From 526d326ecf359d71ccd0a4830d9d975995317570 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=85ke?= <ake.forslund@gmail.com>
Date: Thu, 7 Mar 2019 20:42:00 +0100
Subject: [PATCH] Mute the mic while playing the listening "beep" (#2042)

This also extends the stream mute to actually stopping the recording stream while muted.
---
 mycroft/client/speech/mic.py | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/mycroft/client/speech/mic.py b/mycroft/client/speech/mic.py
index eeb4e8b84b..dbc6902962 100644
--- a/mycroft/client/speech/mic.py
+++ b/mycroft/client/speech/mic.py
@@ -47,16 +47,23 @@ class MutableStream:
     def __init__(self, wrapped_stream, format, muted=False):
         assert wrapped_stream is not None
         self.wrapped_stream = wrapped_stream
+
         self.muted = muted
+        if muted:
+            self.mute()
 
         self.SAMPLE_WIDTH = pyaudio.get_sample_size(format)
         self.muted_buffer = b''.join([b'\x00' * self.SAMPLE_WIDTH])
 
     def mute(self):
+        """ Stop the stream and set the muted flag """
         self.muted = True
+        self.wrapped_stream.stop_stream()
 
     def unmute(self):
+        """ Start the stream and clear the muted flag """
         self.muted = False
+        self.wrapped_stream.start_stream()
 
     def read(self, size, of_exc=False):
         """
@@ -73,6 +80,11 @@ class MutableStream:
         frames = collections.deque()
         remaining = size
         while remaining > 0:
+            # If muted during read return empty buffer. This ensures no
+            # reads occur while the stream is stopped
+            if self.muted:
+                return self.muted_buffer
+
             to_read = min(self.wrapped_stream.get_read_available(), remaining)
             if to_read == 0:
                 sleep(.01)
@@ -82,8 +94,6 @@ class MutableStream:
             frames.append(result)
             remaining -= to_read
 
-        if self.muted:
-            return self.muted_buffer
         input_latency = self.wrapped_stream.get_input_latency()
         if input_latency > 0.2:
             LOG.warning("High input latency: %f" % input_latency)
@@ -503,7 +513,9 @@ class ResponsiveRecognizer(speech_recognition.Recognizer):
             file = resolve_resource_file(
                 self.config.get('sounds').get('start_listening'))
             if file:
-                play_wav(file)
+                source.mute()
+                play_wav(file).wait()
+                source.unmute()
 
         frame_data = self._record_phrase(source, sec_per_buffer)
         audio_data = self._create_audio_data(frame_data, source)