The timestamp not correct after seek

[kerry]

Summary of the bug:

Use ffplay to play a static hls address, if there no seek, the timestamp is normally, but if we do seek(press → or ↑) the timestamp will return to zero and then accumulate again, this issue will cause progress bar not correct after seek.

I have found the code may caused this issue in ffmpeg/libavformat/seek.c#732, if cur_dts is valued as seek_timestamp(the seek value), the timestamp will normally even after seek, but this modify may have side effect. So could you analysis this and give a office solution. Thanks.

How to reproduce:

ffplay http://live.ximalaya.com/radio-first-page-app/history/1994/24.m3u8\?start\=1644363000000\&end\=1644368400000

ffplay version 5.0 Copyright (c) 2003-2022 the FFmpeg developers

built with Apple clang version 13.0.0 (clang-1300.0.29.30)

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.