Add redundancy check to DspMatrix

Removes unnecessary 5.1side<->5.1back overhead.

1 files changed, 22 insertions, 1 deletions

diff --git a/src/DspMatrix.cpp b/src/DspMatrix.cpp
index b118960..b81ab8b 100644
--- a/src/DspMatrix.cpp
+++ b/src/DspMatrix.cpp
@@ -243,7 +243,28 @@ namespace SaneAudioRenderer
         if (inputChannels != outputChannels || inputMask != outputMask)

         {

             m_matrix = BuildMatrix(inputChannels, inputMask, outputChannels, outputMask);

-            m_active = true;

+

+            if (inputChannels != outputChannels)

+            {

+                m_active = true;

+            }

+            else

+            {

+                // Redundancy check.

+                for (size_t y = 0; y < outputChannels; y++)

+                {

+                    for (size_t x = 0; x < inputChannels; x++)

+                    {

+                        float d = m_matrix[y * inputChannels + x];

+

+                        if ((x == y && d != 1.0f) ||

+                            (x != y && d != 0.0f))

+                        {

+                            m_active = true;

+                        }

+                    }

+                }

+            }

         }

 

         m_inputChannels = inputChannels;