Newest 'ffmpeg' Questions - Stack Overflow

Les articles publiés sur le site

• How to record or export the CACA output in FFMPEG ?

  7 octobre 2016, par Rodrigo Campos

  I'm trying to export (pipe) the output device CACA in FFMPEG whithout sucsess.

  The script work's fine, but no OUTPUT is recorded.

  ffmpeg -i final3.mp4 -pix_fmt rgb24 -color fullgray -window_size 244x66 -f caca - | ffmpeg -i - output.mp4
  

  Please help me!!!

• How to use ffmpeg without root access

  6 octobre 2016, par Charlie227

  I've successfully installed ffmpeg using ssh, as root, on my dedicated server (CentOS 7).
  ffmpeg works fine - but now I need to use it without root access.

  When i try to use ffmpeg without root access, I get the following error :

  ffmpeg: error while loading shared libraries: libx264.so.148: 
          cannot open shared object file: No such file or directory
  

  The final goal is to be able to use ffmpeg inside my PHP scripts which do not root access.

  Any help is appreciated.

• FFmpeg screen recording in grayscale to reduce file size ?

  6 octobre 2016, par wetjosh

  First off, I am unable to capture the screen of my Mac in grayscale. I've tried various combinations of -pix_fmt gray (for the input, for the output, and for both) but they never turn out grayscale.

  Secondly, assuming I figure out how to do it, is it actually a viable option for reducing file size? I was surprised that reducing the frame rate (-r) did not affect file size (though -size did).

  ffmpeg -f avfoundation -pix_fmt gray -s 1440x900 -i 1 \
  -pix_fmt gray -r 30 -preset ultrafast -b:v 5000k -t 5 out.mov
  

• Python - OpenCV - VideoCapture

  6 octobre 2016, par Sina Dabiri

  I am using Python 2.7.12 and OpenCV 2.4.13. I am trying the get video frames using cv2.VideoCapture(). But it doesn't work. I already added C:\OpenCV\3rdparty\sources\ffmpeg to the Windows PATH environment variable and copied all files from C:\OpenCV\3rdparty\sources\ffmpeg to C:\Python27\ by renaming opencv_ffmpeg.dll and opencv_ffmpeg_64.dll to opencv_ffmpeg2413.dll and opencv_ffmpeg2413_64.dll in turn. But still doesn't work. Here is my code:

  cap = cv2.VideoCapture("Video1.mp4")
  
  cap.open("Video1.mp4")
  
  print cap.isOpened() 
  

  I receive False. I also used the path instead of Video1.mp4, but again doesnt work. Any suggestion is appreciated.

• Animated overlay for videos on iOS

  6 octobre 2016, par SharpAffair

  What's the common modern standard for animated video overlays? (e.g. if you want to add an animated logo to video recorded from the camera)

  During research, I've found the following options:

  • GIF - seems to be pretty outdated technology

  • FLV - supports alpha-channel, but no longer supported by Adobe. Requires FFMPEG.

  • PNG sequence - the downside of this is having multiple files for each frame.

  What's the right format/technology to use?

  Ideally, what is natively supported on iOS (doesn't require FFMPEG)?