开发者

Can't make IAMStreamConfig.SetFormat() to work with LifeCam Studio

开发者 https://www.devze.com 2023-04-03 23:36 出处：网络
I\'m brand new to DirectShow and am working on adding a video stream to my application.I\'ve looked into many solutions out there (TouchLess, DirectShow.net, etc.) and ended up going with this small p
相关专题：directshowdirectshow.net

I'm brand new to DirectShow and am working on adding a video stream to my application. I've looked into many solutions out there (TouchLess, DirectShow.net, etc.) and ended up going with this small project on Code Project There isn't much to it, which is why I selected it; I wanted a small code base to work with, as I need to get this feature implemented quickly.

After a solid day of reading, experimenting and debugging I finally have everything working nicely. There is a delay which is a bummer but I can worry about that later. The issue I have at this point is that the camera is capable of 1280X720 and I want to use this resolution. However it seems determined to capture at 640x480. As I dug deeper and deeper and deeper learning how to set the resolution, I finally thought I had it figured out. I also found code on that Code Project page in the comments that I used as a base.

After 6 hours of trying, I cannot get this camera to change its resolution. I'm not receiving any errors and the HRESULT returned from SetFormat() is 0, yet the camera will not change resolution.

There is too much code to paste everything, but I would like to include the section that builds up the graph as I imagine that's where the problem is.

Here is the code that sets up the graph

void CameraMethods::StartCamera(int camIndex, interior_ptr<int> width, 
    interior_ptr<int> height)
{
    if (g_pGraphBuilder != NULL)
        throw gcnew ArgumentException("Graph Builder was null");

    IMoniker *pMoniker = GetMoniker(camIndex);
    pMoniker->AddRef();

    HRESULT hr = S_OK;

    // Build all the necessary interfaces to start the capture
    if (SUCCEEDED(hr))
    {
        hr = CoCreateInstance(CLSID_FilterGraph,
            NULL,
            CLSCTX_INPROC,
            IID_IGraphBuilder,
            (LPVOID*)&g_pGraphBuilder);
    }

    if (SUCCEEDED(hr))
        hr = g_pGraphBuilder->QueryInterface(IID_IMediaControl, (LPVOID*)&g_pMediaControl);

    if (SUCCEEDED(hr))
    {
        hr = CoCreateInstance(CLSID_CaptureGraphBuilder2,
            NULL,
            CLSCTX_INPROC,
            IID_ICaptureGraphBuilder2,
            (LPVOID*)&g_pCaptureGraphBuilder);
    }

    // Setup the filter graph
    if (SUCCEEDED(hr))
        hr = g_pCaptureGraphBuilder->SetFiltergraph(g_pGraphBuilder);

    // Build the camera from the moniker
    if (SUCCEEDED(hr))
        hr = pMoniker->BindToObject(NULL, NULL, IID_IBaseFilter, (LPVOID*)&g_pIBaseFilterCam);

    // Add the camera to the filter graph
    if (SUCCEEDED(hr))
        hr = g_pGraphBuilder->AddFilter(g_pIBaseFilterCam, L"WebCam");

    // Create a SampleGrabber
    if (SUCCEEDED(hr))
        hr = CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER, IID_IBaseFilter, 
            (void**)&g_pIBaseFilterSampleGrabber);

    // Configure the Sample Grabber
    if (SUCCEEDED(hr))
        hr = ConfigureSampleGrabber(g_pIBaseFilterSampleGrabber);

    //  Set the resolution - I have NO idea where this should be executed
    SetCaptureFormat(camIndex, *width, *height);

    // Add Sample Grabber to the filter graph
    if (SUCCEEDED(hr))
        hr = g_pGraphBuilder->AddFilter(g_pIBaseFilterSampleGrabber, L"SampleGrabber");

    // Create the NullRender
    if (SUCCEEDED(hr))
        hr = CoCreateInstance(CLSID_NullRenderer, NULL, CLSCTX_INPROC_SERVER, IID_IBaseFilter, 
            (void**)&g_pIBaseFilterNullRenderer);

