From 9bbdcccff05ad4e955b323dc3cd61fbe57808a55 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Thu, 12 Apr 2018 14:28:41 +0300
Subject: Choppy py alsa audio

---
 async_fm_demod.py | 23 +++++++++--------------
 requirements.txt  |  1 +
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/async_fm_demod.py b/async_fm_demod.py
index 8b4aa9e..e89559d 100644
--- a/async_fm_demod.py
+++ b/async_fm_demod.py
@@ -1,18 +1,23 @@
 import asyncio
+import alsaaudio
 import numpy as np
 import scipy.signal as signal
 
 from rtlsdr import RtlSdr
 
 
+device = alsaaudio.PCM(alsaaudio.PCM_PLAYBACK, device='default')
+device.setchannels(1)
+device.setrate(50000)
+device.setformat(alsaaudio.PCM_FORMAT_S16_LE)
+device.setperiodsize(5520)
+
+
 async def streaming():
     sdr = RtlSdr()
     sdr.sample_rate = 1.2e6
     sdr.center_freq = 91.8e6
 
-    audio = None
-    i = 0
-
     async for samples in sdr.stream():
         samples = np.array(samples).astype('complex64')
         samples = signal.decimate(samples, int(1.2e6 / 200e3))
@@ -24,18 +29,8 @@ async def streaming():
         samples = signal.decimate(samples, int(200e3 / 50e3))
         samples *= 10000
 
-        if audio is not None:
-            audio = np.append(audio, samples.astype('int16'))
-        else:
-            audio = samples.astype('int16')
-
-        i += 1
-        if i > 100:
-            break
-        else:
-            print(len(audio))
+        device.write(samples.astype('int16'))
 
-    audio.tofile('test.out')
     await sdr.stop()
     sdr.close()
 
diff --git a/requirements.txt b/requirements.txt
index b4dc1f9..e5912c5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -28,6 +28,7 @@ pexpect==4.4.0
 pickleshare==0.7.4
 prompt-toolkit==1.0.15
 ptyprocess==0.5.2
+pyalsaaudio==0.8.4
 Pygments==2.2.0
 pyparsing==2.2.0
 pyrtlsdr==0.2.7
-- 
cgit v1.3.1