v1.4.0-beta regression gap controller jumps large gaps

[robwalch]

I noticed one undesirable action: gap-controller.ts:264 [warn] > skipping hole, adjusting currentTime from 105.275674 to 170.05533300000002

To reproduce the issue, you need to watch the entire video and seek to 105.
"backBufferLength": 90
08b938f3.hls-js-dev.pages.dev-1680185898252.log

Originally posted by @mtoczko in #2940 (comment)

[robwalch]

Hi @mtoczko,

In this case is there a GAP tag or no loadable media at 105? Is this reproducible in streams without GAP tags?

First thing to try is to clear out any gap fragments from the fragmentTracker on seeking. My guess is that if we don't do this with your test stream the player will not not error->switch to find bufferable fragments and encounter a stall situation that it determines it should jump because of all the tracked gaps.

[mtoczko]

Hi @robwalch
To observe this better, you need to enable throttling in the browser (3G). Seek to 260, seek to 0.
We can observe that almost the entire video is skipped. We only seek to "safe" places.

We should probably clear the buffer when we seek.

[log] > [audio-stream-controller]: Buffered audio sn: 13 of track 0 (frag:[26.005-28.011] > buffer:[0.000-28.011][260.011-266.027])
base-stream-controller.ts:1682 [log] > [audio-stream-controller]: PARSED->IDLE
[warn] > skipping hole, adjusting currentTime from 18.83739 to 260.060666
[log] > [stream-controller]: media seeking to 260.061, state: IDLE

targetTime - It is not validated in any way and you can jump through the entire video

hls.js/src/controller/gap-controller.ts

Lines 260 to 263 in 0a6956b

	const targetTime = Math.max(
	startTime + SKIP_BUFFER_RANGE_START,
	currentTime + SKIP_BUFFER_HOLE_STEP_SECONDS
	);

 if ((startTime + SKIP_BUFFER_RANGE_START) - (currentTime + SKIP_BUFFER_HOLE_STEP_SECONDS) > backBufferLength )
return 0