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ffmpeg use complex_filter with alphamerge only for a part of the video

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0

I am trying to apply a filter to only the first few seconds of a video clip - and leave the rest of the video unchanged.

why?
I got some video clips that I wanted to put on a website - unfortunatelly those clips are starting with a black background, which does not fit the website's design. Therefor I was changing the background to transparent.

I got that filter working from many of the great answers here (thanks to Gyan) and those videos are playing fine in common browsers:

ffmpeg -i $1 -filter_complex "[0]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
[m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

the problem now: of course this replaces all black pixels during the video, which leads to many artefacts later on. Therefor I am searching for a way to apply that filter only to the first 5-ish seconds.

I think I need a second split and a crop or a trim and a concat filter with a timestamp - but I can't make it work :(

ffmpeg -i $1 -filter_complex "[0]split[f][s];
[f]trim=start=0,duration=5[ft];
[s]trim=start=6[st];
[st]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
[m][al]alphamerge,format=yuva420p[mal];
[ft][mal]concat" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

/edit: I am changing the subject slighty, to reflect the actual problem.

filter ffmpeg

share|improve this question

edited Mar 7 at 20:32

Andy P

asked Mar 7 at 11:42

Andy PAndy P

10316

add a comment | 

0

I am trying to apply a filter to only the first few seconds of a video clip - and leave the rest of the video unchanged.

why?
I got some video clips that I wanted to put on a website - unfortunatelly those clips are starting with a black background, which does not fit the website's design. Therefor I was changing the background to transparent.

I got that filter working from many of the great answers here (thanks to Gyan) and those videos are playing fine in common browsers:

ffmpeg -i $1 -filter_complex "[0]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
[m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

the problem now: of course this replaces all black pixels during the video, which leads to many artefacts later on. Therefor I am searching for a way to apply that filter only to the first 5-ish seconds.

I think I need a second split and a crop or a trim and a concat filter with a timestamp - but I can't make it work :(

ffmpeg -i $1 -filter_complex "[0]split[f][s];
[f]trim=start=0,duration=5[ft];
[s]trim=start=6[st];
[st]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
[m][al]alphamerge,format=yuva420p[mal];
[ft][mal]concat" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

/edit: I am changing the subject slighty, to reflect the actual problem.

filter ffmpeg

share|improve this question

edited Mar 7 at 20:32

Andy P

asked Mar 7 at 11:42

Andy PAndy P

10316

add a comment | 

I am trying to apply a filter to only the first few seconds of a video clip - and leave the rest of the video unchanged.

why?
I got some video clips that I wanted to put on a website - unfortunatelly those clips are starting with a black background, which does not fit the website's design. Therefor I was changing the background to transparent.

I got that filter working from many of the great answers here (thanks to Gyan) and those videos are playing fine in common browsers:

ffmpeg -i $1 -filter_complex "[0]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
[m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

the problem now: of course this replaces all black pixels during the video, which leads to many artefacts later on. Therefor I am searching for a way to apply that filter only to the first 5-ish seconds.

I think I need a second split and a crop or a trim and a concat filter with a timestamp - but I can't make it work :(

ffmpeg -i $1 -filter_complex "[0]split[f][s];
[f]trim=start=0,duration=5[ft];
[s]trim=start=6[st];
[st]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
[m][al]alphamerge,format=yuva420p[mal];
[ft][mal]concat" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

/edit: I am changing the subject slighty, to reflect the actual problem.

filter ffmpeg

share|improve this question

edited Mar 7 at 20:32

Andy P

asked Mar 7 at 11:42

Andy PAndy P

10316

ffmpeg -i $1 -filter_complex "[0]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
[m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

ffmpeg -i $1 -filter_complex "[0]split[f][s];
[f]trim=start=0,duration=5[ft];
[s]trim=start=6[st];
[st]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0[al];
[m][al]alphamerge,format=yuva420p[mal];
[ft][mal]concat" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

share|improve this question

edited Mar 7 at 20:32

Andy P

asked Mar 7 at 11:42

Andy PAndy P

10316

share|improve this question

edited Mar 7 at 20:32

Andy P

asked Mar 7 at 11:42

Andy PAndy P

10316

asked Mar 7 at 11:42

Andy PAndy P

10316

asked Mar 7 at 11:42

Andy PAndy P

10316

1 Answer
1

active

oldest

votes

1

Use

ffmpeg -i $1 -filter_complex "[0]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0,drawbox=c=white:t=fill:enable='gte(t,6)'[al];
[m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

Since we're adding an alpha plane, it has to be added to all frames. We just want to skip transparency after a certain point, so we use the drawbox filter to fill it with white starting at 6 seconds, before merging with the main video.

share|improve this answer

answered Mar 7 at 12:12

GyanGyan

33.8k22971

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I was not even close ...
  
