The buffer overflow error is because your frames_per_buffer and read chunksize might be too small. Try larger values for them i.e. 512,2048, 4096, 8192 etc
CHUNK = 1024
FORMAT = pyaudio.paInt16
CHANNELS = 2
RATE = 44100
RECORD_SECONDS = 2
for CHUNK1 in [512,2048,4096,8192,16384]:
for CHUNK2 in [512,2048,4096,8192,16384]:
stream = p.open(format=FORMAT,
channels=CHANNELS,
rate=RATE,
input=True,
frames_per_buffer=CHUNK1)
try:
print CHUNK1,CHUNK2
for i in range(0, int(RATE / CHUNK * RECORD_SECONDS)):
data = stream.read(CHUNK2)
except:
print "Boohoo"
stream.stop_stream()
stream.close()
Update
ok i think I got it. the pyaudio library will raise an overflow error if you wait too long before your next read.
byte_string = ''.join(data)
nums = array.array('h', byte_string)
for elt in nums[1::2]:
left.put(elt)
for elt in nums[0::2]:
right.put(elt)
this does a whole lot of very slow processing here. especially the two for
loops which are in python. let the processing process get a whole chunk of mono-stream data which it can deal with instead of one int at a time.
import numpy as np
...
n=np.fromstring(data,np.uint16)
left.put(n[1::2])
right.put(n[0::2])
I don't even want to imagine what the for
loops were doing to latency, but even the relatively minor performance improvement between using array
and np.array
are worth noting:
a=array.array('h',s)
n=np.array(a)
In [26]: %timeit n[1::2]
1000000 loops, best of 3: 669 ns per loop
In [27]: %timeit n[1::2].copy()
1000 loops, best of 3: 725 us per loop
In [28]: %timeit a[1::2]
1000 loops, best of 3: 1.91 ms per loop