/bilibili-page-reader

name: bilibili-page-reader
description: "Get content from Bilibili videos: official subtitles, danmaku (density/peaks/sample), comments. When no subtitles exist (no 投稿字幕), fall back to downloading audio + ASR transcription via FunASR."

Bilibili Page Reader

Core Rules

• **Browser access** via `kimi-webbridge` for page state, login-only data, Bilibili Evolved (BE) providers.
• **Do not click BE download buttons.** Call providers directly via evaluate.
• **Always use a named session.** A session-less evaluate may land on a different tab and silently return wrong data.
• **Network calls outside the browser** (audio download, playurl API) use Node.js — PowerShell's `curl.exe` and Python's requests both get blocked by Bilibili CDN TLS fingerprinting on this platform.

---

Workflow Overview

                    ┌─ BE downloadSubtitles provider ──→ 投稿字幕 (timestamps)
                    │
BiliBili video ───┼─ BE downloadDanmaku provider ────→ danmaku density/peaks/sample
                    │
                    └─ No subtitles? ──→ Audio transcription fallback
                                         1. Get audio stream URL (Node.js → playurl API)
                                         2. Download .m4s audio
                                         3. ffmpeg → .m4a
                                         4. FunASR paraformer-zh → SRT with timestamps

---

Phase 1: Subtitles (preferred — via BE)

Use the one-shot evaluate below. It returns both subtitles and danmaku in a single call.

Setup

~/.kimi-webbridge/bin/kimi-webbridge status

{"action":"navigate","args":{"url":"https://www.bilibili.com/video/BV.../","newTab":true},"session":"bilibili"}

Wait 2–3 seconds for BE to fully initialize.

One-shot evaluate

(async () => {
  const pa = window.bilibiliEvolved.pluginApis;

  // ── Identifiers ──
  const s = window.__INITIAL_STATE__ || {};
  const vd = s.videoData || {};
  const bvid = vd.bvid || s.bvid || location.pathname.match(/BV[\w]+/)?.[0];
  const aid = vd.aid || s.aid;
  const pages = vd.pages || [];
  const p = parseInt(new URLSearchParams(location.search).get('p') || '1') - 1;
  const cid = pages[p]?.cid || vd.cid || s.cid || pages[0]?.cid;
  const title = vd.title || document.title;

  // ── Register providers ──
  pa.registerData('downloadVideo.assets', []);

  // ── Poll for providers (downloadDanmaku loads async, ~1-2s) ──
  function getProviders() {
    const g = pa.getData('downloadVideo.assets');
    return Array.isArray(g[0]) ? g.flat() : g;
  }
  const deadline = Date.now() + 5000;
  let providers = getProviders();
  while (!providers.find(p => p.name === 'downloadDanmaku') && Date.now() < deadline) {
    await new Promise(r => setTimeout(r, 300));
    providers = getProviders();
  }

  // ── Subtitles: try 投稿字幕 first ──
  let subResult = { count: 0, text: '', source: 'none' };
  const subProvider = providers.find(p => p.name === 'downloadSubtitles');
  if (subProvider) {
    try {
      const subAssets = await subProvider.getAssets([{ input: {} }], { type: 'json', enabled: true });
      const subRaw = subAssets[0].data;
      let subText;
      if (subRaw instanceof Blob) {
        const buf = await subRaw.arrayBuffer();
        subText = new TextDecoder('utf-8').decode(buf);
      } else {
        subText = String(subRaw);
      }
      const subtitles = JSON.parse(subText);
      const subLines = subtitles.map(s => {
        const totalSec = Math.floor(s.from);
        const h = Math.floor(totalSec / 3600);
        const m = Math.floor((totalSec % 3600) / 60);
        const sec = String(totalSec % 60).padStart(2, '0');
        if (h > 0) {
          return '[' + h + ':' + String(m).padStart(2, '0') + ':' + sec + '] ' + s.content;
        }
        return '[' + m + ':' + sec + '] ' + s.content;
      });
      subResult = { count: subtitles.length, text: subLines.join('\n'), source: '投稿字幕' };
    } catch(e) {
      subResult = { count: 0, text: '', source: '投稿字幕_error' };
    }
  }

  // ── Danmaku: analyze in-page, summary only ──
  const dmk = providers.find(p => p.name === 'downloadDanmaku');
  const dmkAssets = await dmk.getAssets(
    [{ input: { aid: String(aid), cid: String(cid) } }],
    { type: 'json', enabled: true }
  );
  const dmkRaw = dmkAssets[0].data;
  let dmkText;
  if (dmkRaw instanceof Blob) {
    const buf = await dmkRaw.arrayBuffer();
    dmkText = new TextDecoder('utf-8').decode(buf);
  } else {
    dmkText = String(dmkRaw);
  }
  const danmaku = JSON.parse(dmkText);

  // Time density: 30s buckets
  const bucketSize = 30;
  const buckets = {};
  for (const d of danmaku) {
    const b = Math.floor(d.progress / 1000 / bucketSize) * bucketSize;
    buckets[b] = (buckets[b] || 0) + 1;
  }
  const density = Object.entries(buckets)
    .map(([t, c]) => [Number(t), c])
    .sort((a, b) => a[0] - b[0]);

  // Top 5 peak moments
  const peaks = density.slice().sort((a, b) => b[1] - a[1]).slice(0, 5);

  // Stratified sample: up to 40 entries across full timeline
  const sampleCount = Math.min(40, danmaku.length);
  const step = Math.max(1, Math.floor(danmaku.length / sampleCount));
  const danmakuSample = [];
  for (let i = 0; i < danmaku.length && danmakuSample.length < sampleCount; i += step) {
    danmakuSample.push({
      t: Math.floor(danmaku[i].progress / 1000),
      c: danmaku[i].content
    });
  }

  const totalDuration = danmaku.length > 0
    ? Math.max(...danmaku.map(d => d.progress)) : 0;

  // ── Return ──
  return JSON.stringify({
    ok: true, bvid, aid: Number(aid), cid: Number(cid), p: p + 1, title,
    sub: subResult,
    dmk: {
      count: danmaku.length,
      timeSpanSec: Math.floor(totalDuration / 1000),
      density,
      peakMoments: peaks.map(pk => ({ timeSec: pk[0], count: pk[1] })),
      sample: danmakuSample
    }
  });
})()

Response shape

{
  "sub": {
    "count": 243,
    "text": "[0:00] 大家好\n[0:01] 这个视频...",
    "source": "投稿字幕"
  },