public HResult Start(IMFPresentationDescriptor pPresentationDescriptor, Guid pguidTimeFormat, ConstPropVariant pvarStartPos)
{
HResult hr = HResult.S_OK;
// Check parameters.
// Start position and presentation descriptor cannot be NULL.
if (pvarStartPos == null || pPresentationDescriptor == null)
{
return(HResult.E_INVALIDARG);
}
// Check the time format.
if ((pguidTimeFormat != null) && (pguidTimeFormat != Guid.Empty))
{
// Unrecognized time format GUID.
return(HResult.MF_E_UNSUPPORTED_TIME_FORMAT);
}
// Check the data type of the start position.
if (pvarStartPos.GetVariantType() != VariantType.None && pvarStartPos.GetVariantType() != VariantType.Int64)
{
return(HResult.MF_E_UNSUPPORTED_TIME_FORMAT);
}
if (_eSourceState != SourceState.SourceState_Stopped && _eSourceState != SourceState.SourceState_Started)
{
hr = HResult.MF_E_INVALIDREQUEST;
}
if (MFError.Succeeded(hr))
{
// Check if the presentation description is valid.
hr = ValidatePresentationDescriptor(pPresentationDescriptor);
}
if (MFError.Succeeded(hr))
{
CSourceOperation op = new CSourceOperation
{
Type = SourceOperationType.Operation_Start,
PresentationDescriptor = pPresentationDescriptor,
Data = pvarStartPos
};
doStart(op);
}
return(hr);
}
/// <summary>
/// Convert a PropVariant to a managed object
/// </summary>
/// <param name="variant">The PropVariant to convert.</param>
/// <returns>A managed object corresponding to the given PropVariant or null if the PropVariant type is unsupported.</returns>
public static object GetObject(this ConstPropVariant variant)
{
if (variant == null)
{
throw new ArgumentNullException("variant");
}
switch (variant.GetVariantType())
{
case ConstPropVariant.VariantType.None:
return(null);
case ConstPropVariant.VariantType.Short:
return(variant.GetShort());
case ConstPropVariant.VariantType.Int32:
return(variant.GetInt());
case ConstPropVariant.VariantType.Float:
return(variant.GetFloat());
case ConstPropVariant.VariantType.Double:
return(variant.GetDouble());
case ConstPropVariant.VariantType.IUnknown:
return(variant.GetIUnknown());
case ConstPropVariant.VariantType.UByte:
return(variant.GetUByte());
case ConstPropVariant.VariantType.UShort:
return(variant.GetUShort());
case ConstPropVariant.VariantType.UInt32:
return(variant.GetUInt());
case ConstPropVariant.VariantType.UInt64:
return(variant.GetULong());
case ConstPropVariant.VariantType.String:
return(variant.GetString());
case ConstPropVariant.VariantType.Guid:
return(variant.GetGuid());
case ConstPropVariant.VariantType.Blob:
return(variant.GetBlob());
case ConstPropVariant.VariantType.StringArray:
return(variant.GetStringArray());
}
return(null);
}
