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I have a C# application that is supposed to build a DirectShow graph to render an H.264 encoded video stream. I'm using DirectShowLib as managed wrapper. I already got it working with different filters for RTSP Source and H.264 (Video Processing Project, DivX, Datastead, ...), but recently, I came across the MontiVision Filters mentioned here. I tried them in GraphStudio, and was very pleased with their performance, so I wanted to use them in my application.

Strange thing though, while the "MV Stream Source" and "MV Video Decoder" filters connect seamlessly in GraphStudio (after setting the RTSP URL), when I try the same thing in C#, I get an HRESULT of VFW_E_NO_ACCEPTABLE_TYPES when trying to connect the same filters. "MV Stream Source" outputs an AVC1 Mediatype, I don't know what mediatype the "MV Video Decoder" accepts, but when I connect the filters in GraphStudio, it seems to accept AVC1.

I am certain that the pin names and GUIDs are correct (same as in GraphStudio). I also tried waiting (Thread.Sleep) up to 10 seconds between filter creation and connection, to no avail.

Does anybody have an idea what I might be doing wrong? Thanks!

The code for connecting the filters looks like this:

int hr = 0;

//add Source Filter 
hr = pGraph.AddFilter(pSourceFilter, "Source Filter");
DsHelper.checkHR(hr, "Can't add Source Filter to graph");


//set source filename 
IFileSourceFilter pVideoSourceFilter_src = pSourceFilter as IFileSourceFilter;
if (pVideoSourceFilter_src == null)
    DsHelper.checkHR(unchecked((int)0x80004002), "Can't get IFileSourceFilter");

hr = pVideoSourceFilter_src.Load(srcFile, null);

DsHelper.checkHR(hr, "Can't load file");

//add Video Decoder 
hr = pGraph.AddFilter(pVideoDecoder, "Video Decoder");
DsHelper.checkHR(hr, "Can't add Video Decoder to graph");

//add Video Renderer 
IBaseFilter pVideoRenderer = DsHelper.FilterFromGUID(DsHelper.CLSID_NullRenderer);
hr = pGraph.AddFilter(pVideoRenderer, "Video Renderer");
DsHelper.checkHR(hr, "Can't add Video Renderer to graph");

        //connect Source Filter and Video Decoder 
hr = pGraph.ConnectDirect(DsHelper.GetPin(pSourceFilter, srcFilterVideoOutName), DsHelper.GetPin(pVideoDecoder, vdVideoInName), null);
DsHelper.checkHR(hr, "Can't connect Source Filter and Video Decoder");

Creating the filters:

IBaseFilter pSourceFilter = (IBaseFilter)DsHelper.FilterFromGUID(DsHelper.CLSID_MVRTSPSourceFilter);
IBaseFilter pVideoDecoder = (IBaseFilter)DsHelper.FilterFromGUID(DsHelper.CLSID_MVDecoder);

Helpers:

public static Guid CLSID_MVDecoder = new Guid("{D8F0E4C9-38DB-40E7-93C3-248A22D587B8}");
public static Guid CLSID_MVRTSPSourceFilter = new Guid("{EDE234EC-157E-4516-9AC5-0F401384918B}");
public static IBaseFilter FilterFromGUID(Guid filterGuid)
    {
        return (IBaseFilter)Activator.CreateInstance(Type.GetTypeFromCLSID(filterGuid));
    }

public static IPin GetPin(IBaseFilter filter, string pinname)
    {
        IEnumPins epins;
        int hr = filter.EnumPins(out epins);
        checkHR(hr, "Can't enumerate pins");
        IntPtr fetched = Marshal.AllocCoTaskMem(4);
        IPin[] pins = new IPin[1];
        while (epins.Next(1, pins, fetched) == 0)
        {
            PinInfo pinfo;
            pins[0].QueryPinInfo(out pinfo);
            bool found = (pinfo.name == pinname);
            DsUtils.FreePinInfo(pinfo);
            if (found) return pins[0];
        }
        checkHR(-1, "Pin not found: " + pinname);
        return null;
    }
user3383340
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  • Welcome to Stack Overflow! Please, do not include information about a language used in a question title unless it wouldn't make sense without it. Tags serve this purpose. – Ondrej Janacek Mar 05 '14 at 12:02
  • Why don't you use RenderStream, i had this problem ones and using this it dynamicaly adds missing filters if needed to make the connection. http://msdn.microsoft.com/en-us/library/aa930715.aspx – Mihai Hantea Mar 05 '14 at 12:05
  • I am using a custom Sample Grabber filter to pull decoded RGB32 data into my application, so I cannot "auto-add" filters, I need to build a custom filter chain (with NullRenderer at its end). Sorry for forgetting to mention that. – user3383340 Mar 05 '14 at 12:36
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    The third party filters might have a "demo mode" to work on GraphEdit and to not work on other apps without proper initialization (license key etc). – Roman R. Apr 26 '14 at 10:56
  • As a simple test, you could temporarily rename your application to graphedit.exe and see if it behaves differently. – persiflage Jan 21 '15 at 13:15

0 Answers0