ytdl_hook.lua: prefer HLS by default to avoid youtube's throttling

[guidocella]

Youtube throttles downloads of DASH streams unless you download them in chunks of up to 10MB, but not HLS. Default to HLS to speed up youtube downloads since it's by far the most popular yt-dlp site and there is no known issue in preferring HLS over DASH in other sites, if DASH is even available.

[github-actions[bot]]

Download the artifacts for this pull request:

Windows

* [mpv-i686-w64-mingw32](https://nightly.link/mpv-player/mpv/actions/artifacts/1627932067.zip) * [mpv-x86_64-w64-mingw32](https://nightly.link/mpv-player/mpv/actions/artifacts/1627933130.zip) * [mpv-x86_64-windows-msvc](https://nightly.link/mpv-player/mpv/actions/artifacts/1627938315.zip)

macOS

* [mpv-macos-12-intel](https://nightly.link/mpv-player/mpv/actions/artifacts/1627931404.zip) * [mpv-macos-13-intel](https://nightly.link/mpv-player/mpv/actions/artifacts/1627932059.zip) * [mpv-macos-14-arm](https://nightly.link/mpv-player/mpv/actions/artifacts/1627931042.zip)

[na-na-hi]

This breaks seeking out of cache.

[guidocella]

Seeking works for me?

[na-na-hi]

Try watching a 1440p or 2160p video.

Also if a video has 4320p available, it won't be selected anymore, 2160p is selected instead.

[guidocella]

I can reproduce that, an ffmpeg bug I assume? So we have to leave DASH as the default?

[na-na-hi]

I think so. And I suspect many reported mpv issues related to YT seeking are related to this.

[guidocella]

Too bad.