Vulture/VApp/node_modules/@videojs/vhs-utils/dist/vhs-utils.js

/*! @name @videojs/vhs-utils @version 4.1.1 @license MIT */
(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
  typeof define === 'function' && define.amd ? define(factory) :
  (global = typeof globalThis !== 'undefined' ? globalThis : global || self, global.vhsUtils = factory());
})(this, (function () { 'use strict';

  const regexs = {
    // to determine mime types
    mp4: /^(av0?1|avc0?[1234]|vp0?9|flac|opus|mp3|mp4a|mp4v|stpp.ttml.im1t)/,
    webm: /^(vp0?[89]|av0?1|opus|vorbis)/,
    ogg: /^(vp0?[89]|theora|flac|opus|vorbis)/,
    // to determine if a codec is audio or video
    video: /^(av0?1|avc0?[1234]|vp0?[89]|hvc1|hev1|theora|mp4v)/,
    audio: /^(mp4a|flac|vorbis|opus|ac-[34]|ec-3|alac|mp3|speex|aac)/,
    text: /^(stpp.ttml.im1t)/,
    // mux.js support regex
    muxerVideo: /^(avc0?1)/,
    muxerAudio: /^(mp4a)/,
    // match nothing as muxer does not support text right now.
    // there cannot never be a character before the start of a string
    // so this matches nothing.
    muxerText: /a^/
  };
  const mediaTypes = ['video', 'audio', 'text'];
  const upperMediaTypes = ['Video', 'Audio', 'Text'];
  /**
   * Replace the old apple-style `avc1.<dd>.<dd>` codec string with the standard
   * `avc1.<hhhhhh>`
   *
   * @param {string} codec
   *        Codec string to translate
   * @return {string}
   *         The translated codec string
   */

  const translateLegacyCodec = function (codec) {
    if (!codec) {
      return codec;
    }

    return codec.replace(/avc1\.(\d+)\.(\d+)/i, function (orig, profile, avcLevel) {
      const profileHex = ('00' + Number(profile).toString(16)).slice(-2);
      const avcLevelHex = ('00' + Number(avcLevel).toString(16)).slice(-2);
      return 'avc1.' + profileHex + '00' + avcLevelHex;
    });
  };
  /**
   * Replace the old apple-style `avc1.<dd>.<dd>` codec strings with the standard
   * `avc1.<hhhhhh>`
   *
   * @param {string[]} codecs
   *        An array of codec strings to translate
   * @return {string[]}
   *         The translated array of codec strings
   */

  const translateLegacyCodecs = function (codecs) {
    return codecs.map(translateLegacyCodec);
  };
  /**
   * Replace codecs in the codec string with the old apple-style `avc1.<dd>.<dd>` to the
   * standard `avc1.<hhhhhh>`.
   *
   * @param {string} codecString
   *        The codec string
   * @return {string}
   *         The codec string with old apple-style codecs replaced
   *
   * @private
   */

  const mapLegacyAvcCodecs = function (codecString) {
    return codecString.replace(/avc1\.(\d+)\.(\d+)/i, match => {
      return translateLegacyCodecs([match])[0];
    });
  };
  /**
   * @typedef {Object} ParsedCodecInfo
   * @property {number} codecCount
   *           Number of codecs parsed
   * @property {string} [videoCodec]
   *           Parsed video codec (if found)
   * @property {string} [videoObjectTypeIndicator]
   *           Video object type indicator (if found)
   * @property {string|null} audioProfile
   *           Audio profile
   */

  /**
   * Parses a codec string to retrieve the number of codecs specified, the video codec and
   * object type indicator, and the audio profile.
   *
   * @param {string} [codecString]
   *        The codec string to parse
   * @return {ParsedCodecInfo}
   *         Parsed codec info
   */

  const parseCodecs = function (codecString = '') {
    const codecs = codecString.split(',');
    const result = [];
    codecs.forEach(function (codec) {
      codec = codec.trim();
      let codecType;
      mediaTypes.forEach(function (name) {
        const match = regexs[name].exec(codec.toLowerCase());

        if (!match || match.length <= 1) {
          return;
        }

        codecType = name; // maintain codec case

        const type = codec.substring(0, match[1].length);
        const details = codec.replace(type, '');
        result.push({
          type,
          details,
          mediaType: name
        });
      });

      if (!codecType) {
        result.push({
          type: codec,
          details: '',
          mediaType: 'unknown'
        });
      }
    });
    return result;
  };
  /**
   * Returns a ParsedCodecInfo object for the default alternate audio playlist if there is
   * a default alternate audio playlist for the provided audio group.
   *
   * @param {Object} master
   *        The master playlist
   * @param {string} audioGroupId
   *        ID of the audio group for which to find the default codec info
   * @return {ParsedCodecInfo}
   *         Parsed codec info
   */

  const codecsFromDefault = (master, audioGroupId) => {
    if (!master.mediaGroups.AUDIO || !audioGroupId) {
      return null;
    }

    const audioGroup = master.mediaGroups.AUDIO[audioGroupId];

    if (!audioGroup) {
      return null;
    }

    for (const name in audioGroup) {
      const audioType = audioGroup[name];

      if (audioType.default && audioType.playlists) {
        // codec should be the same for all playlists within the audio type
        return parseCodecs(audioType.playlists[0].attributes.CODECS);
      }
    }

