Expose tts volume and pitch to the user code like we do with lang. (g…

…oogle#185)

* Expose volume and pitch for tts so they can be changed in the user code.

* Corrected typo

* Corrected some python style errors.

* Volume and pitch removed from create_say(). Removed redundant global declaration

* Sorry for the confusion. Looked at the wrong line.

src/aiy/_drivers/_tts.py

@@ -33,21 +33,24 @@ def create_say(player):
     return functools.partial(say, player, lang=lang)
 
 
-def say(player, words, lang='en-US'):
+def say(player, words, lang='en-US', volume=60, pitch=130):
     """Say the given words with TTS.
 
     Args:
       player: To play the text-to-speech audio.
       words: string to say aloud.
       lang: language for the text-to-speech engine.
+      volume: volume for the text-to-speech engine.
+      pitch: pitch for the text-to-speech engine.
     """
     try:
         (fd, tts_wav) = tempfile.mkstemp(suffix='.wav', dir=TMP_DIR)
     except IOError:
         logger.exception('Using fallback directory for TTS output')
         (fd, tts_wav) = tempfile.mkstemp(suffix='.wav')
     os.close(fd)
-    words = '<volume level="60"><pitch level="130">%s</pitch></volume>' % words
+    words = '<volume level="' + str(volume) + '"><pitch level="' + str(pitch) + \
+            '">' + words + '</pitch></volume>'
     try:
         subprocess.call(['pico2wave', '--lang', lang, '-w', tts_wav, words])
         player.play_wav(tts_wav)

src/aiy/audio.py

@@ -28,6 +28,8 @@
 _voicehat_recorder = None
 _voicehat_player = None
 _status_ui = None
+_tts_volume = 60
+_tts_pitch = 130
 
 
 class _WaveDump(object):
@@ -108,15 +110,24 @@ def play_audio(audio_data):
     player.play_bytes(audio_data, sample_width=AUDIO_SAMPLE_SIZE, sample_rate=AUDIO_SAMPLE_RATE_HZ)
 
 
-def say(words, lang=None):
+def say(words, lang=None, volume=None, pitch=None):
     """Says the given words in the given language with Google TTS engine.
 
-    If lang is specified, e.g. "en-US', it will be used to say the given words.
+    If lang is specified, e.g. "en-US", it will be used to say the given words.
     Otherwise, the language from aiy.i18n will be used.
+    volume (optional) volume used to say the given words.
+    pitch (optional) pitch to say the given words.
+    Example: aiy.audio.say('This is an example', lang="en-US", volume=75, pitch=135)
+    Any of the optional variables can be left out.
     """
+
     if not lang:
         lang = aiy.i18n.get_language_code()
-    aiy._drivers._tts.say(aiy.audio.get_player(), words, lang=lang)
+    if not volume:
+        volume = aiy.audio.get_tts_volume()
+    if not pitch:
+        pitch = aiy.audio.get_tts_pitch()
+    aiy._drivers._tts.say(aiy.audio.get_player(), words, lang=lang, volume=volume, pitch=pitch)
 
 
 def get_status_ui():
@@ -129,3 +140,23 @@ def get_status_ui():
     if not _status_ui:
         _status_ui = aiy._drivers._StatusUi()
     return _status_ui
+
+
+def set_tts_volume(volume):
+    global _tts_volume
+    _tts_volume = volume
+
+
+def get_tts_volume():
+    global _tts_volume
+    return _tts_volume
+
+
+def set_tts_pitch(pitch):
+    global _tts_pitch
+    _tts_pitch = pitch
+
+
+def get_tts_pitch():
+    global _tts_pitch
+    return _tts_pitch