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• FFmpeg : loop first and last frame in a frame sequence [migrated]

  22 avril 2023, par Carlos Cabo

  I have a frame sequence of 180 .png files named this way :

  


  fr_f6a20_0001.png
...
fr_f6a20_0180.png


  


  I want to create an .mp4 file of the sequence, but making the first and last frame a little longer.

  


  In plain text, I want to get an output video composed of three concatenated sections :

  


  

  • 1 second length loop of the first frame (30 frames)

  


  • frame sequence (180 frames)

  


  • 1 second length loop of the last frame (30 frames)

  


  


  After reading the documentation, I came out with this command :

  


  ffmpeg -framerate 30 -pattern_type sequence -i fr_f6a20_%04d.png -filter_complex "[0]loop=30:1:0[first];[0]loop=30:1:180[last];[first][0][last]concat=n=3:v=1:a=0[out]" -map "[out]" -pix_fmt yuv420p out.mp4


  


  What I'm getting out of the command :

  


  

  • 1s loop of the first frame (30 frames)

  


  • frame sequence rendered THREE TIMES (180 x 3 frames)

  


  • 1 second length loop of the last frame (30 frames)

  


  


  I suppose that I'm missing something, but I don't know what it is :(

  


• How to use the result of guardian-ffmpeg-Android ?

  4 avril 2013, par user1914692

  I am trying to build ffmpeg on Android. There are many tutorials. Some are very old.
  So I want to try one that can use newer version of ffmpeg and Android NDK.
  After long time searching, I find one, guardianproject / android-ffmpeg

  The project was updated several months ago.
  NDK r8 is used. ffmpeg is put from online, so a latest version.

  After I follow all the instruction, I am confused which result I should use, and how to use it.
  The README mentions testing, like :

  # embedding metadata into a matroska video /data/local/ffmpeg -y -i test.mp4 \
  
      -attach attach.txt -metadata:s:2 mimetype=text/plain \
  
      -acodec copy -vcodec copy testattach.mkv

  First, I fail to find the path : /data/local
  Second, this is a command. How will I use it in Android ?

  Totall confused.
  Any light ?

• ffmpeg is dropping frames of second video in concat

  17 juin 2018, par bugwheels94

  I did a screen share and when sharing the screen I minimized the sharing window so the video that I am sharing has some thing weird going on. Seeking does not work on mplayer but works on VLC. However, when doing the concat

  ffmpeg -i test.webm -f lavfi -i color=c=blue:s=1366x768:d=71 \
  
  -filter_complex "[0]scale=w='min(1366\, iw)':h='min(768\, ih)':force_original_aspect_ratio=decrease,\
  
  pad=width=1366:height=768:x=(ow-iw)/2:y=(oh-ih)/2,setsar=1/1[v1];\
  
  [1][v1]concat=n=2[v]" -map [v] -qscale 7 result.mp4

  The webm video of length 155 seconds is not showing complete. Ideally the result should be 71 + 156 = 227 but I am getting 155 seconds and the webm video of concat being cropped.

  If I reverse the concat order to [v1][1]concat=n=2[v] then everything is perfect at 227 seconds

  Download test.webm

  May you please tell me about what might be wrong here ? Thanks