    return null;
  };
  const isVideoCodec = (codec = '') => regexs.video.test(codec.trim().toLowerCase());
  const isAudioCodec = (codec = '') => regexs.audio.test(codec.trim().toLowerCase());
  const isTextCodec = (codec = '') => regexs.text.test(codec.trim().toLowerCase());
  const getMimeForCodec = codecString => {
    if (!codecString || typeof codecString !== 'string') {
      return;
    }

    const codecs = codecString.toLowerCase().split(',').map(c => translateLegacyCodec(c.trim())); // default to video type

    let type = 'video'; // only change to audio type if the only codec we have is
    // audio

    if (codecs.length === 1 && isAudioCodec(codecs[0])) {
      type = 'audio';
    } else if (codecs.length === 1 && isTextCodec(codecs[0])) {
      // text uses application/<container> for now
      type = 'application';
    } // default the container to mp4


    let container = 'mp4'; // every codec must be able to go into the container
    // for that container to be the correct one

    if (codecs.every(c => regexs.mp4.test(c))) {
      container = 'mp4';
    } else if (codecs.every(c => regexs.webm.test(c))) {
      container = 'webm';
    } else if (codecs.every(c => regexs.ogg.test(c))) {
      container = 'ogg';
    }

    return `${type}/${container};codecs="${codecString}"`;
  };
  /**
   * Tests whether the codec is supported by MediaSource. Optionally also tests ManagedMediaSource.
   *
   * @param {string} codecString
   *        Codec to test
   * @param {boolean} [withMMS]
   *        Whether to check if ManagedMediaSource supports it
   * @return {boolean}
   *          Codec is supported
   */

  const browserSupportsCodec = (codecString = '', withMMS = false) => window.MediaSource && window.MediaSource.isTypeSupported && window.MediaSource.isTypeSupported(getMimeForCodec(codecString)) || withMMS && window.ManagedMediaSource && window.ManagedMediaSource.isTypeSupported && window.ManagedMediaSource.isTypeSupported(getMimeForCodec(codecString)) || false;
  const muxerSupportsCodec = (codecString = '') => codecString.toLowerCase().split(',').every(codec => {
    codec = codec.trim(); // any match is supported.

    for (let i = 0; i < upperMediaTypes.length; i++) {
      const type = upperMediaTypes[i];

      if (regexs[`muxer${type}`].test(codec)) {
        return true;
      }
    }

    return false;
  });
  const DEFAULT_AUDIO_CODEC = 'mp4a.40.2';
  const DEFAULT_VIDEO_CODEC = 'avc1.4d400d';

  var codecs = /*#__PURE__*/Object.freeze({
    __proto__: null,
    translateLegacyCodec: translateLegacyCodec,
    translateLegacyCodecs: translateLegacyCodecs,
    mapLegacyAvcCodecs: mapLegacyAvcCodecs,
    parseCodecs: parseCodecs,
    codecsFromDefault: codecsFromDefault,
    isVideoCodec: isVideoCodec,
    isAudioCodec: isAudioCodec,
    isTextCodec: isTextCodec,
    getMimeForCodec: getMimeForCodec,
    browserSupportsCodec: browserSupportsCodec,
    muxerSupportsCodec: muxerSupportsCodec,
    DEFAULT_AUDIO_CODEC: DEFAULT_AUDIO_CODEC,
    DEFAULT_VIDEO_CODEC: DEFAULT_VIDEO_CODEC
  });

  // const log2 = Math.log2 ? Math.log2 : (x) => (Math.log(x) / Math.log(2));
  const repeat = function (str, len) {
    let acc = '';

    while (len--) {
      acc += str;
    }

    return acc;
  }; // count the number of bits it would take to represent a number
  // we used to do this with log2 but BigInt does not support builtin math
  // Math.ceil(log2(x));


  const countBits = x => x.toString(2).length; // count the number of whole bytes it would take to represent a number

  const countBytes = x => Math.ceil(countBits(x) / 8);
  const padStart = (b, len, str = ' ') => (repeat(str, len) + b.toString()).slice(-len);
  const isArrayBufferView = obj => {
    if (ArrayBuffer.isView === 'function') {
      return ArrayBuffer.isView(obj);
    }

    return obj && obj.buffer instanceof ArrayBuffer;
  };
  const isTypedArray = obj => isArrayBufferView(obj);
  const toUint8 = function (bytes) {
    if (bytes instanceof Uint8Array) {
      return bytes;
    }

    if (!Array.isArray(bytes) && !isTypedArray(bytes) && !(bytes instanceof ArrayBuffer)) {
      // any non-number or NaN leads to empty uint8array
      // eslint-disable-next-line
      if (typeof bytes !== 'number' || typeof bytes === 'number' && bytes !== bytes) {
        bytes = 0;
      } else {
        bytes = [bytes];
      }
    }

    return new Uint8Array(bytes && bytes.buffer || bytes, bytes && bytes.byteOffset || 0, bytes && bytes.byteLength || 0);
  };
  const toHexString = function (bytes) {
    bytes = toUint8(bytes);
    let str = '';

    for (let i = 0; i < bytes.length; i++) {
      str += padStart(bytes[i].toString(16), 2, '0');
    }

