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"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.parseData = exports.parseTracks = exports.decodeBlock = exports.findEbml = exports.EBML_TAGS = void 0;
var _byteHelpers = require("./byte-helpers");
var _codecHelpers = require("./codec-helpers.js");
// relevant specs for this parser:
// https://matroska-org.github.io/libebml/specs.html
// https://www.matroska.org/technical/elements.html
// https://www.webmproject.org/docs/container/
var EBML_TAGS = {
EBML: (0, _byteHelpers.toUint8)([0x1A, 0x45, 0xDF, 0xA3]),
DocType: (0, _byteHelpers.toUint8)([0x42, 0x82]),
Segment: (0, _byteHelpers.toUint8)([0x18, 0x53, 0x80, 0x67]),
SegmentInfo: (0, _byteHelpers.toUint8)([0x15, 0x49, 0xA9, 0x66]),
Tracks: (0, _byteHelpers.toUint8)([0x16, 0x54, 0xAE, 0x6B]),
Track: (0, _byteHelpers.toUint8)([0xAE]),
TrackNumber: (0, _byteHelpers.toUint8)([0xd7]),
DefaultDuration: (0, _byteHelpers.toUint8)([0x23, 0xe3, 0x83]),
TrackEntry: (0, _byteHelpers.toUint8)([0xAE]),
TrackType: (0, _byteHelpers.toUint8)([0x83]),
FlagDefault: (0, _byteHelpers.toUint8)([0x88]),
CodecID: (0, _byteHelpers.toUint8)([0x86]),
CodecPrivate: (0, _byteHelpers.toUint8)([0x63, 0xA2]),
VideoTrack: (0, _byteHelpers.toUint8)([0xe0]),
AudioTrack: (0, _byteHelpers.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: (0, _byteHelpers.toUint8)([0x1F, 0x43, 0xB6, 0x75]),
Timestamp: (0, _byteHelpers.toUint8)([0xE7]),
TimestampScale: (0, _byteHelpers.toUint8)([0x2A, 0xD7, 0xB1]),
BlockGroup: (0, _byteHelpers.toUint8)([0xA0]),
BlockDuration: (0, _byteHelpers.toUint8)([0x9B]),
Block: (0, _byteHelpers.toUint8)([0xA1]),
SimpleBlock: (0, _byteHelpers.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.
*/
exports.EBML_TAGS = EBML_TAGS;
var LENGTH_TABLE = [128, 64, 32, 16, 8, 4, 2, 1];
var getLength = function getLength(byte) {
var len = 1;
for (var 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.
var getvint = function getvint(bytes, offset, removeLength, signed) {
if (removeLength === void 0) {
removeLength = true;
}
if (signed === void 0) {
signed = false;
}
var length = getLength(bytes[offset]);
var 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: length,
value: (0, _byteHelpers.bytesToNumber)(valueBytes, {
signed: signed
}),
bytes: valueBytes
};
};
var normalizePath = function normalizePath(path) {
if (typeof path === 'string') {
return path.match(/.{1,2}/g).map(function (p) {
return normalizePath(p);
});
}
if (typeof path === 'number') {
return (0, _byteHelpers.numberToBytes)(path);
}
return path;
};
var normalizePaths = function normalizePaths(paths) {
if (!Array.isArray(paths)) {
return [normalizePath(paths)];
}
return paths.map(function (p) {
return normalizePath(p);
});
};
var getInfinityDataSize = function getInfinityDataSize(id, bytes, offset) {
if (offset >= bytes.length) {
return bytes.length;
}
var innerid = getvint(bytes, offset, false);
if ((0, _byteHelpers.bytesMatch)(id.bytes, innerid.bytes)) {
return offset;
}
var 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.
