mirror of
https://github.com/shaka-project/shaka-player.git
synced 2026-06-19 16:47:01 +03:00
Joey Parrish
74 lines
1.9 KiB
JavaScript
74 lines
1.9 KiB
JavaScript
/**
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* Copyright 2014 Google Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* @fileoverview Implements a PSSH parser.
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*/
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goog.provide('shaka.util.Pssh');
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goog.require('shaka.util.DataViewReader');
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goog.require('shaka.util.StringUtils');
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/**
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* Parse a PSSH box and extract the system IDs.
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*
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* @param {!Uint8Array} psshBox
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* @constructor
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* @throws {RangeError} in the unlikely event that a PSSH box contains a size
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* field over 53 bits.
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*/
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shaka.util.Pssh = function(psshBox) {
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/**
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* @type {!Array.<string>}
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* @expose
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*/
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this.systemIds = [];
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// Parse the PSSH box.
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var reader = new shaka.util.DataViewReader(
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new DataView(psshBox.buffer),
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shaka.util.DataViewReader.Endianness.BIG_ENDIAN);
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// There could be multiple boxes concatenated together.
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while (reader.hasMoreData()) {
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var headerSize = 8;
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var size = reader.readUint32();
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var type = reader.readUint32();
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if (size == 1) {
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size = reader.readUint64();
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headerSize += 8;
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}
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if (type != shaka.util.Pssh.BOX_TYPE) {
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reader.skip(size - headerSize);
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continue;
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}
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var versionAndFlags = reader.readUint32();
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var systemId = shaka.util.StringUtils.fromUint8Array(reader.readBytes(16));
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var dataSize = reader.readUint32();
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reader.skip(dataSize); // Ignore the data section.
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this.systemIds.push(systemId);
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}
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};
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/** @const {number} */
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shaka.util.Pssh.BOX_TYPE = 0x70737368;
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