    return str;
  };
  const toBinaryString = function (bytes) {
    bytes = toUint8(bytes);
    let str = '';

    for (let i = 0; i < bytes.length; i++) {
      str += padStart(bytes[i].toString(2), 8, '0');
    }

    return str;
  };
  const BigInt = window.BigInt || Number;
  const BYTE_TABLE = [BigInt('0x1'), BigInt('0x100'), BigInt('0x10000'), BigInt('0x1000000'), BigInt('0x100000000'), BigInt('0x10000000000'), BigInt('0x1000000000000'), BigInt('0x100000000000000'), BigInt('0x10000000000000000')];
  const ENDIANNESS = function () {
    const a = new Uint16Array([0xFFCC]);
    const b = new Uint8Array(a.buffer, a.byteOffset, a.byteLength);

    if (b[0] === 0xFF) {
      return 'big';
    }

    if (b[0] === 0xCC) {
      return 'little';
    }

    return 'unknown';
  }();
  const IS_BIG_ENDIAN = ENDIANNESS === 'big';
  const IS_LITTLE_ENDIAN = ENDIANNESS === 'little';
  const bytesToNumber = function (bytes, {
    signed = false,
    le = false
  } = {}) {
    bytes = toUint8(bytes);
    const fn = le ? 'reduce' : 'reduceRight';
    const obj = bytes[fn] ? bytes[fn] : Array.prototype[fn];
    let number = obj.call(bytes, function (total, byte, i) {
      const exponent = le ? i : Math.abs(i + 1 - bytes.length);
      return total + BigInt(byte) * BYTE_TABLE[exponent];
    }, BigInt(0));

    if (signed) {
      const max = BYTE_TABLE[bytes.length] / BigInt(2) - BigInt(1);
      number = BigInt(number);

      if (number > max) {
        number -= max;
        number -= max;
        number -= BigInt(2);
      }
    }

    return Number(number);
  };
  const numberToBytes = function (number, {
    le = false
  } = {}) {
    // eslint-disable-next-line
    if (typeof number !== 'bigint' && typeof number !== 'number' || typeof number === 'number' && number !== number) {
      number = 0;
    }

    number = BigInt(number);
    const byteCount = countBytes(number);
    const bytes = new Uint8Array(new ArrayBuffer(byteCount));

    for (let i = 0; i < byteCount; i++) {
      const byteIndex = le ? i : Math.abs(i + 1 - bytes.length);
      bytes[byteIndex] = Number(number / BYTE_TABLE[i] & BigInt(0xFF));

      if (number < 0) {
        bytes[byteIndex] = Math.abs(~bytes[byteIndex]);
        bytes[byteIndex] -= i === 0 ? 1 : 2;
      }
    }

    return bytes;
  };
  const bytesToString = bytes => {
    if (!bytes) {
      return '';
    } // TODO: should toUint8 handle cases where we only have 8 bytes
    // but report more since this is a Uint16+ Array?


    bytes = Array.prototype.slice.call(bytes);
    const string = String.fromCharCode.apply(null, toUint8(bytes));

    try {
      return decodeURIComponent(escape(string));
    } catch (e) {// if decodeURIComponent/escape fails, we are dealing with partial
      // or full non string data. Just return the potentially garbled string.
    }

    return string;
  };
  const stringToBytes = (string, stringIsBytes) => {
    if (typeof string !== 'string' && string && typeof string.toString === 'function') {
      string = string.toString();
    }

    if (typeof string !== 'string') {
      return new Uint8Array();
    } // If the string already is bytes, we don't have to do this
    // otherwise we do this so that we split multi length characters
    // into individual bytes


    if (!stringIsBytes) {
      string = unescape(encodeURIComponent(string));
    }

    const view = new Uint8Array(string.length);

    for (let i = 0; i < string.length; i++) {
      view[i] = string.charCodeAt(i);
    }

    return view;
  };
  const concatTypedArrays = (...buffers) => {
    buffers = buffers.filter(b => b && (b.byteLength || b.length) && typeof b !== 'string');

    if (buffers.length <= 1) {
      // for 0 length we will return empty uint8
      // for 1 length we return the first uint8
      return toUint8(buffers[0]);
    }

    const totalLen = buffers.reduce((total, buf, i) => total + (buf.byteLength || buf.length), 0);
    const tempBuffer = new Uint8Array(totalLen);
    let offset = 0;
    buffers.forEach(function (buf) {
      buf = toUint8(buf);
      tempBuffer.set(buf, offset);
      offset += buf.byteLength;
    });
    return tempBuffer;
  };
  /**
   * Check if the bytes "b" are contained within bytes "a".
   *
   * @param {Uint8Array|Array} a
   *        Bytes to check in
   *
   * @param {Uint8Array|Array} b
   *        Bytes to check for
   *
   * @param {Object} options
   *        options
   *
   * @param {Array|Uint8Array} [offset=0]
   *        offset to use when looking at bytes in a
   *
   * @param {Array|Uint8Array} [mask=[]]
   *        mask to use on bytes before comparison.
   *
   * @return {boolean}
   *         If all bytes in b are inside of a, taking into account
   *         bit masks.
   */

  const bytesMatch = (a, b, {
    offset = 0,
    mask = []
  } = {}) => {
    a = toUint8(a);
    b = toUint8(b); // ie 11 does not support uint8 every

