Add vendor dict fallback logic

docs/configuration.md

@@ -555,6 +555,12 @@ See `config.example.jsonc` for detailed configuration options.
 | `fontStyle`       | string      | `"normal"` or `"italic"` (default: `"normal"`)                                |
 | `backgroundColor` | string      | Any CSS color, including `"transparent"` (default: `"rgba(54, 58, 79, 0.5)"`) |
 | `enableJlpt`      | boolean     | Enable JLPT level underline styling (`false` by default)                        |
+| `frequencyDictionary.enabled` | boolean | Enable frequency highlighting from dictionary lookups (`false` by default) |
+| `frequencyDictionary.sourcePath` | string | Optional absolute path used for dictionary discovery (defaults to built-in paths) |
+| `frequencyDictionary.topX` | number | Only color tokens whose frequency rank is `<= topX` (`1000` by default) |
+| `frequencyDictionary.mode` | string | `"single"` or `"banded"` (`"single"` by default) |
+| `frequencyDictionary.singleColor` | string | Color used for all highlighted tokens in single mode |
+| `frequencyDictionary.bandedColors` | string[] | Array of five hex colors used for ranked bands in banded mode |
 | `nPlusOneColor`   | string      | Existing n+1 highlight color (default: `#c6a0f6`)                            |
 | `knownWordColor`  | string      | Existing known-word highlight color (default: `#a6da95`)                       |
 | `jlptColors`      | object      | JLPT level underline colors object (`N1`..`N5`)                               |
@@ -562,6 +568,8 @@ See `config.example.jsonc` for detailed configuration options.
 
 JLPT underlining is powered by offline term-meta bank files at runtime. See [`docs/jlpt-vocab-bundle.md`](jlpt-vocab-bundle.md) for required files, source/version refresh steps, and deterministic fallback behavior.
 
+Frequency dictionary highlighting uses the same dictionary file format as JLPT bundle lookups (`term_meta_bank_*.json` under discovered dictionary directories). A token is highlighted when it has a positive integer `frequencyRank` (lower is more common) and the rank is within `topX`. In `single` mode all highlights use `singleColor`; in `banded` mode tokens map to five ascending color bands from most common to least common inside the topX window.
+
 Secondary subtitle defaults: `fontSize: 24`, `fontColor: "#ffffff"`, `backgroundColor: "transparent"`. Any property not set in `secondary` falls back to the CSS defaults.
 
 **See `config.example.jsonc`** for the complete list of subtitle style configuration options.

docs/public/config.example.jsonc

@@ -151,6 +151,20 @@
   // ==========================================
   "subtitleStyle": {
     "enableJlpt": false,
+    "frequencyDictionary": {
+      "enabled": false,
+      "sourcePath": "",
+      "topX": 1000,
+      "mode": "single",
+      "singleColor": "#f5a97f",
+      "bandedColors": [
+        "#ed8796",
+        "#f5a97f",
+        "#f9e2af",
+        "#a6e3a1",
+        "#8aadf4"
+      ]
+    },
     "fontFamily": "Noto Sans CJK JP Regular, Noto Sans CJK JP, Arial Unicode MS, Arial, sans-serif",
     "fontSize": 35,
     "fontColor": "#cad3f5",

package.json

@@ -103,6 +103,10 @@
         "from": "vendor/yomitan-jlpt-vocab",
         "to": "yomitan-jlpt-vocab"
       },
+      {
+        "from": "vendor/jiten_freq_global",
+        "to": "jiten_freq_global"
+      },
       {
         "from": "assets",
         "to": "assets"

plugin/subminer.lua

@@ -28,6 +28,31 @@ local function is_linux()
 	return not is_windows() and not is_macos()
 end
 
