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• How to extract frame video to images with removing duplicate area pixel

  8 juin 2022, par yuwiek

  Can ffmpeg to extract 1 second frames by auto transparent area that duplicate within that 1 second frames ? ex. 1 second have 24 frames. typical default cinema fps. by default ffmpeg just extract that 24 frames to image even only little movement. in simply i can just drop that frame that look same. but i dont want, i want it that area frames from 24 frames. look same, sequential be transparent, so it can reduce size of output. than later i will construct it back to 1 second frames. by just stack it frame by frame.

  


  for clearly, lets say again 1 second have 24 frames, frame 1 and frame 2. only have different in top left, like a rectangle black area. because of that, frame 2 should only output that rectangle black area. so later i just stack it to reconstruct that 1 second frames. then next one frame 3 will compare again with new stack frame 2 to know which area that different. and make it transparent again in frame 3. so on. look this image https://i.ibb.co/25hcrpB/Untitled.png

  


• Playing H.264 video in an application through ffmpeg using DXVA2 acceleration

  28 avril 2012, par cloudraven

  I am trying to output H.264 video in a Windows application. I am moderately familiar with FFMPEG and I have been successful at getting it to play H.264 in a SDL window without a problem. Still, I would really benefit from using Hardware Acceleration (probably through DXVA2)

  I am reading raw H264 video, no container, no audio ... just raw video (and no B-frames, just I and P). Also, I know that all the systems that will use this applications have Nvidia GPUs supporting at least VP3.
  Given that set of assumptions I was hoping to cut some corners, make it simple instead of general, just have it working for my particular scenario.

  So far I know that I need to set the hardware acceleration in the codec context by filling the hwaccel member through a call to ff_find_hwaccel. My plan is to look at Media Player Classic Home Cinema which does a pretty good job at supporting DXVA2 using FFMPEG when decoding H.264. However, the code is quite large and I am not exactly sure where to look. I can find the place where ff_find_hwaccel is called in h264.c, but I was wondering where else should I be looking at.

  More specifically, I would like to know what is the minimum set of steps that I have to code to get DXVA2 through FFMPEG working ?

  EDIT : I am open to look at VLC or anything else if someone knows where I can find the "important" piece of code that does the trick. I just mentioned MPC-HC because I think it is the easiest to get to compile in Windows.

• Screencasting with hardware-accelerated gnome-3 [closed]

  30 octobre 2012, par Jeroen

  I am running Ubuntu 12.04 with gnome 3 shell, and I would like to create a screencast. I have tried using recordMyDesktop, Kazam Screencaster, and ffmpeg but all suffer from the same problem, which I think has to do with hardware acceleration in Gnome 3. The recorded videos all get very glitchy with blue space for all operations that use some sort of effect. Here is an example recording : http://www.stat.ucla.edu/ jeroen/files/screencast.mkv.

  The only method that does not seem to suffer from this, is the (largely undocumented) CTRL+SHIFT+R shortcut in gnome 3 that will start a recording. However, this feature is very buggy otherwise and often crashes when I enable audio input.

  My machine has a GeForce GT 120 with Apple LED Cinema monitor. I am using the proprietary nvidia drivers that ship with Ubuntu 12.04. Is there any way I can record the video as it appears on my screen ? I know I can avoid the problem by switching to gnome2 or unity 2d or anything that does not use effects, but I would prefer to make the recordings in my regular gnome 3 environment.