[FFmpeg-user] ffmpeg makes some sources darker

[Andy Furniss]

Jim Worrall wrote:
>> Yes, that's probably it.
>>
>> Maybe you could try below to see if the original shows 709 -
>>
>> ffmpeg -analyzeduration 100M -probesize 100M -i original.m2ts
>>
>> FWIW I just noticed another issue - using pass 1 and pass 2 via ffmpeg doesn't work for libx265.
>>
>> It does work if you use it via -x265-params pass=
>
> No, the original m2ts with the analyze/probe options gives
>      Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 90k tbn, 47.95 tbc

Oh, I hadn't noticed that before - it's the same if I test my own m2ts 
files.


> So is it possible to use the -colormatrix and other color options
> as input options?  Is that what I should be doing?  Incidentally,
> those don’t seem to be in the documentation at all.

For the transcode they should be OK as output options - AFAIK all they 
do is set some metadata.

For making a png from the input they do seem to work as input options.

They do show in ffmpeg -h full.

> pass has been working for me - maybe they fixed that in x265 v. 1.8?

I'll have to try that - I was using some old Hg now on new Hg (not 
videolans as that doesn't seem to get updated anymore).

Currently I just get an empty ffmpeg2pass-0.log and pass 1 is as slow as 
pass 2. As expected he result is worse as well.