How to change video gamma
1. Drop a video you already have. An audio-only file or a picture is refused here. 2. Leave brighter, or pick darker, a little darker or much brighter. 3. Press “Change gamma” and download the MP4.
GustKit runs the FFmpeg eq filter with gamma. Darker uses 0.55. A little darker uses 0.8. Brighter uses 1.45. Much brighter uses 1.9. A value of 1 would leave the picture alone. Below 1 the midtones drop. Above 1 they lift. Width and height stay the same. A soundtrack is kept when the file has one. A silent video stays silent.
Gamma moves the midtones
Video brightness adds or subtracts light with eq=brightness. Video contrast pulls lights and darks apart with eq=contrast. Adjust brightness does that job for a photo, on the canvas, and can change contrast too. This page changes only the gamma of a short clip and saves MP4. A long video is refused, because every frame is re-encoded here.
The clip stays in this tab
The first visit downloads FFmpeg. Later visits reuse the browser cache. GustKit does not fetch video from a link. Leave the tab open until the download appears.
How to check the gamma
1. Play the download next to the original. 2. A gray wall should look lighter on Brighter and darker on Darker. 3. If the frame grew, you added a border on another page.
Video brightness shifts the whole picture. This page changes gamma with the eq filter and saves MP4. Nothing is uploaded.