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• How to use timeline editing with a single image input in ffmpeg ?

  29 septembre 2017, par Serge

  Small image should be animated over a background video in a simple way :

  1. change position - move along a straight line, no easing. Starting at frame A, till frame B (i.e. frames 11 to 31) ;
  2. zoom in - between frames C and D (i.e. 45 and 55).

  Filters I intend to use :

  • overlay filter has x and y parameters for image position ;
  • zoompan filter allows zooming (preceeded with a static scale up to avoid jitter).

  My filtergraph :

  video.avi >----------------------------------->|-------|
  
                                                 |overlay|-> out.mp4
  
  image.png >-> scale >-> zoompan >-> zoompan >->|-------|

  ---

  The problem is with timeline editing. Both filter support the enable option. I thought I could add instructions like enable='between(n, 11, 31)' to "place" the animations at right times.

  Appears that the image input has only two values of n : zero and 1. Checked that by wrapping n with print(n) in zoompan filter to output during rendering.

  Inside overlay filter, in opposite, n outputs sequence of numbers as expected.

  ---

  Question : how can I make the single image input "look" like a normal video stream to ffmpeg filters – so that every generated frame has its unique number ?

  ---

  One of the latest tests. Video is hd720, image is 1000x200 transparent png with the logo occupying about 150x50 area in the center, not to be cropped out when zoomed in.

  ffmpeg -i $FOOTAGE -loop 1 -i $IMAGE -filter_complex \
  
  "
  
  [1:v]
  
    scale=10*iw:-2
  
    ,zoompan=
  
      z='1'
  
      :x='iw/2-(iw/zoom/2)+80'
  
      :y='ih/2-(ih/zoom/2)'
  
      :d=26
  
      :s=500x100
  
      :enable='lt(print(n),24)'
  
    ,zoompan=
  
      z='min(zoom+1.3/18,2.3)'
  
      :x='iw/2-(iw/zoom/2)'
  
      :y='ih/2-(ih/zoom/2)'
  
      :d=20
  
      :s=500x100
  
      :enable='between(n,24,42)'
  
  [name];
  
  [0:v][name]
  
    overlay=
  
      x=1005-250
  
      :y=406-50
  
      :enable='lte(n,173)'
  
  " -t 7 -y  -hide_banner  out.mp4

• Annual Release of External-Videos plugin – we’ve hit v1.0

  13 janvier 2017, par silvia

  This is the annual release of my external-videos wordpress plugin and with the help of Andrew Nimmolo I’m proud to annouce we’ve reached version 1.0 !

  So yes, my external-videos wordpress plugin is now roughly 7 years old, who would have thought ! During the year, I don’t get the luxury of spending time on maintaining this open source love child of mine, but at Christmas, my bad conscience catches up with me – every year ! I then spend some time going through bug reports, upgrading the plugin to the latest wordpress version, upgrading to the latest video site APIs, testing functionality and of course making a new release.

  This year has been quite special. The power of open source has kicked in and a new developer took an interest in external-videos. Andrew Nimmolo submitted patches over all of 2016. He decided to bring the external-videos plugin into the new decade with a huge update to the layout of the settings pages, general improvements, and an all-round update of all the video site APIs which included removing their overly complex SDKs and going straight for the REST APIs.

  Therefore, I’m very proud to be able to release version 1.0 today. Thanks, Andrew !

  Enjoy – and I look forward to many more contributions – have a Happy 2017 !

  —

  NOTE : If you’re upgrading from an older version, you might need to remove and re-add your social video sites because the API details have changed a bit. Also, we noticed that there were layout issues on WordPress 4.3.7, so try and make sure your WordPress version is up to date.

  The post Annual Release of External-Videos plugin – we’ve hit v1.0 first appeared on ginger’s thoughts.

• AccessViolationException occurred in AForge.Video.FFMPEG.dll

  4 août 2018, par Prakash M

  I have a camera class, in this class I used a timer and in its tick event I am saving video using AForge.Net’s VideoFileWriter in C++/Cli (x86, .net framework : v4.6).
  This is not supposed to happen, as this is managed code. But even if I wrap in try catch block, program crashes because of AccessViolationException. I have verified that Image is not null. Something to do with VideoFileWriter. This happens anytime between app start to 30 minutes of running.

  An unhandled exception of type ’System.AccessViolationException’
  occurred in AForge.Video.FFMPEG.dll
  Additional information : Attempted to read or write protected memory.
  This is often an indication that other memory is corrupt.

  In Visual Studio’s output I see

  Exception thrown at 0x0C4D689F (swscale-2.dll) in test.exe : 0xC0000005 : Access violation writing location 0x09F83D80.
  Exception thrown : ’System.AccessViolationException’ in
  AForge.Video.FFMPEG.dll

  code :

   private: System::Void Video_Recorder_Tick(System::Object^  sender, System::Timers::ElapsedEventArgs^  e)
  
    {
  
        Bitmap^ save = ConvertMatToBitmap(image); //function to convert opencv's Mat to .net's Bitmap        
  
        if(writer!= nullptr)
  
         writer->WriteVideoFrame(save);
  
         delete save;
  
     }
  
  
  
    VideoFileWriter ^writer = gcnew VideoFileWriter();
  
  
  
    private: Void load_VideoWriter()
  
    {
  
      writer->Open("C:/video.avi", 640, 480, 10, VideoCodec::Default);        
  
    }

  Visual Studio showed few values for writer

  BitRate 400000
  Codec Default
  FrameRate 10
  Height 480
  IsOpen true
  Width 640
  

  Let me know if anybody needs more info.
  call stack didn’t help much

  

  To my surprise no one on internet is having this issue !
  Code seems straight forward, what could possibly be the issue ?