ffmpeg # copyts

-copyts

-copyts
Do not process input timestamps, but keep their values without trying to sanitize them.
In particular, do not remove the initial start time offset value.

Note that, depending on the vsync option or on specific muxer processing (e.g. in case the format option avoid_negative_ts is enabled) the output timestamps may mismatch with the input timestamps even when this option is selected.

    { "copyts",         OPT_BOOL | OPT_EXPERT,                       { &copy_ts },
        "copy timestamps" },

-muxdelay

-muxdelay seconds (input)
Set the maximum demux-decode delay.

References:

https://superuser.com/questions/1109852/ffmpeg-transcode-each-segment-individually/1112663