[FFmpeg-user] ffmpeg makes some sources darker

[Jim Worrall]

> On 2016 Jan 6, at 4:04 AM, Andy Furniss <adf.lists at gmail.com> wrote:
> I guess superfast hides the gain of the first pass. I am not sure I
> would want to encode with it using 3M ABR - which is quite low, but
> then libx265 is quite slow.

Normally I use ‘medium', or now ‘slow' because I’ve got my NAS set up
with ffmpeg and just let it crank there in its own sweet time.  

I started with testing a range of bitrates at medium 2-pass from a bluray
source.  At least looking at the pngs, I found I couldn’t really see any 
clear improvement above 2 Mb/sec, so I chose 3.  I can’t distinguish it
from the source (except for the light/dark business in some cases).  
Do you think the ‘png test’ doesn’t give a good comparison?