Migrate Rtx modifier

modules/sdp/RtxModifier.spec.ts

@@ -1,6 +1,6 @@
 import * as transform from 'sdp-transform';
 
-import RtxModifier from './RtxModifier.js';
+import RtxModifier from './RtxModifier.ts';
 import SDPUtil from './SDPUtil';
 import { default as SampleSdpStrings } from './SampleSdpStrings';
 

modules/sdp/RtxModifier.js → modules/sdp/RtxModifier.ts

@@ -5,10 +5,20 @@ import { MediaType } from '../../service/RTC/MediaType';
 import { SSRC_GROUP_SEMANTICS } from '../../service/RTC/StandardVideoQualitySettings';
 
 import SDPUtil from './SDPUtil';
-import { SdpTransformWrap, parseSecondarySSRC } from './SdpTransformUtil';
+import { MLineWrap, SdpTransformWrap, parseSecondarySSRC } from './SdpTransformUtil';
 
 const logger = getLogger('sdp:RtxModifier');
 
+/**
+ * Helper interfaces for type safety.
+ */
+export interface IPrimarySsrcInfo {
+    cname?: string;
+    id: number;
+    msid?: string;
+}
+
+
 /**
  * Begin helper functions
  */
@@ -22,7 +32,11 @@ const logger = getLogger('sdp:RtxModifier');
  *  primary ssrc
  * @param {number} rtxSsrc the rtx ssrc to associate with the primary ssrc
  */
-function updateAssociatedRtxStream(mLine, primarySsrcInfo, rtxSsrc) {
+function updateAssociatedRtxStream(
+        mLine: MLineWrap,
+        primarySsrcInfo: IPrimarySsrcInfo,
+        rtxSsrc: number
+): void {
     const primarySsrc = primarySsrcInfo.id;
     const primarySsrcMsid = primarySsrcInfo.msid;
     const primarySsrcCname = primarySsrcInfo.cname;
@@ -63,6 +77,12 @@ function updateAssociatedRtxStream(mLine, primarySsrcInfo, rtxSsrc) {
  *  and makes sure that they remain consistent
  */
 export default class RtxModifier {
+    /**
+     * Map of video ssrc to corresponding RTX
+     *  ssrc
+     */
+    private correspondingRtxSsrcs: Map<number, number>;
+
     /**
      * Constructor
      */
@@ -71,15 +91,15 @@ export default class RtxModifier {
          * Map of video ssrc to corresponding RTX
          *  ssrc
          */
-        this.correspondingRtxSsrcs = new Map();
+        this.correspondingRtxSsrcs = new Map<number, number>();
     }
 
     /**
      * Clear the cached map of primary video ssrcs to
      *  their corresponding rtx ssrcs so that they will
      *  not be used for the next call to modifyRtxSsrcs
      */
-    clearSsrcCache() {
+    clearSsrcCache(): void {
         this.correspondingRtxSsrcs.clear();
     }
 
@@ -89,7 +109,7 @@ export default class RtxModifier {
      * @param {Map} ssrcMapping a mapping of primary video
      *  ssrcs to their corresponding rtx ssrcs
      */
-    setSsrcCache(ssrcMapping) {
+    setSsrcCache(ssrcMapping: Map<number, number>): void {
         logger.debug('Setting ssrc cache to ', ssrcMapping);
         this.correspondingRtxSsrcs = ssrcMapping;
     }
@@ -101,19 +121,19 @@ export default class RtxModifier {
      * @param {string} sdpStr sdp in raw string format
      * @returns {string} The modified sdp in raw string format.
      */
-    modifyRtxSsrcs(sdpStr) {
+    modifyRtxSsrcs(sdpStr: string): string {
         let modified = false;
         const sdpTransformer = new SdpTransformWrap(sdpStr);
         const videoMLines = sdpTransformer.selectMedia(MediaType.VIDEO);
 
-        if (!videoMLines?.length) {
+        if (!videoMLines || (Array.isArray(videoMLines) && videoMLines.length === 0)) {
             logger.debug(`No 'video' media found in the sdp: ${sdpStr}`);
 
             return sdpStr;
         }
 
-        for (const videoMLine of videoMLines) {
-            if (this.modifyRtxSsrcs2(videoMLine)) {
+        for (const videoMLine of Array.isArray(videoMLines) ? videoMLines : [ videoMLines ]) {
+            if (this.modifyRtxSsrcs2(videoMLine as MLineWrap)) {
                 modified = true;
             }
         }
@@ -128,7 +148,7 @@ export default class RtxModifier {
      * @return {boolean} <tt>true</tt> if the SDP wrapped by {@link SdpTransformWrap} has been modified or
      * <tt>false</tt> otherwise.
      */
-    modifyRtxSsrcs2(videoMLine) {
+    modifyRtxSsrcs2(videoMLine: MLineWrap): boolean {
         if (videoMLine.direction === MediaDirection.RECVONLY) {
             return false;
         }
@@ -161,7 +181,8 @@ export default class RtxModifier {
                     id: ssrc,
                     msid
                 },
-                correspondingRtxSsrc);
+                correspondingRtxSsrc
+            );
         }
 
         // FIXME we're not looking into much details whether the SDP has been
@@ -175,20 +196,22 @@ export default class RtxModifier {
      * @param {string} sdpStr sdp in raw string format
      * @returns {string} sdp string with all rtx streams stripped
      */
-    stripRtx(sdpStr) {
+    stripRtx(sdpStr: string): string {
         const sdpTransformer = new SdpTransformWrap(sdpStr);
         const videoMLines = sdpTransformer.selectMedia(MediaType.VIDEO);
 
-        if (!videoMLines?.length) {
+        if (!videoMLines || (Array.isArray(videoMLines) && videoMLines.length === 0)) {
             logger.debug(`No 'video' media found in the sdp: ${sdpStr}`);
 
             return sdpStr;
         }
 
-        for (const videoMLine of videoMLines) {
-            if (videoMLine.direction !== MediaDirection.RECVONLY
+        for (const videoMLine of Array.isArray(videoMLines) ? videoMLines : [ videoMLines ]) {
+            if (
+                videoMLine.direction !== MediaDirection.RECVONLY
                 && videoMLine.getSSRCCount()
-                && videoMLine.containsAnySSRCGroups()) {
+                && videoMLine.containsAnySSRCGroups()
+            ) {
                 const fidGroups = videoMLine.findGroups(SSRC_GROUP_SEMANTICS.FID);
 
                 // Remove the fid groups from the mline