2a09d1a4
 liuqimichale
添加宜春 天水 宣化
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/**
* @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
*/
const isAudioCodec = function(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
*/
const isVideoCodec = function(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
*/
const parseContentType = function(type) {
let object = {type: '', parameters: {}};
let parameters = type.trim().split(';');
// first parameter should always be content-type
object.type = parameters.shift().trim();
parameters.forEach((parameter) => {
let pair = parameter.trim().split('=');
if (pair.length > 1) {
let name = pair[0].replace(/"/g, '').trim();
let 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
*/
const translateLegacyCodecs = function(codecs) {
return codecs.map((codec) => {
return codec.replace(/avc1\.(\d+)\.(\d+)/i, function(orig, profile, avcLevel) {
let profileHex = ('00' + Number(profile).toString(16)).slice(-2);
let avcLevelHex = ('00' + Number(avcLevel).toString(16)).slice(-2);
return 'avc1.' + profileHex + '00' + avcLevelHex;
});
});
};
export default {
isAudioCodec,
parseContentType,
isVideoCodec,
translateLegacyCodecs
};
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