Issues with Brightness after exporting


#1

So I’ve gotten into using shotcut in order to edit videos files for my (nearly complete playthrough of Starlancer. While I have heard about “lossless” editing I doubt it is on par with what is called “direct stream”. I don’t have a big issue with that, however I’ve noticed the overall picture is a tad darker after editing. I would like to minimize any loss to quality after editing before running it through handbrake. So, my question is is there any chance there may be an option or setting that is making it unusually darker than the source? Starlancer takes place in the dead of space so most of the light sources are either the sun, engines or people shooting at you…maybe a contrast issue I am overlooking? Also is there any advice to minimize any form of loss overall from the source? Yes I’ve manually inputted the source frame rate after selecting “lossless” h264 and bumping up the quality to 100 from the apparent default 60.

A screenshot is below. To the left we have the untouched file and to the right is post-shotcut with "lossless h.264/ 100% quality. I didn’t touch any other values so it may be a tad obvious to you guys. You can see the “floor” panel practically black in the right screenshot.

One last thing that I noted. Before exporting there are two options in settings>player>gamma> the 1st is "sRGB (Computer) and the 2nd is REC. 709 (TV). It’s set to default on RGB and it appears identical to the source file, however when I export it over it seems to mirror the second option for some reason.


#2

I’m having this same issue. Did you find a fix?


#3

Is the source clip full range or using MPEG limits? A full range clip will often appear as yuvj420p in Shotcut Properties > Video > Format. Shotcut does not yet output full range.
Since you see Gamma in Settings, it tells me you are using GPU processing, which is experimental.


#4

I have the same problem. All my videos processed in Shotcut (using x264) have their brightness changed and colors slightly off (washed out). An example video I’m just editing has yuv420p as the source format. I noticed that my exported videos show this in mediainfo:

Color range                              : Limited
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

After searching on the internet, I blame the limited color range. Not sure if I’m right. I found that x264 has this option:

       --range <string>
              Specify color range ["auto"] - auto, tv, pc

but I don’t know how to make Shotcut use a custom x264 option (I wanted to use --range pc).

Is there any way to make Shotcut use a full color range, or does it simply not support anything else then the limited color range?


GoPro, full color range and pix_fmt=yuvj420p -- what to hope for and what to avoid?
#5

There is a way to export full range, but it depends on the video actually being full range. As soon as you use any RGB-based filter, the range becomes limited again when converting back to YUV for most video codecs. The library used for RGB-to-YUV conversion only supports limited range at last check. Thus, the full range option for export is not exposed.


#6

So, how can I tell whether it’s full range or not? I have some videos for which mediainfo doesn’t show Color range line at all (I assumed that means full range), and some videos for which I see Color range: Limited. All of them have Color space: YUV and Chroma subsampling: 4:2:0. And in all cases the brightness and color tone gets shifted. (In other words, I haven’t seen a video yet that wouldn’t get brightness and color shifted when processed through Shotcut. It happens for all my videos, whether they are camera recordings or trailers downloaded from the net).

In the Filters tab, I don’t see any filters being applied. So why is it happening?


#7

Videos processed with kdenlive have also the same drawback. I did not notice it with Openshot, which also uses ffmpeg, but it provides few filters (maybe not RGB-based?), and I’m not an expert with this software.


#8

You should not reply to a two year old thread with that little bit of information and so many changes since. See the recent threads on color accuracy and intermediate files for recent information and evidence.


#9