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• output example : store the scaling context in the stream context

  24 juin 2014, par Anton Khirnov

  output example : store the scaling context in the stream context
  

  • [DBH] doc/examples/output.c

• How create a circular video (transparent area on top of video) effect without applying image mask to video

  26 septembre 2024, par Arina Lubimova

  Basically i googled a lot and solutions suggests apply some PNG mask or do not provide needed solution.

  


  What i've found.

  


  ffmpeg -i main.mkv -i facecloseup.mkv
 -filter_complex "[1]trim=end_frame=1,
  geq='st(3,pow(X-(W/2),2)+pow(Y-(H/2),2));if(lte(ld(3),pow(min(W/2,H/2),2)),255,0)':128:128,
  loop=-1:1,setpts=N/FRAME_RATE/TB[mask];
  [1][mask]alphamerge[cutout];
  [0][cutout]overlay=x=W-w:y=0[v];
  [0][1]amix=2[a]"
 -map "[v]" -map "[a]"  out.mp4


  


  command = "-i " + this.video1Path.getPath() + " -i " + this.video2Path.getPath() + " -filter_complex [1]trim=end_frame=1,geq=lum_expr='st(3,pow(X-(W/2),2)+pow(Y-(H/2),2));if(lte(ld(3)," + (this.mZoomLayout.getZoomedWidth()/2) + "*" + (this.mZoomLayout.getZoomedWidth()/2) + "),255,0)':128:128,format=gray,loop=-1:1,setpts=N/FRAME_RATE/TB[mask];[1][mask]alphamerge,format=rgba,lutrgb=a=if(gte(val\\,16)\\,val)[cutout];[0][cutout]overlay=" + this.mZoomLayout.getCircleX() + ":" + this.mZoomLayout.getCircleY() + ":enable='between(t,0," + this.videoTwoDuration + ") -c:v libx264 -crf 24 -preset ultrafast " + videoPath.getPath(); 


  


  So i tried to extract needed things from them, but i don't understand how exactly i need to do that, i did this :

  


  ffmpeg -i video.mp4 -filter_complex "[0]geq='st(3,pow(X-(W/2),2)+pow(Y-(H/2),2));if(lte(ld(3),pow(min(W/2,H/2),2)),255,0)':H:W; [0:v][mask]alphamerge" out.mp4


  


  [mov,mp4,m4a,3gp,3g2,mj2 @ 000001f761dd8e40] Invalid stream specifier: mask.
    Last message repeated 1 times
Stream specifier 'mask' in filtergraph description [0]geq='st(3,pow(X-(W/2),2)+pow(Y-(H/2),2));if(lte(ld(3),pow(min(W/2,H/2),2)),255,0)':H:W; [0:v][mask]alphamerge matches no streams.


  


  ffmpeg -i video.mp4 -filter_complex "[0]geq=lum_expr='st(3,pow(X-(W/2),2)+pow(Y-(H/2),2));if(lte(ld(3),pow(min(W/2,H/2),2)),255,0)':H:W; [0:v][mask]alphamerge" out.mp4


  


  [mov,mp4,m4a,3gp,3g2,mj2 @ 000001bfd9218e80] Invalid stream specifier: mask.
    Last message repeated 1 times
Stream specifier 'mask' in filtergraph description [0]geq=lum_expr='st(3,pow(X-(W/2),2)+pow(Y-(H/2),2));if(lte(ld(3),pow(min(W/2,H/2),2)),255,0)':H:W; [0:v][mask]alphamerge matches no streams.


  


  And one more time, guys, if you are going to post some "prepared image mask" solution - just leave, the question is about creating mask on air.

  


  So, let's say we have red square (yes, ratio is static, always 1:1), yes, i can't post it because i dont have 10 rep. (...).

  


  https://i.sstatic.net/MsL71.png - red square.

  


  https://i.sstatic.net/aIFEV.png - circle

  


  https://i.sstatic.net/R8EAx.png - result

  


  https://i.sstatic.net/WtqQg.png - final result

  


  I actually want to get the answer from @Gyan or @llogan because i searched a lot and only these two guys do understand how to make things programmatically.

  


  More tech details :
Aspect ratio is constant - 1:1, width and height should be taken from the video in auto way, we need to create a white square with transparent circle inside it, the end result must contain "rounded" video with white background.

  


• Adding a color filter at specific intervals in ffmpeg

  9 avril 2015, par JamieL

  I am looking to add the color filter to a rtmp stream in ffmpeg at specific time intervals, say for 10 seconds every 10 seconds. I have tried two approaches. The first :

  -vf "color=#8EABB8@0.9:480x208,select='gte(t,10)*lte(t,20)' [color];[in][color] overlay [out]"

  This streams only the 10 seconds indicated by the select and applies the color filter rather than playing the whole stream and applying the filter to just those 20 seconds.

  I then learnt about split and fifo and tried this approach :

  -vf "[in] split [no-color], fifo, [with-color] overlay [out]; [no-color] fifo, select='gte(t,10)*lte(t,20)' [with-color]"

  I would expect this to play the entire stream, and then select the 10 seconds specified so that I can apply filters, but it does the same as first approach and just plays the 10 seconds selected rather than the entire stream.

  Thanks in advance.