+local function normalize_binary_path_candidate(candidate)
+	if type(candidate) ~= "string" then
+		return nil
+	end
+	local trimmed = candidate:match("^%s*(.-)%s*$") or ""
+	if trimmed == "" then
+		return nil
+	end
+	if #trimmed >= 2 then
+		local first = trimmed:sub(1, 1)
+		local last = trimmed:sub(-1)
+		if (first == '"' and last == '"') or (first == "'" and last == "'") then
+			trimmed = trimmed:sub(2, -2)
+		end
+	end
+	return trimmed ~= "" and trimmed or nil
+end
+
+local function binary_candidates_from_app_path(app_path)
+	return {
+		utils.join_path(app_path, "Contents", "MacOS", "SubMiner"),
+		utils.join_path(app_path, "Contents", "MacOS", "subminer"),
+	}
+end
+
 local opts = {
 	binary_path = "",
 	socket_path = default_socket_path(),
@@ -131,12 +156,68 @@ end
 
 local function file_exists(path)
 	local info = utils.file_info(path)
-	return info ~= nil
+	if not info then return false end
+	if info.is_dir ~= nil then
+		return not info.is_dir
+	end
+	return true
+end
+
+local function resolve_binary_candidate(candidate)
+	local normalized = normalize_binary_path_candidate(candidate)
+	if not normalized then
+		return nil
+	end
+
+	if file_exists(normalized) then
+		return normalized
+	end
+
+	if not normalized:lower():find("%.app") then
+		return nil
+	end
+
+	local app_root = normalized
+	if not app_root:lower():match("%.app$") then
+		app_root = normalized:match("(.+%.app)")
+	end
+	if not app_root then
+		return nil
+	end
+
+	for _, path in ipairs(binary_candidates_from_app_path(app_root)) do
+		if file_exists(path) then
+			return path
+		end
+	end
+
+	return nil
+end
+
+local function find_binary_override()
+	local candidates = {
+		resolve_binary_candidate(os.getenv("SUBMINER_APPIMAGE_PATH")),
+		resolve_binary_candidate(os.getenv("SUBMINER_BINARY_PATH")),
+	}
+
+	for _, path in ipairs(candidates) do
+		if path and path ~= "" then
+			return path
+		end
+	end
+
+	return nil
 end
 
 local function find_binary()
-	if opts.binary_path ~= "" and file_exists(opts.binary_path) then
-		return opts.binary_path
+	local override = find_binary_override()
+	if override then
+		return override
+	end
+
+	local configured = resolve_binary_candidate(opts.binary_path)
+	if configured then
+		return configured
 	end
 
 	local search_paths = {

src/config/definitions.ts

@@ -195,6 +195,20 @@ export const DEFAULT_CONFIG: ResolvedConfig = {
       N4: "#a6e3a1",
       N5: "#8aadf4",
     },
+    frequencyDictionary: {
+      enabled: false,
+      sourcePath: "",
+      topX: 1000,
+      mode: "single",
+      singleColor: "#f5a97f",
+      bandedColors: [
+        "#ed8796",
+        "#f5a97f",
+        "#f9e2af",
+        "#a6e3a1",
+        "#8aadf4",
+      ],
+    },
     secondary: {
       fontSize: 24,
       fontColor: "#ffffff",
@@ -306,6 +320,48 @@ export const CONFIG_OPTION_REGISTRY: ConfigOptionRegistryEntry[] = [
     description: "Enable JLPT vocabulary level underlines. "
       + "When disabled, JLPT tagging lookup and underlines are skipped.",
   },
+  {
+    path: "subtitleStyle.frequencyDictionary.enabled",
+    kind: "boolean",
+    defaultValue: DEFAULT_CONFIG.subtitleStyle.frequencyDictionary.enabled,
+    description:
+      "Enable frequency-dictionary-based highlighting based on token rank.",
+  },
+  {
+    path: "subtitleStyle.frequencyDictionary.sourcePath",
+    kind: "string",
+    defaultValue: DEFAULT_CONFIG.subtitleStyle.frequencyDictionary.sourcePath,
+    description:
+      "Optional absolute path to a frequency dictionary directory."
+      + " If empty, built-in discovery search paths are used.",
+  },
+  {
+    path: "subtitleStyle.frequencyDictionary.topX",
+    kind: "number",
+    defaultValue: DEFAULT_CONFIG.subtitleStyle.frequencyDictionary.topX,
+    description: "Only color tokens with frequency rank <= topX (default: 1000).",
+  },
+  {
+    path: "subtitleStyle.frequencyDictionary.mode",
+    kind: "enum",
+    enumValues: ["single", "banded"],
+    defaultValue: DEFAULT_CONFIG.subtitleStyle.frequencyDictionary.mode,
+    description:
+      "single: use one color for all matching tokens. banded: use color ramp by frequency band.",
+  },
+  {
+    path: "subtitleStyle.frequencyDictionary.singleColor",
+    kind: "string",
+    defaultValue: DEFAULT_CONFIG.subtitleStyle.frequencyDictionary.singleColor,
+    description: "Color used when frequencyDictionary.mode is `single`.",
+  },
+  {
+    path: "subtitleStyle.frequencyDictionary.bandedColors",
+    kind: "array",
+    defaultValue: DEFAULT_CONFIG.subtitleStyle.frequencyDictionary.bandedColors,
+    description:
+      "Five colors used for rank bands when mode is `banded` (from most common to least within topX).",
+  },
   {
     path: "ankiConnect.enabled",
     kind: "boolean",

