[FFmpeg-user] VBR encoding for libsvtav1.

[Aditya Dandavate]

On Sun, 26 Nov, 2023, 8:18 pm Aditya Dandavate, <adityadandavate04 at gmail.com>
wrote:

>
>
> On Sun, 26 Nov, 2023, 7:38 pm Gyan Doshi, <ffmpeg at gyani.pro> wrote:
>
>>
>>
>> On 2023-11-26 07:21 pm, Aditya Dandavate wrote:
>> > On Sun, 26 Nov, 2023, 6:44 pm Ferdi Scholten, <ferdi at sttc-nlp.nl>
>> wrote:
>> >
>> >> I was trying and searching the web to 'how to encode videos with
>> libsvtav1
>> >>> with help of VBR rate control mode and I found on this page that
>> setting
>> >>> -rc 1 will enable Variable Bitrate mode.
>> >>>
>> >>>
>> >>>
>> >>
>> https://gitlab.com/AOMediaCodec/SVT-AV1/-/blob/master/Docs/svt-av1_encoder_user_guide.md
>> >>>
>> >>> I tried to set '-rc 1' but the it says :
>> >>>
>> >>> `[out#0/nut @ 00000208aba3eac0] Codec AVOption rc (Override the preset
>> >>> rate-control) has not been used for any stream. The most likely
>> reason is
>> >>> either wrong type (e.g. a video option with no video streams) or that
>> it
>>
>> The doc link is for the standalone encoder program supplied with the
>> library, not for use with ffmpeg.
>>
>> For ffmpeg, you should add
>>
>> -svtav1-params rc=1
>>
>> Regards,
>> Gyan
>>
>
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 ?