*
*/
var findEbml = function findEbml(bytes, paths) {
paths = normalizePaths(paths);
bytes = (0, _byteHelpers.toUint8)(bytes);
var results = [];
if (!paths.length) {
return results;
}
var i = 0;
while (i < bytes.length) {
var id = getvint(bytes, i, false);
var dataHeader = getvint(bytes, i + id.length);
var 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;
}
}
var dataEnd = dataStart + dataHeader.value > bytes.length ? bytes.length : dataStart + dataHeader.value;
var data = bytes.subarray(dataStart, dataEnd);
if ((0, _byteHelpers.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)));
}
}
var 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
exports.findEbml = findEbml;
var decodeBlock = function decodeBlock(block, type, timestampScale, clusterTimestamp) {
var duration;
if (type === 'group') {
duration = findEbml(block, [EBML_TAGS.BlockDuration])[0];
if (duration) {
duration = (0, _byteHelpers.bytesToNumber)(duration);
duration = 1 / timestampScale * duration * timestampScale / 1000;
}
block = findEbml(block, [EBML_TAGS.Block])[0];
type = 'block'; // treat data as a block after this point
}
var dv = new DataView(block.buffer, block.byteOffset, block.byteLength);
var trackNumber = getvint(block, 0);
var timestamp = dv.getInt16(trackNumber.length, false);
var flags = block[trackNumber.length + 2];
var data = block.subarray(trackNumber.length + 3); // pts/dts in seconds
var ptsdts = 1 / timestampScale * (clusterTimestamp + timestamp) * timestampScale / 1000; // return the frame
var parsed = {
duration: duration,
trackNumber: trackNumber.value,
keyframe: type === 'simple' && flags >> 7 === 1,
invisible: (flags & 0x08) >> 3 === 1,
lacing: (flags & 0x06) >> 1,
discardable: type === 'simple' && (flags & 0x01) === 1,
frames: [],
pts: ptsdts,
dts: ptsdts,
timestamp: timestamp
};
if (!parsed.lacing) {
parsed.frames.push(data);
return parsed;
}
var numberOfFrames = data[0] + 1;
var frameSizes = [];
var offset = 1; // Fixed
if (parsed.lacing === 2) {
var sizeOfFrame = (data.length - offset) / numberOfFrames;
for (var i = 0; i < numberOfFrames; i++) {
frameSizes.push(sizeOfFrame);
}
} // xiph
if (parsed.lacing === 1) {
for (var _i = 0; _i < numberOfFrames - 1; _i++) {
var size = 0;
do {
size += data[offset];
offset++;
} while (data[offset - 1] === 0xFF);
frameSizes.push(size);
}
} // ebml
if (parsed.lacing === 3) {
// first vint is unsinged
// after that vints are singed and
// based on a compounding size
var _size = 0;
for (var _i2 = 0; _i2 < numberOfFrames - 1; _i2++) {
var vint = _i2 === 0 ? getvint(data, offset) : getvint(data, offset, true, true);
_size += vint.value;
frameSizes.push(_size);
offset += vint.length;
}
}
frameSizes.forEach(function (size) {
parsed.frames.push(data.subarray(offset, offset + size));
offset += size;
});
return parsed;
}; // VP9 Codec Feature Metadata (CodecPrivate)
// https://www.webmproject.org/docs/container/
exports.decodeBlock = decodeBlock;
var parseVp9Private = function parseVp9Private(bytes) {
var i = 0;
var params = {};
while (i < bytes.length) {
var id = bytes[i] & 0x7f;
var len = bytes[i + 1];
var val = void 0;
if (len === 1) {
val = bytes[i + 2];
} else {
val = bytes.subarray(i + 2, i + 2 + len);