    const fn = b.every ? b.every : Array.prototype.every;
    return b.length && a.length - offset >= b.length && // ie 11 doesn't support every on uin8
    fn.call(b, (bByte, i) => {
      const aByte = mask[i] ? mask[i] & a[offset + i] : a[offset + i];
      return bByte === aByte;
    });
  };
  const sliceBytes = function (src, start, end) {
    if (Uint8Array.prototype.slice) {
      return Uint8Array.prototype.slice.call(src, start, end);
    }

    return new Uint8Array(Array.prototype.slice.call(src, start, end));
  };
  const reverseBytes = function (src) {
    if (src.reverse) {
      return src.reverse();
    }

    return Array.prototype.reverse.call(src);
  };

  var byteHelpers = /*#__PURE__*/Object.freeze({
    __proto__: null,
    countBits: countBits,
    countBytes: countBytes,
    padStart: padStart,
    isArrayBufferView: isArrayBufferView,
    isTypedArray: isTypedArray,
    toUint8: toUint8,
    toHexString: toHexString,
    toBinaryString: toBinaryString,
    ENDIANNESS: ENDIANNESS,
    IS_BIG_ENDIAN: IS_BIG_ENDIAN,
    IS_LITTLE_ENDIAN: IS_LITTLE_ENDIAN,
    bytesToNumber: bytesToNumber,
    numberToBytes: numberToBytes,
    bytesToString: bytesToString,
    stringToBytes: stringToBytes,
    concatTypedArrays: concatTypedArrays,
    bytesMatch: bytesMatch,
    sliceBytes: sliceBytes,
    reverseBytes: reverseBytes
  });

  const normalizePath$1 = function (path) {
    if (typeof path === 'string') {
      return stringToBytes(path);
    }

    if (typeof path === 'number') {
      return path;
    }

    return path;
  };

  const normalizePaths$1 = function (paths) {
    if (!Array.isArray(paths)) {
      return [normalizePath$1(paths)];
    }

    return paths.map(p => normalizePath$1(p));
  };
  /**
   * find any number of boxes by name given a path to it in an iso bmff
   * such as mp4.
   *
   * @param {TypedArray} bytes
   *        bytes for the iso bmff to search for boxes in
   *
   * @param {Uint8Array[]|string[]|string|Uint8Array} name
   *        An array of paths or a single path representing the name
   *        of boxes to search through in bytes. Paths may be
   *        uint8 (character codes) or strings.
   *
   * @param {boolean} [complete=false]
   *        Should we search only for complete boxes on the final path.
   *        This is very useful when you do not want to get back partial boxes
   *        in the case of streaming files.
   *
   * @return {Uint8Array[]}
   *         An array of the end paths that we found.
   */

  const findBox = function (bytes, paths, complete = false) {
    paths = normalizePaths$1(paths);
    bytes = toUint8(bytes);
    const results = [];

    if (!paths.length) {
      // short-circuit the search for empty paths
      return results;
    }

    let i = 0;

    while (i < bytes.length) {
      const size = (bytes[i] << 24 | bytes[i + 1] << 16 | bytes[i + 2] << 8 | bytes[i + 3]) >>> 0;
      const type = bytes.subarray(i + 4, i + 8); // invalid box format.

      if (size === 0) {
        break;
      }

      let end = i + size;

      if (end > bytes.length) {
        // this box is bigger than the number of bytes we have
        // and complete is set, we cannot find any more boxes.
        if (complete) {
          break;
        }

        end = bytes.length;
      }

      const data = bytes.subarray(i + 8, end);

      if (bytesMatch(type, paths[0])) {
        if (paths.length === 1) {
          // this is the end of the path and we've found the box we were
          // looking for
          results.push(data);
        } else {
          // recursively search for the next box along the path
          results.push.apply(results, findBox(data, paths.slice(1), complete));
        }
      }

      i = end;
    } // we've finished searching all of bytes


    return results;
  };

  // https://matroska-org.github.io/libebml/specs.html
  // https://www.matroska.org/technical/elements.html
  // https://www.webmproject.org/docs/container/

  const EBML_TAGS = {
    EBML: toUint8([0x1A, 0x45, 0xDF, 0xA3]),
    DocType: toUint8([0x42, 0x82]),
    Segment: toUint8([0x18, 0x53, 0x80, 0x67]),
    SegmentInfo: toUint8([0x15, 0x49, 0xA9, 0x66]),
    Tracks: toUint8([0x16, 0x54, 0xAE, 0x6B]),
    Track: toUint8([0xAE]),
    TrackNumber: toUint8([0xd7]),
    DefaultDuration: toUint8([0x23, 0xe3, 0x83]),
    TrackEntry: toUint8([0xAE]),
    TrackType: toUint8([0x83]),
    FlagDefault: toUint8([0x88]),
    CodecID: toUint8([0x86]),
    CodecPrivate: toUint8([0x63, 0xA2]),
    VideoTrack: toUint8([0xe0]),
    AudioTrack: toUint8([0xe1]),
    // Not used yet, but will be used for live webm/mkv
    // see https://www.matroska.org/technical/basics.html#block-structure
    // see https://www.matroska.org/technical/basics.html#simpleblock-structure
    Cluster: toUint8([0x1F, 0x43, 0xB6, 0x75]),
    Timestamp: toUint8([0xE7]),
    TimestampScale: toUint8([0x2A, 0xD7, 0xB1]),
    BlockGroup: toUint8([0xA0]),
    BlockDuration: toUint8([0x9B]),
    Block: toUint8([0xA1]),
    SimpleBlock: toUint8([0xA3])
  };
  /**
   * This is a simple table to determine the length
   * of things in ebml. The length is one based (starts at 1,
   * rather than zero) and for every zero bit before a one bit
   * we add one to length. We also need this table because in some
   * case we have to xor all the length bits from another value.
   */

