Fooling Around

I am sharing a couple of utilities to be able to quick check system settings. TimeZoneInformation prints in a human friendly style TIME_ZONE_INFORMATION structure as reported by Windows through GetTimeZoneInformation API.

TIME_ZONE_INFORMATION:
.Bias: -120
.StandardName: FLE Standard Time
.StandardDate: { .wYear 0, .wMonth 10, .wDay 5, .wDayOfWeek 0, .wHour 4, .wMinute 0, .wSecond 0, .wMilliseconds 0 }
.StandardBias: 0
.DaylightName: FLE Daylight Time
.DaylightDate: { .wYear 0, .wMonth 3, .wDay 5, .wDayOfWeek 0, .wHour 3, .wMinute 0, .wSecond 0, .wMilliseconds 0 }
.DaylightBias: -60
[...]

A Visual C++ .NET 2008 source code is available from SVN, release binary included.

And the second utility is MonitorInformation to print multi-monitor related information again as reported by Windows, GetSystemMetrics and EnumDisplayMonitors APIs.

System Metrics:
  SM_XVIRTUALSCREEN: 0
  SM_YVIRTUALSCREEN: 0
  SM_CXVIRTUALSCREEN: 1680
  SM_CYVIRTUALSCREEN: 1050
  SM_CMONITORS: 1
  SM_SAMEDISPLAYFORMAT: 1

Monitor 0 at (0, 0) - (1680, 1050):
  Coordinates (rcMonitor): (0, 0) - (1680, 1050)
  Work Area (rcWork): (0, 0) - (1680, 1026)
  Flags (dwFlags): 0x1
  Device Name (szDevice): \\.\DISPLAY1

A Visual C++ .NET 2008 source code is available from SVN, release binary included.

While troubleshooting released application on remote production site, it is very useful to grasp a state of the process for further analysis. There are several scenarios in which the following information about process state is helpful:

• modules (DLLs) loaded into process and their versions
• threads and their call stacks
• process and thread performance

An utility ProcessSnapshot takes advantage of Debugging Tools API (dbghelp.dll - note the dialog also displays DLL version in the right bottom corner) and writes this helpful information to text file and it can also take a sequence of the snapshots to compare thread performance and/or stacks and check the difference.

The generated file is in the directory of the utility application and looks like:

Snapshot
  System Time: 10/14/2008 8:46:33 PM
  Local Time: 10/14/2008 11:46:33 PM

Performance
  Creation System Time: 10/14/2008 8:46:28 PM
  Kernel Time: 0.094 s
  User Time: 0.031 s

Modules

  Module: ProcessSnapshot.exe @00400000
    Base Address: 0x00400000
    Base Size: 0x0005b000 (372736)
    Name: ProcessSnapshot.exe
    Path: D:\Projects\Utilities\ProcessSnapshot\Release\ProcessSnapshot.exe
    Product Version: 1.0.0.1
    File Version: 1.0.0.125

  Module: ntdll.dll @7c900000
    Base Address: 0x7c900000
    Base Size: 0x000af000 (716800)
    Name: ntdll.dll
    Path: C:\WINDOWS\system32\ntdll.dll
    Product Version: 5.1.2600.5512
    File Version: 5.1.2600.5512
[...]

Threads

  Thread: 3824
    Base Priority: 8
    Creation System Time: 10/14/2008 8:46:57 PM
    Kernel Time: 0.063 s
    User Time: 0.031 s
    Call Stack
      ntdll!7c90e4f4 KiFastSystemCallRet (+ 0) @7c900000
      USER32!7e4249c4 GetCursorFrameInfo (+ 460) @7e410000
      USER32!7e424a06 DialogBoxIndirectParamAorW (+ 54) @7e410000
      USER32!7e4247ea DialogBoxParamW (+ 63) @7e410000
      ProcessSnapshot!00403f45 ATL::CDialogImpl<CMainDialog,ATL::CWindow>::DoModal (+ 67) [c:\program files\microsoft visual studio 9.0\vc\atlmfc\include\atlwin.h, 3478] (+ 28) @00400000
      ProcessSnapshot!00403b6f CProcessSnapshotModule::RunMessageLoop (+ 74) [d:\projects\utilities\processsnapshot\processsnapshot.cpp, 67] (+ 0) @00400000
      ProcessSnapshot!004049b9 ATL::CAtlExeModuleT<CProcessSnapshotModule>::Run (+ 17) [c:\program files\microsoft visual studio 9.0\vc\atlmfc\include\atlbase.h, 3552] (+ 0) @00400000
      ProcessSnapshot!004041c3 ATL::CAtlExeModuleT<CProcessSnapshotModule>::WinMain (+ 48) [c:\program files\microsoft visual studio 9.0\vc\atlmfc\include\atlbase.h, 3364] (+ 5) @00400000
      ProcessSnapshot!00434477 wWinMain (+ 5) [*d:\projects\utilities\processsnapshot\release\processsnapshot.inj:5, 14] (+ 0) @00400000
      ProcessSnapshot!00415058 __tmainCRTStartup (+ 274) [f:\dd\vctools\crt_bld\self_x86\crt\src\crt0.c, 263] (+ 27) @00400000
      !00360033

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Previously on the topic:

• Part 1: Starting the Project
• Part 2: Video Processing
• Part 3: Persistence, Automation and Property Pages
• Part 4: Merit

Due to the nature of the brightness and constract correction processing, it would make sense to combine and simplify processing to apply correction “in-place”, that is without copying data from input to output buffer, but instead processing the same buffer before it is passed further downstream.

DMO API offers additional optional IMediaObjectInPlace interface to be implemented on the DMO which the hosting object might prefer to regular IMediaObject.

The interface itself is simple with basically the only Process method to actually handle the processing:

// IMediaObjectInPlace
	STDMETHOD(Process)(ULONG nSize, BYTE* pnData, REFERENCE_TIME nStartTime, DWORD nFlags)
	STDMETHOD(Clone)(IMediaObjectInPlace** ppMediaObject)
	STDMETHOD(GetLatency)(REFERENCE_TIME* pnLatencyTime)

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Previously on the topic:

• Part 1: Starting the Project
• Part 2: Video Processing
• Part 3: Persistence, Automation and Property Pages

The implemented so far filter/DMO shown a problem related to its unexpectedly high “importance” in the system with the symptom of “auto-insertion” the filter when it is not necessary. For example, let us render an AVI file through Infinite Tee Pin Filter:

The problem is that DirectShow auto-inserts our Brightness/Contrast filter into the graph while it is obviously not expected, wanted or necessary:

The problem is high filter/DMO merit value and a popular YUY2 video format the filter is advertised to accept on input during DMO registration.

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Previously on the topic:

• Part 1: Starting the Project
• Part 2: Video Processing

The principal task of video processing is done but there are still things mandatory for the filter to be usable. First of all, a custom interface is required to be able to control the filter from higher level application and to adjust brightness and constract correction values on the run time. Additionally, persistence would not hurt at all to be able to store correction settings along with other graph settings in GraphEdit graph file or anywhere else. Additionally, it would also be convenient to have a property page for the filter to be able to adjust the correction settings through GUI, both on graph composition and while the graph is running.

All the mentioned tasks are interconnected and ATL has an answer in implementation of:

• IDispatch-derived automation interface through IDispatchImpl class to implement custom interface to be used for external control over the filter/DMO and also to be used to access persistent properties
• IPersistStream/IPersistStreamInit interfaces through IPersistStreamInitImpl class and PROP_MAP macro map to implement persistence capabilities
• ISpecifyPropertyPages interface through ISpecifyPropertyPagesImpl class to provide custom property page

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