Live Source Cannot create device. The device may be in use by another program.

Question

I have a DirectShow filter registered that I am selecting as a live source.  The direct show filter outputs MPEG2 Transport stream, which I Expression encoder pro 4 supports as a live input.

Expression encoder pro 4 comes back with a pop up and the error :
"Cannot create device.  The device may be in use by another program."

I have access to the Direct show filter source code, if I had some idea of why it reports this error I could investigate?

Many thanks

John

 

Answer 1

I have been debugging the interaction of Expression encoder with my DirectShow capture device.

When selected it calls the GetMediaType which is most of note.  The code is as shown below  ;

So my assumption is Expression encoder does not support MEDIATYPE_Stream and MEDIASUBTYPE_MPEG2_TRANSPORT??

Can you confirm it should support this type, or suggest somewhere else to investigate?

Thanks

John

 

HRESULT  CTsPin::GetMediaType(int Pos, CMediaType* pType)
{
  if ( Pos<0 || pType==NULL )    return E_INVALIDARG;

  if ( Pos>=1 )    return VFW_S_NO_MORE_ITEMS;

  pType->SetType(&MEDIATYPE_Stream);
  pType->SetSubtype(&MEDIASUBTYPE_MPEG2_TRANSPORT);

  return S_OK;
}