Black screen after rendering multiple video streams

Question

Currently I am working on rendering two different videos at the same time using one VMR9 renderer and putting it on a XNA texture. The code I am currently using manages one video rendering however it does some cheesiness at two videos. On my working setup the complete video playing works flawlessly, but when I try to switch computers it gets me the black screen.

I am using a filter graph as suggested in this topic: Can one Video Mixing Renderer 9 (VMR9) render more video streams?

If I attach GraphStudioNext on the currently running program it displays the following graph: http://s11.postimg.org/z7d3qyyxf/graph.png

At first I tought the problem would be some differences between codec settings, but after I managed the same configuration on two different machines only the graphs changed: they became identical even though one machine displays the video correctly and the other just displays a black screen.

I even tried to remake the graph by hand to see if there is any problem with the graph itself and it runs smoothly.

I use the following code snippet to add the video sources to the VMR9 renderer:

protected override HRESULT OnInitInterfaces()
{
    IBaseFilter bsFilter;
    m_GraphBuilder.AddSourceFilter(@"C:\Video\Digitales CLP_tic tac Strawberry Mix_HUN_FIN.mp4", "first", out bsFilter);
    IEnumPins ePins;
    bsFilter.EnumPins(out ePins);
    IPin[] pins = new IPin[1];
    IntPtr fetched = IntPtr.Zero;
    ePins.Next(1, pins, fetched);
    int hr = m_GraphBuilder.Render(pins[0]);

    m_GraphBuilder.AddSourceFilter(@"C:\Video\UIP_StarTrek.mp4", "second", out bsFilter);
    bsFilter.EnumPins(out ePins);
    ePins.Next(1, pins, fetched);
    hr = m_GraphBuilder.Render(pins[0]);

    return (HRESULT)hr;
}

Any help would be appreciated.

Answer 1

The problem was with NVidia drivers. The following code snippet caused the error:

VMR9NormalizedRect r1 = new VMR9NormalizedRect(0, 0, 0.5f, 1);
VMR9NormalizedRect r2 = new VMR9NormalizedRect(0.5f, 0, 1, 1);
hr = (HRESULT)mix.SetOutputRect(0, ref r1);
hr = (HRESULT)mix.SetOutputRect(1, ref r2);

If a VMR9NormalizedRect gets initialized with any parameters apart from 0, 0, 1, 1 it will only display a black screen. The code runs perfect on any ATI card I tried.

It seems like that NVidia couldn't fix this error since 2006: https://forums.geforce.com/default/topic/358347/.