Scale the input video to a size of 200x100
scale=w=200:h=100
This is equivalent to:
scale=200:100
or:
scale=200x100
Specify a size abbreviation for the output size:
scale=qcif
which can also be written as:
scale=size=qcif
Scale the input to 2x:
scale=w=2*iw:h=2*ih
The above is the same as:
scale=2*in_w:2*in_h
Scale the input to 2x with forced interlaced scaling:
scale=2*iw:2*ih:interl=1
Scale the input to half size:
scale=w=iw/2:h=ih/2
Increase the width, and set the height to the same size:
scale=3/2*iw:ow
Seek Greek harmony:
scale=iw:1/PHI*iw scale=ih*PHI:ih
Increase the height, and set the width to 3/2 of the height:
scale=w=3/2*oh:h=3/5*ih
Increase the size, making the size a multiple of the chroma subsample values:
scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"
Increase the width to a maximum of 500 pixels, keeping the same aspect ratio as the input:
scale=w='min(500\, iw*3/2):h=-1'
Make pixels square by combining scale and setsar:
scale='trunc(ih*dar):ih',setsar=1/1
Make pixels square by combining scale and setsar, making sure the resulting resolution is even (required by some codecs):
scale='trunc(ih*dar/2)*2:trunc(ih/2)*2',setsar=1/1