Windows Mobile上的Directshow中的图像捕获（照片）太慢 - 建议？

I'm using Directshow to capture images on a winmo device. I've based my native code on the "CameraCapture" example found in the Windows Mobile 6 sdk, with a few minor tweaks (simplified the graph, added a live preview window, upped the photo resolution, etc...).I'm using Directshow to capture images on a win