Once upon a time Windows SDK (or it was Visual Studio) had a tool named IROTVIEW which enumerated Running Object Table (ROT). Running Object Table Viewer IROTVIEW displays information about ActiveX and OLE objects currently existing in memory. People ask “Where is IROTVIEW?” and there is no answer. The API is really simple, but if [...]
Posts Tagged ‘COM’
RotView: What is on ROT?
Posted: 4th January 2013 by Roman in UtilitiesTags: COM, GetRunningObjectTable, irotview, IRunningObjectTable, RegisterActiveObject, rot, rotview
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DirectShow Spy: ROT fix and evrprop.dll
Posted: 4th January 2013 by Roman in ATL, UtilitiesTags: COM, DirectShow, directshowspy
A small issue appears to be affecting DirectShow applications with DirectShow Spy installed. As underlying COM base is non-standard, the spy implements a few hacks to run smoothly and to keep reference counting correct in particular. Under certain conditions, DirectShow-enabled ActiveX control hosted by Internet Explorer seems to be unable to put its graph onto [...]
DirectShow Spy: Easier Registration
Posted: 24th November 2012 by Roman in ATL, Utilities, WTLTags: COM, DirectShow, directshowspy, registration, regsvr32, rundll32, spy
Because DirectShow Spy is often a troubleshooting tool, one of its use scenarios is its being a drop-in module to quickly install on a system of interest in order to connect to graphs for troubleshooting purposes, such as to check topology and media types. Its installation requires COM registration, and over time it changed gradually [...]
Reading HRESULT codes
Posted: 18th August 2012 by Roman in ATL, Source, UtilitiesTags: code, COM, DirectShow, error, hresult, media foundation
Although HRESULT codes are so common and structure is simple and well known, and even Visual Studio helps decoding the values nowadays, looking up for code takes some effort: hexadecimal value, searching through SDK headers or online, overlapped regions of codes in FACILITY_ITF etc. MSDN describes the codes in the following sections: Structure of COM [...]
Three ways to implement VBScript (VB6, VBA) callback from C++/ATL class
Posted: 11th August 2012 by Roman in ATL, SourceTags: ATL, automation, C++, COM, scripting, vb, vba, vbs
Suppose you have an automation object that needs to implement a callback into caller Visual Basic environment, which can be Scripting Host, Visual Basic for Applications, ASP etc. With all the late binding in VB scripting and so much different C++ code – how to put everything together? There are great choices, let us have [...]