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diff --git a/AVStream/avssamp/README.md b/AVStream/avssamp/README.md new file mode 100644 index 00000000..6188c5b3 --- /dev/null +++ b/AVStream/avssamp/README.md @@ -0,0 +1,51 @@ +AVStream filter-centric simulated capture sample driver (Avssamp) +================================================================= + +The AVStream filter-centric simulated capture sample driver (Avssamp) provides a filter-centric [AVStream](http://msdn.microsoft.com/en-us/library/windows/hardware/ff554240) capture driver with functional audio. This streaming media driver performs video captures at 320 x 240 pixel resolution in RGB24 or YUV422 format while playing a user-provided Pulse Code Modulation (PCM) wave audio file in a loop. The sample demonstrates how to write a filter-centric AVStream minidriver. + + +Installation instructions +------------------------- + +1. Copy AVssamp.inf to a directory, for example, C:\\Avstream\\. +2. In this directory, create a new subdirectory named objfre\_x86 if the target operating system is x86-based, or objfre\_amd64 for an x64-based target operating system, for example, C:\\AVstream\\objfre\_x86\\. +3. Copy the processor-appropriate Avssamp.sys file to the objfre\_\* directory. +4. Start a command prompt with administrator privilege and run the processor-specific WDK tool Devcon.exe to launch the installation. For example: + + `C:\WinDDK\7600.16384.0\tools\devcon\i386\devcon.exe install C:\AVstream\avssamp.inf SW\{20698827-7099-4c4e-861A-4879D639A35F}` + +Programming Tour +---------------- + +[**DriverEntry**](http://msdn.microsoft.com/en-us/library/windows/hardware/ff558717) in Avssamp.cpp is the initial point of entry into the driver. This routine passes control to AVStream by calling [**KsInitializeDriver**](http://msdn.microsoft.com/en-us/library/windows/hardware/ff562683). In this call, the minidriver passes the device descriptor, an AVStream structure that recursively defines the AVStream object hierarchy for a driver. This is common behavior for an AVStream minidriver. + +Filter.cpp is where the sample lays out the [**KSPIN\_DESCRIPTOR\_EX**](http://msdn.microsoft.com/en-us/library/windows/hardware/ff563534) structure for the single capture pin. Audio.cpp contains the **KSPIN\_DESCRIPTOR\_EX** structure for the audio capture pin. This pin is dynamically created only if C:\\avssamp.wav exists and is a valid and readable PCM format wave file. + +The filter dispatch structure [**KSFILTER\_DISPATCH**](http://msdn.microsoft.com/en-us/library/windows/hardware/ff562554) in Filter.cpp provides dispatches to create and process data. The **DispatchProcess** method is defined inline in Filter.h. It calls the **Process** method in Filter.cpp in the context of the **CCaptureFilter** class. Be aware that the process dispatch is provided in **KSFILTER\_DISPATCH** because this sample is filter-centric. + +Audio.cpp lays out a [**KSPIN\_DISPATCH**](http://msdn.microsoft.com/en-us/library/windows/hardware/ff563535) pin dispatch structure, which contains the dispatch table for the audio pin. Be aware that the **Process** member of this structure is **NULL** because the sample is filter-centric. Similarly, Video.cpp contains the **KSPIN\_DISPATCH** structure for the video capture pin, again with the **Process** member set to **NULL**. + +For more information, see the comments in all .cpp files. + +File Manifest +------------- + +File | Description +-----|---------- +Audio.cpp | Audio capture pin implementation. +Audio.h | Header file for Audio.cpp. +Avssamp.cpp | Main file for the AVStream filter-centric sample. +Avssamp.h | Main header for the AVStream filter-centric sample. +Avssamp.inf | Installation information for the AVStream sample driver (avssamp.sys). +Capture.cpp | Capture pin implementation for all capture pins on the sample filter. +Capture .h | Capture pin level header for all capture pins on the sample filter. +Filter.cpp | Capture filter implementation (including frame synthesis) for the fake capture filter. +Filter.h | Filter level header for the filter-centric capture filter. +Image.cpp | Image synthesis and overlay code. These objects provide image synthesis (pixel, color-bar, etc) onto RGB24 and UYVY buffers as well as software string overlay into these buffers. +Image.h | Image synthesis and overlay header. +Purecall.h | _purecall stub necessary for virtual function usage in drivers. +Video.cpp | Video capture pin implementation. +Video.h | Video capture pin header. +Wave.cpp | Wave object implementation +Wave.h | Wave object header + |