CinePlay

Frame a rectangle on a wall with a command, and play a Bilibili video on it. Playback starts when players walk close and stops when they leave.

A screen is geometry, not blocks: nothing is placed in the world, nothing goes into chunk data — just four corner coordinates. Actual playback is handled by the client mod CineDuct; this plugin only decides what plays, where, and from when.

Requires a client-side mod: CineDuct (NeoForge 1.21.1, Windows x64). Players without it are unaffected — they simply don't see the screen.

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Features

• Zero footprint: a screen is only coordinates — stick it on a wall, float it in the air, hang it over water, even watch it through glass
• Automatic start/stop: playback begins within 48 blocks and stops past 64 blocks (configurable per screen)
• Per-screen permissions: whoever creates a screen owns it, and "control playback" can be granted separately from "delete the screen"
• Server-authoritative state: playlist, progress and volume live on the server, so progress survives relogging and switching machines

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Creating

/cineplay create                 enter selection mode (auto-cancels after 5 minutes)
right-click twice with a wooden hoe   the two opposite corners
/cineplay confirm <name>         confirm and name it
/cineplay add <name> <url>       queue a video — starts immediately

A third right-click re-selects the first corner. While selecting, only you see the particles (corner markers plus a dashed guide line).

Geometry rules:

Rule	Behaviour
Plane	Taken from the block face you clicked, not your view direction — where you stand doesn't matter
Orientation	Vertical, facing the side you clicked from
Size	Counted in blocks you covered (clicking block 10 and block 12 gives a width of 3, inclusive)
Offset	Floats 0.05 blocks off the wall to avoid z-fighting with block faces
Aspect	Videos are letterboxed when their ratio differs from the screen — never stretched

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Commands

Everything is screen-centric. There is deliberately no "play for one specific player" mode — a screen belongs to the world, so whoever walks close sees it.

Menu

/cineplay menu

A clickable chat menu, one line per screen. Click [Manage] to open that screen's action page:

==================== CinePlay ====================
 main  [Playing 00:12/03:33]  3 items  [Manage]
 hall  [Empty]  —  [Manage]
  [+ New screen] [Refresh] [Help]
==================== CinePlay ====================

The screen page has every action as a button: [Playlist] [Next] [Add] [Volume] [Range] [Admin] [Trusted] [Delete].

Actions that need a value (add / volume / range / grant) ask you to type the value in chat after clicking — no command syntax to remember, and normal chat keeps working afterwards.

Reference

Command	Purpose
/cineplay menu [screen]	Clickable menu (top level / per screen)
/cineplay screens	List all screens
/cineplay create / cancel / confirm <name>	Creation flow
/cineplay add [screen] <url> [seconds]	Append to the playlist
/cineplay playlist|next|prev [screen]	Show list / skip
/cineplay volume <screen> <0-100>	Per-screen volume
/cineplay range <screen> <enter> [exit]	Per-screen view distance
/cineplay access <screen> …	Admin (can delete + grant) / public true = trust everyone
/cineplay trust <screen> …	Trusted (can control playback, cannot delete)
/cineplay remove <screen>	Delete a screen (asks for confirmation)
/cineplay slot [name]	Screen used by commands that omit the name
/cineplay status / reload / help	Status / reload config / help

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Permissions

Role	Control playback	Delete screen	Grant others
Owner (creator)	✅	✅	✅
Admin	✅	✅	✅
Trusted	✅	❌	❌
Public (access <screen> public true)	✅	❌	❌
OP	✅	✅	✅

Deleting is irreversible, so "can play" and "can tear down" are kept apart: opening a screen to everyone only grants usage — nobody gains the right to delete it that way.

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Playlist

• Added items queue up; when one finishes the next starts automatically
• Duration comes from /cineplay add <screen> <url> 300 if you provide it; otherwise the plugin queries Bilibili, and as a last resort the client reports the real duration once at playback start — a value that naturally includes "non-premium accounts can only preview 6 minutes"
• When the last item ends the queue is cleared by default: /cineplay playlist becomes empty and /cineplay status reports finished. That makes "is it actually done?" observable instead of the server idling forever on item 1
• Set playlistLoop: true for looping playback (showcases, lobby reels)

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Configuration

Key	Default	Meaning
token	empty	Must match the client's token; both empty = no check
defaultSlot	main	Screen used when a command omits the name
premiumPreviewSeconds	360	Preview-length fallback for premium content
playlistLoop	false	Loop the playlist
menuRange	64	"Nearby" radius for the menu, in blocks
playCooldownMs	1500	Cooldown between play requests
requireChannel	false	Only send when the client advertised the channel
pasteTimeoutSeconds	60	How long an input prompt stays armed

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Installation

1. Drop the jar into the server's plugins/ and restart.
2. Clients need no configuration at all (CineDuct accepts control messages from any server). Optional hardening: a <gameDir>/cineduct-packet.json restricting token, allowedHosts and maxPerSecond.
3. On the client, verify the channel with /cineduct packet status.

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FAQ

The screen stays blank. Check the client log first: 虚拟屏 slot=… means the geometry arrived, 进入范围：开始播放 means playback started. Geometry present but no picture is usually the video source itself (dead link or membership-only content).

The size doesn't match what I selected. Geometry is computed at confirm and stored in screens.yml, but the plugin also keeps the raw corner points: after changing geometry rules, restarting the server recomputes from those points, so you never have to rebuild screens.

It still reports playing after the video ended. By default the queue is cleared and marked finished. If you set playlistLoop: true it keeps looping.

Audio but no video, or video but no audio. Make sure the client's CineDuct build matches the plugin (protocol v=1), then check the client log for 服务端控制被拒 (message rejected by the gate).

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License

MIT. CinePlay and the CineDuct client mod (GPL-3.0-or-later) are two independent programs that only exchange JSON over Minecraft plugin channels; neither contains the other's code.

Client mod: github.com/hxwi1/CineDuct-API