Thursday, April 19, 2012

Increase brightness of video with minimal noise

I recently came upon a video that was way, way too dark. Unfortunately Handbrake does not have any brightness/contrast/gamma corrections. So I played the video in VLC and used the Extended Controls to increase the gamma slightly. As far as I can tell, the slider is from 0 - 10 with 1.0 being the default.

So my solution is to transcode the video with VLC at a high bitrate (the source video bitrate was about 22Mbps I believe) at about 15Mbps, mux the audio back in, and then re-encode with Handbrake with my preset.

This is the command line I used with VLC:
/Applications/Video/ Source.m4v --intf=rc --sout="#transcode{vcodec=h264,vb=15000,gamma=1.3}:standard{mux=mp4,dst=Dest.mp4,access=file}"

Edit: In the end I found that this wouldn't really work too well, so I used avidemux2 with a gamma filter, encoded at the highest possible bitrate, then used Subler to remux the audio and chapter tracks, then ran it through handbrake for my HD settings.

1 comment:

  1. It is very irritating that 1) so many movies and TV shows today are so gol durn DARK. Some sequences are barely visible in a darkened theater. SHAME! and 2) Handbrake and other encoders don't have controls to make these sequences brighter/visible. Nearly the entirety of Game of Thrones and the "raid" sequence in Zero Dark Thirty are perfect examples.

    I use an excellent paid application from Wondershare calle "Filmora" which does have a brightness slider, but it is not adequate in many cases.



Ryan Kuhn