  const LENGTH_TABLE = [0b10000000, 0b01000000, 0b00100000, 0b00010000, 0b00001000, 0b00000100, 0b00000010, 0b00000001];

  const getLength = function (byte) {
    let len = 1;

    for (let i = 0; i < LENGTH_TABLE.length; i++) {
      if (byte & LENGTH_TABLE[i]) {
        break;
      }

      len++;
    }

    return len;
  }; // length in ebml is stored in the first 4 to 8 bits
  // of the first byte. 4 for the id length and 8 for the
  // data size length. Length is measured by converting the number to binary
  // then 1 + the number of zeros before a 1 is encountered starting
  // from the left.


  const getvint = function (bytes, offset, removeLength = true, signed = false) {
    const length = getLength(bytes[offset]);
    let valueBytes = bytes.subarray(offset, offset + length); // NOTE that we do **not** subarray here because we need to copy these bytes
    // as they will be modified below to remove the dataSizeLen bits and we do not
    // want to modify the original data. normally we could just call slice on
    // uint8array but ie 11 does not support that...

    if (removeLength) {
      valueBytes = Array.prototype.slice.call(bytes, offset, offset + length);
      valueBytes[0] ^= LENGTH_TABLE[length - 1];
    }

    return {
      length,
      value: bytesToNumber(valueBytes, {
        signed
      }),
      bytes: valueBytes
    };
  };

  const normalizePath = function (path) {
    if (typeof path === 'string') {
      return path.match(/.{1,2}/g).map(p => normalizePath(p));
    }

    if (typeof path === 'number') {
      return numberToBytes(path);
    }

    return path;
  };

  const normalizePaths = function (paths) {
    if (!Array.isArray(paths)) {
      return [normalizePath(paths)];
    }

    return paths.map(p => normalizePath(p));
  };

  const getInfinityDataSize = (id, bytes, offset) => {
    if (offset >= bytes.length) {
      return bytes.length;
    }

    const innerid = getvint(bytes, offset, false);

    if (bytesMatch(id.bytes, innerid.bytes)) {
      return offset;
    }

    const dataHeader = getvint(bytes, offset + innerid.length);
    return getInfinityDataSize(id, bytes, offset + dataHeader.length + dataHeader.value + innerid.length);
  };
  /**
   * Notes on the EBLM format.
   *
   * EBLM uses "vints" tags. Every vint tag contains
   * two parts
   *
   * 1. The length from the first byte. You get this by
   *    converting the byte to binary and counting the zeros
   *    before a 1. Then you add 1 to that. Examples
   *    00011111 = length 4 because there are 3 zeros before a 1.
   *    00100000 = length 3 because there are 2 zeros before a 1.
   *    00000011 = length 7 because there are 6 zeros before a 1.
   *
   * 2. The bits used for length are removed from the first byte
   *    Then all the bytes are merged into a value. NOTE: this
   *    is not the case for id ebml tags as there id includes
   *    length bits.
   *
   */


  const findEbml = function (bytes, paths) {
    paths = normalizePaths(paths);
    bytes = toUint8(bytes);
    let results = [];

    if (!paths.length) {
      return results;
    }

    let i = 0;

    while (i < bytes.length) {
      const id = getvint(bytes, i, false);
      const dataHeader = getvint(bytes, i + id.length);
      const dataStart = i + id.length + dataHeader.length; // dataSize is unknown or this is a live stream

      if (dataHeader.value === 0x7f) {
        dataHeader.value = getInfinityDataSize(id, bytes, dataStart);

        if (dataHeader.value !== bytes.length) {
          dataHeader.value -= dataStart;
        }
      }

      const dataEnd = dataStart + dataHeader.value > bytes.length ? bytes.length : dataStart + dataHeader.value;
      const data = bytes.subarray(dataStart, dataEnd);

      if (bytesMatch(paths[0], id.bytes)) {
        if (paths.length === 1) {
          // this is the end of the paths and we've found the tag we were
          // looking for
          results.push(data);
        } else {
          // recursively search for the next tag inside of the data
          // of this one
          results = results.concat(findEbml(data, paths.slice(1)));
        }
      }

      const totalLength = id.length + dataHeader.length + data.length; // move past this tag entirely, we are not looking for it

      i += totalLength;
    }

    return results;
  }; // see https://www.matroska.org/technical/basics.html#block-structure

  const ID3 = toUint8([0x49, 0x44, 0x33]);
  const getId3Size = function (bytes, offset = 0) {
    bytes = toUint8(bytes);
    const flags = bytes[offset + 5];
    const returnSize = bytes[offset + 6] << 21 | bytes[offset + 7] << 14 | bytes[offset + 8] << 7 | bytes[offset + 9];
    const footerPresent = (flags & 16) >> 4;

    if (footerPresent) {
      return returnSize + 20;
    }

    return returnSize + 10;
  };
  const getId3Offset = function (bytes, offset = 0) {
    bytes = toUint8(bytes);

    if (bytes.length - offset < 10 || !bytesMatch(bytes, ID3, {
      offset
    })) {
      return offset;
    }

    offset += getId3Size(bytes, offset); // recursive check for id3 tags as some files
    // have multiple ID3 tag sections even though
    // they should not.

