Is it possible to autocrop black borders of a video with ffmpeg?
34,851
Solution 1
Yes, it is possible.
First play your video to see if it is OK:
ffplay -i YourMovie.mp4 -vf "cropdetect=24:16:0"
The cropdetect
filter values are:
cropdetect=limit:round:reset
limit = black threshold (default 24)
round = output resolution must be divisible to this
reset = after how many frames the detection process will start over
If it looks OK, crop it:
ffmpeg -i YourMovie.mp4 -vf "crop=640:256:0:36" YourCroppedMovie.mp4
Source and more info: René Calles blog renevolution.com
Solution 2
From: https://stackoverflow.com/questions/17265381/ffmpeg-get-value-from-cropdetect
ffmpeg -i input -t 1 -vf cropdetect -f null - 2>&1 | awk '/crop/ { print $NF }' | tail -1
Solution 3
Putting the other two answers together into a script:
#!/bin/sh
#ffmpeg_zoom ver 20180128202453
I="$@";X=${I##*.};O=${I%.*}_zoomed.${X};f=$(which ffmpeg 2>/dev/null)
if [ ! "$f" ]||[ "$f" = '' ];then echo "Install ffmpeg";exit 1;fi
C=$($f -i "$I" -t 1 -vf cropdetect -f null - 2>&1|awk '/crop/{print $NF}'|tail -n1)
echo $f -i "$I" -vf "$C" "$O"; $f -i "$I" -vf "$C" "$O"
This question has some relevant ffmpeg examples
Related videos on Youtube
Author by
Konstantin
Updated on September 18, 2022Comments
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Konstantin almost 2 years
I think it has a "blackness" video filter, which can determine if a picture sequence is black. Maybe it also has a filter to determine crop values automatically to remove black borders form edges of a video. Or maybe it is possible somehow to write a script using the "blackness" filter.
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James Amos about 9 yearsIt might be helpful to put a start point (-ss 00:05:00) in when using cropdetect (before input -i) as some video will have a solid black screen when starting.
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ryanjdillon over 8 yearsI would like to use this to crop
python
matplotlib.animation
videos, which have a white border. Is it possible to alter the color of the border being detected? -
Aquarius Power about 8 yearsok, this will generate the "crop values" to use with ffmpeg in a simple and very clear way :), thx!
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DanMan over 6 yearsCan you specify something else than black as border color? White for example?
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Freedo almost 5 yearsThis does not answer the question as you still need to do manual action
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Adil almost 5 yearsHey @Cornelius can you please help me to find one command - i want to crop video.mp4 from Square to Round using ffmpeg - not want to use overlay command for this
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Ryan about 4 yearsYour ffplay cropdetect command played my video but still had black on the right and bottom sides. Then I saw superuser.com/a/1035399/74576. And it occurs to me that maybe ffmpeg.org/ffmpeg-filters.html#cropdetect can't help at all for videos that have black sides of asymmetrical thicknesses. The documentation is not great.
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Ryan about 4 yearsA manual crop worked for my case: ffmpeg.org/ffmpeg-filters.html#crop
ffplay -i "myvid.mp4" -vf "crop=w=1104:h=830:x=0:y=0"
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Hashim Aziz about 3 yearsThis fails miserably if there's a bit of black at the beginning of the video, such as in an intro. This is solved by adding
-ss 5
before-i
, to runcropdetect
after skipping the first 5 seconds.