    // Add the Null Render to the filter graph
    if (SUCCEEDED(hr))
        hr = g_pGraphBuilder->AddFilter(g_pIBaseFilterNullRenderer, L"NullRenderer");

    // Configure the render stream
    if (SUCCEEDED(hr))
        hr = g_pCaptureGraphBuilder->RenderStream(&PIN_CATEGORY_CAPTURE, &MEDIATYPE_Video, 
            g_pIBaseFilterCam, g_pIBaseFilterSampleGrabber, g_pIBaseFilterNullRenderer);

    // Grab the capture width and height
    if (SUCCEEDED(hr))
    {
        ISampleGrabber* pGrabber = NULL;
        hr = g_pIBaseFilterSampleGrabber->QueryInterface(IID_ISampleGrabber, (LPVOID*)&pGrabber);
        if (SUCCEEDED(hr))
        {
            AM_MEDIA_TYPE mt;
            hr = pGrabber->GetConnectedMediaType(&mt);
            if (SUCCEEDED(hr))
            {
                VIDEOINFOHEADER *pVih;
                if ((mt.formattype == FORMAT_VideoInfo) &&
                    (mt.cbFormat >= sizeof(VIDEOINFOHEADER)) &&
                    (mt.pbFormat != NULL) )
                {
                    pVih = (VIDEOINFOHEADER*)mt.pbFormat;
                    *width = pVih->bmiHeader.biWidth;
                    *height = pVih->bmiHeader.biHeight;
                }
                else
                {
                    hr = E_FAIL;  // Wrong format
                }

                // FreeMediaType(mt); (from MSDN)
                if (mt.cbFormat != 0)
                {
                    CoTaskMemFree((PVOID)mt.pbFormat);
                    mt.cbFormat = 0;
                    mt.pbFormat = NULL;
                }
                if (mt.pUnk != NULL)
                {
                    // Unecessary because pUnk should not be used, but safest.
                    mt.pUnk->Release();
                    mt.pUnk = NULL;
                }
            }
        }

        if (pGrabber != NULL)
        {
            pGrabber->Release();
            pGrabber = NULL;
        }
    }

    // Start the capture
    if (SUCCEEDED(hr))
        hr = g_pMediaControl->Run();

    // If init fails then ensure that you cleanup
    if (FAILED(hr))
        StopCamera();
    else
        hr = S_OK;  // Make sure we return S_OK for success

    // Cleanup
    if (pMoniker != NULL)
    {
        pMoniker->Release();
        pMoniker = NULL;
    }

    if (SUCCEEDED(hr))
        this->activeCameraIndex = camIndex;
    else
        throw gcnew COMException("Error Starting Camera", hr);
}

[UPDATE] Added the ConfigureSampleGrabber() method below

HRESULT CameraMethods::ConfigureSampleGrabber(IBaseFilter *pIBaseFilter)
{
    HRESULT hr = S_OK;
    ISampleGrabber *pGrabber = NULL;

    hr = pIBaseFilter->QueryInterface(IID_ISampleGrabber, (void**)&pGrabber);
    if (SUCCEEDED(hr))
    {
        AM_MEDIA_TYPE mt;
        ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE));
        mt.majortype = MEDIATYPE_Video;
        mt.subtype = MEDIASUBTYPE_RGB24;
        mt.formattype = FORMAT_VideoInfo;
        hr = pGrabber->SetMediaType(&mt);
    }

    if (SUCCEEDED(hr))
        hr = pGrabber->SetCallback(new SampleGrabberCB(), 1);

    if (pGrabber != NULL)
    {
        pGrabber->Release();
        pGrabber = NULL;
    }

    return hr;
}

That is pretty much the exact code from the CodeProject source code. I then added this method to set the resolution:

void CameraMethods::SetCaptureFormat(int camIndex, int width, int height)
{
    HRESULT hr = S_OK;
    IMoniker* pMoniker = GetMoniker(camIndex);

