Issue with --vpp-subburn and burning in subtitles using both track=<int> & filename=<string> parameters

[MartyMcNuts]

Hi Rigaya,

I have been having issues with burning in subtitles for a while now. I am referring to PGS (.sup) subtitles from BD/UHD.

Using the track= perameter:

This has not worked since v7.68. On all versions newer than v7.68, the burnt in subtitles do not show at all.

Using the filename= parameter:

This does still work but I have to always add ts_offset= (ts_offset=11.678 seems to work).

I am not sure why using track= no longer works on any version newer than v7.68 and I don't know why I always have to add the ts_offset when using the filename= parameter. Any ideas why or how to fix it?

Here are a couple of command examples for you. The PGS subtitle track in this example does include both forced and non-forced subtitles (not the issue BTW) but this issue regards burning in any PGS (.sup) subtitle file:

NVEncC64.exe --avhw -i bluray:D:\Movies\ANACONDA_2025\ --input-option playlist:00001 --vpp-subburn track=1,forced_subs_only=on,scale=2.0 --codec h265 --level 5.1 --profile main10 --tier high --output-depth 10 --lookahead 32 --vbr 25000 --tune uhq --multipass 2pass-full --output-buf 64 --aud --colorprim auto --colormatrix auto --dhdr10-info copy --transfer auto --chromaloc 2 --master-display copy --max-cll copy -o D:\Movies\ANACONDA_2025\video.mkv

NVEncC64.exe --avhw -i bluray:D:\Movies\ANACONDA_2025\ --input-option playlist:00001 --vpp-subburn filename="D:\Movies\ANACONDA_2025\ANACONDA_2025_F1_T12_Subtitle - English.sup",forced_subs_only=on,ts_offset=11.678,scale=2.0 --codec h265 --level 5.1 --profile main10 --tier high --output-depth 10 --lookahead 32 --vbr 25000 --tune uhq --multipass 2pass-full --output-buf 64 --aud --colorprim auto --colormatrix auto --dhdr10-info copy --transfer auto --chromaloc 2 --master-display copy --max-cll copy -o F:\Movies\ANACONDA_2025\BL_external.mkv

So, as I mentioned, when using the filename= perameter, if I don't also add the ts_offset perameter, the subtitles do not align. If I use the track= perameter on any version newer than v7.68, the subtitles do not show in the video at all. Hope you can fix this...

Thanks,
MM