diff --git a/index.bs b/index.bs
index e7aabd4..794dab4 100644
--- a/index.bs
+++ b/index.bs
@@ -426,12 +426,32 @@ dictionary RTCEncodedVideoFrameMetadata {
 // re-use or extend the equivalent defined in WebCodecs.
 [Exposed=(Window,DedicatedWorker), Serializable]
 interface RTCEncodedVideoFrame {
+    constructor(RTCEncodedVideoFrame originalFrame, RTCEncodedVideoFrameMetadata newMetadata);
     readonly attribute RTCEncodedVideoFrameType type;
     attribute ArrayBuffer data;
     RTCEncodedVideoFrameMetadata getMetadata();
 };
 </pre>
 
+### Constructor ### {#RTCEncodedVideoFrame-members}
+<dl dfn-for="RTCEncodedVideoFrame" class="dictionary-members">
+    <dt>
+        <dfn for="RTCEncodedVideoFrame" method>constructor()</dfn>
+    </dt>
+    <dd>
+        <p>
+            Create a new RTCEncodedVideoFrame from the given |originalFrame| and sets its metadata to |newMetadata|.
+            
+            When called, run the following steps:
+
+            1. Set this.`[[type]]` to |originalFrame|.`[[type]]`.
+            1. Set this.`[[data]]` to |originalFrame|.`[[data]]`.
+            1. Set the internal representation of metadata to |newMetadata| such that this.`[[getMetadata()]]` returns |newMetadata|.
+
+        </p>
+    </dd>
+</dl>
+
 ### Members ### {#RTCEncodedVideoFrame-members}
 <dl dfn-for="RTCEncodedVideoFrame" class="dictionary-members">
     <dt>
@@ -626,11 +646,30 @@ dictionary RTCEncodedAudioFrameMetadata {
 <pre class="idl">
 [Exposed=(Window,DedicatedWorker), Serializable]
 interface RTCEncodedAudioFrame {
+    constructor(RTCEncodedAudioFrame originalFrame, RTCEncodedAudioFrameMetadata newMetadata);
     attribute ArrayBuffer data;
     RTCEncodedAudioFrameMetadata getMetadata();
 };
 </pre>
 
+### Constructor ### {#RTCEncodedAudioFrame-members}
+<dl dfn-for="RTCEncodedAudioFrame" class="dictionary-members">
+    <dt>
+        <dfn for="RTCEncodedAudioFrame" method>constructor()</dfn>
+    </dt>
+    <dd>
+        <p>
+            Create a new RTCEncodedAudioFrame from the given |originalFrame| and sets its metadata to |newMetadata|.
+            
+            When called, run the following steps:
+
+            1. Set this.`[[data]]` to |originalFrame|.`[[data]]`.
+            1. Set the internal representation of metadata to |newMetadata| such that this.`[[getMetadata()]]` returns |newMetadata|.
+
+        </p>
+    </dd>
+</dl>
+
 ### Members ### {#RTCEncodedAudioFrame-members}
 <dl dfn-for="RTCEncodedAudioFrame" class="dictionary-members">
     <dt>