    IBaseFilter* pCap;
    hr=pMoniker->BindToObject(0,0,IID_IBaseFilter,(void **)&pCap);

    if(!SUCCEEDED(hr))
        return;

    IAMStreamConfig *pConfig = NULL;

    if(g_pCaptureGraphBuilder == NULL)  // no CaptureGraphBuilder initialised
        return;

    hr = g_pCaptureGraphBuilder->FindInterface(
        &PIN_CATEGORY_CAPTURE, // Preview pin.
        0,    // Any media type.
        pCap, // Pointer to the capture filter.
        IID_IAMStreamConfig, (void**)&pConfig);

    if(!SUCCEEDED(hr))
        return;

    int iCount = 0, iSize = 0;
    hr = pConfig->GetNumberOfCapabilities(&iCount, &iSize);

    // Check the size to make sure we pass in the correct structure.
    if (iSize == sizeof(VIDEO_STREAM_CONFIG_CAPS)) {

        // Use the video capabilities structure.
        for (int iFormat = 0; iFormat < iCount; iFormat++)
        {
            VIDEO_STREAM_CONFIG_CAPS scc;
            AM_MEDIA_TYPE *pmt;
            /* Note:  Use of the VIDEO_STREAM_CONFIG_CAPS structure to configure a video device is 
            deprecated. Although the caller must allocate the buffer, it should ignore the 
            contents after the method returns. The capture device will return its supported 
            formats through the pmt parameter. */
            hr = pConfig->GetStreamCaps(iFormat, &pmt, (BYTE*)&scc);
            if (SUCCEEDED(hr))
            {
                /* Examine the format, and possibly use it. */
                if (pmt->formattype == FORMAT_VideoInfo) {
                    // Check the buffer size.
                    if (pmt->cbFormat >= sizeof(VIDEOINFOHEADER))
                    {
                        VIDEOINFOHEADER *pVih =  reinterpret_cast<VIDEOINFOHEADER*>(pmt->pbFormat);
                        BITMAPINFOHEADER *bmiHeader = &pVih->bmiHeader;

                        /* Access VIDEOINFOHEADER members through pVih. */
                        if( bmiHeader->biWidth == width && bmiHeader->biHeight == height && 
                            bmiHeader->biBitCount == 24)
                        {
                            hr = pConfig->SetFormat(pmt);
                        }
                    }
                }

                // Delete the media type when you are done.
                DeleteMediaType(pmt);
            }
        }
    }
}

I've stepped through the code and verified that the call to SetFormat() is executed and return a valid HRESULT. No changes to the captured frames though.

With no error messages it's difficult to know where to start. I'm hoping there are some DirectShow experts here that will see the problem, I'd even be happy with a good ol' fashion condescending "Well yeah, how do you expect the camera to change frame size once the buffer is allocated on the filter stack and the widget is initialized to the foobar! Pft... lol" ;)

Teach me, oh DirectShow/COM god!

[UPDATE #2] (FYI, it's odd that we can't just add a new message to this system and need to edit the original like this)

Per Roman's suggestion I have used GraphStudio to look under the hood of my graph. I will admit that I still don't understand what exactly I'm looking at. I found a "text report" function and thought it would be helpful to post that report here in case it shows some valuable information.

--------------------------------------------------
  Filters
--------------------------------------------------
  1. Smart Tee
  2. MJPEG Decompressor
  3. SampleGrabber
  4. NullRenderer
  5. WebCam

