diff --git a/baselines/dom.generated.d.ts b/baselines/dom.generated.d.ts
index d3b64fd20..ad12bbd62 100644
--- a/baselines/dom.generated.d.ts
+++ b/baselines/dom.generated.d.ts
@@ -973,11 +973,11 @@ interface MIDIOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
@@ -1632,21 +1632,27 @@ interface RTCDtlsFingerprint {
     value?: string;
 }
 
-interface RTCEncodedAudioFrameMetadata {
+interface RTCEncodedAudioFrameMetadata extends RTCEncodedFrameMetadata {
+    audioLevel?: number;
+    sequenceNumber?: number;
+}
+
+interface RTCEncodedFrameMetadata {
+    captureTime?: DOMHighResTimeStamp;
     contributingSources?: number[];
+    mimeType?: string;
     payloadType?: number;
-    sequenceNumber?: number;
+    receiveTime?: DOMHighResTimeStamp;
+    rtpTimestamp?: number;
+    senderCaptureTimeOffset?: DOMHighResTimeStamp;
     synchronizationSource?: number;
 }
 
-interface RTCEncodedVideoFrameMetadata {
-    contributingSources?: number[];
+interface RTCEncodedVideoFrameMetadata extends RTCEncodedFrameMetadata {
     dependencies?: number[];
     frameId?: number;
     height?: number;
-    payloadType?: number;
     spatialIndex?: number;
-    synchronizationSource?: number;
     temporalIndex?: number;
     timestamp?: number;
     width?: number;
diff --git a/baselines/serviceworker.generated.d.ts b/baselines/serviceworker.generated.d.ts
index 5cee0af7b..d86a88e20 100644
--- a/baselines/serviceworker.generated.d.ts
+++ b/baselines/serviceworker.generated.d.ts
@@ -378,11 +378,11 @@ interface LockOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
diff --git a/baselines/sharedworker.generated.d.ts b/baselines/sharedworker.generated.d.ts
index 19f7785cc..69f6a82da 100644
--- a/baselines/sharedworker.generated.d.ts
+++ b/baselines/sharedworker.generated.d.ts
@@ -322,11 +322,11 @@ interface LockOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
diff --git a/baselines/ts5.5/dom.generated.d.ts b/baselines/ts5.5/dom.generated.d.ts
index 31829ff26..f5ee8b21c 100644
--- a/baselines/ts5.5/dom.generated.d.ts
+++ b/baselines/ts5.5/dom.generated.d.ts
@@ -973,11 +973,11 @@ interface MIDIOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
@@ -1632,21 +1632,27 @@ interface RTCDtlsFingerprint {
     value?: string;
 }
 
-interface RTCEncodedAudioFrameMetadata {
+interface RTCEncodedAudioFrameMetadata extends RTCEncodedFrameMetadata {
+    audioLevel?: number;
+    sequenceNumber?: number;
+}
+
+interface RTCEncodedFrameMetadata {
+    captureTime?: DOMHighResTimeStamp;
     contributingSources?: number[];
+    mimeType?: string;
     payloadType?: number;
-    sequenceNumber?: number;
+    receiveTime?: DOMHighResTimeStamp;
+    rtpTimestamp?: number;
+    senderCaptureTimeOffset?: DOMHighResTimeStamp;
     synchronizationSource?: number;
 }
 
-interface RTCEncodedVideoFrameMetadata {
-    contributingSources?: number[];
+interface RTCEncodedVideoFrameMetadata extends RTCEncodedFrameMetadata {
     dependencies?: number[];
     frameId?: number;
     height?: number;
-    payloadType?: number;
     spatialIndex?: number;
-    synchronizationSource?: number;
     temporalIndex?: number;
     timestamp?: number;
     width?: number;
diff --git a/baselines/ts5.5/serviceworker.generated.d.ts b/baselines/ts5.5/serviceworker.generated.d.ts
index 7c78f95fd..974bd93e4 100644
--- a/baselines/ts5.5/serviceworker.generated.d.ts
+++ b/baselines/ts5.5/serviceworker.generated.d.ts
@@ -378,11 +378,11 @@ interface LockOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
diff --git a/baselines/ts5.5/sharedworker.generated.d.ts b/baselines/ts5.5/sharedworker.generated.d.ts
index 27f0207b1..3583e34e0 100644
--- a/baselines/ts5.5/sharedworker.generated.d.ts
+++ b/baselines/ts5.5/sharedworker.generated.d.ts
@@ -322,11 +322,11 @@ interface LockOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
diff --git a/baselines/ts5.5/webworker.generated.d.ts b/baselines/ts5.5/webworker.generated.d.ts
index 2f5543684..ce8d02ff1 100644
--- a/baselines/ts5.5/webworker.generated.d.ts
+++ b/baselines/ts5.5/webworker.generated.d.ts
@@ -482,11 +482,11 @@ interface LockOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
@@ -633,21 +633,27 @@ interface QueuingStrategyInit {
     highWaterMark: number;
 }
 
