Add reinitialization function? about python-sounddevice HOT 6 CLOSED

@mgeier
Well, first of all, some information.
The environment is pretty complex and is working below a gRPC server. The idea is to use complex sound-card and run a sequence, but not at the same time, of measurements.
Till now I was using a single thread application and everything was fine, but in the moment a concurrent situation comes to life also a lot of problems present their business cards.

Accordingly to https://app.assembla.com/wiki/show/portaudio/Tips_Threading this is bad and needs special precaution. So definitely the problem is how I am using PA and sounddevice

So, if my analysis is correct (maybe I am missing something) I have to face with these problems:

• When a file with Soundcard is imported then the PortAudio is loaded and init, Pa_Initialize is called through _initialized()
• Because I embedded the whole code inside a class (a state machine of the soundcard) if I run two differents cycles of any playrec operation I experience some kinf of problem
• To make everything more difficult is then a multithread environment which needs more sync
• if the user add a sound card I need to reset the library

So, what I am doing now is to load/unload the library with some very simple methods, but this approach seems promising.

def terminate():
    if sd._initialized:
        sd._terminate()
       return True
    else:
        return False

def initialize()
 if not sd._initialized:
        sd._initialize()

def reset()
    terminate()
    initialize()

Furthermore, just my two cents.
What about load/unload the library in every call that needs to use the PA library? This should increase the robustness against multithread access, isn't it? And it shouldn't break any compatibilities

from python-sounddevice.

For now, the "hidden" functions sd._terminate() and sd._initialize() can be used.

If anyone needs those to be part of the "official" API, please speak up!

from python-sounddevice.

Hi There,

could you add this to the public API?
Also, a method like is_initalized() should be nice to have.

I am asking because I am having a strange issue since I installed several ASIO sound card (but using once at time)
Not to mention this would fix also the issue when a refresh of the sound card list is needed
bastibe/PySoundCard#44

Thanks!

from python-sounddevice.

@lawrence-iviani

Do you have an idea how the API should look like?

Also, a method like is_initalized() should be nice to have.

For now, you can use sd._initialized.

I am having a strange issue since I installed several ASIO sound card (but using once at time)

Can you describe the issue?
Is it an issue with the sounddevice module or a more general PortAudio issue?

from python-sounddevice.

@lawrence-iviani

I'm very reluctant to add this to the public API because I think it would confuse users that don't have such complicated setups.

If using sd._terminate() and sd._initialize() works for you, that's fine, even if they start with underscores. I would consider them, together with _StreamBase, as features for power-users, and "normal" users don't have to worry about them.

Regarding your case, you indeed have to be very careful with multithreading.
I don't know the exact requirements of your situation, but what about using a single callback for audio I/O?
Have you seen https://github.com/mgeier/python-rtmixer? Probably something like that would be a possible strategy in your case?

What about load/unload the library in every call that needs to use the PA library?

This wouldn't really work when using long-living streams.

Anyway, if that works for you, you can just wrap all of your calls into sd._initialize() and sd._terminate() in your own code. You could even create a little context manager for that.
I don't think it's a good idea to force this in all cases.

from python-sounddevice.

I'm closing this for now, but I'm open for further suggestions regarding the topic.

from python-sounddevice.