Add muted support for transport-in

Author: ovistoica

src/simulflow/transport/in.clj

@@ -100,14 +100,21 @@
   "Base input transport logic that is used by most transport input processors.
   Assumes audio-input-raw frames that come in are 16kHz PCM mono. Conversion to
   this format should be done beforehand."
-  [{:keys [pipeline/supports-interrupt?] :as state} _ msg]
+  [{:keys [pipeline/supports-interrupt? ::muted?] :as state} _ msg]
   (t/log! {:id :transport-in
            :msg "Processing frame"
            :data (:frame/type msg)
            :level :debug
            :sample 0.01})
   (cond
-    (frame/audio-input-raw? msg)
+    (frame/mute-input-start? msg)
+    [(assoc state ::muted? true)]
+
+    (frame/mute-input-stop? msg)
+    [(assoc state ::muted? false)]
+
+    (and (frame/audio-input-raw? msg)
+         (not muted?))
     (if-let [analyser (:vad/analyser state)]
       (let [vad-state (vad/analyze-audio analyser (:frame/data msg))
             prev-vad-state (:vad/state state :vad.state/quiet)

test/simulflow/transport/in_test.clj

@@ -114,7 +114,20 @@
             [rs {:keys [out sys-out]}] (in/base-input-transport-transform state :in (frame/bot-interrupt true))]
         (is (= rs state))
         (is (nil? out))
-        (is (nil? sys-out))))))
+        (is (nil? sys-out))))
+
+    (testing "Toggles muted state when mute-input-start frame is received"
+      (let [[rs out] (in/base-input-transport-transform {} :sys-in (frame/mute-input-start))]
+        (is (= rs {::in/muted? true}))
+        (is (empty? out))))
+    (testing "Toggles muted state off when mute-input-stop frame is received"
+      (let [[rs out] (in/base-input-transport-transform {::in/muted? true} :sys-in (frame/mute-input-stop))]
+        (is (= rs {::in/muted? false}))
+        (is (empty? out))))
+    (testing "When muted state is active, audio frames aren't processed"
+      (let [[rs out] (in/base-input-transport-transform {::in/muted? true} :in (frame/audio-input-raw (byte-array (range 200))))]
+        (is (= rs {::in/muted? true}))
+        (is (empty? out))))))
 
 ;; =============================================================================
 ;; Twilio Transport Tests