--------------------------------------------------
  Connections
--------------------------------------------------
  1. [Smart Tee]/(Capture) -> [MJPEG Decompressor]/(XForm In)
      Major:   MEDIATYPE_Video
      Subtype: MEDIASUBTYPE_MJPG
          bFixedSizeSamples:    TRUE
          bTemporalCompression: FALSE
          lSampleSize:          921600
          cbFormat:             88
      Format:  FORMAT_VideoInfo
      VIDEOINFOHEADER:
          rcSource:             (0,0,0,0)
          rcTarget:             (0,0,0,0)
          dwBitRate:            221184000
          dwBitErrorRate:       0
          AvgTimePerFrame:      333333
      BITMAPINFOHEADER:
          biSize:               40
          biWidth:              640
          biHeight:             480
          biPlanes:             1
          biBitCount:           24
          biCompression:        0x47504A4D
          biSizeImage:          921600
          biXPelsPerMeter:      0
          biYPelsPerMeter:      0
          biClrUsed:            0
          biClrImportant:       0

  2. [MJPEG Decompressor]/(XForm Out) -> [SampleGrabber]/(Input)
      Major:   MEDIATYPE_Video
      Subtype: MEDIASUBTYPE_RGB24
          bFixedSizeSamples:    TRUE
          bTemporalCompression: FALSE
          lSampleSize:          921600
          cbFormat:             88
      Format:  FORMAT_VideoInfo
      VIDEOINFOHEADER:
          rcSource:             (0,0,0,0)
          rcTarget:             (0,0,0,0)
          dwBitRate:            221184221
          dwBitErrorRate:       0
          AvgTimePerFrame:      333333
      BITMAPINFOHEADER:
          biSize:               40
          biWidth:              640
          biHeight:             480
          biPlanes:             1
          biBitCount:           24
          biCompression:        0x00000000
          biSizeImage:          921600
          biXPelsPerMeter:      0
          biYPelsPerMeter:      0
          biClrUsed:            0
          biClrImportant:       0

  3. [SampleGrabber]/(Output) -> [NullRenderer]/(In)
      Major:   MEDIATYPE_Video
      Subtype: MEDIASUBTYPE_RGB24
          bFixedSizeSamples:    TRUE
          bTemporalCompression: FALSE
          lSampleSize:          921600
          cbFormat:             88
      Format:  FORMAT_VideoInfo
      VIDEOINFOHEADER:
          rcSource:             (0,0,0,0)
          rcTarget:             (0,0,0,0)
          dwBitRate:            221184221
          dwBitErrorRate:       0
          AvgTimePerFrame:      333333
      BITMAPINFOHEADER:
          biSize:               40
          biWidth:              640
          biHeight:             480
          biPlanes:             1
          biBitCo开发者_StackOverflowunt:           24
          biCompression:        0x00000000
          biSizeImage:          921600
          biXPelsPerMeter:      0
          biYPelsPerMeter:      0
          biClrUsed:            0
          biClrImportant:       0

  4. [WebCam]/(Capture) -> [Smart Tee]/(Input)
      Major:   MEDIATYPE_Video
      Subtype: MEDIASUBTYPE_MJPG
          bFixedSizeSamples:    TRUE
          bTemporalCompression: FALSE
          lSampleSize:          921600
          cbFormat:             88
      Format:  FORMAT_VideoInfo
      VIDEOINFOHEADER:
          rcSource:             (0,0,0,0)
          rcTarget:             (0,0,0,0)
          dwBitRate:            221184000
          dwBitErrorRate:       0
          AvgTimePerFrame:      333333
      BITMAPINFOHEADER:
          biSize:               40
          biWidth:              640
          biHeight:             480
          biPlanes:             1
          biBitCount:           24
          biCompression:        0x47504A4D
          biSizeImage:          921600
          biXPelsPerMeter:      0
          biYPelsPerMeter:      0
          biClrUsed:            0
          biClrImportant:       0

[Update #3] - Holy COW, what have I started?! Why googling deeper than I have ever googled before I came across something that supports Roman's theory of mismatched colorspaces. I downloaded the app and right away had to fix a bug with a buffer that was too small. After solving that I was able to generate the following report:

