HLS supports slicing not according to GOP.

[winlinvip]

https://github.com/winlinvip/simple-rtmp-server/issues/381

TRANS_BY_GPT3

[winlinvip]

See bellow:

        # whether wait keyframe to reap segment,
        # if off, reap segment when duration exceed the fragment,
        # if on, reap segment when duration exceed and got keyframe.
        # default: on
        hls_wait_keyframe       on;