yanchengPowerSupply/node_modules/videojs-contrib-media-sources/es5/codec-utils.js

87 lines
2.2 KiB
JavaScript

/**
* @file codec-utils.js
*/
/**
* Check if a codec string refers to an audio codec.
*
* @param {String} codec codec string to check
* @return {Boolean} if this is an audio codec
* @private
*/
'use strict';
Object.defineProperty(exports, '__esModule', {
value: true
});
var isAudioCodec = function isAudioCodec(codec) {
return (/mp4a\.\d+.\d+/i.test(codec)
);
};
/**
* Check if a codec string refers to a video codec.
*
* @param {String} codec codec string to check
* @return {Boolean} if this is a video codec
* @private
*/
var isVideoCodec = function isVideoCodec(codec) {
return (/avc1\.[\da-f]+/i.test(codec)
);
};
/**
* Parse a content type header into a type and parameters
* object
*
* @param {String} type the content type header
* @return {Object} the parsed content-type
* @private
*/
var parseContentType = function parseContentType(type) {
var object = { type: '', parameters: {} };
var parameters = type.trim().split(';');
// first parameter should always be content-type
object.type = parameters.shift().trim();
parameters.forEach(function (parameter) {
var pair = parameter.trim().split('=');
if (pair.length > 1) {
var _name = pair[0].replace(/"/g, '').trim();
var value = pair[1].replace(/"/g, '').trim();
object.parameters[_name] = value;
}
});
return object;
};
/**
* Replace the old apple-style `avc1.<dd>.<dd>` codec string with the standard
* `avc1.<hhhhhh>`
*
* @param {Array} codecs an array of codec strings to fix
* @return {Array} the translated codec array
* @private
*/
var translateLegacyCodecs = function translateLegacyCodecs(codecs) {
return codecs.map(function (codec) {
return codec.replace(/avc1\.(\d+)\.(\d+)/i, function (orig, profile, avcLevel) {
var profileHex = ('00' + Number(profile).toString(16)).slice(-2);
var avcLevelHex = ('00' + Number(avcLevel).toString(16)).slice(-2);
return 'avc1.' + profileHex + '00' + avcLevelHex;
});
});
};
exports['default'] = {
isAudioCodec: isAudioCodec,
parseContentType: parseContentType,
isVideoCodec: isVideoCodec,
translateLegacyCodecs: translateLegacyCodecs
};
module.exports = exports['default'];