eq (4) - gamma

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doc

https://ffmpeg.org/ffmpeg-filters.html#eq

gamma=0.1 … 10.0

The value must be a float value in range 0.1 to 10.0. The default value is “1”.

eq=gamma=0.1

00:00:00
#! /bin/sh
ifn="Pexels_flowers_fast.mp4"
ifnb="`basename \"${ifn}\" .mp4`"
pref="`basename $0 .sh`"

ffmpeg -y -i "${ifn}" \
  -vf "eq=gamma=0.1" \
  -an "${pref}_${ifnb}.mp4"

eq=gamma=0.5

00:00:08
#! /bin/sh
ifn="Pexels_flowers_fast.mp4"
ifnb="`basename \"${ifn}\" .mp4`"
pref="`basename $0 .sh`"

ffmpeg -y -i "${ifn}" \
  -vf "eq=gamma=0.5" \
  -an "${pref}_${ifnb}.mp4"

eq=gamma=1.0

00:00:15
#! /bin/sh
ifn="Pexels_flowers_fast.mp4"
ifnb="`basename \"${ifn}\" .mp4`"
pref="`basename $0 .sh`"

ffmpeg -y -i "${ifn}" \
  -vf "eq=gamma=1.0" \
  -an "${pref}_${ifnb}.mp4"

eq=gamma=5.0

00:00:23
#! /bin/sh
ifn="Pexels_flowers_fast.mp4"
ifnb="`basename \"${ifn}\" .mp4`"
pref="`basename $0 .sh`"

ffmpeg -y -i "${ifn}" \
  -vf "eq=gamma=5.0" \
  -an "${pref}_${ifnb}.mp4"

eq=gamma=10.0

00:00:31
#! /bin/sh
ifn="Pexels_flowers_fast.mp4"
ifnb="`basename \"${ifn}\" .mp4`"
pref="`basename $0 .sh`"

ffmpeg -y -i "${ifn}" \
  -vf "eq=gamma=10.0" \
  -an "${pref}_${ifnb}.mp4"

Using expression

In these examples, since “${ifn}” is a video of 30 seconds, it instructs to change by approximately 1 / 3 per second.

gamma_weight can be used to reduce the effect of a high gamma value on bright image areas, e.g. keep them from getting overamplified and just plain white. The value must be a float in range 0.0 to 1.0. A value of 0.0 turns the gamma correction all the way down while 1.0 leaves it at its full strength. Default is “1”.

eq=gamma=(0.1+t/30.4*10.0):eval=frame:gamma_weight=1.0

00:00:38
#! /bin/sh
ifn="Pexels_flowers.mp4"
ifnb="`basename \"${ifn}\" .mp4`"
pref="`basename $0 .sh`"

ffmpeg -y -i "${ifn}" \
  -vf "eq=gamma=(0.1+t/30.4*10.0):eval=frame:gamma_weight=1.0" \
  -an "${pref}_${ifnb}.mp4"

eq=gamma=(0.1+t/30.4*10.0):eval=frame:gamma_weight=0.5

00:01:08
#! /bin/sh
ifn="Pexels_flowers.mp4"
ifnb="`basename \"${ifn}\" .mp4`"
pref="`basename $0 .sh`"

ffmpeg -y -i "${ifn}" \
  -vf "eq=gamma=(0.1+t/30.4*10.0):eval=frame:gamma_weight=0.5" \
  -an "${pref}_${ifnb}.mp4"

eq=gamma=(0.1+t/30.4*10.0):eval=frame:gamma_weight=0.0

00:01:38
#! /bin/sh
ifn="Pexels_flowers.mp4"
ifnb="`basename \"${ifn}\" .mp4`"
pref="`basename $0 .sh`"

ffmpeg -y -i "${ifn}" \
  -vf "eq=gamma=(0.1+t/30.4*10.0):eval=frame:gamma_weight=0.0" \
  -an "${pref}_${ifnb}.mp4"