How to get PCM data after dsp processing

I am confused about this problem for couple of days.
I add some DSP effect in the input sound and want to get the PCM data from this processed sound. I tried to use sound:: lock, but it seems that it only returns the PCM data from the original input sound (before DSP processing). Is there any ways to solve such problems? Thanks a lot!

To get access to the signal you need to create a custom DSP and add it after any effects you want to capture.

Thank you for your reply Mathew, but apologize I am still confused about what you said about the function of the custon DSP. Is this custom DSP added after the effect is used for sample the PCM data? If so how I can access to sample this data?

Yes, the idea is you use the custom DSP to read the sample data.

I’ve locked this thread as a duplicate of Get sound data after dsp processing.