I have a strange performance issue when using any DXTn compressed Format within the D3DXCreateTextureFromFileInMemoryEx function.
I have all my images in memory after loading them from file. Using a regular D3DFMT_X8R8G8B8 works fine, but when I try D3DFMT_DXT1 this function causes major halts in rendering.
When profiling my application I noticed that the d3d DLL takes up to 70% of the run-time. Only about 6% without compression.
My images are Jpeg's containing YuV ( YCbCr ) colors. I don't know if this is relevant. I haven't tried it using regular RGB jpegs yet.
Does anyone ever had similar problems?