-interface RTCEncodedAudioFrameMetadata {
+interface RTCEncodedAudioFrameMetadata extends RTCEncodedFrameMetadata {
+    audioLevel?: number;
+    sequenceNumber?: number;
+}
+
+interface RTCEncodedFrameMetadata {
+    captureTime?: DOMHighResTimeStamp;
     contributingSources?: number[];
+    mimeType?: string;
     payloadType?: number;
-    sequenceNumber?: number;
+    receiveTime?: DOMHighResTimeStamp;
+    rtpTimestamp?: number;
+    senderCaptureTimeOffset?: DOMHighResTimeStamp;
     synchronizationSource?: number;
 }
 
-interface RTCEncodedVideoFrameMetadata {
-    contributingSources?: number[];
+interface RTCEncodedVideoFrameMetadata extends RTCEncodedFrameMetadata {
     dependencies?: number[];
     frameId?: number;
     height?: number;
-    payloadType?: number;
     spatialIndex?: number;
-    synchronizationSource?: number;
     temporalIndex?: number;
     timestamp?: number;
     width?: number;
diff --git a/baselines/ts5.6/dom.generated.d.ts b/baselines/ts5.6/dom.generated.d.ts
index 435ce4c60..06898eb66 100644
--- a/baselines/ts5.6/dom.generated.d.ts
+++ b/baselines/ts5.6/dom.generated.d.ts
@@ -973,11 +973,11 @@ interface MIDIOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
@@ -1632,21 +1632,27 @@ interface RTCDtlsFingerprint {
     value?: string;
 }
 
-interface RTCEncodedAudioFrameMetadata {
+interface RTCEncodedAudioFrameMetadata extends RTCEncodedFrameMetadata {
+    audioLevel?: number;
+    sequenceNumber?: number;
+}
+
+interface RTCEncodedFrameMetadata {
+    captureTime?: DOMHighResTimeStamp;
     contributingSources?: number[];
+    mimeType?: string;
     payloadType?: number;
-    sequenceNumber?: number;
+    receiveTime?: DOMHighResTimeStamp;
+    rtpTimestamp?: number;
+    senderCaptureTimeOffset?: DOMHighResTimeStamp;
     synchronizationSource?: number;
 }
 
-interface RTCEncodedVideoFrameMetadata {
-    contributingSources?: number[];
+interface RTCEncodedVideoFrameMetadata extends RTCEncodedFrameMetadata {
     dependencies?: number[];
     frameId?: number;
     height?: number;
-    payloadType?: number;
     spatialIndex?: number;
-    synchronizationSource?: number;
     temporalIndex?: number;
     timestamp?: number;
     width?: number;
diff --git a/baselines/ts5.6/serviceworker.generated.d.ts b/baselines/ts5.6/serviceworker.generated.d.ts
index 7c78f95fd..974bd93e4 100644
--- a/baselines/ts5.6/serviceworker.generated.d.ts
+++ b/baselines/ts5.6/serviceworker.generated.d.ts
@@ -378,11 +378,11 @@ interface LockOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
diff --git a/baselines/ts5.6/sharedworker.generated.d.ts b/baselines/ts5.6/sharedworker.generated.d.ts
index 27f0207b1..3583e34e0 100644
--- a/baselines/ts5.6/sharedworker.generated.d.ts
+++ b/baselines/ts5.6/sharedworker.generated.d.ts
@@ -322,11 +322,11 @@ interface LockOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
diff --git a/baselines/ts5.6/webworker.generated.d.ts b/baselines/ts5.6/webworker.generated.d.ts
index 2f5543684..ce8d02ff1 100644
--- a/baselines/ts5.6/webworker.generated.d.ts
+++ b/baselines/ts5.6/webworker.generated.d.ts
@@ -482,11 +482,11 @@ interface LockOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
@@ -633,21 +633,27 @@ interface QueuingStrategyInit {
     highWaterMark: number;
 }
 
-interface RTCEncodedAudioFrameMetadata {
+interface RTCEncodedAudioFrameMetadata extends RTCEncodedFrameMetadata {
+    audioLevel?: number;
+    sequenceNumber?: number;
+}
+
+interface RTCEncodedFrameMetadata {
+    captureTime?: DOMHighResTimeStamp;
     contributingSources?: number[];
+    mimeType?: string;
     payloadType?: number;
-    sequenceNumber?: number;
+    receiveTime?: DOMHighResTimeStamp;
+    rtpTimestamp?: number;
+    senderCaptureTimeOffset?: DOMHighResTimeStamp;
     synchronizationSource?: number;
 }
 
-interface RTCEncodedVideoFrameMetadata {
-    contributingSources?: number[];
+interface RTCEncodedVideoFrameMetadata extends RTCEncodedFrameMetadata {
     dependencies?: number[];
     frameId?: number;
     height?: number;
-    payloadType?: number;
     spatialIndex?: number;
-    synchronizationSource?: number;
     temporalIndex?: number;
     timestamp?: number;
     width?: number;
diff --git a/baselines/webworker.generated.d.ts b/baselines/webworker.generated.d.ts
index 95e743c50..924a7de5b 100644
--- a/baselines/webworker.generated.d.ts
+++ b/baselines/webworker.generated.d.ts
@@ -482,11 +482,11 @@ interface LockOptions {
 }
 
 interface MediaCapabilitiesDecodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaDecodingConfiguration;
+    configuration: MediaDecodingConfiguration;
 }
 
 interface MediaCapabilitiesEncodingInfo extends MediaCapabilitiesInfo {
-    configuration?: MediaEncodingConfiguration;
+    configuration: MediaEncodingConfiguration;
 }
 
 interface MediaCapabilitiesInfo {
@@ -633,21 +633,27 @@ interface QueuingStrategyInit {
     highWaterMark: number;
 }
 
