I am sometimes using a rework of earlier DxgiTakeSnapshot application for one specific purpose mentioned below. In addition to Desktop Duplication API, recent version of Windows offer a similar (in sense of acquisition of external video content) API: Windows.Graphics.Capture (hereinafter “WGC”), and the new rework is using this API to capture visual content as a snapshot or, now, as a video stream.
I will skip the technical details and just link Robert Mikhayelyan’s Win32CaptureSample project on GitHub, which is perhaps the best place to ask questions about this new API.
The today’s application takes a snapshot of given monitor, window or process windows (each window separately) similar to original DxgiTakeSnapshot application, and this might be worth a separate post, but at this time I just wanted to mention an quick hack with -Video command line argument.
The hack uses the API along with taking audio currently played and records the audiovisual stream into MP4 file until you stop it with Control+Break.
For example, this way I recorded video below by recording browser window with YouTube playback. I started the app first to quickly identify HWND of interest.
C:\>DxgiTakeWindowSnapshot.exe -Process msedge.exe DxgiTakeWindowSnapshot.exe 20210717.1-16-g34e6c97 (Release) 34e6c972dad5568347d44e58ab0338b7daa1dba7 HEAD -> video, origin/video 2021-11-20 21:07:46 +0200 -- Found process 023228 "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" Found 2 windows for process 023228 Trying to capture window 0x0000000000A608E0, Filatov & Karas - ????? ? ?????? (Live @????????? ) - YouTube - Personal - Microsoft??? Edge Trying to capture window 0x00000000016D066E, Filatov & Karas - Don???t Be So Shy (RuSongTV - Turkey) - YouTube and 3 more pages - Personal - Microsoft??? Edge Found process 013944 "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" Found 0 windows for process 013944 C:\>DxgiTakeWindowSnapshot.exe -Window 0x0000000000A608E0 -Video DxgiTakeWindowSnapshot.exe 20210717.1-16-g34e6c97 (Release) 34e6c972dad5568347d44e58ab0338b7daa1dba7 HEAD -> video, origin/video 2021-11-20 21:07:46 +0200 -- Trying to capture window 0x0000000000A608E0, Filatov & Karas - ????? ? ?????? (Live @????????? ) - YouTube - Personal - Microsoft??? Edge Stopping: CTRL_C_EVENT
(see next post on why video below is blocked here)
The application is currently hardcoding produced video as 1920×1080@60 with 10 MBps bitrate, and is subject to certain limitations because of quick and hacky implementation:
- as mentioned, 1920×1080@60 with 10 MBps video bitrate (& max documented bitrate for stock AAC audio encoder)
- video might be letterboxed to preserve aspect ratio (default behavior of Media Foundation XVP)
- compatible Media Foundation video encoder which is expected to be discoverable as default (hardware encoding is used as designed)
- a pretty much regular audio device expected, certain not so usual settings like 5.1 audio as shared format are likely to cause exceptions
- the application picks default multimedia audio device for recording (actual code line is
auto const Device = DefaultAudioEndpoint(eRender, eMultimedia);)
So that one specific purpose the application is good for is meeting recording: record a window with Google Meet session, Microsoft Teams or alike and you have a convenient copy of content for review or share.
As of now the application is recording only audio playback device, but not the microphone – I will reach this some time later.
If you want something more convenient, there is also Robert’s Simple Screen Recorder in Windows Store, however this will be video only yet with source code on GitHub.
DxgiTakeWindowSnapshot uses Media Foundation in old-school way: it creates a Microsoft Media Foundation Media Session pipeline with a few custom primitives and some stock ones, esp. video encoder, video processor and audio encoder it takes all this stuff off to record media…
Download links
Binaries:
- 64-bit: DxgiTakeWindowSnapshot.exe (in .ZIP archive)
- License: This software is free to use