    return getId3Offset(bytes, offset);
  };

  const NAL_TYPE_ONE = toUint8([0x00, 0x00, 0x00, 0x01]);
  const NAL_TYPE_TWO = toUint8([0x00, 0x00, 0x01]);
  const EMULATION_PREVENTION = toUint8([0x00, 0x00, 0x03]);
  /**
   * Expunge any "Emulation Prevention" bytes from a "Raw Byte
   * Sequence Payload"
   *
   * @param data {Uint8Array} the bytes of a RBSP from a NAL
   * unit
   * @return {Uint8Array} the RBSP without any Emulation
   * Prevention Bytes
   */

  const discardEmulationPreventionBytes = function (bytes) {
    const positions = [];
    let i = 1; // Find all `Emulation Prevention Bytes`

    while (i < bytes.length - 2) {
      if (bytesMatch(bytes.subarray(i, i + 3), EMULATION_PREVENTION)) {
        positions.push(i + 2);
        i++;
      }

      i++;
    } // If no Emulation Prevention Bytes were found just return the original
    // array


    if (positions.length === 0) {
      return bytes;
    } // Create a new array to hold the NAL unit data


    const newLength = bytes.length - positions.length;
    const newData = new Uint8Array(newLength);
    let sourceIndex = 0;

    for (i = 0; i < newLength; sourceIndex++, i++) {
      if (sourceIndex === positions[0]) {
        // Skip this byte
        sourceIndex++; // Remove this position index

        positions.shift();
      }

      newData[i] = bytes[sourceIndex];
    }

    return newData;
  };
  const findNal = function (bytes, dataType, types, nalLimit = Infinity) {
    bytes = toUint8(bytes);
    types = [].concat(types);
    let i = 0;
    let nalStart;
    let nalsFound = 0; // keep searching until:
    // we reach the end of bytes
    // we reach the maximum number of nals they want to seach
    // NOTE: that we disregard nalLimit when we have found the start
    // of the nal we want so that we can find the end of the nal we want.

    while (i < bytes.length && (nalsFound < nalLimit || nalStart)) {
      let nalOffset;

      if (bytesMatch(bytes.subarray(i), NAL_TYPE_ONE)) {
        nalOffset = 4;
      } else if (bytesMatch(bytes.subarray(i), NAL_TYPE_TWO)) {
        nalOffset = 3;
      } // we are unsynced,
      // find the next nal unit


      if (!nalOffset) {
        i++;
        continue;
      }

      nalsFound++;

      if (nalStart) {
        return discardEmulationPreventionBytes(bytes.subarray(nalStart, i));
      }

      let nalType;

      if (dataType === 'h264') {
        nalType = bytes[i + nalOffset] & 0x1f;
      } else if (dataType === 'h265') {
        nalType = bytes[i + nalOffset] >> 1 & 0x3f;
      }

      if (types.indexOf(nalType) !== -1) {
        nalStart = i + nalOffset;
      } // nal header is 1 length for h264, and 2 for h265


      i += nalOffset + (dataType === 'h264' ? 1 : 2);
    }

    return bytes.subarray(0, 0);
  };
  const findH264Nal = (bytes, type, nalLimit) => findNal(bytes, 'h264', type, nalLimit);
  const findH265Nal = (bytes, type, nalLimit) => findNal(bytes, 'h265', type, nalLimit);

  const CONSTANTS = {
    // "webm" string literal in hex
    'webm': toUint8([0x77, 0x65, 0x62, 0x6d]),
    // "matroska" string literal in hex
    'matroska': toUint8([0x6d, 0x61, 0x74, 0x72, 0x6f, 0x73, 0x6b, 0x61]),
    // "fLaC" string literal in hex
    'flac': toUint8([0x66, 0x4c, 0x61, 0x43]),
    // "OggS" string literal in hex
    'ogg': toUint8([0x4f, 0x67, 0x67, 0x53]),
    // ac-3 sync byte, also works for ec-3 as that is simply a codec
    // of ac-3
    'ac3': toUint8([0x0b, 0x77]),
    // "RIFF" string literal in hex used for wav and avi
    'riff': toUint8([0x52, 0x49, 0x46, 0x46]),
    // "AVI" string literal in hex
    'avi': toUint8([0x41, 0x56, 0x49]),
    // "WAVE" string literal in hex
    'wav': toUint8([0x57, 0x41, 0x56, 0x45]),
    // "ftyp3g" string literal in hex
    '3gp': toUint8([0x66, 0x74, 0x79, 0x70, 0x33, 0x67]),
    // "ftyp" string literal in hex
    'mp4': toUint8([0x66, 0x74, 0x79, 0x70]),
    // "styp" string literal in hex
    'fmp4': toUint8([0x73, 0x74, 0x79, 0x70]),
    // "ftypqt" string literal in hex
    'mov': toUint8([0x66, 0x74, 0x79, 0x70, 0x71, 0x74]),
    // moov string literal in hex
    'moov': toUint8([0x6D, 0x6F, 0x6F, 0x76]),
    // moof string literal in hex
    'moof': toUint8([0x6D, 0x6F, 0x6F, 0x66])
  };
  const _isLikely = {
    aac(bytes) {
      const offset = getId3Offset(bytes);
      return bytesMatch(bytes, [0xFF, 0x10], {
        offset,
        mask: [0xFF, 0x16]
      });
    },

