GetPinCapabilitiesAndConfigureSizeAndRate() does not release streamConfig

What steps will reproduce the problem?
1. use the sample Samples\Video\Player
2. use a real hardware camera, e.g.Basler ace USB3 (will not show up with avi / 
file accessing simulators). Should come up with many cameras as it is not 
Basler camera specific
3. run sample

What is the expected output? What do you see instead?

No live image is shown. After a call to  
GetPinCapabilitiesAndConfigureSizeAndRate() , the camera is exclusivliy locked, 
streamConfig internally holds a ref count to the filter subsystem and the 
camera cannot be opened again. (i guess the player first builds up a temporary 
graph to fetch camera capabilities)

What version of the product are you using?
svn trunk as of 12.1.2015

Please provide any additional information below.

The fix is easy:

just use
 Marshal.ReleaseComObject(streamConfigObject); 

<code>
at the end of GetPinCapabilitiesAndConfigureSizeAndRate(...), e.g.:

      // Configure specified pin and collect its capabilities if required
        private void GetPinCapabilitiesAndConfigureSizeAndRate( ICaptureGraphBuilder2 graphBuilder, IBaseFilter baseFilter,
            Guid pinCategory, VideoCapabilities resolutionToSet, ref VideoCapabilities[] capabilities )
        {
            object streamConfigObject;
            graphBuilder.FindInterface( pinCategory, MediaType.Video, baseFilter, typeof( IAMStreamConfig ).GUID, out streamConfigObject );

            if ( streamConfigObject != null )
            {
                IAMStreamConfig streamConfig = null;

                try
                {
                    streamConfig = (IAMStreamConfig) streamConfigObject;
                }
                catch ( InvalidCastException )
                {
                }

                if ( streamConfig != null )
                {
                    if ( capabilities == null )
                    {
                        try
                        {
                            // get all video capabilities
                            capabilities = AForge.Video.DirectShow.VideoCapabilities.FromStreamConfig( streamConfig );
                        }
                        catch
                        {
                        }
                    }

                    // check if it is required to change capture settings
                    if ( resolutionToSet != null )
                    {
                        SetResolution( streamConfig, resolutionToSet );
                    }
                }
                // release interface was missing here, Cameras could be left locked if not released 
                Marshal.ReleaseComObject(streamConfigObject);
             }

            // if failed resolving capabilities, then just create empty capabilities array,
            // so we don't try again
            if ( capabilities == null )
            {
                capabilities = new VideoCapabilities[0];
            }
        }

</code>

best regards,

Timm von der Mehden
Software Developer

Basler AG
An der Strusbek 60-62
22926 Ahrensburg
Germany
www.baslerweb.com
Original issue reported on code.google.com by vdMeh...@gmail.com on 13 Jan 2015 at 8:37
pushsos / aforge

GetPinCapabilitiesAndConfigureSizeAndRate() does not release streamConfig #394
