update wording of metadata

Author: palak8669

index.bs

@@ -446,7 +446,9 @@ interface RTCEncodedVideoFrame {
 
             1. Set this.`[[type]]` to |originalFrame|.`[[type]]`.
             1. Let this.`[[data]]` be a new ArrayBuffer object whose `[[ArrayBufferData]]` internal slot value is |originalFrame|.`[[data]]`.`[[ArrayBufferData]]`, and whose `[[ArrayBufferByteLength]]` internal slot value is |originalFrame|.`[[data]]`.`[[ArrayBufferByteLength]]`.
-            1. If |newMetadata| is not empty, set the internal representation of metadata to |newMetadata| such that {{RTCEncodedVideoFrame/getMetadata()}} returns |newMetadata|. Otherwise, set the internal representation of metadata to originalFrame.`[[getMetadata()]]`.
+            1. Let `[[metadata]]` represent the metadata associated with this newly constructed frame.
+                1. For each {`[[key]]`,`[[value]]`} pair of |originalFrame|.`[[getMetadata()]]`, set `[[metadata]]`.`[[key]]` to `[[value]]`.
+                1. For each {`[[key]]`,`[[value]]`} pair of |newMetadata|, if the `[[value]]` exists, set `[[metadata]]`.`[[key]]` to `[[value]]`.
 
         </p>
     </dd>
@@ -664,7 +666,9 @@ interface RTCEncodedAudioFrame {
             When called, run the following steps:
 
             1. Let this.`[[data]]` be a new ArrayBuffer object whose `[[ArrayBufferData]]` internal slot value is |originalFrame|.`[[data]]`.`[[ArrayBufferData]]`, and whose `[[ArrayBufferByteLength]]` internal slot value is |originalFrame|.`[[data]]`.`[[ArrayBufferByteLength]]`.
-            1. If |newMetadata| is not empty, set the internal representation of metadata to |newMetadata| such that {{RTCEncodedAudioFrame/getMetadata()}} returns |newMetadata|. Otherwise, set the internal representation of metadata to originalFrame.`[[getMetadata()]]`.
+            1. Let `[[metadata]]` represent the metadata associated with this newly constructed frame.
+                1. For each {`[[key]]`,`[[value]]`} pair of |originalFrame|.`[[getMetadata()]]`, set `[[metadata]]`.`[[key]]` to `[[value]]`.
+                1. For each {`[[key]]`,`[[value]]`} pair of |newMetadata|, if the `[[value]]` exists, set `[[metadata]]`.`[[key]]` to `[[value]]`.
 
         </p>
     </dd>