    mp3(bytes) {
      const offset = getId3Offset(bytes);
      return bytesMatch(bytes, [0xFF, 0x02], {
        offset,
        mask: [0xFF, 0x06]
      });
    },

    webm(bytes) {
      const docType = findEbml(bytes, [EBML_TAGS.EBML, EBML_TAGS.DocType])[0]; // check if DocType EBML tag is webm

      return bytesMatch(docType, CONSTANTS.webm);
    },

    mkv(bytes) {
      const docType = findEbml(bytes, [EBML_TAGS.EBML, EBML_TAGS.DocType])[0]; // check if DocType EBML tag is matroska

      return bytesMatch(docType, CONSTANTS.matroska);
    },

    mp4(bytes) {
      // if this file is another base media file format, it is not mp4
      if (_isLikely['3gp'](bytes) || _isLikely.mov(bytes)) {
        return false;
      } // if this file starts with a ftyp or styp box its mp4


      if (bytesMatch(bytes, CONSTANTS.mp4, {
        offset: 4
      }) || bytesMatch(bytes, CONSTANTS.fmp4, {
        offset: 4
      })) {
        return true;
      } // if this file starts with a moof/moov box its mp4


      if (bytesMatch(bytes, CONSTANTS.moof, {
        offset: 4
      }) || bytesMatch(bytes, CONSTANTS.moov, {
        offset: 4
      })) {
        return true;
      }
    },

    mov(bytes) {
      return bytesMatch(bytes, CONSTANTS.mov, {
        offset: 4
      });
    },

    '3gp'(bytes) {
      return bytesMatch(bytes, CONSTANTS['3gp'], {
        offset: 4
      });
    },

    ac3(bytes) {
      const offset = getId3Offset(bytes);
      return bytesMatch(bytes, CONSTANTS.ac3, {
        offset
      });
    },

    ts(bytes) {
      if (bytes.length < 189 && bytes.length >= 1) {
        return bytes[0] === 0x47;
      }

      let i = 0; // check the first 376 bytes for two matching sync bytes

      while (i + 188 < bytes.length && i < 188) {
        if (bytes[i] === 0x47 && bytes[i + 188] === 0x47) {
          return true;
        }

        i += 1;
      }

      return false;
    },

    flac(bytes) {
      const offset = getId3Offset(bytes);
      return bytesMatch(bytes, CONSTANTS.flac, {
        offset
      });
    },

    ogg(bytes) {
      return bytesMatch(bytes, CONSTANTS.ogg);
    },

    avi(bytes) {
      return bytesMatch(bytes, CONSTANTS.riff) && bytesMatch(bytes, CONSTANTS.avi, {
        offset: 8
      });
    },

    wav(bytes) {
      return bytesMatch(bytes, CONSTANTS.riff) && bytesMatch(bytes, CONSTANTS.wav, {
        offset: 8
      });
    },

    'h264'(bytes) {
      // find seq_parameter_set_rbsp
      return findH264Nal(bytes, 7, 3).length;
    },

    'h265'(bytes) {
      // find video_parameter_set_rbsp or seq_parameter_set_rbsp
      return findH265Nal(bytes, [32, 33], 3).length;
    }

  }; // get all the isLikely functions
  // but make sure 'ts' is above h264 and h265
  // but below everything else as it is the least specific

  const isLikelyTypes = Object.keys(_isLikely) // remove ts, h264, h265
  .filter(t => t !== 'ts' && t !== 'h264' && t !== 'h265') // add it back to the bottom
  .concat(['ts', 'h264', 'h265']); // make sure we are dealing with uint8 data.

  isLikelyTypes.forEach(function (type) {
    const isLikelyFn = _isLikely[type];

    _isLikely[type] = bytes => isLikelyFn(toUint8(bytes));
  }); // export after wrapping

  const isLikely = _isLikely; // A useful list of file signatures can be found here
  // https://en.wikipedia.org/wiki/List_of_file_signatures

  const detectContainerForBytes = bytes => {
    bytes = toUint8(bytes);

    for (let i = 0; i < isLikelyTypes.length; i++) {
      const type = isLikelyTypes[i];

      if (isLikely[type](bytes)) {
        return type;
      }
    }

    return '';
  }; // fmp4 is not a container

  const isLikelyFmp4MediaSegment = bytes => {
    return findBox(bytes, ['moof']).length > 0;
  };

  var containers = /*#__PURE__*/Object.freeze({
    __proto__: null,
    isLikely: isLikely,
    detectContainerForBytes: detectContainerForBytes,
    isLikelyFmp4MediaSegment: isLikelyFmp4MediaSegment
  });

