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• How do I independently fade in/out multiple (3+) overlay images over video using FFMPEG ?

  3 mars 2017, par blahblahber

  Using an arbitrary source video, I would like to INDEPENDENTLY fade in/fade out a minimum of three .png overlays/watermarks at various times throughout the video. I’m having trouble getting the syntax right for the filter chain.

  In these failed attempts below, I’m using four transparent .png images all at 1920x1080 using the same sized source input video. No scaling/positioning needed, just the overlays fading in and out at the defined times.

  I have the functionality working without fade, unsing ’enable’, like so :

  ffmpeg -i vid1.mp4 -loop 1 -i img1.png -i img2.png -i img3.png -i img4.png -filter_complex 
  
  "overlay=0:0:enable='between(t,8,11)' [tmp];
  
  [tmp]overlay=0:0:enable='between(t,10,15)'[tmp1];
  
  [tmp1]overlay=0:0:enable='between(t,15,138)'[tmp2];
  
  [tmp2]overlay=0:0:enable='between(t,140,150)" 
  
  -c:v libx264 -c:a copy 
  
  -flags +global_header -shortest -s 1920x1080 -y out.mp4

  I just want the same control, using fade in/out.

  The following almost works as I’d like but I obviously don’t want the entire output stream to fade out. I realize that adding the fade=out to lines 7, 8 & 9 is fading the combined output (starting at line 7), but this is as close as I’ve come where I see each overlay image actually fading. The defined fades in lines 3, 4 and 5 apparently don’t affect anything, and that’s where I defined them originally. When I copied them to the output stream, the fade works on each overlay image, but again I don’t want it to affect the entire output stream, just the individual overlays.

  ffmpeg -i vid1.mp4 -loop 1 -i img1.png -i img2.png -i img3.png -i img4.png -filter_complex 
  
      "[1:v]fade=out:st=3:d=1[watermark0]; 
  
      [2:v]fade=out:st=4:d=1[watermark1]; 
  
      [3:v]fade=out:st=5:d=1[watermark2]; 
  
      [4:v]fade=out:st=6:d=1[watermark3]; 
  
      [0:v][watermark0] overlay=0:0 [tmp0]; 
  
      [tmp0][watermark1] overlay=0:0,fade=out:st=4:d=1 [tmp1]; 
  
      [tmp1][watermark2] overlay=0:0,fade=out:st=6:d=1 [tmp2]; 
  
      [tmp2][watermark3] overlay=0:0,fade=out:st=8:d=1 [out]" -map "[out]" -c:v libx264 -c:a copy 
  
      -flags +global_header -shortest -s 1920x1080 -y out.mp4

  I’ve also tried ’split’ with similar results to the above, but the fade only seems to work on the first image (this one uses fade in as well) :

  ffmpeg -i vid.mp4 -loop 1 -i img1.png -i img2.png -i img3.png -i img4.png -filter_complex 
  
  "[1:v]split=4[wm1][wm2][wm3][wm4]; 
  
  [wm1]fade=in:st=1:d=1:alpha=1,fade=out:st=3:d=1:alpha=1[ovr1]; 
  
  [wm2]fade=in:st=2:d=1:alpha=1,fade=out:st=4:d=1:alpha=1[ovr2]; 
  
  [wm3]fade=in:st=3:d=1:alpha=1,fade=out:st=5:d=1:alpha=1[ovr3]; 
  
  [wm4]fade=in:st=4:d=1:alpha=1,fade=out:st=6:d=1:alpha=1[ovr4]; 
  
  [0:v][ovr1]overlay=0:0[base1]; 
  
  [base1][ovr2]overlay=0:0[base2]; 
  
  [base2][ovr3]overlay=0:0[base3]; 
  
  [base3][ovr4]overlay=0:0[out]" -map "[out]" 
  
  -t 10 -c:v libx264 -c:a copy -flags +global_header -shortest -s 1920x1080 -y out.mp4

  Any help is greatly appreciated ! :)

• How to create Automator service for multiple ffmpeg command

  31 janvier 2017, par user413734

  There are many tutorials for creating an automator service that calls an ffmpeg one liner script, like so e.g :

  http://apple.stackexchange.com/questions/129929/automating-ffmpeg-using-automator-service

  But I would like this service to do more than just a one liner. There is the option to chain commands with && but that makes it rather confusing.
  How can I create an automator service that does one transformation and after it is done the next line etc, e.g :

  for f in "$@"
  
  do
  
      ffmpeg -i "$f" -c:v copy -c:a copy "${f%.*}.mp4"
  
      ffmpeg -ss 00:00:01 -i "$f" -frames:v 1 "${f%.*}.jpg"
  
      ....
  
  done

  Or attach this service to one folder that if I drop a file it automatically does the require conversions.

  Thanks

• avcodec/bsf : Add custom item name function for bsf list

  21 août 2016, par Jan Sebechlebsky

  avcodec/bsf : Add custom item name function for bsf list
  which will
  
  construct string description of filter chain. This is
  
  done using lazy-initialization, so there is no overhead
  
  if item name is never accessed.
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/bsf.c