Link allocator size to number of threads

Samples/BackgroundBlur/BackgroundBlur/TransformAsync.cpp

@@ -232,6 +232,7 @@ HRESULT TransformAsync::SubmitEval(IMFSample* pInput)
     CHECK_HR(hr = CheckDX11Device());
     // Ensure the allocator is set up 
     CHECK_HR(hr = SetupAlloc());
+
     // CheckDX11Device & SetupAlloc ensure we can now allocate a D3D-backed output sample. 
     (hr = m_spOutputSampleAllocator->AllocateSample(pOutputSample.put()));
     if (FAILED(hr))
@@ -481,7 +482,7 @@ HRESULT TransformAsync::SetupAlloc()
                 m_spOutputSampleAllocator.attach(spVideoSampleAllocator.detach());
             }
 
-            CHECK_HR(hr = m_spOutputSampleAllocator->InitializeSampleAllocatorEx(2, 15, m_spAllocatorAttributes.get(), m_spOutputType.get()));
+            CHECK_HR(hr = m_spOutputSampleAllocator->InitializeSampleAllocatorEx(2, m_numThreads, m_spAllocatorAttributes.get(), m_spOutputType.get()));
 
             // Set up IMFVideoSampleAllocatorCallback
             m_spOutputSampleCallback = m_spOutputSampleAllocator.try_as<IMFVideoSampleAllocatorCallback>();
@@ -1045,7 +1046,7 @@ HRESULT TransformAsync::OnFlush(void)
     HRESULT hr = S_OK;
     do
     {
-
+        // TODO: Remove fence values so that framerate can restart
         std::lock_guard<std::recursive_mutex> lock(m_mutex);
 
         m_dwStatus &= (~MYMFT_STATUS_STREAM_STARTED);

Samples/BackgroundBlur/BackgroundBlur/TransformAsync.h

@@ -346,7 +346,7 @@ protected:
 
     // Model Inference fields
     int m_numThreads =                                     // Number of threads running inference in parallel.
-         max(std::thread::hardware_concurrency() - 2, 5);
+         max(std::thread::hardware_concurrency(), 5);
     std::vector<std::unique_ptr<IStreamModel>> m_models;    // m_numThreads number of models to run inference in parallel. 
     int modelIndex = 0;