[FFmpeg-user] MP4-->JPG changes brightness?

[Steven Kan]

> On May 15, 2021, at 11:06 AM, Steven Kan <steven at kan.org> wrote:
> 
>> On May 15, 2021, at 8:53 AM, Reino Wijnsma <rwijnsma at xs4all.nl> wrote:
>> 
>> On 2021-05-15T08:15:16+0200, Steven Kan <steven at kan.org> wrote:
>>> Is there a flag I need to set in ffmpeg to get a jpg that looks like what Preview produces? Is this error related to my issue?
>> 
>> Your 'TrailDownStillffmpeg.jpg' looks exactly like what I see when I open your 'TrailDown.mp4', so if you ask me, there's no "error" at all.
>> 
>> -- 
>> Reino
> 
> Hi Reino,
> 
> Thanks for checking. They do look very, very similar, but if you put the two windows on top of each other and toggle the windows back and forth, you can see a very slight difference in the brightness. It’s not that obvious if you look at them side by side, but if you sequence them in a video editor, there is a noticeable visual discontinuity, which is what I’m trying to avoid. 

Here’s an animated GIF showing the difference as I toggle back and forth:

https://www.kan.org/pictures/StillsFromFFmpegVsQTPreview.gif