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• Creating a transparent video out of an input video

  28 juillet 2021, par poldown

  I'm trying to create a video with a transparent background out of an input video (with the same dimensions, etc.). I tried several strategies (using the chromakey filter and others) and none worked... I got this far :

  


  ffmpeg -i input.mp4 -filter_complex "color=color=black@0.0,format=yuva420p[bg],[bg][0:v]scale2ref[bg][0v],[bg]drawbox=x=10:y=10:w=100:h=100:color=pink@0.5;[0v]nullsink" -c:v qtrle -an "alpha.mov"


  


  

  • creating a video stream with transparency, and setting a transparent background (black@0.0)

  


  • scaling the transparent video according to the input video

  


  • [for testing purposes : drawing a box over the transparent video. I omitted the part in which I embed subtitles onto the video, for simplicity's sake]

  


  • discarding the input video stream

  


  • removing the audio stream

  


  


  It basically works, but the processing never ends - I can't manage to limit the output video length so it'll match the input video's length...
I've tried using the -shortest option anywhere in the command - with no success.

  


• Concat Command Issue in FFMPEG

  19 septembre 2024, par Vinesh Chauhan

  i am trying to Build a FFMPEG command that accept 4 input Videos and generate the output video with 2x2 Grid also play all those video one after another one. so Archive this I have pass lavfi 4 inputs with duration with size. then I have passed 4 input videos. then I have first generate thumbnail of those videos, so what I am gonna do is I place first video and second thumbnail in hstack, third thumbnail and fourth thumbnail in hstack the both hstack output in vstack. i will do it this 4 times for all videos respectively and then lastly I am trying to contact all those video in one. but I am getting overflow buffer warnings (as shown in image 1). and also getting not a proper video output(as link 1). then I try to create 4 videos using map to test whether its a stack issue or not so I have successfully create 4 videos and its working fine as expect but in 4 output files. i want it in one and also I want it in one command execution I don't want to execute multiple command for this.

  


  the code that generate 4 output videos with is working fine

  


  ffmpeg -y -f lavfi -t 00:00:37.000 -i color=black:s=360x360 -f lavfi -t 00:01:15.000 -i color=black:s=360x360 -f lavfi -t 00:00:14.000 -i color=black:s=360x360 -f lavfi -t 00:00:50.000 -i color=black:s=360x360 -i instagram_1.mp4 -i instagram_2.mp4 -i instagram_3.mp4 -i instagram_4.mp4 -filter_complex "[4:v]select='eq(n\,0)',scale=-2:360:force_original_aspect_ratio=decrease[thumb_1];[5:v]select='eq(n\,0)',scale=-2:360:force_original_aspect_ratio=decrease[thumb_2];[6:v]select='eq(n\,0)',scale=-2:360:force_original_aspect_ratio=decrease[thumb_3];[7:v]select='eq(n\,0)',scale=-2:360:force_original_aspect_ratio=decrease[thumb_4];[4:v]scale=-2:360:force_original_aspect_ratio=decrease[sc1];[0:v][sc1]overlay=(W-w)/2:(H-h)/2[ovv1];[5:v]scale=-2:360:force_original_aspect_ratio=decrease[sc2];[1:v][sc2]overlay=(W-w)/2:(H-h)/2[ovv2];[6:v]scale=-2:360:force_original_aspect_ratio=decrease[sc3];[2:v][sc3]overlay=(W-w)/2:(H-h)/2[ovv3];[7:v]scale=-2:360:force_original_aspect_ratio=decrease[sc4];[3:v][sc4]overlay=(W-w)/2:(H-h)/2[ovv4];[0:v][thumb_1]overlay=(W-w)/2:(H-h)/2[ov1];[1:v][thumb_2]overlay=(W-w)/2:(H-h)/2[ov2];[2:v][thumb_3]overlay=(W-w)/2:(H-h)/2[ov3];[3:v][thumb_4]overlay=(W-w)/2:(H-h)/2[ov4];[ov1][ov2]hstack[hs1];[ov3][ov4]hstack[hs2];[hs1][hs2]vstack[vs1];[vs1]split=4[vss1][vss2][vss3][vss4];[vss1][ovv1]overlay=0:0[final1];[vss2][ovv2]overlay=w:0[final2];[vss3][ovv3]overlay=0:h[final3];[vss4][ovv4]overlay=w:h[final4]" -map "[final1]" -t 00:00:37.000 outPut1.mp4 -map "[final2]" -t 00:01:15.000 outPut2.mp4 -map "[final3]" -t 00:00:14.000 outPut3.mp4 -map "[final4]" -t 00:00:50.000 outPut4.mp4 


