@l5i/dashjs
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A reference client implementation for the playback of MPEG DASH via Javascript and compliant browsers.
430 lines (376 loc) • 19.1 kB
JavaScript
/**
* The copyright in this software is being made available under the BSD License,
* included below. This software may be subject to other third party and contributor
* rights, including patent rights, and no such rights are granted under this license.
*
* Copyright (c) 2013, Dash Industry Forum.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
* * Neither the name of Dash Industry Forum nor the names of its
* contributors may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/**
* Initial implementation of EME
*
* Implemented by Google Chrome prior to v36
*
* @implements ProtectionModel
* @class
*/
import ProtectionKeyController from '../controllers/ProtectionKeyController';
import NeedKey from '../vo/NeedKey';
import DashJSError from '../../vo/DashJSError';
import KeyMessage from '../vo/KeyMessage';
import KeySystemConfiguration from '../vo/KeySystemConfiguration';
import KeySystemAccess from '../vo/KeySystemAccess';
import ProtectionErrors from '../errors/ProtectionErrors';
function ProtectionModel_01b(config) {
config = config || {};
const context = this.context;
const eventBus = config.eventBus;//Need to pass in here so we can use same instance since this is optional module
const events = config.events;
const debug = config.debug;
const api = config.api;
const errHandler = config.errHandler;
let instance,
logger,
videoElement,
keySystem,
protectionKeyController,
// With this version of the EME APIs, sessionIDs are not assigned to
// sessions until the first key message is received. We are assuming
// that in the case of multiple sessions, key messages will be received
// in the order that generateKeyRequest() is called.
// Holding spot for newly-created sessions until we determine whether or
// not the CDM supports sessionIDs
pendingSessions,
// List of sessions that have been initialized. Only the first position will
// be used in the case that the CDM does not support sessionIDs
sessions,
// Not all CDMs support the notion of sessionIDs. Without sessionIDs
// there is no way for us to differentiate between sessions, therefore
// we must only allow a single session. Once we receive the first key
// message we can set this flag to determine if more sessions are allowed
moreSessionsAllowed,
// This is our main event handler for all desired HTMLMediaElement events
// related to EME. These events are translated into our API-independent
// versions of the same events
eventHandler;
function setup() {
logger = debug.getLogger(instance);
videoElement = null;
keySystem = null;
pendingSessions = [];
sessions = [];
protectionKeyController = ProtectionKeyController(context).getInstance();
eventHandler = createEventHandler();
}
function reset() {
if (videoElement) {
removeEventListeners();
}
for (let i = 0; i < sessions.length; i++) {
closeKeySession(sessions[i]);
}
eventBus.trigger(events.TEARDOWN_COMPLETE);
}
function getKeySystem() {
return keySystem;
}
function getAllInitData() {
const retVal = [];
for (let i = 0; i < pendingSessions.length; i++) {
retVal.push(pendingSessions[i].initData);
}
for (let i = 0; i < sessions.length; i++) {
retVal.push(sessions[i].initData);
}
return retVal;
}
function requestKeySystemAccess(ksConfigurations) {
let ve = videoElement;
if (!ve) { // Must have a video element to do this capability tests
ve = document.createElement('video');
}
// Try key systems in order, first one with supported key system configuration
// is used
let found = false;
for (let ksIdx = 0; ksIdx < ksConfigurations.length; ksIdx++) {
const systemString = ksConfigurations[ksIdx].ks.systemString;
const configs = ksConfigurations[ksIdx].configs;
let supportedAudio = null;
let supportedVideo = null;
// Try key system configs in order, first one with supported audio/video
// is used
for (let configIdx = 0; configIdx < configs.length; configIdx++) {
//let audios = configs[configIdx].audioCapabilities;
const videos = configs[configIdx].videoCapabilities;
// Look for supported video container/codecs
if (videos && videos.length !== 0) {
supportedVideo = []; // Indicates that we have a requested video config
for (let videoIdx = 0; videoIdx < videos.length; videoIdx++) {
if (ve.canPlayType(videos[videoIdx].contentType, systemString) !== '') {
supportedVideo.push(videos[videoIdx]);
}
}
}
// No supported audio or video in this configuration OR we have
// requested audio or video configuration that is not supported
if ((!supportedAudio && !supportedVideo) ||
(supportedAudio && supportedAudio.length === 0) ||
(supportedVideo && supportedVideo.length === 0)) {
continue;
}
// This configuration is supported
found = true;
const ksConfig = new KeySystemConfiguration(supportedAudio, supportedVideo);
