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• Using FFmpeg and IPython

  25 février 2014, par Kreger51

  I am relatively new to Python (I used MATLAB a lot more). I essentially want to be able to make and save animations. So I went and checked how it's done and found this :
  http://jakevdp.github.io/blog/2012/08/18/matplotlib-animation-tutorial/

  I straight up copied/pasted the code in an IPython Notebook.

  I understand that ffmpeg must be installed, which I thought I did (according to http://www.wikihow.com/Install-FFmpeg-on-Windows). The path is C :/ffmpeg. It does work when I try ffmpeg -version in the command prompt. It also works in WinPython's command prompt. I don't know if it helps, but the path for Ipython is :
  C :\Users\Sal\WinPython-32bit-3.3.2.3\python-3.3.2\Scripts /

  However, it still doesn't work. The error given is :
  AttributeError : 'str' object has no attribute 'saving'
  This error occurs at the .save command of course.
  I even tried to add what's below. Doesn't do anything extra.
  writer = 'ffmpeg'

  I am using Windows 7, WinPython3.3.

  Thank you very much

• Python and ffmpeg

  7 septembre 2013, par Cory Gwin

  I am attempting to call ffmpeg to create an image from a frame in a video, I am using python to do this with subprocess.Popen on a mac, eventually this will move to a unix server.

  I can successfully create a video from the command line with this line

  ffmpeg -i /Users/bimemployee/Movies/ski\ commute.m4v -r .5 -vframes 1 -ss 00:01:14 /Users/bimemployee/Movies/untitled\ folder/image-%d.jpeg

  I then turn this into a python iterable and passed it Popen

  s=["ffmpeg","-i","Users/bimemployee/Movies/ski\ commute.m4v","-r","1","-vframes","1","-ss","00:01:14","/Users/bimemployee/Movies/untitled\ folder/image-%d.jpeg"]
  
  subprocess.Popen(s)

  When I do so I get the standard info screen from ffmpeg and an error that says Users/bimemployee/Movies/ski\ commute.m4v : No such file or directory

  Why would this path work ok from the command line but not from python ?

  Secondly is their a better library for handling this, the ones I could find don't seem to be active projects or don't work with straight python but require things like cython.

  Thanks,
  CG

• ffmpeg delay video in overlay

  4 août 2020, par Sam

  I am trying to overlay 2 videos, and one of them (the one on the "bottom"), I want to delay the start of (let's say by 2 seconds).

  


  So, either hold the first frame for the duration of the delay, or have black frames for the duration of the delay. I have no preference as to which.

  


  Here is what I tried based on this similar question : https://superuser.com/questions/734234/delayed-video-overlay-using-ffmpeg

  


  ffmpeg
-i video_top
-i video_bottom
-filter_complex
"[0:v]trim=start='00\:04\:17.8':end='00\:04\:32.8',setpts=PTS-STARTPTS, scale=-1:'ih-ih*.5':eval=frame[v0];
[0:a]atrim=start='00\:04\:17.8':end='00\:04\:32.8',asetpts=PTS-STARTPTS[a0];
[1:v]setpts=PTS-STARTPTS+2/TB, format=yuva420p[v1];
[v1][v0]overlay=y=(main_h-overlay_h)*.074:format=yuv444:shortest=0:alpha='straight',format=yuv420p[out]"
-map [out] -map [a0] -vcodec libx264 testing_14.mp4


  


  However, the result of this is that BOTH videos freeze the first frame for the delayed duration (of 2 seconds in this case). I have tried a bunch of alternative options, including

  


  

  • Only setting PTS on one of the video streams instead of both

  


  • Using -itsoffset instead of PTS

  


  


  Nothing seems to work.