Video seeking issues for AV1 encoded files

[Selur]

Muxing was done with ffmpeg:

ffmpeg -y  -r 100/1 -i "/media/pawel/WINDOWS_11/_VIDEO RECODE/2025-10-11@10_42_08_1410_04.av1" -i "/media/pawel/WINDOWS_11/_VIDEO RECODE/iId_1_aid_0_2025-10-11@10_42_08_1410_02.opus" -metadata encoding_tool="Hybrid 2025.07.27.1" -c:v copy -c:1 copy -map 0:0  -map 1:0  -aspect 1920:1080 -r 100/1 "/media/pawel/WINDOWS_11/_VIDEO RECODE/2025-09-30 21-20-14 - TEST CUT_HYBRID_.mkv"

which is not the default, but remuxing with mkvmerge doesn't help so I suspect it's not a muxing problem.

SvtAv1EncApp --input stdin  --width 1920 --height 1080 --fps-num 100 --fps-denom 1 --profile 0 --tile-rows 0 --tile-columns 0 --progress 2 --rc 0 --crf 60 --mbr 5000 --aq-mode 2 --preset 13 --irefresh-type 1 --lookahead 33  --scm 0 --matrix-coefficients 1 --color-range 0 --output "/media/pawel/WINDOWS_11/_VIDEO RECODE/2025-09-30 21-20-14 - TEST CUT_HYBRID__1.av1"

looking at the defaults:

--keyint                     GOP size (frames), default is -2 [-2: ~5 seconds, -1: "infinite" and only applicable for CRF, 0: same as -1]
      --irefresh-type              Intra refresh type, default is 2 [1: FWD Frame (Open GOP), 2: KEY Frame (Closed GOP)]

so svtav1 will create a gop every 5 seconds @100fps this means every 500 frames.

Looking at the content: I suspect the problem is that there are a really few key frames.
What version of SvtAv1EncApp are you using?

Playing the file with ffplay ant trying to seek it reports:

[matroska,webm @ 0000020a0afffa80] seek_frame_generic failed as this stream seems to contain no keyframes after the target timestamp, 1002 non keyframes found

=> try different key frame related settings

Cu Selur