rx-player
Version:
Canal+ HTML5 Video Player
47 lines (46 loc) • 1.66 kB
JavaScript
;
/**
* Copyright 2015 CANAL+ Group
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.default = getAacesHeader;
var byte_parsing_1 = require("../../../utils/byte_parsing");
var string_parsing_1 = require("../../../utils/string_parsing");
/**
* Sampling frequencies defined in MPEG-4 Audio.
* @type {Array.<Number>}
*/
var SAMPLING_FREQUENCIES = [
96000, 88200, 64000, 48000, 44100, 32000, 24000, 22050, 16000, 12000, 11025, 8000, 7350,
];
/**
* Return AAC ES Header (hexstr form)
*
* @param {Number} type
* 1 = AAC Main
* 2 = AAC LC
* cf http://wiki.multimedia.cx/index.php?title=MPEG-4_Audio
* @param {Number} frequency
* @param {Number} chans (1 or 2)
* @returns {string}
*/
function getAacesHeader(type, frequency, chans) {
var freq = SAMPLING_FREQUENCIES.indexOf(frequency); // TODO : handle Idx = 15...
var val;
val = (type & 0x3f) << 0x4;
val = (val | (freq & 0x1f)) << 0x4;
val = (val | (chans & 0x1f)) << 0x3;
return (0, string_parsing_1.bytesToHex)((0, byte_parsing_1.itobe2)(val));
}