/// <summary>
/// Returns an array of DsDevices of type devcat.
/// </summary>
/// <param name="cat">Any one of FilterCategory</param>
public static MFDevice[] GetDevicesOfCat(Guid FilterCategory)
{
// Use arrayList to build the retun list since it is easily resizable
MFDevice[] devret = null;
IMFActivate[] ppDevices;
//////////
HResult hr = 0;
IMFAttributes pAttributes = null;
// Initialize an attribute store. We will use this to
// specify the enumeration parameters.
hr = MFExtern.MFCreateAttributes(out pAttributes, 1);
// Ask for source type = video capture devices
if (hr >= 0)
{
hr = pAttributes.SetGUID(
MFAttributesClsid.MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE,
FilterCategory
);
}
// Enumerate devices.
int cDevices;
if (hr >= 0)
{
hr = MFExtern.MFEnumDeviceSources(pAttributes, out ppDevices, out cDevices);
if (hr >= 0)
{
devret = new MFDevice[cDevices];
for (int x = 0; x < cDevices; x++)
{
devret[x] = new MFDevice(ppDevices[x]);
}
}
}
if (pAttributes != null)
{
Marshal.ReleaseComObject(pAttributes);
}
return(devret);
}
private void LoadDevicesList()
{
// Populate the list with the friendly names of the devices.
MFDevice[] arDevices = MFDevice.GetDevicesOfCat(CLSID.MF_DEVSOURCE_ATTRIBUTE_SOURCE_TYPE_VIDCAP_GUID);
lstbDevices.BeginUpdate();
lstbDevices.Items.Clear();
foreach (MFDevice m in arDevices)
{
lstbDevices.Items.Add(m);
}
lstbDevices.EndUpdate();
bttOK.Enabled = false;
}
//-------------------------------------------------------------------
// SetDevice
//
// Set up preview for a specified video capture device.
//-------------------------------------------------------------------
public HResult SetDevice(MFDevice pDevice)
{
HResult hr = HResult.S_OK;
IMFActivate pActivate = pDevice.Activator;
IMFMediaSource pSource = null;
IMFAttributes pAttributes = null;
object o = null;
lock (this)
{
try
{
// Release the current device, if any.
hr = CloseDevice();
if (Succeeded(hr))
{
// Create the media source for the device.
hr = pActivate.ActivateObject(typeof(IMFMediaSource).GUID, out o);
}
if (Succeeded(hr))
{
pSource = (IMFMediaSource)o;
}
// Get Symbolic device link
m_pwszSymbolicLink = pDevice.SymbolicName;
//
// Create the source reader.
//
// Create an attribute store to hold initialization settings.
if (Succeeded(hr))
{
hr = MFExtern.MFCreateAttributes(out pAttributes, 2);
}
if (Succeeded(hr))
{
hr = pAttributes.SetUINT32(MFAttributesClsid.MF_READWRITE_DISABLE_CONVERTERS, 1);
}
if (Succeeded(hr))
{
hr = pAttributes.SetUnknown(MFAttributesClsid.MF_SOURCE_READER_ASYNC_CALLBACK, this);
}
IMFSourceReader pRead = null;
if (Succeeded(hr))
{
hr = MFExtern.MFCreateSourceReaderFromMediaSource(pSource, pAttributes, out pRead);
}
if (Succeeded(hr))
{
m_pReader = (IMFSourceReaderAsync)pRead;
}
if (Succeeded(hr))
{
// Try to find a suitable output type.
for (int i = 0; ; i++)
{
IMFMediaType pType;
hr = m_pReader.GetNativeMediaType((int)MF_SOURCE_READER.FirstVideoStream, i, out pType);
if (Failed(hr))
{
break;
}
try
{
hr = TryMediaType(pType);
if (Succeeded(hr))
{
// Found an output type.
break;
}
}
finally
{
SafeRelease(pType);
}
}
}
if (Succeeded(hr))
{
hr = ConfigWriter();
if (Succeeded(hr))
{
m_draw.SetBitmap(BitmapOverlayFile);
// Ask for the first sample.
hr = m_pReader.ReadSample((int)MF_SOURCE_READER.FirstVideoStream, 0, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero);
}
}
if (Failed(hr))
{
if (pSource != null)
{
pSource.Shutdown();
// NOTE: The source reader shuts down the media source
// by default, but we might not have gotten that far.
}
CloseDevice();
}
}
finally
{
SafeRelease(pSource);
SafeRelease(pAttributes);
}
}
return(hr);
}