Record audio with any duration.

[rodrimaia]

Hi, I am trying to create a 'loop pedal' emulator, and I need to start recording audio without a duration already specified. Something like 'record audio until I want'. I dont know how to do that in sounddevice. Is this possible?

[mgeier]

This is certainly possible but you'll have to implement it yourself using the callback API.

The reason why sounddevice.rec() uses a pre-defined duration, is to be able to allocate all necessary memory in one big NumPy array beforehand.

You could extend that to arbitrary durations by appending to a list of audio blocks in each callback.
Once you have enough, you can stop() (or abort()) the stream and afterwards join your list of audio blocks into a big NumPy array (if needed).

Note that allocating memory within the time-constrained callback may take too long, which may lead to drop-outs in your recording. You should be able to detect those with the status argument of your callback function. As long as status doesn't contain any error bits, you should be fine.

[mgeier]

I've created an example showing how to record for an arbitrary amount of time: rec_unlimited.py.

Does this help?

[rodrimaia]

Helps A LOT! thank you so much. I will experiment a little bit and try to do my 'loop pedal emulator'. this is extremely helpful. This module is awesome.

[ghost]

Dude you gave me the exact thing which i needed, thanks

[egzon-korenica]

I've created an example showing how to record for an arbitrary amount of time: rec_unlimited.py.

Does this help?

This code is amazing, I was wondering though, is it possible to do multiple recordings in one session? I mean when you click ctrl+c the whole program shuts down.

[HaHeho]

This code is amazing, I was wondering though, is it possible to do multiple recordings in one session? I mean when you click ctrl+c the whole program shuts down.

I mean, that is what the code does. There is nothing happening after catching the KeyboardInterrupt. You can modify that of course, like adding similar code afterwards or putting it inside a loop.