[FFmpeg-user] Question about -noauto_conversion_filters

Michael Koch astroelectronic at t-online.de
Mon Sep 14 13:11:53 EEST 2020


Am 14.09.2020 um 11:26 schrieb Gyan Doshi:
>
>
> On 14-09-2020 02:47 pm, Michael Koch wrote:
>> ffmpeg -v verbose -f lavfi -i testsrc2=s=svga:d=5,format=yuv422p10le 
>> -vf format=rgb48le,lut3d="VLog_to_V709.cube",format=yuv422p10le 
>> -noauto_conversion_filters -pix_fmt yuv422p10le -c:v h264 -y out.mov 
>
> Format conversion is carried out by libswscale and auto conversion 
> inserts the scale filter.
>
> So,
>
>     ffmpeg -v verbose -f lavfi -i 
> testsrc2=s=svga:d=5,format=yuv422p10le -vf 
> scale,format=rgb48le,lut3d="VLog_to_V709.cube",scale 
> -noauto_conversion_filters -pix_fmt yuv422p10le -c:v h264 -y out.mov
>
> The final format filter is redundant with -pix_fmt, so I removed one 
> of them.

Thank you, with "scale" it works fine. Although it's hard to understand 
what "scale" (without any options) is actually doing.

I have another question. Is this the correct and easiest way to make a 
10-bit test video?
-f lavfi -i testsrc2=s=svga:d=5,format=yuv422p10le

In the documentation is written
"The |testsrc2|source is similar to testsrc, but supports more pixel 
formats instead of just |rgb24|. This allows using it as an input for 
other tests without requiring a format conversion."
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

But in my above command, I think "format=yuv422p10le" is a format 
conversion.

Michael



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