;

  private samplesPerFrame: number | null = null;

  private buf_frame_header = new Uint8Array(4);

  /**

   * Number of bytes already parsed since beginning of stream / file

   */

  private mpegOffset: number | null = null;

  private syncPeek = {

    buf: new Uint8Array(maxPeekLen),

    len: 0

  };

  /**

   * Called after ID3 headers have been parsed

   */

  public async postId3v2Parse(): Promise<void> {

    this.metadata.setFormat('lossless', false);

    try {

      let quit = false;

      while (!quit) {

        await this.sync();

        quit = await this.parseCommonMpegHeader();

      }

    } catch (err) {

      if (err instanceof EndOfStreamError) {

        debug("End-of-stream");

        if (this.calculateEofDuration) {

          if (this.samplesPerFrame !== null) {

            const numberOfSamples = this.frameCount * this.samplesPerFrame;

            this.metadata.setFormat('numberOfSamples', numberOfSamples);

            if (this.metadata.format.sampleRate) {

              const duration = numberOfSamples / this.metadata.format.sampleRate;

              debug(`Calculate duration at EOF: ${duration} sec.`, duration);

              this.metadata.setFormat('duration', duration);

            }

          }

        }

    }

  }

  /**

   * Called after file has been fully parsed, this allows, if present, to exclude the ID3v1.1 header length

   */

  protected finalize() {

    const format = this.metadata.format;

    const hasID3v1 = !!this.metadata.native.ID3v1;

    if (this.mpegOffset !== null) {

      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);

        if (this.frame_size !== null && this.samplesPerFrame !== null) {

          const numberOfSamples = Math.round(mpegSize / this.frame_size) * this.samplesPerFrame;

          this.metadata.setFormat('numberOfSamples', numberOfSamples);

          if (format.sampleRate) {

            const duration = numberOfSamples / format.sampleRate;

            debug("Calculate CBR duration based on file size: %s", duration);

            this.metadata.setFormat('duration', duration);

          }

        }

      }

    }

  }

  private async sync(): Promise<void> {

    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 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

        }

          gotFirstSync = false;

          bo = this.syncPeek.buf.indexOf(MpegFrameHeader.SyncByte1, bo);

          if (bo === -1) {

            if (this.syncPeek.len < this.syncPeek.buf.length) {

              throw new EndOfStreamError();

            }

            await this.tokenizer.ignore(this.syncPeek.len);

            break; // continue with next buffer

          }

            ++bo;

            gotFirstSync = true;

      }

    }

  }

  /**

   * Combined ADTS & MPEG (MP2 & MP3) header handling

   * @return {Promise<boolean>} true if parser should quit

   */

  private async parseCommonMpegHeader(): Promise<boolean> {

    if (this.frameCount === 0) {

      this.mpegOffset = this.tokenizer.position - 1;

    }

    await this.tokenizer.peekBuffer(this.buf_frame_header, {offset: 1, length: 3});

    let header: MpegFrameHeader;

    try {

      header = FrameHeader.get(this.buf_frame_header, 0);

    } catch (err) {

      await this.tokenizer.ignore(1);

      if (err instanceof Error) {

        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 !== null && header.version >= 2 && header.layer === 0 ? this.parseAdts(header) : this.parseAudioFrameHeader(header);

  }

  /**

   * @return {Promise<boolean>} true if parser should quit

   */

  private async parseAudioFrameHeader(header: MpegFrameHeader): Promise<boolean> {

    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();

    const samples_per_frame = header.calcSamplesPerFrame();

    debug(`samples_per_frame=${samples_per_frame}`);

    const bps = samples_per_frame / 8.0;

    if (header.bitrate !== null && header.samplingRate != null) {

      const fsize = (bps * header.bitrate / header.samplingRate) + ((header.padding) ? slot_size : 0);

      this.frame_size = Math.floor(fsize);

    }

    this.audioFrameHeader = header;

    if (header.bitrate !== null) {

      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;

    }

      await this.skipSideInformation();

      return false;

  }

  private async parseAdts(header: MpegFrameHeader): Promise<boolean> {

    const buf = new Uint8Array(3);

    await this.tokenizer.readBuffer(buf);

    header.frameLength += common.getBitAllignedNumber(buf, 0, 0, 11);

    this.totalDataLength += header.frameLength;

    this.samplesPerFrame = 1024;

    if (header.samplingRate !== null) {

      const framesPerSec = header.samplingRate / this.samplesPerFrame;

      const bitrate = 8 * bytesPerFrame * framesPerSec + 0.5;

      this.metadata.setFormat('bitrate', bitrate);

      debug(`frame-count=${this.frameCount}, size=${header.frameLength} bytes, bit-rate=${bitrate}`);

    }

    // 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;

    }

    return false;

  }

  private async parseCrc(): Promise<void> {

    this.crc = await this.tokenizer.readNumber(Token.INT16_BE);

    this.offset += 2;

    return this.skipSideInformation();

  }

  private async skipSideInformation(): Promise<void> {

    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;

  }

  private async readXtraInfoHeader(): Promise<IXingInfoTag | null> {

    const headerTag = await this.tokenizer.readToken(InfoTagHeaderTag);

    this.offset += 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 'LAME': {

        const version = await this.tokenizer.readToken(LameEncoderVersion);

        if (this.frame_size !== null && this.frame_size >= this.offset + LameEncoderVersion.len) {

          this.offset += LameEncoderVersion.len;

          this.metadata.setFormat('tool', `LAME ${version}`);

          await this.skipFrameData(this.frame_size - this.offset);

          return null;

        }

          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>}

   */

  private async readXingInfoHeader(): Promise<IXingInfoTag> {

    const offset = this.tokenizer.position;

    const infoTag = await 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);

        }

        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;

    }

  private async skipFrameData(frameDataLeft: number): Promise<void> {

    await this.tokenizer.ignore(frameDataLeft);

    this.countSkipFrameData += frameDataLeft;

  }

  private areAllSame(array) {

    const first = array[0];

    return array.every(element => {

      return element === first;

    });

  }

}