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• DXGI Desktop Duplication : encoding frames to send them over the network

  31 août 2018, par prazuber

  I’m trying to write an app which will capture a video stream of the screen and send it to a remote client. I’ve found out that the best way to capture a screen on Windows is to use DXGI Desktop Duplication API (available since Windows 8). Microsoft provides a neat sample which streams duplicated frames to screen. Now, I’ve been wondering what is the easiest, but still relatively fast way to encode those frames and send them over the network.

  The frames come from AcquireNextFrame with a surface that contains the desktop bitmap and metadata which contains dirty and move regions that were updated. From here, I have a couple of options :

  1. Extract a bitmap from a DirectX surface and then use an external library like ffmpeg to encode series of bitmaps to H.264 and send it over RTSP. While straightforward, I fear that this method will be too slow as it isn’t taking advantage of any native Windows methods. Converting D3D texture to a ffmpeg-compatible bitmap seems like unnecessary work.
  2. From this answer : convert D3D texture to IMFSample and use MediaFoundation’s SinkWriter to encode the frame. I found this tutorial of video encoding, but I haven’t yet found a way to immediately get the encoded frame and send it instead of dumping all of them to a video file.

  Since I haven’t done anything like this before, I’m asking if I’m moving in the right direction. In the end, I want to have a simple, preferably low latency desktop capture video stream, which I can view from a remote device.

  Also, I’m wondering if I can make use of dirty and move regions provided by Desktop Duplication. Instead of encoding the frame, I can send them over the network and do the processing on the client side, but this means that my client has to have DirectX 11.1 or higher available, which is impossible if I would want to stream to a mobile platform.

• Running PowerShell command in Universal Windows Platform C#

  6 juin 2017, par stephen

  So I am trying to write a basic application to cut and export a subsection of a video. I have come across (and decided to use) the FFMPEG command line tools to do the cropping. This seemed straight forward (https://stackoverflow.com/a/5047426/6728859), but Universal Windows apps do not support System.Diagnostics.Process. Instead, it was suggested that they do support Powershell, which means I could do it by following (https://blogs.msdn.microsoft.com/kebab/2014/04/28/executing-powershell-scripts-from-c/). However, I get the following errors

  Cannot find type System.SystemException in module CommonLanguageRuntimeLibrary

  Cannot resolve Assembly or Windows Metadata file 'System.Configuration.Install.dll'

  From my limited understanding System.SystemException was removed in UWP, and I’m not sure where to find System.Configuration.Install.dll.

  Now to get PowerShell I had to include System.Management.Automation which I got from C:\Program Files (x86)\Reference Assemblies\Microsoft\WindowsPowerShell\3.0 which doesn’t seem correct to me, but I could be wrong.

  Is it possible to run commands in a UWP, or does anyone have any suggestions ?

• fate : Add test for vc1test demuxer

  23 octobre 2018, par Jun Zhao

  fate : Add test for vc1test demuxer
  Signed-off-by : Jun Zhao <mypopydev@gmail.com>
  

  • [DH] tests/fate/microsoft.mak
  • [DH] tests/ref/fate/vc1test_smm0005
  • [DH] tests/ref/fate/vc1test_smm0015