Filter duplicate initData from manifest by key ID

Adds a new field to initDataOverride, key Id, that contains the
default key Id corresponding to this initData. This is used to filter
initDatas by their key Ids, hopefully cutting down on unnecessary
license requests.

Closes #580

Change-Id: Ie228d6c0f4c693b19b4119ec4f72a85d555215c1

externs/shaka/manifest.js

@@ -113,7 +113,8 @@ shakaExtern.Period;
 /**
  * @typedef {{
  *   initData: !Uint8Array,
- *   initDataType: string
+ *   initDataType: string,
+ *   keyId: ?string
  * }}
  *
  * @description
@@ -125,6 +126,8 @@ shakaExtern.Period;
  *   Initialization data in the format indicated by initDataType.
  * @property {string} initDataType
  *   A string to indicate what format initData is in.
+ * @property {?string} keyId
+ *   The key Id that corresponds to this initData.
  *
  * @exportDoc
  */

lib/dash/content_protection.js

@@ -173,6 +173,15 @@ shaka.dash.ContentProtection.parseFromAdaptationSet = function(
             });
   }
 
+  // attach the default keyId, if it exists, to every initData
+  if (defaultKeyId) {
+    drmInfos.forEach(function(drmInfo) {
+      drmInfo.initData.forEach(function(initData) {
+        initData.keyId = defaultKeyId;
+      });
+    });
+  }
+
   return {
     defaultKeyId: defaultKeyId,
     defaultInit: defaultInit,
@@ -334,7 +343,8 @@ shaka.dash.ContentProtection.parseElements_ = function(elems) {
             /** @type {shakaExtern.InitDataOverride} */
             var ret = {
               initDataType: 'cenc',
-              initData: shaka.util.Uint8ArrayUtils.fromBase64(pssh)
+              initData: shaka.util.Uint8ArrayUtils.fromBase64(pssh),
+              keyId: null
             };
             return ret;
           });

lib/media/drm_engine.js

@@ -765,6 +765,11 @@ shaka.media.DrmEngine.prototype.processDrmInfos_ =
    * @return {boolean}
    */
   function initDataOverrideEqual(a, b) {
+    if (a.keyId && a.keyId == b.keyId) {
+      // Two initDatas with the same keyId are considered to be the same,
+      // unless that "same keyId" is null.
+      return true;
+    }
     return a.initDataType == b.initDataType &&
            shaka.util.Uint8ArrayUtils.equal(a.initData, b.initData);
   }

test/dash/dash_parser_content_protection_unit.js

@@ -91,34 +91,31 @@ describe('DashParser ContentProtection', function() {
    * Build an expected manifest which checks DRM-related fields.
    *
    * @param {!Array.<!Object>} drmInfos A list of DrmInfo-like objects.
+   * @param {number=} opt_numVariants The number of variants, default 2.
    * @return {Object} A Manifest-like object.
    */
-  function buildExpectedManifest(drmInfos) {
+  function buildExpectedManifest(drmInfos, opt_numVariants) {
+    var numVariants = opt_numVariants || 2;
     var keyIds = [];
     if (drmInfos.length > 0) {
       keyIds = drmInfos[0].sample.keyIds;
     }
-    if (keyIds.length == 0) {
-      keyIds = [null, null];
+
+    var variants = [];
+    for (var i = 0; i < numVariants; i++) {
+      var variant = jasmine.objectContaining({
+        drmInfos: drmInfos,
+        video: jasmine.objectContaining({
+          keyId: keyIds[i] || null
+        })
+      });
+      variants.push(variant);
     }
 
     return jasmine.objectContaining({
       periods: [
         jasmine.objectContaining({
-          variants: [
-            jasmine.objectContaining({
-              drmInfos: drmInfos,
-              video: jasmine.objectContaining({
-                keyId: keyIds[0]
-              })
-            }),
-            jasmine.objectContaining({
-              drmInfos: drmInfos,
-              video: jasmine.objectContaining({
-                keyId: keyIds[1]
-              })
-            })
-          ], // variants
+          variants: variants,
           textStreams: []
         })
       ]  // periods
@@ -131,15 +128,20 @@ describe('DashParser ContentProtection', function() {
    * @param {string} keySystem
    * @param {Array.<string>=} opt_keyIds
    * @param {Array.<string>=} opt_base64Psshs
+   * @param {Array.<string>=} opt_initDataKeyIds
    * @return {Object} A DrmInfo-like object.
    */
-  function buildDrmInfo(keySystem, opt_keyIds, opt_base64Psshs) {
+  function buildDrmInfo(keySystem, opt_keyIds,
+      opt_base64Psshs, opt_initDataKeyIds) {
     var base64Psshs = opt_base64Psshs || [];
-    var initData = base64Psshs.map(function(base64) {
-      return {
+    var initData = base64Psshs.map(function(base64, index) {
+      /** @type {shakaExtern.InitDataOverride} */
+      var initData = {
         initDataType: 'cenc',
-        initData: shaka.util.Uint8ArrayUtils.fromBase64(base64)
+        initData: shaka.util.Uint8ArrayUtils.fromBase64(base64),
+        keyId: opt_initDataKeyIds ? opt_initDataKeyIds[index] : null
       };
+      return initData;
     });
     var keyIds = opt_keyIds || [];
     var containing = {keySystem: keySystem, initData: initData, keyIds: keyIds};
@@ -223,6 +225,27 @@ describe('DashParser ContentProtection', function() {
     testDashParser(done, source, expected);
   });
 
+  it('sets key IDs for the init data', function(done) {
+    var source = buildManifestText([
+      // AdaptationSet lines
+    ], [
+      // Representation 1 lines
+      '<ContentProtection',
+      '    schemeIdUri="urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed"',
+      '    value="cenc"',
+      '    cenc:default_KID="DEADBEEF-FEED-BAAD-F00D-000008675309">',
+      '  <cenc:pssh>bm8gaHVtYW4gY2FuIHJlYWQgYmFzZTY0IGRpcmVjdGx5</cenc:pssh>',
+      '</ContentProtection'
+    ], []);
+    var expected = buildExpectedManifest([
+      buildDrmInfo('com.widevine.alpha',
+          ['deadbeeffeedbaadf00d000008675309'], // key Id
+          ['bm8gaHVtYW4gY2FuIHJlYWQgYmFzZTY0IGRpcmVjdGx5'], // initData
+          ['deadbeeffeedbaadf00d000008675309'])], // key Id for initData
+    1); // one variant
+    testDashParser(done, source, expected);
+  });
+
   it('lets Representations override key IDs', function(done) {
     var source = buildManifestText([
       // AdaptationSet lines