const ks = protectionKeyController.getKeySystemBySystemString(systemString);
eventBus.trigger(events.KEY_SYSTEM_ACCESS_COMPLETE, { data: new KeySystemAccess(ks, ksConfig) });
break;
}
}
if (!found) {
eventBus.trigger(events.KEY_SYSTEM_ACCESS_COMPLETE, {error: 'Key system access denied! -- No valid audio/video content configurations detected!'});
}
}
function selectKeySystem(keySystemAccess) {
keySystem = keySystemAccess.keySystem;
eventBus.trigger(events.INTERNAL_KEY_SYSTEM_SELECTED);
}
function setMediaElement(mediaElement) {
if (videoElement === mediaElement) {
return;
}
// Replacing the previous element
if (videoElement) {
removeEventListeners();
}
videoElement = mediaElement;
// Only if we are not detaching from the existing element
if (videoElement) {
videoElement.addEventListener(api.keyerror, eventHandler);
videoElement.addEventListener(api.needkey, eventHandler);
videoElement.addEventListener(api.keymessage, eventHandler);
videoElement.addEventListener(api.keyadded, eventHandler);
eventBus.trigger(events.VIDEO_ELEMENT_SELECTED);
}
}
function createKeySession(initData /*, protData, keySystemType */) {
if (!keySystem) {
throw new Error('Can not create sessions until you have selected a key system');
}
// Determine if creating a new session is allowed
if (moreSessionsAllowed || sessions.length === 0) {
const newSession = { // Implements SessionToken
sessionID: null,
initData: initData,
getSessionID: function () {
return this.sessionID;
},
getExpirationTime: function () {
return NaN;
},
getSessionType: function () {
return 'temporary';
}
};
pendingSessions.push(newSession);
// Send our request to the CDM
videoElement[api.generateKeyRequest](keySystem.systemString, new Uint8Array(initData));
return newSession;
} else {
throw new Error('Multiple sessions not allowed!');
}
}
function updateKeySession(sessionToken, message) {
const sessionID = sessionToken.sessionID;
if (!protectionKeyController.isClearKey(keySystem)) {
// Send our request to the CDM
videoElement[api.addKey](keySystem.systemString,
new Uint8Array(message), new Uint8Array(sessionToken.initData), sessionID);
} else {
// For clearkey, message is a ClearKeyKeySet
for (let i = 0; i < message.keyPairs.length; i++) {
videoElement[api.addKey](keySystem.systemString,
message.keyPairs[i].key, message.keyPairs[i].keyID, sessionID);
}
}
}
function closeKeySession(sessionToken) {
// Send our request to the CDM
try {
videoElement[api.cancelKeyRequest](keySystem.systemString, sessionToken.sessionID);
} catch (error) {
eventBus.trigger(events.KEY_SESSION_CLOSED, {data: null, error: 'Error closing session (' + sessionToken.sessionID + ') ' + error.message});
}
}
function setServerCertificate(/*serverCertificate*/) { /* Not supported */ }
function loadKeySession(/*sessionID*/) { /* Not supported */ }
function removeKeySession(/*sessionToken*/) { /* Not supported */ }
function createEventHandler() {
return {
handleEvent: function (event) {
let sessionToken = null;
switch (event.type) {
case api.needkey:
let initData = ArrayBuffer.isView(event.initData) ? event.initData.buffer : event.initData;
eventBus.trigger(events.NEED_KEY, {key: new NeedKey(initData, 'cenc')});
break;
case api.keyerror:
sessionToken = findSessionByID(sessions, event.sessionId);
if (!sessionToken) {
sessionToken = findSessionByID(pendingSessions, event.sessionId);
}
if (sessionToken) {
let code = ProtectionErrors.MEDIA_KEYERR_CODE;
let msg = '';
switch (event.errorCode.code) {
case 1:
code = ProtectionErrors.MEDIA_KEYERR_UNKNOWN_CODE;
msg += 'MEDIA_KEYERR_UNKNOWN - ' + ProtectionErrors.MEDIA_KEYERR_UNKNOWN_MESSAGE;
break;
case 2:
code = ProtectionErrors.MEDIA_KEYERR_CLIENT_CODE;
msg += 'MEDIA_KEYERR_CLIENT - ' + ProtectionErrors.MEDIA_KEYERR_CLIENT_MESSAGE;
break;
case 3:
code = ProtectionErrors.MEDIA_KEYERR_SERVICE_CODE;
msg += 'MEDIA_KEYERR_SERVICE - ' + ProtectionErrors.MEDIA_KEYERR_SERVICE_MESSAGE;
break;
case 4:
code = ProtectionErrors.MEDIA_KEYERR_OUTPUT_CODE;
msg += 'MEDIA_KEYERR_OUTPUT - ' + ProtectionErrors.MEDIA_KEYERR_OUTPUT_MESSAGE;
break;
case 5:
code = ProtectionErrors.MEDIA_KEYERR_HARDWARECHANGE_CODE;
msg += 'MEDIA_KEYERR_HARDWARECHANGE - ' + ProtectionErrors.MEDIA_KEYERR_HARDWARECHANGE_MESSAGE;
break;
case 6:
code = ProtectionErrors.MEDIA_KEYERR_DOMAIN_CODE;
msg += 'MEDIA_KEYERR_DOMAIN - ' + ProtectionErrors.MEDIA_KEYERR_DOMAIN_MESSAGE;
break;
}
msg += ' System Code = ' + event.systemCode;
// TODO: Build error string based on key error
eventBus.trigger(events.KEY_ERROR, {data: new DashJSError(code, msg, sessionToken)});
} else {
logger.error('No session token found for key error');
}
break;
case api.keyadded:
sessionToken = findSessionByID(sessions, event.sessionId);
if (!sessionToken) {
sessionToken = findSessionByID(pendingSessions, event.sessionId);
}
if (sessionToken) {
logger.debug('DRM: Key added.');
eventBus.trigger(events.KEY_ADDED, {data: sessionToken});//TODO not sure anything is using sessionToken? why there?