  


  the command I am getting problem

  


  ffmpeg -y -f lavfi -t 00:00:37.000 -i color=black:s=360x360 -f lavfi -t 00:01:15.000 -i color=black:s=360x360 -f lavfi -t 00:00:14.000 -i color=black:s=360x360 -f lavfi -t 00:00:50.000 -i color=black:s=360x360 -i instagram_1.mp4 -i instagram_2.mp4 -i instagram_3.mp4 -i instagram_4.mp4 -filter_complex "[4:v]select='eq(n\,0)',scale=-2:360:force_original_aspect_ratio=decrease[thumb_1];[5:v]select='eq(n\,0)',scale=-2:360:force_original_aspect_ratio=decrease[thumb_2];[6:v]select='eq(n\,0)',scale=-2:360:force_original_aspect_ratio=decrease[thumb_3];[7:v]select='eq(n\,0)',scale=-2:360:force_original_aspect_ratio=decrease[thumb_4];[4:v]scale=-2:360:force_original_aspect_ratio=decrease[sc1];[0:v][sc1]overlay=(W-w)/2:(H-h)/2[ovv1];[5:v]scale=-2:360:force_original_aspect_ratio=decrease[sc2];[1:v][sc2]overlay=(W-w)/2:(H-h)/2[ovv2];[6:v]scale=-2:360:force_original_aspect_ratio=decrease[sc3];[2:v][sc3]overlay=(W-w)/2:(H-h)/2[ovv3];[7:v]scale=-2:360:force_original_aspect_ratio=decrease[sc4];[3:v][sc4]overlay=(W-w)/2:(H-h)/2[ovv4];[0:v][thumb_1]overlay=(W-w)/2:(H-h)/2[ov1];[1:v][thumb_2]overlay=(W-w)/2:(H-h)/2[ov2];[2:v][thumb_3]overlay=(W-w)/2:(H-h)/2[ov3];[3:v][thumb_4]overlay=(W-w)/2:(H-h)/2[ov4];[ov1][ov2]hstack[hs1];[ov3][ov4]hstack[hs2];[hs1][hs2]vstack[vs1];[vs1]split=4[vss1][vss2][vss3][vss4];[vss1][ovv1]overlay=0:0[final1];[vss2][ovv2]overlay=w:0[final2];[vss3][ovv3]overlay=0:h[final3];[vss4][ovv4]overlay=w:h[final4];[final1][final2][final3][final4]concat=n=4:v=1:a=0[final]" -map "[final]" -t 00:02:56.000 outPutIMagesFinaLCheck.mp4   


  


  Link 1(output video that has issue)
https://zippyshare.day/c0vhq9MvIMUTb8i/file

  


• lavf/qtpalette : Treat 1-bit video as palettized

  29 décembre 2015, par Mats Peterson

  lavf/qtpalette : Treat 1-bit video as palettized
  This commit for qtpalette.c and qtpalette.h adds 1-bit video to the
  
  "palettized video" category, since if the video sample description
  
  contains a palette, the two colors in the palette can be any color, not
  
  necessarily black & white.
  Unfortunately, I’ve noticed that the qtrle (QuickTime Animation) decoder
  
  blindly assumes that 1-bit video is black & white. I don’t have enough
  
  knowledge about the decoder to fix this, though.
  Below is a link to a sample 1-bit QuickTime Animation clip of a rotating
  
  earth that uses blueish colors, and they will be correctly rendered in
  
  QuickTime, but not in FFmpeg (which will use black & white).
  https://drive.google.com/open?id=0B3_pEBoLs0faUlItWm9KaGJSTEE
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavformat/qtpalette.c
  • [DH] libavformat/qtpalette.h