containers.js
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import { toUint8, bytesMatch } from './byte-helpers.js';
import { findBox } from './mp4-helpers.js';
import { findEbml, EBML_TAGS } from './ebml-helpers.js';
import { getId3Offset } from './id3-helpers.js';
import { findH264Nal, findH265Nal } from './nal-helpers.js';
var 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])
};
var _isLikely = {
aac: function aac(bytes) {
var offset = getId3Offset(bytes);
return bytesMatch(bytes, [0xFF, 0x10], {
offset: offset,
mask: [0xFF, 0x16]
});
},
mp3: function mp3(bytes) {
var offset = getId3Offset(bytes);
return bytesMatch(bytes, [0xFF, 0x02], {
offset: offset,
mask: [0xFF, 0x06]
});
},
webm: function webm(bytes) {
var docType = findEbml(bytes, [EBML_TAGS.EBML, EBML_TAGS.DocType])[0]; // check if DocType EBML tag is webm
return bytesMatch(docType, CONSTANTS.webm);
},
mkv: function mkv(bytes) {
var docType = findEbml(bytes, [EBML_TAGS.EBML, EBML_TAGS.DocType])[0]; // check if DocType EBML tag is matroska
return bytesMatch(docType, CONSTANTS.matroska);
},
mp4: function 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: function mov(bytes) {
return bytesMatch(bytes, CONSTANTS.mov, {
offset: 4
});
},
'3gp': function gp(bytes) {
return bytesMatch(bytes, CONSTANTS['3gp'], {
offset: 4
});
},
ac3: function ac3(bytes) {
var offset = getId3Offset(bytes);
return bytesMatch(bytes, CONSTANTS.ac3, {
offset: offset
});
},
ts: function ts(bytes) {
if (bytes.length < 189 && bytes.length >= 1) {
return bytes[0] === 0x47;
}
var 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: function flac(bytes) {
var offset = getId3Offset(bytes);
return bytesMatch(bytes, CONSTANTS.flac, {
offset: offset
});
},
ogg: function ogg(bytes) {
return bytesMatch(bytes, CONSTANTS.ogg);
},
avi: function avi(bytes) {
return bytesMatch(bytes, CONSTANTS.riff) && bytesMatch(bytes, CONSTANTS.avi, {
offset: 8
});
},
wav: function wav(bytes) {
return bytesMatch(bytes, CONSTANTS.riff) && bytesMatch(bytes, CONSTANTS.wav, {
offset: 8
});
},
'h264': function h264(bytes) {
// find seq_parameter_set_rbsp
return findH264Nal(bytes, 7, 3).length;
},
'h265': function 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
var isLikelyTypes = Object.keys(_isLikely) // remove ts, h264, h265
.filter(function (t) {
return 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) {
var isLikelyFn = _isLikely[type];
_isLikely[type] = function (bytes) {
return isLikelyFn(toUint8(bytes));
};
}); // export after wrapping
export var isLikely = _isLikely; // A useful list of file signatures can be found here
// https://en.wikipedia.org/wiki/List_of_file_signatures
export var detectContainerForBytes = function detectContainerForBytes(bytes) {
bytes = toUint8(bytes);
for (var i = 0; i < isLikelyTypes.length; i++) {
var type = isLikelyTypes[i];
if (isLikely[type](bytes)) {
return type;
}
}
return '';
}; // fmp4 is not a container
export var isLikelyFmp4MediaSegment = function isLikelyFmp4MediaSegment(bytes) {
return findBox(bytes, ['moof']).length > 0;
};