Dump Version:   1.2

Using device:   Microsoft® LifeCam Studio(TM)
Interface:  USB

Pin Name:   Capture
Pin direction:  Output
Pin category:   Capture

IAMVideoCompression:    No
ISpecifyPropertyPages:  Yes
IMediaSeeking:  Yes
IPinConnection: No
IPinFlowControl:    No
IAMDroppedFrames:   No
IAMVideoProcAmp:    No
IAMVideoControlCaps:    0

Major Type  Sub Type    Format Type FixedSamples    Temporal Compression    Sample Size Max Input Size  Min Output Size Max Output Size Min-Max FPS Video Standard
Video   YUY2    VideoInfo   Fixed   NotTemporal 614400  640x480 640x480 640x480 7.50-30.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 614400  640x480 640x480 640x480 7.50-30.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 1843200 1280x720    1280x720    1280x720    7.50-10.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 1843200 1280x720    1280x720    1280x720    7.50-10.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 1044480 960x544 960x544 960x544 7.50-20.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 1044480 960x544 960x544 960x544 7.50-20.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 716800  800x448 800x448 800x448 7.50-30.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 716800  800x448 800x448 800x448 7.50-30.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 460800  640x360 640x360 640x360 7.50-30.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 460800  640x360 640x360 640x360 7.50-30.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 203520  424x240 424x240 424x240 7.50-30.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 203520  424x240 424x240 424x240 7.50-30.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 202752  352x288 352x288 352x288 7.50-30.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 202752  352x288 352x288 352x288 7.50-30.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 153600  320x240 320x240 320x240 7.50-30.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 153600  320x240 320x240 320x240 7.50-30.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 960000  800x600 800x600 800x600 7.50-20.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 960000  800x600 800x600 800x600 7.50-20.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 50688   176x144 176x144 176x144 7.50-30.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 50688   176x144 176x144 176x144 7.50-30.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 38400   160x120 160x120 160x120 7.50-30.00  {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 38400   160x120 160x120 160x120 7.50-30.00  {none}
Video   YUY2    VideoInfo   Fixed   NotTemporal 4147200 1920x1080   1920x1080   1920x1080   5.00-5.00   {none}
Video   YUY2    VideoInfo2  Fixed   NotTemporal 4147200 1920x1080   1920x1080   1920x1080   5.00-5.00   {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 921600  640x480 640x480 640x480 7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 921600  640x480 640x480 640x480 7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 6220800 1920x1080   1920x1080   1920x1080   7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 6220800 1920x1080   1920x1080   1920x1080   7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 2764800 1280x720    1280x720    1280x720    7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 2764800 1280x720    1280x720    1280x720    7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 1566720 960x544 960x544 960x544 7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 1566720 960x544 960x544 960x544 7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 1075200 800x448 800x448 800x448 7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 1075200 800x448 800x448 800x448 7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 691200  640x360 640x360 640x360 7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 691200  640x360 640x360 640x360 7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 1440000 800x600 800x600 800x600 7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 1440000 800x600 800x600 800x600 7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 311040  432x240 432x240 432x240 7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 311040  432x240 432x240 432x240 7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 304128  352x288 352x288 352x288 7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 304128  352x288 352x288 352x288 7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 76032   176x144 176x144 176x144 7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 76032   176x144 176x144 176x144 7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 230400  320x240 320x240 320x240 7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 230400  320x240 320x240 320x240 7.50-30.00  {none}
Video   MJPG    VideoInfo   Fixed   NotTemporal 57600   160x120 160x120 160x120 7.50-30.00  {none}
Video   MJPG    VideoInfo2  Fixed   NotTemporal 57600   160x120 160x120 160x120 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 460800  640x480 640x480 640x480 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 460800  640x480 640x480 640x480 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 1382400 1280x720    1280x720    1280x720    7.50-15.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 1382400 1280x720    1280x720    1280x720    7.50-15.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 783360  960x544 960x544 960x544 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 783360  960x544 960x544 960x544 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 537600  800x448 800x448 800x448 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 537600  800x448 800x448 800x448 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 345600  640x360 640x360 640x360 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 345600  640x360 640x360 640x360 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 152640  424x240 424x240 424x240 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 152640  424x240 424x240 424x240 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 152064  352x288 352x288 352x288 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 152064  352x288 352x288 352x288 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 115200  320x240 320x240 320x240 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 115200  320x240 320x240 320x240 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 720000  800x600 800x600 800x600 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 720000  800x600 800x600 800x600 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 38016   176x144 176x144 176x144 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 38016   176x144 176x144 176x144 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 28800   160x120 160x120 160x120 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 28800   160x120 160x120 160x120 7.50-30.00  {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo   Fixed   NotTemporal 3110400 1920x1080   1920x1080   1920x1080   7.50-7.50   {none}
Video   {3032344D-0000-0010-8000-00AA00389B71}  VideoInfo2  Fixed   NotTemporal 3110400 1920x1080   1920x1080   1920x1080   7.50-7.50   {none}

