nips/61.md

NIP-61

Danmaku

draft optional

This NIP defines a new kind of event, 2333, for danmaku.

Danmaku is a subtitle system in online videos where users post comments synchronized with the video timeline. It's also used in music, podcasts, and other media.

Format

The format uses a regular event kind 2333.

The .content of these events is the content of the danmaku comment.

The list of tags are as follows:

• i (required) universally unique identifier of the video. The format is <platform (lowercase)>:<identity> where <platform> is the platform of the video and <identity> is the unique identifier of the video on that platform. For example, a YouTube video with the identifier aA-jiiepOrE would have the identifier youtube:aA-jiiepOrE.
• time (required) the time of the video when the danmaku comment is sent in seconds.
• duration (optional) the duration of the danmaku comment shown in seconds.
• speed (optional) the speed of the danmaku comment in pixels per second.
• color (optional) the color of the danmaku comment in hexadecimal format.
• mode (optional) the display mode of the danmaku comment. The following values are possible:
  • rtl the danmaku comment scrolls from right to left.
  • top the danmaku comment is displayed at the top of the screen.
  • bottom the danmaku comment is displayed at the bottom of the screen.

Any other styling tags are allowed. And, client implementations should ignore any tags they do not understand.

Example

{
  "id": "<...>",
  "pubkey": "<...>",
  "kind": 2333,
  "tags": [
    ["i", "youtube:aA-jiiepOrE"],
    ["time", "3.018597"],
    ["color", "#FFFFFF"],
    ["mode", "rtl"]
  ],
  "content": "Hello Nostr!",
  "sig": "<...>",
  "created_at": 1713368851
}