IDeviceTopology how to activate interfaces of devicetopology.h? - c++

Question

Context: I am trying to activate some of the Core Audio Interfaces of "devicetopology.h" such as IAudioLoudness and IAudioPeakMeter using Component Object Model (COM), I need to get the current volume peak of the system's audio and I believe to have written most of the code necessary to make this work, but I am having trouble when trying to activate these interfaces using IPart::Activate.
Issue: When trying to access the IAudioPeakMeter Interface after the supposed activation, my console application throws an error 'Debug Assertion Failed!' and the description just says 'Expression: p!=0'. In Visual Studio an exception is thrown stating: 'Access violation reading location 0x00000000', and a deeper look inside the memory tells me that the variable audio has a value of 0x00000000 <NULL>
Additional Info: While attempting to fix the issue myself, I rewrote the entire code in a separate environment without the use of the CComPtr (Smart Pointer Class for Interfaces) and it threw me a similar error : 'audio is nullptr'
#include <iostream>
#include <devicetopology.h>
#include <mmdeviceapi.h>
#include "atlbase.h"
#include "Functiondiscoverykeys_devpkey.h"
#include "main.h"
int main()
{
HRESULT hr = S_OK;
CoInitialize(NULL);
CComPtr<IMMDeviceEnumerator> enumerator;
hr = enumerator.CoCreateInstance(__uuidof(MMDeviceEnumerator));
if (SUCCEEDED(hr) == true)
{
CComPtr<IMMDeviceCollection> devices;
hr = enumerator->EnumAudioEndpoints(EDataFlow::eRender, DEVICE_STATEMASK_ALL, &devices);
if (SUCCEEDED(hr) == true)
{
UINT count = 0;
devices->GetCount(&count);
for (int i = 0; i < count; i++)
{
CComPtr<IMMDevice> device;
hr = devices->Item(i, &device);
if (SUCCEEDED(hr) == true)
{
CComPtr<IDeviceTopology> topology;
hr = device->Activate(__uuidof(IDeviceTopology), CLSCTX_ALL, NULL, (void**)&topology);
if (SUCCEEDED(hr) == true)
{
CComPtr<IConnector> connector;
hr = topology->GetConnector(0, &connector);
if (SUCCEEDED(hr) == true)
{
CComPtr<IConnector> connectedTo;
hr = connector->GetConnectedTo(&connectedTo);
if (SUCCEEDED(hr) == true)
{
CComPtr<IPart> part;
hr = connectedTo->QueryInterface(&part);
if (SUCCEEDED(hr) == true)
{
CComPtr<IAudioPeakMeter> audio;
hr = part->Activate(CLSCTX_INPROC_SERVER, __uuidof(IAudioPeakMeter), (void**)&audio);
UINT channels;
audio->GetChannelCount(&channels); // Causes reading violation
}
}
}
}
}
}
}
}
I am new to programming with COM and haven't been able to figure out how to move forward from this point, I have tried googling the issue and also looking at some examples using other interfaces from DeviceTopology but haven't been able to fix the issue as of yet.
Thanks in advance.