}
if (id === 1) {
params.profile = val;
} else if (id === 2) {
params.level = val;
} else if (id === 3) {
params.bitDepth = val;
} else if (id === 4) {
params.chromaSubsampling = val;
} else {
params[id] = val;
}
i += 2 + len;
}
return params;
};
var parseTracks = function parseTracks(bytes) {
bytes = (0, _byteHelpers.toUint8)(bytes);
var decodedTracks = [];
var tracks = findEbml(bytes, [EBML_TAGS.Segment, EBML_TAGS.Tracks, EBML_TAGS.Track]);
if (!tracks.length) {
tracks = findEbml(bytes, [EBML_TAGS.Tracks, EBML_TAGS.Track]);
}
if (!tracks.length) {
tracks = findEbml(bytes, [EBML_TAGS.Track]);
}
if (!tracks.length) {
return decodedTracks;
}
tracks.forEach(function (track) {
var trackType = findEbml(track, EBML_TAGS.TrackType)[0];
if (!trackType || !trackType.length) {
return;
} // 1 is video, 2 is audio, 17 is subtitle
// other values are unimportant in this context
if (trackType[0] === 1) {
trackType = 'video';
} else if (trackType[0] === 2) {
trackType = 'audio';
} else if (trackType[0] === 17) {
trackType = 'subtitle';
} else {
return;
} // todo parse language
var decodedTrack = {
rawCodec: (0, _byteHelpers.bytesToString)(findEbml(track, [EBML_TAGS.CodecID])[0]),
type: trackType,
codecPrivate: findEbml(track, [EBML_TAGS.CodecPrivate])[0],
number: (0, _byteHelpers.bytesToNumber)(findEbml(track, [EBML_TAGS.TrackNumber])[0]),
defaultDuration: (0, _byteHelpers.bytesToNumber)(findEbml(track, [EBML_TAGS.DefaultDuration])[0]),
default: findEbml(track, [EBML_TAGS.FlagDefault])[0],
rawData: track
};
var codec = '';
if (/V_MPEG4\/ISO\/AVC/.test(decodedTrack.rawCodec)) {
codec = "avc1." + (0, _codecHelpers.getAvcCodec)(decodedTrack.codecPrivate);
} else if (/V_MPEGH\/ISO\/HEVC/.test(decodedTrack.rawCodec)) {
codec = "hev1." + (0, _codecHelpers.getHvcCodec)(decodedTrack.codecPrivate);
} else if (/V_MPEG4\/ISO\/ASP/.test(decodedTrack.rawCodec)) {
if (decodedTrack.codecPrivate) {
codec = 'mp4v.20.' + decodedTrack.codecPrivate[4].toString();
} else {
codec = 'mp4v.20.9';
}
} else if (/^V_THEORA/.test(decodedTrack.rawCodec)) {
codec = 'theora';
} else if (/^V_VP8/.test(decodedTrack.rawCodec)) {
codec = 'vp8';
} else if (/^V_VP9/.test(decodedTrack.rawCodec)) {
if (decodedTrack.codecPrivate) {
var _parseVp9Private = parseVp9Private(decodedTrack.codecPrivate),
profile = _parseVp9Private.profile,
level = _parseVp9Private.level,
bitDepth = _parseVp9Private.bitDepth,
chromaSubsampling = _parseVp9Private.chromaSubsampling;
codec = 'vp09.';
codec += (0, _byteHelpers.padStart)(profile, 2, '0') + ".";
codec += (0, _byteHelpers.padStart)(level, 2, '0') + ".";
codec += (0, _byteHelpers.padStart)(bitDepth, 2, '0') + ".";
codec += "" + (0, _byteHelpers.padStart)(chromaSubsampling, 2, '0'); // Video -> Colour -> Ebml name
var matrixCoefficients = findEbml(track, [0xE0, [0x55, 0xB0], [0x55, 0xB1]])[0] || [];
var videoFullRangeFlag = findEbml(track, [0xE0, [0x55, 0xB0], [0x55, 0xB9]])[0] || [];
var transferCharacteristics = findEbml(track, [0xE0, [0x55, 0xB0], [0x55, 0xBA]])[0] || [];
var colourPrimaries = findEbml(track, [0xE0, [0x55, 0xB0], [0x55, 0xBB]])[0] || []; // if we find any optional codec parameter specify them all.