} else {
logger.debug('No session token found for key added');
}
break;
case api.keymessage:
// If this CDM does not support session IDs, we will be limited
// to a single session
moreSessionsAllowed = (event.sessionId !== null) && (event.sessionId !== undefined);
// SessionIDs supported
if (moreSessionsAllowed) {
// Attempt to find an uninitialized token with this sessionID
sessionToken = findSessionByID(sessions, event.sessionId);
if (!sessionToken && pendingSessions.length > 0) {
// This is the first message for our latest session, so set the
// sessionID and add it to our list
sessionToken = pendingSessions.shift();
sessions.push(sessionToken);
sessionToken.sessionID = event.sessionId;
eventBus.trigger(events.KEY_SESSION_CREATED, {data: sessionToken});
}
} else if (pendingSessions.length > 0) { // SessionIDs not supported
sessionToken = pendingSessions.shift();
sessions.push(sessionToken);
if (pendingSessions.length !== 0) {
errHandler.mediaKeyMessageError(ProtectionErrors.MEDIA_KEY_MESSAGE_ERROR_MESSAGE);
errHandler.error(new DashJSError(ProtectionErrors.MEDIA_KEY_MESSAGE_ERROR_CODE, ProtectionErrors.MEDIA_KEY_MESSAGE_ERROR_MESSAGE));
}
}
if (sessionToken) {
let message = ArrayBuffer.isView(event.message) ? event.message.buffer : event.message;
// For ClearKey, the spec mandates that you pass this message to the
// addKey method, so we always save it to the token since there is no
// way to tell which key system is in use
sessionToken.keyMessage = message;
eventBus.trigger(events.INTERNAL_KEY_MESSAGE, {data: new KeyMessage(sessionToken, message, event.defaultURL)});
} else {
logger.warn('No session token found for key message');
}
break;
}
}
};
}
/**
* Helper function to retrieve the stored session token based on a given
* sessionID value
*
* @param {Array} sessionArray - the array of sessions to search
* @param {*} sessionID - the sessionID to search for
* @returns {*} the session token with the given sessionID
*/
function findSessionByID(sessionArray, sessionID) {
if (!sessionID || !sessionArray) {
return null;
} else {
const len = sessionArray.length;
for (let i = 0; i < len; i++) {
if (sessionArray[i].sessionID == sessionID) {
return sessionArray[i];
}
}
return null;
}
}
function removeEventListeners() {
videoElement.removeEventListener(api.keyerror, eventHandler);
videoElement.removeEventListener(api.needkey, eventHandler);
videoElement.removeEventListener(api.keymessage, eventHandler);
videoElement.removeEventListener(api.keyadded, eventHandler);
}
instance = {
getAllInitData: getAllInitData,
requestKeySystemAccess: requestKeySystemAccess,
getKeySystem: getKeySystem,
selectKeySystem: selectKeySystem,
setMediaElement: setMediaElement,
createKeySession: createKeySession,
updateKeySession: updateKeySession,
closeKeySession: closeKeySession,
setServerCertificate: setServerCertificate,
loadKeySession: loadKeySession,
removeKeySession: removeKeySession,
stop: reset,
reset: reset
};
setup();
return instance;
}
ProtectionModel_01b.__dashjs_factory_name = 'ProtectionModel_01b';
export default dashjs.FactoryMaker.getClassFactory(ProtectionModel_01b); /* jshint ignore:line */