Hi, I guess there is also a ffmpeg issue, because with the libsvtav1 codec : -> if I use the ffmpeg 6.1 release : the "-maxrate" parameter is allowed -> whereas if I use the 8.0 release : the "-maxrate" parameter triggers an error and this, with the same video codec, libsvtav1.
That's why, in the command line below, there is no "-maxrate" parameter : because it was with the 8.0 release. Regards, HA ________________________________ From: Nicolas Gaullier via ffmpeg-user <[email protected]> Sent: Friday, August 29, 2025 13:51 To: [email protected] <[email protected]> Cc: Nicolas Gaullier <[email protected]> Subject: [FFmpeg-user] ISSUE ABOUT VIDEO BITRATE Hello, AFAIK, this is a libsvtav1 issue, not an ffmpeg issue. The kind of setup and target you have is possible with libx264, for example, but not with libsvtav1. You can give a try to the CBR mode of libsvtav1, but it is very restricted, it involves the low delay mode, I feel you won't be very happy with the resulting quality, but actually you should obtain the desired bitrate. Nicolas On 8/29/25 10:03, Hervé ANSELME via ffmpeg-user wrote: > ATTENTION : Ce message provient d’une source externe. Ne cliquez sur aucun > lien ou pièce jointe sauf si vous êtes sûr de l’expéditeur. > > > Hello all, > > I am using the release 8.0 of ffmpeg/ffprobe, running on Windows 11 Family OS. > > I executed the following command : > > ffmpeg -i "initial movie.mkv" -y -loglevel error -sn ^ > -map 0:a:0 -acodec aac -ar 44100 -b:a 128k ^ > -map 0:v:0 -vcodec libsvtav1 -vf "scale=768:432" -sws_flags > lanczos+accurate_rnd -b:v 1200k -minrate 1200k ^ > -svtav1-params > "lossless=lower:nal-hrd=cbr:force-cfr=1:vbv-maxrate=1200k:vbv-bufsize=2400k" ^ > -bufsize 2400k "final movie.mkv" > > then, to see the result in the final film, regarding the video > characteristics, I executed : > > ffprobe -v error -select_streams v -show_entries > stream=codec_name,width,height,avg_frame_rate -of default=noprint_wrappers=1 > "final movie.mkv" > > which result is : > > bit_rate=930911 > codec_name=av1 > width=768 > height=432 > avg_frame_rate=25/1 > > which raises the question : how is it that there is such a large difference, > between the desired video bitrate (1200k) and the actual video bitrate > obtained (930911 = 930k) ? > > How should I modify my command line to obtain an effective video bitrate that > is, if not equal, at least as close as possible, to 1200k ? > > Thank you in advance for your replies and advices. > > Cdlt, > HA > _______________________________________________ > ffmpeg-user mailing list -- [email protected] > To unsubscribe send an email to [email protected] _______________________________________________ ffmpeg-user mailing list -- [email protected] To unsubscribe send an email to [email protected] _______________________________________________ ffmpeg-user mailing list -- [email protected] To unsubscribe send an email to [email protected]
