[FFmpeg-user] VBR encoding for libsvtav1.

[Aditya Dandavate]

On Mon, 27 Nov, 2023, 4:16 am Ferdi Scholten, <ferdi at sttc-nlp.nl> wrote:

> What is the quality rate control when encoding in VBR mode ?
> > I get message :
> >
> > Svt[warn]: The input q value is ignored in vbr mode 20 when I set the
> -crf
> > to 20 when enabling the -svtav1-params rc=1.
> > When I set -qp 20, the conversion fails.
> >
> > Which mode to set quality when encoding in VBR mode ?
> >
> vbr encoding does not support quality setting, you get the maximum
> quality that fits the specified bitrate and it uses lower bitrates if
> possible if the content does not require high bitrates.
>
>
> If you want CRF with a cap on the bitrate you need to set mbr
> (MaximumBitRate)
>
>      -crf 20 -svtav1-params mbr=5000k
>
> You do not need to specify rc=0, because that is default. You also do not
> specify -b:v 5000k
>
>
> Or if you want VBR
>
>      -svtav1-params rc=1 -b:v 5000k
>
> No quality settings like crf or qp as they require rc=0 you can however
> set -qmin (default 1) and -qmax (default 63)
>
>
> OR if you want CQP
>
>      -qp 20 -svtparams aq-mode=0 -b:v 5000k
>
> qp only works when aq-mode=0 (default aq-mode=2)
>
>
> Hope that helps?
>

Yes, that helped me a lot. Thank you sir for your help 🙏

>