-interface RTCEncodedAudioFrameMetadata {
+interface RTCEncodedAudioFrameMetadata extends RTCEncodedFrameMetadata {
+    audioLevel?: number;
+    sequenceNumber?: number;
+}
+
+interface RTCEncodedFrameMetadata {
+    captureTime?: DOMHighResTimeStamp;
     contributingSources?: number[];
+    mimeType?: string;
     payloadType?: number;
-    sequenceNumber?: number;
+    receiveTime?: DOMHighResTimeStamp;
+    rtpTimestamp?: number;
+    senderCaptureTimeOffset?: DOMHighResTimeStamp;
     synchronizationSource?: number;
 }
 
-interface RTCEncodedVideoFrameMetadata {
-    contributingSources?: number[];
+interface RTCEncodedVideoFrameMetadata extends RTCEncodedFrameMetadata {
     dependencies?: number[];
     frameId?: number;
     height?: number;
-    payloadType?: number;
     spatialIndex?: number;
-    synchronizationSource?: number;
     temporalIndex?: number;
     timestamp?: number;
     width?: number;
diff --git a/inputfiles/mdn b/inputfiles/mdn
index c99b4f2d0..364a4d02b 160000
--- a/inputfiles/mdn
+++ b/inputfiles/mdn
@@ -1 +1 @@
-Subproject commit c99b4f2d0ea81c0e8822a749d218015c75995b5b
+Subproject commit 364a4d02b10854ab7cef4ff4b0ec3616d4e1c8ab
diff --git a/package-lock.json b/package-lock.json
index 2e565a23f..687186ba5 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -348,9 +348,9 @@
       }
     },
     "node_modules/@mdn/browser-compat-data": {
-      "version": "6.0.14",
-      "resolved": "https://registry.npmjs.org/@mdn/browser-compat-data/-/browser-compat-data-6.0.14.tgz",
-      "integrity": "sha512-WyNFl0UDRo/gUgp6bwvW/N0zv2DDQlmJB6G9svGBi9VSTXSww2IJj1PKwhlcXVQSD0B2fzL9bIFyCMJl4A1aLA==",
+      "version": "6.0.16",
+      "resolved": "https://registry.npmjs.org/@mdn/browser-compat-data/-/browser-compat-data-6.0.16.tgz",
+      "integrity": "sha512-j8VB83nzHFhRyu48V3DRpWySUfMuvbbJ1Cu/yIMadfnn5ZhfC45+NxAKGq3CntSSGTLOsSwbujbFxmFRJekasQ==",
       "dev": true,
       "license": "CC0-1.0"
     },
@@ -949,9 +949,9 @@
       }
     },
     "node_modules/@webref/css": {
-      "version": "6.21.0",
-      "resolved": "https://registry.npmjs.org/@webref/css/-/css-6.21.0.tgz",
-      "integrity": "sha512-cSSJibUctBM3Ht/ieVfm7/wvq+YO4z1YYGKi8vm4yoPh1Z7yxtyKiEh8+aM8B89grSzTXjRys7Q+PtwX6/Cmgg==",
+      "version": "6.21.1",
+      "resolved": "https://registry.npmjs.org/@webref/css/-/css-6.21.1.tgz",
+      "integrity": "sha512-IATwZkF8tK5SueyyF8VPKE7EhrjAeS5esmCVQqowNLSaW0Gpv5Z8ZzjCh1FPEKIGfCfhzYmSL+vMEPKfvE7wcg==",
       "dev": true,
       "license": "MIT",
       "peerDependencies": {
@@ -973,9 +973,9 @@
       "license": "MIT"
     },
     "node_modules/@webref/idl": {
-      "version": "3.63.0",
-      "resolved": "https://registry.npmjs.org/@webref/idl/-/idl-3.63.0.tgz",
-      "integrity": "sha512-ccHJi1I4jMSJ0ojpJ7Tnwc78V7aWxGVVyNx4pkQujepAG6RTVVQg0VAfNYvUFGaOISv4FM9BlhRCS4En69g4zg==",
+      "version": "3.64.0",
+      "resolved": "https://registry.npmjs.org/@webref/idl/-/idl-3.64.0.tgz",
+      "integrity": "sha512-cNSin5QAkddjOOk8PeqUqyUDo+wTIyVazaGXjXrxQhTcXva3nIn+ac+rLiBgMLRirHCB5+6MDRkjmVx1rBkfkQ==",
       "dev": true,
       "license": "MIT",
       "peerDependencies": {