I want to use pyaudio frequently to play audio. Although it is not a multi-threaded module, it only uses one sub-thread to play. There should be no problem with the main thread controlling the playback switch. But when I used it to play, I ran into trouble that I couldn't solve.
import threading
import wave
import pyaudio
import time
pa=pyaudio.PyAudio()
f=wave.open('/home/dyan/catkin_ws/src/hlf_robot/scripts/hlf_voice/my.wav','rb')
raw_data=f.readframes(f.getnframes())
f.close()
samplewidth,channels,framerate,raw_data=2,1,16000,raw_data
i=0
stream1=''
def test():
while True:
global i,pa,stream1
try:
print i
stream1=pa.open(format=pa.get_format_from_width(samplewidth),
channels=channels,
rate=framerate,
output=True)
stream1.write(raw_data)
i+=1
print i
except IOError,e:
print e
except Exception,e:
print e
break
t0=threading.Thread(target=test)
t0.start()
time.sleep(3)
while True:
if stream1.is_active():
print "is_active"
else:
print "not active"
if stream1.is_stopped():
print "is_stopped"
else:
print "not stopped"
print stream1._is_running
print stream1._stream
print '123'
try:
stream1.stop_stream()
print '456'
stream1.close()
except Exception,e:
print e
break
print '789'
time.sleep(3)
The output is like this, and then it crashes
0 #子线程循环第一次
is_active #
not stopped #
True #stream1._is_running
<_portaudio.Stream object at 0x7efd71e00cb0> #stream1._stream
123 #调用stop_stream()之前
456 #调用stop_stream()之后,close()之前
[Errno Unanticipated host error] -9999 #子线程捕获到主线程调用stream1.stop_stream()时由stream1.write()抛出的异常IOError,忽略这个异常继续执行
0 #子线程stream1.write()抛出异常i+=1未执行继续循环在pa.open()之前的print
1. In other words, calling stream1.close() after calling stream1.stop_stream() caused the program to crash, and neither the child thread nor the main thread caught the exception! ! ! !
2. If you comment out the close() after stop_stream(), there will be no problem for a short time. However, if it continues to run for about 10 minutes, it will not crash but will no longer be able to continue playing. pa.open() keeps throwing an exception [Errno Illegal combination of I/O devices] -9993. When I close the program and restart it, pa.open() will throw an exception ('Invalid sample rate', -9997). For playback No more! ! !
How to solve this problem?
Temporarily use the method of reopening a pyaudio.Pyaudio() object for each playback, which uses about 10ms of additional CPU time. I ran it continuously for nearly 20 hours without any problems.
...
try:
self.pa=pyaudio.PyAudio()
self.stream=self.pa.open(format=self.pa.get_format_from_width(samplewidth),
channels=channels,
rate=framerate,
output=True)
self.stream.write(raw_data)
except IOError,e:
pass
finally:
self.stream.close()
self.pa.terminate()
...
Here is a possible workaround, ghost commented on 30 Jul 2016