directshow - Black video using multiple instances VMR 9

Question

I am working on creating a video wall like application. The application creates multiple windows to display video and each window has its own filter graph. In a typical configuration, these windows would be spread over two displays for a total of 12 windows.

But the problem is whenever I try to run the application, a few of the windows display black video. There are no crashes and each graph is rendered correctly without throwing any errors. The windows displaying the black video are random.

I have tested this on two different graphics card with similar results.

Can someone please help identify the issue

Answer 1

VMR9s/EVRs are backed by limited resource, you are hitting the limit. There is no distinctive error code or otherwise well known/reliable way to detect that you are in trouble.

Your workaround is to either implement custom allocator/presenter to manage surfaces, or use VMR7 instead.

See also:

• StressEvr: So, how many EVRs you can do? with a small tool/testbed to see how many instances you can create, VMR7/EVR, at specific resolutions and pixel formats