src/config/service.ts

@@ -45,6 +45,21 @@ function asColor(value: unknown): string | undefined {
   return hexColorPattern.test(text) ? text : undefined;
 }
 
+function asFrequencyBandedColors(
+  value: unknown,
+): [string, string, string, string, string] | undefined {
+  if (!Array.isArray(value) || value.length !== 5) {
+    return undefined;
+  }
+
+  const colors = value.map((item) => asColor(item));
+  if (colors.some((color) => color === undefined)) {
+    return undefined;
+  }
+
+  return colors as [string, string, string, string, string];
+}
+
 export class ConfigService {
   private readonly configDir: string;
   private readonly configFileJsonc: string;
@@ -468,6 +483,108 @@ export class ConfigService {
           "Expected boolean.",
         );
       }
+
+      const frequencyDictionary = isObject(
+        (src.subtitleStyle as { frequencyDictionary?: unknown })
+          .frequencyDictionary,
+      )
+        ? ((src.subtitleStyle as { frequencyDictionary?: unknown })
+            .frequencyDictionary as Record<string, unknown>)
+        : {};
+      const frequencyEnabled = asBoolean(
+        (frequencyDictionary as { enabled?: unknown }).enabled,
+      );
+      if (frequencyEnabled !== undefined) {
+        resolved.subtitleStyle.frequencyDictionary.enabled = frequencyEnabled;
+      } else if (
+        (frequencyDictionary as { enabled?: unknown }).enabled !== undefined
+      ) {
+        warn(
+          "subtitleStyle.frequencyDictionary.enabled",
+          (frequencyDictionary as { enabled?: unknown }).enabled,
+          resolved.subtitleStyle.frequencyDictionary.enabled,
+          "Expected boolean.",
+        );
+      }
+
+      const sourcePath = asString(
+        (frequencyDictionary as { sourcePath?: unknown }).sourcePath,
+      );
+      if (sourcePath !== undefined) {
+        resolved.subtitleStyle.frequencyDictionary.sourcePath = sourcePath;
+      } else if (
+        (frequencyDictionary as { sourcePath?: unknown }).sourcePath !== undefined
+      ) {
+        warn(
+          "subtitleStyle.frequencyDictionary.sourcePath",
+          (frequencyDictionary as { sourcePath?: unknown }).sourcePath,
+          resolved.subtitleStyle.frequencyDictionary.sourcePath,
+          "Expected string.",
+        );
+      }
+
+      const topX = asNumber((frequencyDictionary as { topX?: unknown }).topX);
+      if (
+        topX !== undefined &&
+        Number.isInteger(topX) &&
+        topX > 0
+      ) {
+        resolved.subtitleStyle.frequencyDictionary.topX = Math.floor(topX);
+      } else if ((frequencyDictionary as { topX?: unknown }).topX !== undefined) {
+        warn(
+          "subtitleStyle.frequencyDictionary.topX",
+          (frequencyDictionary as { topX?: unknown }).topX,
+          resolved.subtitleStyle.frequencyDictionary.topX,
+          "Expected a positive integer.",
+        );
+      }
+
+      const frequencyMode = frequencyDictionary.mode;
+      if (
+        frequencyMode === "single" ||
+        frequencyMode === "banded"
+      ) {
+        resolved.subtitleStyle.frequencyDictionary.mode = frequencyMode;
+      } else if (frequencyMode !== undefined) {
+        warn(
+          "subtitleStyle.frequencyDictionary.mode",
+          frequencyDictionary.mode,
+          resolved.subtitleStyle.frequencyDictionary.mode,
+          "Expected 'single' or 'banded'.",
+        );
+      }
+
+      const singleColor = asColor(
+        (frequencyDictionary as { singleColor?: unknown }).singleColor,
+      );
+      if (singleColor !== undefined) {
+        resolved.subtitleStyle.frequencyDictionary.singleColor = singleColor;
+      } else if (
+        (frequencyDictionary as { singleColor?: unknown }).singleColor !== undefined
+      ) {
+        warn(
+          "subtitleStyle.frequencyDictionary.singleColor",
+          (frequencyDictionary as { singleColor?: unknown }).singleColor,
+          resolved.subtitleStyle.frequencyDictionary.singleColor,
+          "Expected hex color.",
+        );
+      }
+
+      const bandedColors = asFrequencyBandedColors(
+        (frequencyDictionary as { bandedColors?: unknown }).bandedColors,
+      );
+      if (bandedColors !== undefined) {
+        resolved.subtitleStyle.frequencyDictionary.bandedColors = bandedColors;
+      } else if (
+        (frequencyDictionary as { bandedColors?: unknown }).bandedColors !== undefined
+      ) {
+        warn(
+          "subtitleStyle.frequencyDictionary.bandedColors",
+          (frequencyDictionary as { bandedColors?: unknown }).bandedColors,
+          resolved.subtitleStyle.frequencyDictionary.bandedColors,
+          "Expected an array of five hex colors.",
+        );
+      }
     }
 
