From 08834afe216945867c2c1e27b149f845802a8bec Mon Sep 17 00:00:00 2001
From: Correl Roush <correl@gmail.com>
Date: Fri, 4 Sep 2020 22:12:14 +0100
Subject: [PATCH] Add audio playback

---
 turntable/application.py | 17 ++++++++++----
 turntable/audio.py       | 49 ++++++++++++++++++++++++++++++++++++----
 2 files changed, 58 insertions(+), 8 deletions(-)

diff --git a/turntable/application.py b/turntable/application.py
index f4b49f8..43a9bdb 100644
--- a/turntable/application.py
+++ b/turntable/application.py
@@ -9,7 +9,7 @@ from typing import Any, Dict, Iterator
 
 from dejavu import Dejavu  # type: ignore
 
-from turntable.audio import Listener
+from turntable.audio import Listener, Player
 from turntable.icecast import Icecast
 from turntable.models import PCM
 from turntable.turntable import (
@@ -38,11 +38,12 @@ def run() -> "Iterator[Queue[Event]]":
 
 
     pcm_in: "Queue[PCM]" = Queue()
+    pcm_out: "Queue[PCM]" = Queue()
     events: "Queue[Event]" = Queue()
 
     audio_config = config.get("audio", dict())
     listener = Listener(
-        pcm_in,
+        [pcm_in, pcm_out],
         events,
         audio_config.get("device", "default"),
         framerate=audio_config.get("framerate", 44100),
@@ -50,9 +51,17 @@ def run() -> "Iterator[Queue[Event]]":
         period_size=audio_config.get("period_size", 4096),
     )
 
+    player = Player(
+        pcm_out,
+        audio_config.get("output_device", "null"),
+        framerate=audio_config.get("framerate", 44100),
+        channels=audio_config.get("channels", 2),
+        period_size=audio_config.get("period_size", 4096),
+    )
+
     dejavu = Dejavu(config.get("dejavu", dict()))
 
-    player = Turntable(listener.framerate, listener.channels, dejavu, pcm_in, events)
+    turntable = Turntable(listener.framerate, listener.channels, dejavu, pcm_in, events)
 
     icecast_config = config.get("icecast", dict())
     icecast = Icecast(
@@ -63,7 +72,7 @@ def run() -> "Iterator[Queue[Event]]":
         password=icecast_config.get("admin_password", "hackme"),
     )
 
-    processes = [listener, player]
+    processes = [listener, player, turntable]
     for process in processes:
         process.daemon = True
         process.start()
diff --git a/turntable/audio.py b/turntable/audio.py
index 2250432..317c1c8 100644
--- a/turntable/audio.py
+++ b/turntable/audio.py
@@ -16,7 +16,7 @@ logger = logging.getLogger(__name__)
 class Listener(Process):
     def __init__(
         self,
-        pcm_in: "Queue[PCM]",
+        pcm_in: "List[Queue[PCM]]",
         events: Queue,
         device: str,
         sample_length: int = 30,
@@ -25,7 +25,7 @@ class Listener(Process):
         period_size: int = 1024,
     ) -> None:
         super().__init__()
-        logger.info("Initializing Listener")
+        logger.info(f"Initializing Listener using '{device}'")
         self.pcm_in = pcm_in
         self.events = events
         self.framerate = framerate
@@ -55,13 +55,54 @@ class Listener(Process):
         )
 
     def run(self) -> None:
+        framecount = 0
+        event_limit = self.framerate
         while True:
             length, data = self.capture.read()
             if length > 0:
                 pcm = PCM(self.framerate, self.channels, data)
-                self.pcm_in.put(pcm)
-                self.events.put(Audio(pcm))
+                for queue in self.pcm_in:
+                    queue.put(pcm)
+                framecount += length
+                if framecount >= event_limit:
+                    framecount = 0
+                    self.events.put(Audio(pcm))
             else:
                 logger.warning(
                     "Sampler error (length={}, bytes={})".format(length, len(data))
                 )
+
+class Player(Process):
+    def __init__(
+        self,
+            pcm_in: "Queue[PCM]",
+        device: str,
+        sample_length: int = 30,
+        framerate: int = 44100,
+        channels: int = 2,
+        period_size: int = 1024,
+    ) -> None:
+        super().__init__()
+        logger.info(f"Initializing Player using '{device}'")
+        self.pcm_in = pcm_in
+        self.framerate = framerate
+        self.channels = channels
+        self.playback = alsaaudio.PCM(
+            device=device,
+            type=alsaaudio.PCM_PLAYBACK,
+            format=alsaaudio.PCM_FORMAT_S16_LE,
+            periodsize=period_size,
+            rate=framerate,
+            channels=channels,
+        )
+        logger.info(
+            "Player started on '%s' [rate=%d, channels=%d, periodsize=%d]",
+            device,
+            framerate,
+            channels,
+            period_size,
+        )
+
+    def run(self) -> None:
+        while pcm := self.pcm_in.get():
+            self.playback.write(pcm.raw)