Pin Name:   Video Camera Terminal
Pin direction:  Input
Pin category:   {3EBC7959-3310-493B-AA81-C7E132D56F71}

IAMVideoCompression:    No
ISpecifyPropertyPages:  Yes
IMediaSeeking:  No
IPinConnection: No
IPinFlowControl:    No
IAMDroppedFrames:   No
IAMVideoProcAmp:    No
IAMVideoControlCaps:    0

Major Type  Sub Type    Format Type FixedSamples    Temporal Compression    Sample Size

You put it into right place - after it's already in the graph by AddFilter, but yet before its output pin is connected. If you have successful HRESULT, then you could be expecting changed format, but there might be exceptions, such as for example this media type was not accepted by downstream filter and they started negotiating from the start.

You're not showing your ConfigureSampleGrabber here, so it might be the case that this media type you want is not accepted by sample grabber making filter graph to try alternate media types and/or intermediate filters (such as decoders).

There are a few things you can actually do.

  1. For troubleshooting you might want to:

    1. add the filter graph to ROT, or instead just install DirectShow Spy to have the same done for you automatically
    2. add a MessageBox in your code right after your SetCaptureFormat
    3. while the message box is still on the screen, use GraphEdit (GraphStudio) to inspect your filter graph and to see what media types it enumerates on its output pin; typically the first media type will be the one used for real connection, so your successfull HRESULT in SetFormat basically assumes the media type is now on top of this list

  2. To force the media type, you might want to use IFilterGraph::ConnectDirect with the configured pin, it's immediate neighbor downstream pin and media type of your interest.

Hope this helps.

Steve, you should not rebuild the camera (from moniker) in SetCaptureFormat but use the g_pIBaseFilterCam.

0

上一篇:

:下一篇

更多 问答 相关资讯：

精彩评论

暂无评论...
登录 注册
Qedev.com
验证码 换一张
取 消

关注公众号

热门标签

图文推荐

Delphi - Custom drawing a message list

Delphi - Custom drawing a message list
C++ header-only include pattern

C++ header-only include pattern
IE7 Margin Collapses Into Padding

IE7 Margin Collapses Into Padding
in CoffeeScript, how can I use a variable as a key in a hash?

in CoffeeScript, how can I use a variable as a key in a hash?
Interactive visualization of a graph in python [closed]

Interactive visualization of a graph in python [closed]
How to customise PHP MYSQL tables?

How to customise PHP MYSQL tables?
High quality, simple random password generator

High quality, simple random password generator
Image Recognition ApI in android

Image Recognition ApI in android

开发者开发者网给大家分享系统运维,大数据运维,云计算,编程开发技巧,路由交换,运维和开发相关的资讯及技术文章，同时StackOverflow中文社区，知识经验交流分享。

法律声明：本站内容均为网友上传，网站举办方负责审核和监督，如存在版权或非法内容，欢迎举报，我们将尽快予以删除。邮箱：devze@qq.com

Copyright © 2018-2020 开发者. All rights reserved. Powered by 开发者ICP备案号: 京ICP备10032868号-9