     if (isObject(src.ankiConnect)) {

src/core/services/frequency-dictionary-service.ts

@@ -0,0 +1,189 @@
+import * as fs from "node:fs";
+import * as path from "node:path";
+
+export interface FrequencyDictionaryLookupOptions {
+  searchPaths: string[];
+  log: (message: string) => void;
+}
+
+interface FrequencyDictionaryEntry {
+  rank: number;
+  term: string;
+}
+
+const FREQUENCY_BANK_FILE_GLOB = /^term_meta_bank_.*\.json$/;
+const NOOP_LOOKUP = (): null => null;
+
+function normalizeFrequencyTerm(value: string): string {
+  return value.trim().toLowerCase();
+}
+
+function extractFrequencyDisplayValue(meta: unknown): number | null {
+  if (!meta || typeof meta !== "object") return null;
+  const frequency = (meta as { frequency?: unknown }).frequency;
+  if (!frequency || typeof frequency !== "object") return null;
+  const displayValue = (frequency as { displayValue?: unknown }).displayValue;
+  if (typeof displayValue === "number") {
+    if (!Number.isFinite(displayValue) || displayValue <= 0) return null;
+    return Math.floor(displayValue);
+  }
+  if (typeof displayValue === "string") {
+    const normalized = displayValue.trim().replace(/,/g, "");
+    const parsed = Number.parseInt(normalized, 10);
+    if (!Number.isFinite(parsed) || parsed <= 0) return null;
+    return parsed;
+  }
+
+  return null;
+}
+
+function asFrequencyDictionaryEntry(
+  entry: unknown,
+): FrequencyDictionaryEntry | null {
+  if (!Array.isArray(entry) || entry.length < 3) {
+    return null;
+  }
+
+  const [term, _id, meta] = entry as [
+    unknown,
+    unknown,
+    unknown,
+  ];
+  if (typeof term !== "string") {
+    return null;
+  }
+
+  const frequency = extractFrequencyDisplayValue(meta);
+  if (frequency === null) return null;
+
+  const normalizedTerm = normalizeFrequencyTerm(term);
+  if (!normalizedTerm) return null;
+
+  return {
+    term: normalizedTerm,
+    rank: frequency,
+  };
+}
+
+function addEntriesToMap(
+  rawEntries: unknown,
+  terms: Map<string, number>,
+  log: (message: string) => void,
+): void {
+  if (!Array.isArray(rawEntries)) {
+    return;
+  }
+
+  for (const rawEntry of rawEntries) {
+    const entry = asFrequencyDictionaryEntry(rawEntry);
+    if (!entry) {
+      continue;
+    }
+    const currentRank = terms.get(entry.term);
+    if (currentRank === undefined || entry.rank < currentRank) {
+      terms.set(entry.term, entry.rank);
+      continue;
+    }
+
+    log(
+      `Frequency dictionary duplicate term ${entry.term} with weaker rank ${entry.rank}; keeping ${currentRank}.`,
+    );
+  }
+}
+
+function collectDictionaryFromPath(
+  dictionaryPath: string,
+  log: (message: string) => void,
+): Map<string, number> {
+  const terms = new Map<string, number>();
+
+  let fileNames: string[];
+  try {
+    fileNames = fs.readdirSync(dictionaryPath);
+  } catch {
+    return terms;
+  }
+
+  const bankFiles = fileNames
+    .filter((name) => FREQUENCY_BANK_FILE_GLOB.test(name))
+    .sort();
+
+  if (bankFiles.length === 0) {
+    return terms;
+  }
+
+  for (const bankFile of bankFiles) {
+    const bankPath = path.join(dictionaryPath, bankFile);
