Extended consumer options to provide way to override MID. (#586)

lib/Consumer.d.ts

@@ -27,6 +27,11 @@ export declare type ConsumerOptions = {
      * by itself.
      */
     paused?: boolean;
+    /**
+     * The MID for the Consumer. If not specified, a sequentially growing
+     * number will be assigned.
+     */
+    mid?: string;
     /**
      * Preferred spatial and temporal layer for simulcast or SVC media sources.
      * If unset, the highest ones are selected.

lib/Transport.d.ts

@@ -170,7 +170,7 @@ export declare class Transport extends EnhancedEventEmitter {
      *
      * @virtual
      */
-    consume({ producerId, rtpCapabilities, paused, preferredLayers, pipe, appData }: ConsumerOptions): Promise<Consumer>;
+    consume({ producerId, rtpCapabilities, paused, mid, preferredLayers, pipe, appData }: ConsumerOptions): Promise<Consumer>;
     /**
      * Create a DataProducer.
      */

lib/Transport.js

@@ -283,12 +283,14 @@ class Transport extends EnhancedEventEmitter_1.EnhancedEventEmitter {
      *
      * @virtual
      */
-    async consume({ producerId, rtpCapabilities, paused = false, preferredLayers, pipe = false, appData = {} }) {
+    async consume({ producerId, rtpCapabilities, paused = false, mid, preferredLayers, pipe = false, appData = {} }) {
         logger.debug('consume()');
         if (!producerId || typeof producerId !== 'string')
             throw new TypeError('missing producerId');
         else if (appData && typeof appData !== 'object')
             throw new TypeError('if given, appData must be an object');
+        else if (mid && (typeof mid !== 'string' || mid.length === 0))
+            throw new TypeError('if given, mid must be non empty string');
         // This may throw.
         ortc.validateRtpCapabilities(rtpCapabilities);
         const producer = this._getProducerById(producerId);
@@ -298,11 +300,16 @@ class Transport extends EnhancedEventEmitter_1.EnhancedEventEmitter {
         const rtpParameters = ortc.getConsumerRtpParameters(producer.consumableRtpParameters, rtpCapabilities, pipe);
         // Set MID.
         if (!pipe) {
-            rtpParameters.mid = `${this._nextMidForConsumers++}`;
-            // We use up to 8 bytes for MID (string).
-            if (this._nextMidForConsumers === 100000000) {
-                logger.error(`consume() | reaching max MID value "${this._nextMidForConsumers}"`);
-                this._nextMidForConsumers = 0;
+            if (mid) {
+                rtpParameters.mid = mid;
+            }
+            else {
+                rtpParameters.mid = `${this._nextMidForConsumers++}`;
+                // We use up to 8 bytes for MID (string).
+                if (this._nextMidForConsumers === 100000000) {
+                    logger.error(`consume() | reaching max MID value "${this._nextMidForConsumers}"`);
+                    this._nextMidForConsumers = 0;
+                }
             }
         }
         const internal = { ...this._internal, consumerId: uuid_1.v4(), producerId };

rust/src/router/consumer.rs

@@ -76,6 +76,8 @@ pub struct ConsumerOptions {
     /// consuming endpoint even before it's ready to consume it, generating “black” video until the
     /// device requests a keyframe by itself.
     pub paused: bool,
+    /// The MID for the Consumer. If not specified, a sequentially growing number will be assigned.
+    pub mid: Option<String>,
     /// Preferred spatial and temporal layer for simulcast or SVC media sources.
     /// If `None`, the highest ones are selected.
     pub preferred_layers: Option<ConsumerLayers>,
@@ -95,6 +97,7 @@ impl ConsumerOptions {
             paused: false,
             preferred_layers: None,
             pipe: false,
+            mid: None,
             app_data: AppData::default(),
         }
     }