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• how to fix focus on x11 window / Keep x11 always on TOP [on hold]

  19 septembre 2017, par SIM

  I am doing one project with openGL animations and videos.
  openGL animations initializing the x11 window with transparency and full screen. I am using ffplay to run the video which use SDL window system.

  when X11 is in fullscreen, and then I run the video in resized mode, then x11/animation is on top and everything is working OK.

  But when I initialized the video with fullscreen, then SDL is acquiring the focus and x11 is going behind the SDL.

  What can be the possible solution to this ?

• ffmpeg video of image list within a folder

  31 mars 2020, par Gergely Szarka

  I am trying to create an animation from a png files. They are all in the same folder and are named

  



  step0.png
step1.png
step2.png
.....

step19998.png
step19999.png


  



  I frame represents 0.01s, so I think I need 100 fps.

  



  the command I was trying :

  



  ffmpeg -r 100 -f image2 -pattern_type glob -i '*.png' -vcodec libx264 -crf 1  -pix_fmt yuv420p test.mp4


  



  For some reason it doesnt put them together in the correct order, but when i put the last 500 into another folder and ran the command there it worked perfectly.

  


• How to use ffmpeg to transcode many live streamed videos ? [closed]

  21 septembre 2020, par user14258924

  PREMISE

  


  As a pet project, I am writing a live video streaming service, in Go, that can consume video streams from OBS via SRT(TS -> h264/aac) and RTMP(FLV -> h264/aac) protocols and am planning to support streaming video from web browser as well, captured from a web camera via JS. This ingress server will receive many video streams in various containers and codecs and I need to normalize them into single container and codec and then create multiple versions for various bitrates(ie. 240p, 360p, 480p, 720p, 1080p...) to pass along where needed in the application. Each stream is split into 2 second GOP segments, separate for audio and video track, that will produce fragmented MP4 as the end result - which can be consumed by web browser.

  


  The issue is that I am using Go which has no libraries for transcoding video so I need to use either ffmpeg or vlc, which is a C code. I have decided to avoid the CGo route and use ffmpeg/vlc as standalone binaries.

  


  QUESTION

  


  My question is how to use either of these project in the most efficient way - avoiding the use of files in favour of unix sockets/streams and also the performance aspect - handling hundreds of video segments in any one time and in sufficient time to avoid creating too much of a lag beteen producer and consumer.

  


  So let's say I will pick the most used one - ffmpeg, how should I actually use it to achieve what I have described ? How would you set it up and which flags/config to use with it ?

  


  Can the performance be even achieved or is it just too much and I will need some sort of ffmpeg cluser to even come close to some useful performance/low delay ?