  const atob = s => window.atob ? window.atob(s) : Buffer.from(s, 'base64').toString('binary');

  function decodeB64ToUint8Array(b64Text) {
    const decodedString = atob(b64Text);
    const array = new Uint8Array(decodedString.length);

    for (let i = 0; i < decodedString.length; i++) {
      array[i] = decodedString.charCodeAt(i);
    }

    return array;
  }

  /**
   * Loops through all supported media groups in master and calls the provided
   * callback for each group
   *
   * @param {Object} master
   *        The parsed master manifest object
   * @param {string[]} groups
   *        The media groups to call the callback for
   * @param {Function} callback
   *        Callback to call for each media group
   */
  const forEachMediaGroup = (master, groups, callback) => {
    groups.forEach(mediaType => {
      for (const groupKey in master.mediaGroups[mediaType]) {
        for (const labelKey in master.mediaGroups[mediaType][groupKey]) {
          const mediaProperties = master.mediaGroups[mediaType][groupKey][labelKey];
          callback(mediaProperties, mediaType, groupKey, labelKey);
        }
      }
    });
  };

  var mediaGroups = /*#__PURE__*/Object.freeze({
    __proto__: null,
    forEachMediaGroup: forEachMediaGroup
  });

  const DEFAULT_LOCATION = 'https://example.com';

  const resolveUrl = (baseUrl, relativeUrl) => {
    // return early if we don't need to resolve
    if (/^[a-z]+:/i.test(relativeUrl)) {
      return relativeUrl;
    } // if baseUrl is a data URI, ignore it and resolve everything relative to window.location


    if (/^data:/.test(baseUrl)) {
      baseUrl = window.location && window.location.href || '';
    }

    const protocolLess = /^\/\//.test(baseUrl); // remove location if window.location isn't available (i.e. we're in node)
    // and if baseUrl isn't an absolute url

    const removeLocation = !window.location && !/\/\//i.test(baseUrl); // if the base URL is relative then combine with the current location

    baseUrl = new window.URL(baseUrl, window.location || DEFAULT_LOCATION);
    const newUrl = new URL(relativeUrl, baseUrl); // if we're a protocol-less url, remove the protocol
    // and if we're location-less, remove the location
    // otherwise, return the url unmodified

    if (removeLocation) {
      return newUrl.href.slice(DEFAULT_LOCATION.length);
    } else if (protocolLess) {
      return newUrl.href.slice(newUrl.protocol.length);
    }

    return newUrl.href;
  };

  /**
   * @file stream.js
   */

  /**
   * A lightweight readable stream implemention that handles event dispatching.
   *
   * @class Stream
   */
  class Stream {
    constructor() {
      this.listeners = {};
    }
    /**
     * Add a listener for a specified event type.
     *
     * @param {string} type the event name
     * @param {Function} listener the callback to be invoked when an event of
     * the specified type occurs
     */


    on(type, listener) {
      if (!this.listeners[type]) {
        this.listeners[type] = [];
      }

      this.listeners[type].push(listener);
    }
    /**
     * Remove a listener for a specified event type.
     *
     * @param {string} type the event name
     * @param {Function} listener  a function previously registered for this
     * type of event through `on`
     * @return {boolean} if we could turn it off or not
     */


    off(type, listener) {
      if (!this.listeners[type]) {
        return false;
      }

      const index = this.listeners[type].indexOf(listener); // TODO: which is better?
      // In Video.js we slice listener functions
      // on trigger so that it does not mess up the order
      // while we loop through.
      //
      // Here we slice on off so that the loop in trigger
      // can continue using it's old reference to loop without
      // messing up the order.

      this.listeners[type] = this.listeners[type].slice(0);
      this.listeners[type].splice(index, 1);
      return index > -1;
    }
    /**
     * Trigger an event of the specified type on this stream. Any additional
     * arguments to this function are passed as parameters to event listeners.
     *
     * @param {string} type the event name
     */


    trigger(type) {
      const callbacks = this.listeners[type];

      if (!callbacks) {
        return;
      } // Slicing the arguments on every invocation of this method
      // can add a significant amount of overhead. Avoid the
      // intermediate object creation for the common case of a
      // single callback argument


      if (arguments.length === 2) {
        const length = callbacks.length;

        for (let i = 0; i < length; ++i) {
          callbacks[i].call(this, arguments[1]);
        }
      } else {
        const args = Array.prototype.slice.call(arguments, 1);
        const length = callbacks.length;

        for (let i = 0; i < length; ++i) {
          callbacks[i].apply(this, args);
        }
      }
    }
    /**
     * Destroys the stream and cleans up.
     */


    dispose() {
      this.listeners = {};
    }
    /**
     * Forwards all `data` events on this stream to the destination stream. The
     * destination stream should provide a method `push` to receive the data
     * events as they arrive.
     *
     * @param {Stream} destination the stream that will receive all `data` events
     * @see http://nodejs.org/api/stream.html#stream_readable_pipe_destination_options
     */


    pipe(destination) {
      this.on('data', function (data) {
        destination.push(data);
      });
    }

  }

  var index = {
    codecs,
    byteHelpers,
    containers,
    decodeB64ToUint8Array,
    mediaGroups,
    resolveUrl,
    Stream
  };

  return index;

}));