[FFmpeg-user] ffmpeg MP4/x264 output colours change when input source is different resolution (bug?)

[Michael Koch]

Am 15.09.2022 um 13:43 schrieb Dan:
> On Thu, 15 Sep 2022 12:07:08 +0100, Michael Koch 
> <astroelectronic at t-online.de> wrote:
>
>> Am 15.09.2022 um 11:53 schrieb Dan:
>>>> This seems to work with VLC player:
>>>>
>>>> ffmpeg -f lavfi -i color=0x19be0f:s=400x576 -colorspace bt709 -crf 0
>>>> -vcodec libx264 -t 5 -y out1.mp4
>>>> ffmpeg -f lavfi -i color=0x19be0f:s=400x578 -colorspace bt709 -crf 0
>>>> -vcodec libx264 -t 5 -y out2.mp4
>>>
>>> Unfortunately, doesn't work for me in MPC or Chrome. Can you try a
>>> height of 720 instead of 578 to see if that fails for you?
>>
>> Please try this, for me it works with VLC player, the color is exactly
>> the same:
>>
>> ffmpeg -f lavfi -i color=0x19be0f:s=400x576 -colorspace bt709
>> -color_primaries bt709 -color_trc bt709 -crf 0 -vcodec libx264 -t 5 -y
>> out1.mp4
>> ffmpeg -f lavfi -i color=0x19be0f:s=400x720 -colorspace bt709
>> -color_primaries bt709 -color_trc bt709 -crf 0 -vcodec libx264 -t 5 -y
>> out2.mp4
>
> Sure.
>
> The colour is both the same now (for both Chrome and MPC), except it's
> the darker, wrong colour (green=164 instead of 190).

Try some other values instead of "bt709".