A screen recording tool for Windows that takes screenshots and logs ETW events at a specified framerate.
The tool allows you to start and stop recording from the command line. When a recording is started, the framerate, monitor, and buffer size can be specified. When a recording is stopped, a folder must be provided in which to store the screenshots.
screenrecorder.exe -start ... Starts screen recording.
Usage: screenrecorder.exe -start [-framerate <framerate>] [-monitor <monitor index>] [-framebuffer -mb <# of frames>] [-monitor <monitor # to record>]
Ex> screenrecorder.exe -start -framerate 10
Ex> screenrecorder.exe -start -framerate 1 -monitor 0 -framebuffer -mb 100
-framerate Specifies the rate at which screenshots will be taken, in frames per second.
-monitor Specifies the monitor to record, as an index. The highest index will record all monitors.
-framebuffer Specifies the size of the circular memory buffer in which to store screenshots, in number of screenshots. Adding the -mb flag specifies the size of the buffer in megabytes.
screenrecorder.exe -stop ... Stops screen recording saves all screenshots in buffer to a folder.
Usage: screenrecorder.exe -stop <recording folder>
Ex> screenrecorder.exe -stop "D:\screenrecorder"
screenrecorder.exe -cancel ... Cancels the screen recording.
screenrecorder.exe -help ... Prints usage information.
An ETW event is emitted by the tool every time it receives a frame from DirectX. The event for each frame contains the filename to be used if the frame is saved to disk, allowing for direct correlation between each event and screenshot. The tool does not receive frames from DirectX unless there has been a change in the screen, so desired framerates may not be exact.
To capture the ETW events, you must use a ETW tracing tool like WPR and watch for events from the following provider guid: fe8fc3d0-1e6a-42f2-be28-9f8a0fcf7b04.
Create a WPR profile with the following provider and collectors defined:
...
<EventProvider Id="screenrecorder" Name="fe8fc3d0-1e6a-42f2-be28-9f8a0fcf7b04">
</EventProvider>
...
<EventCollectorId Value="Standard_EventCollector_Misc">
<EventProviders>
<EventProviderId Value="screenrecorder"/>
</EventProviders>
</EventCollectorId>
...
Take an ETW trace using WPR while you use the tool to capture some scenario.
wpr -start profile.wprp
ScreenRecorder.exe -start
... excercise some scenario of interest ...
ScreenRecorder.exe -stop "D:\"
wpr -stop trace.etl
Now opening the trace in WPA, we can see the events produced by the tool in the Generic Events table under the ScreenRecorder provider. Each event contains the filename for the screenshot.
