Use ffmpeg to resize image

Question

Is it possible to resize an image using FFMPEG?

I have this so far:

ffmpeg. -i 1.jpg -vf scale=360:240 > 2.jpg

I get the error message that 'At least one output file must be specified'

Is it possible?

@LordNeckbeard You are quite. I have just learned that recently :) — Andrew Simpson, Mar 02 '15 at 17:18

score 86 · Accepted Answer · edited Jul 23 '18 at 12:58

86

You can try this:

ffmpeg -i input.jpg -vf scale=320:240 output_320x240.png

I got this from source

Note: The scale filter can also automatically calculate a dimension while preserving the aspect ratio: scale=320:-1, or scale=-1:240

edited Jul 23 '18 at 12:58

Killer

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answered Mar 02 '15 at 09:57

Andri Kurnia

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Hi, beat you to it. It was what I just found. But, as you got the right answer and you gave me your time I give you a tick :) – Andrew Simpson Mar 02 '15 at 11:03
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The scale filter can also automatically calculate a dimension while preserving the aspect ratio: `scale=320:-1`, or `scale=-1:240`. – llogan Mar 02 '15 at 18:13
This results in a corrupt image for me. Just a bunch of lines and colors. jpg to jpg – Tyguy7 Nov 09 '15 at 18:26
2

Interesting, png output works fine though. JPG is borked. – Tyguy7 Nov 09 '15 at 18:27
What if I want to keep the output file name unchanged? Can I have a shorter command? Thank you. – Alston Mar 01 '19 at 03:22

score 17 · Answer 2 · edited Sep 05 '20 at 18:10

17

If you want to retain aspect ratio you can do -

./ffmpeg -i 1.jpg -vf scale="360:-1" 2.jpg

or if you want to resize based on input width and height, let's say half of input width and height you can do -

./ffmpeg -i 1.jpg -vf scale="iw/1:ih/2" 2.jpg

where

iw: input width
ih: input height

edited Sep 05 '20 at 18:10

VxJasonxV

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answered Feb 24 '18 at 07:05

Aniket Thakur

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score 2 · Answer 3 · answered Aug 02 '19 at 20:57

It is also possible to resize an image to fit inside some dimensions and letterbox the rest.

Example command:

ffmpeg -i IN.png -vf "scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2" OUT.jpg

See this answer for more details.

score 1 · Answer 4 · answered May 18 '20 at 06:27

To reduce image scale to the bounding box of width:320px and height:240px.

ffmpeg -i src_image_path -vf 'scale=if(gte(a\,320/240)\,min(320\,iw)\,-2):if(gte(a\,320/240)\,-2\,min(240\,ih))' dst_image_path

a: aspect ratio
iw: in width
ih: in height

If the src image size is in the bounding box do no resize on it. If image has a big aspect ration than 320/240 and width is bigger then 320, resize width to 320 and keep the aspect ration. If image has a small aspect ration than 320/240 and height is bigger then 240, resize height to 240 and keep the aspect ration.

Use ffmpeg to resize image

4 Answers4

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