if (matrixCoefficients.length || videoFullRangeFlag.length || transferCharacteristics.length || colourPrimaries.length) {
codec += "." + (0, _byteHelpers.padStart)(colourPrimaries[0], 2, '0');
codec += "." + (0, _byteHelpers.padStart)(transferCharacteristics[0], 2, '0');
codec += "." + (0, _byteHelpers.padStart)(matrixCoefficients[0], 2, '0');
codec += "." + (0, _byteHelpers.padStart)(videoFullRangeFlag[0], 2, '0');
}
} else {
codec = 'vp9';
}
} else if (/^V_AV1/.test(decodedTrack.rawCodec)) {
codec = "av01." + (0, _codecHelpers.getAv1Codec)(decodedTrack.codecPrivate);
} else if (/A_ALAC/.test(decodedTrack.rawCodec)) {
codec = 'alac';
} else if (/A_MPEG\/L2/.test(decodedTrack.rawCodec)) {
codec = 'mp2';
} else if (/A_MPEG\/L3/.test(decodedTrack.rawCodec)) {
codec = 'mp3';
} else if (/^A_AAC/.test(decodedTrack.rawCodec)) {
if (decodedTrack.codecPrivate) {
codec = 'mp4a.40.' + (decodedTrack.codecPrivate[0] >>> 3).toString();
} else {
codec = 'mp4a.40.2';
}
} else if (/^A_AC3/.test(decodedTrack.rawCodec)) {
codec = 'ac-3';
} else if (/^A_PCM/.test(decodedTrack.rawCodec)) {
codec = 'pcm';
} else if (/^A_MS\/ACM/.test(decodedTrack.rawCodec)) {
codec = 'speex';
} else if (/^A_EAC3/.test(decodedTrack.rawCodec)) {
codec = 'ec-3';
} else if (/^A_VORBIS/.test(decodedTrack.rawCodec)) {
codec = 'vorbis';
} else if (/^A_FLAC/.test(decodedTrack.rawCodec)) {
codec = 'flac';
} else if (/^A_OPUS/.test(decodedTrack.rawCodec)) {
codec = 'opus';
}
decodedTrack.codec = codec;
decodedTracks.push(decodedTrack);
});
return decodedTracks.sort(function (a, b) {
return a.number - b.number;
});
};
exports.parseTracks = parseTracks;
var parseData = function parseData(data, tracks) {
var allBlocks = [];
var segment = findEbml(data, [EBML_TAGS.Segment])[0];
var timestampScale = findEbml(segment, [EBML_TAGS.SegmentInfo, EBML_TAGS.TimestampScale])[0]; // in nanoseconds, defaults to 1ms
if (timestampScale && timestampScale.length) {
timestampScale = (0, _byteHelpers.bytesToNumber)(timestampScale);
} else {
timestampScale = 1000000;
}
var clusters = findEbml(segment, [EBML_TAGS.Cluster]);
if (!tracks) {
tracks = parseTracks(segment);
}
clusters.forEach(function (cluster, ci) {
var simpleBlocks = findEbml(cluster, [EBML_TAGS.SimpleBlock]).map(function (b) {
return {
type: 'simple',
data: b
};
});
var blockGroups = findEbml(cluster, [EBML_TAGS.BlockGroup]).map(function (b) {
return {
type: 'group',
data: b
};
});
var timestamp = findEbml(cluster, [EBML_TAGS.Timestamp])[0] || 0;
if (timestamp && timestamp.length) {
timestamp = (0, _byteHelpers.bytesToNumber)(timestamp);
} // get all blocks then sort them into the correct order
var blocks = simpleBlocks.concat(blockGroups).sort(function (a, b) {
return a.data.byteOffset - b.data.byteOffset;
});
blocks.forEach(function (block, bi) {
var decoded = decodeBlock(block.data, block.type, timestampScale, timestamp);
allBlocks.push(decoded);
});
});
return {
tracks: tracks,
blocks: allBlocks
};
};
exports.parseData = parseData;