rx-player
Version:
Canal+ HTML5 Video Player
66 lines (65 loc) • 2.25 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.
*/
import { concat, itobe4, itobe8 } from "../../../utils/byte_parsing";
import { strToUtf8 } from "../../../utils/string_parsing";
import { MAX_32_BIT_INT } from "./constants";
/**
* Speed up string to bytes conversion by memorizing the result
*
* The keys here are ISOBMFF box names. The values are the corresponding
* bytes conversion for putting as an ISOBMFF boxes.
*
* Used by the boxName method.
* @type {Object}
*/
const boxNamesMem = {};
/**
* Convert the string name of an ISOBMFF box into the corresponding bytes.
* Has a memorization mechanism to speed-up if you want to translate the
* same string multiple times.
* @param {string} str
* @returns {Uint8Array}
*/
function boxName(str) {
if (boxNamesMem[str] !== undefined) {
return boxNamesMem[str];
}
const nameInBytes = strToUtf8(str);
boxNamesMem[str] = nameInBytes;
return nameInBytes;
}
/**
* Create a new ISOBMFF "box" with the given name.
* @param {string} name - name of the box you want to create, must always
* be 4 characters (uuid boxes not supported)
* @param {Uint8Array} buff - content of the box
* @returns {Uint8Array} - The entire ISOBMFF box (length+name+content)
*/
function createBox(name, buff) {
const len = buff.length + 8;
return len <= MAX_32_BIT_INT
? concat(itobe4(len), boxName(name), buff)
: concat(itobe4(1), boxName(name), itobe8(len + 8), buff);
}
/**
* @param {string} name
* @param {Array.<Uint8Array>} children
* @returns {Uint8Array}
*/
function createBoxWithChildren(name, children) {
return createBox(name, concat(...children));
}
export { createBox, createBoxWithChildren };