  – Andy P
  Mar 7 at 19:20
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  a follow: is there a way to aply the filter to the end of the video as well? t=fill:enable='if(gte(t,6)*lte(t,-1),1,0) e.g. for the last second?
  
  – Andy P
  Mar 7 at 20:37
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I think i found a way using ffprobe: DURATION=`ffprobe -i "$1" -show_entries stream=codec_type,duration -of compact=p=0:nk=1 2> /dev/null | grep 'video|' | sed -E 's/^video.([0-9]*).[0-9]*$/1/g'`` then: `DURATION=$(expr $DURATION - 1) and use this as parameter in between: ffmpeg-static -i "$1" -filter_complex "[0]split[m][a]; [a]geq='if(lt(lum(X,Y),16.001),0,255)',hue=s=0,drawbox=c=white:t=fill:enable='between(t,6,$DURATION)'[al]; [m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -pix_fmt yuva420p -auto-alt-ref 0 "$1.webm"
  
  – Andy P
  Mar 7 at 21:38
  
  

  
  
  
  

add a comment | 

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1

Use

ffmpeg -i $1 -filter_complex "[0]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0,drawbox=c=white:t=fill:enable='gte(t,6)'[al];
[m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

Since we're adding an alpha plane, it has to be added to all frames. We just want to skip transparency after a certain point, so we use the drawbox filter to fill it with white starting at 6 seconds, before merging with the main video.

share|improve this answer

answered Mar 7 at 12:12

GyanGyan

33.8k22971

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I was not even close ...
  
  – Andy P
  Mar 7 at 19:20
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  a follow: is there a way to aply the filter to the end of the video as well? t=fill:enable='if(gte(t,6)*lte(t,-1),1,0) e.g. for the last second?
  
  – Andy P
  Mar 7 at 20:37
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I think i found a way using ffprobe: DURATION=`ffprobe -i "$1" -show_entries stream=codec_type,duration -of compact=p=0:nk=1 2> /dev/null | grep 'video|' | sed -E 's/^video.([0-9]*).[0-9]*$/1/g'`` then: `DURATION=$(expr $DURATION - 1) and use this as parameter in between: ffmpeg-static -i "$1" -filter_complex "[0]split[m][a]; [a]geq='if(lt(lum(X,Y),16.001),0,255)',hue=s=0,drawbox=c=white:t=fill:enable='between(t,6,$DURATION)'[al]; [m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -pix_fmt yuva420p -auto-alt-ref 0 "$1.webm"
  
  – Andy P
  Mar 7 at 21:38
  
  

  
  
  
  

add a comment | 

1

Use

ffmpeg -i $1 -filter_complex "[0]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0,drawbox=c=white:t=fill:enable='gte(t,6)'[al];
[m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

Since we're adding an alpha plane, it has to be added to all frames. We just want to skip transparency after a certain point, so we use the drawbox filter to fill it with white starting at 6 seconds, before merging with the main video.

share|improve this answer

answered Mar 7 at 12:12

GyanGyan

33.8k22971

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I was not even close ...
  
  – Andy P
  Mar 7 at 19:20
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  a follow: is there a way to aply the filter to the end of the video as well? t=fill:enable='if(gte(t,6)*lte(t,-1),1,0) e.g. for the last second?
  
  – Andy P
  Mar 7 at 20:37
  
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  I think i found a way using ffprobe: DURATION=`ffprobe -i "$1" -show_entries stream=codec_type,duration -of compact=p=0:nk=1 2> /dev/null | grep 'video|' | sed -E 's/^video.([0-9]*).[0-9]*$/1/g'`` then: `DURATION=$(expr $DURATION - 1) and use this as parameter in between: ffmpeg-static -i "$1" -filter_complex "[0]split[m][a]; [a]geq='if(lt(lum(X,Y),16.001),0,255)',hue=s=0,drawbox=c=white:t=fill:enable='between(t,6,$DURATION)'[al]; [m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -pix_fmt yuva420p -auto-alt-ref 0 "$1.webm"
  
  – Andy P
  Mar 7 at 21:38
  
  

  
  
  
  

add a comment | 

Use

ffmpeg -i $1 -filter_complex "[0]split[m][a];
[a]geq='if(lt(lum(X,Y),16),0,255)',hue=s=0,drawbox=c=white:t=fill:enable='gte(t,6)'[al];
[m][al]alphamerge,format=yuva420p" -c:v libvpx-vp9 -b:v 0 -crf 18 -an -auto-alt-ref 0 $1.webm

Since we're adding an alpha plane, it has to be added to all frames. We just want to skip transparency after a certain point, so we use the drawbox filter to fill it with white starting at 6 seconds, before merging with the main video.

share|improve this answer

answered Mar 7 at 12:12

GyanGyan

33.8k22971

share|improve this answer

answered Mar 7 at 12:12

GyanGyan

33.8k22971

answered Mar 7 at 12:12

GyanGyan

33.8k22971

answered Mar 7 at 12:12

GyanGyan

33.8k22971