Recherche avancée

Sur d’autres sites (12394)

• 4K Screen Recording on 1080p Monitors [closed]

  10 avril, par Souhail Benlhachemi

  I have created a basic windows screen recording app (ffmpeg + GUI), but I noticed that the quality of the recording depends on the monitor used to record, the video recording quality when recorded using a full HD is different from he video recording quality when recorded using a 4k monitor (which is obvious).

  


  There is not much difference between the two when playing the recorded video with a scale of 100%, but when I zoom to 150% or more, we clearly can see the difference between the two recorded videos (1920x1080 VS the 4k).

  


  I did some research on how to do screen recording with a 4k quality on a full hd monitor, and here is what I found :

  


  I played with the windows duplicate API (AcquireNextFrame function which gives you the next frame on the swap chain), I successfully managed to convert the buffer to a PNG image and save it locally to my machine, but as you expect the quality was the same as a normal screenshot ! Because AcquireNextFrame return a frame after it is rasterized.

  


  Then I came across what’s called “Graphics pipeline”, I spent some time to understand the basics, and finally I came to a conclusion that I need to intercept somehow the pre-rasterize data (the data that comes before the Rasterizer Stage - Geometry shaders, etc...) and then duplicate this data and do an off-screen render on a new 4k render target, but the windows API don’t allow that, there is no way to do that ! The only option they have on docs is what’s called Stream Output Stage, but this is useful only if you want to render your own shaders, not the ones that my display is using. (I tried to use MinHook to intercept data but no luck).

  


  After that, I tried a different approach, I managed to create a virtual display as extended monitor with 4k resolution, and record it using ffmpeg, but as you know what I’m seeing on my main display on my monitor is different from the virtual display (only an empty desktop), what I need to do is drag and drop app windows using my mouse to that screen manually, but this will put us in a problem when recording, we are not seeing what we are recording xD.

  


  I found some YouTube videos that talk about DSR (Dynamic Super Resolution), I tried that on my nvidia control panel (manually with GUI) and it works. I managed to fake the system that I have a 4k monitor and the quality of the recording was crystal clear. But I didn’t find anyway to do that programmatically using NVAPI + there is no API for that on AMD.

  


  Has anyone worked on a similar project ? Or know a similar project that I can use as reference ?

  


  suggestions ?

  


• Developing a multi-tool video & audio program

  14 février 2019, par Risviltsov

  I’m in the middle of the Microsoft TEALS Java program, and we’ve just done a picture editor. I got an idea to develop a multi-tool program that edits video and audio programs professionally for those who can’t afford $2,000 in editing programs but demand all the tools. I’ve ran into a brick wall with the planning :

  What tools should I put in it ? I want this program to have most, if not all possible ways to change media files (as if I was to combine programs like Audacity, a lot of Adobe programs, etc.)

  I’m learning up FFMPEG and AWT, but I really want to tackle this project’s planning this year, to tackle on the programming in the next two years independently. Yay straightforward freeware* & too much time !

  (I don’t think this post belongs here, but I’m in search of help for I have no budget nor any help [it’s going into culinary])

  Thanks for your time.

• Revision 80577dff4b : Revert "Changing webmenc to use libwebm" Temporary revert. Problems with confli

  2 avril 2014, par Paul Wilkins

  Changed Paths :
   Modify /build/make/Makefile

  
   Modify /configure

  
   Modify /examples.mk

  
   Modify /vpxenc.c

  
   Add /webmenc.c

  
   Delete /webmenc.cc

  
   Modify /webmenc.h

  
  
  Revert "Changing webmenc to use libwebm"

  Temporary revert.
  Problems with conflicting definitions of type off_t
  in MSVC builds that need resolving.

  c :\Program Files (x86)\
  Microsoft Visual Studio 9.0\VC\include\wchar.h(479) :
  "error C2371 : 'off_t' : redefinition ; different basic types
  c :\on2experimental\libvpx\tools_common.h(26) :
  see declaration of 'off_t'"

  This reverts commit 92a4c591122fa406a1d7aed834a5283a86d9758a.

  Change-Id : I535e40a18842a92e3e6e0b29e5fba66313010803