+    let rawText: string;
+    try {
+      rawText = fs.readFileSync(bankPath, "utf-8");
+    } catch {
+      log(`Failed to read frequency dictionary file ${bankPath}`);
+      continue;
+    }
+
+    let rawEntries: unknown;
+    try {
+      rawEntries = JSON.parse(rawText) as unknown;
+    } catch {
+      log(`Failed to parse frequency dictionary file as JSON: ${bankPath}`);
+      continue;
+    }
+
+    const beforeSize = terms.size;
+    addEntriesToMap(rawEntries, terms, log);
+    if (terms.size === beforeSize) {
+      log(
+        `Frequency dictionary file contained no extractable entries: ${bankPath}`,
+      );
+    }
+  }
+
+  return terms;
+}
+
+export async function createFrequencyDictionaryLookupService(
+  options: FrequencyDictionaryLookupOptions,
+): Promise<(term: string) => number | null> {
+  const attemptedPaths: string[] = [];
+  let foundDictionaryPathCount = 0;
+
+  for (const dictionaryPath of options.searchPaths) {
+    attemptedPaths.push(dictionaryPath);
+    if (!fs.existsSync(dictionaryPath)) {
+      continue;
+    }
+    if (!fs.statSync(dictionaryPath).isDirectory()) {
+      continue;
+    }
+
+    foundDictionaryPathCount += 1;
+    const terms = collectDictionaryFromPath(dictionaryPath, options.log);
+    if (terms.size > 0) {
+      options.log(
+        `Frequency dictionary loaded from ${dictionaryPath} (${terms.size} entries)`,
+      );
+      return (term: string): number | null => {
+        const normalized = normalizeFrequencyTerm(term);
+        if (!normalized) return null;
+        return terms.get(normalized) ?? null;
+      };
+    }
+
+    options.log(
+      `Frequency dictionary directory exists but contains no readable term_meta_bank_*.json files: ${dictionaryPath}`,
+    );
+  }
+
+  options.log(
+    `Frequency dictionary not found. Searched ${attemptedPaths.length} candidate path(s): ${attemptedPaths.join(", ")}`,
+  );
+  if (foundDictionaryPathCount > 0) {
+    options.log(
+      "Frequency dictionary directories found, but no usable term_meta_bank_*.json files were loaded.",
+    );
+  }
+
+  return NOOP_LOOKUP;
+}
+

src/core/services/index.ts

@@ -32,6 +32,7 @@ export {
 } from "./startup-service";
 export { openYomitanSettingsWindow } from "./yomitan-settings-service";
 export { createTokenizerDepsRuntimeService, tokenizeSubtitleService } from "./tokenizer-service";
+export { createFrequencyDictionaryLookupService } from "./frequency-dictionary-service";
 export { createJlptVocabularyLookupService } from "./jlpt-vocab-service";
 export {
   getIgnoredPos1Entries,

src/core/services/tokenizer-service.test.ts

@@ -190,6 +190,75 @@ test("tokenizeSubtitleService skips JLPT lookups when disabled", async () => {
   assert.equal(lookupCalls, 0);
 });
 
+test("tokenizeSubtitleService applies frequency dictionary ranks", async () => {
+  const result = await tokenizeSubtitleService(
+    "猫です",
+    makeDeps({
+      getFrequencyDictionaryEnabled: () => true,
+      tokenizeWithMecab: async () => [
+        {
+          headword: "猫",
+          surface: "猫",
+          reading: "ネコ",
+          startPos: 0,
+          endPos: 1,
+          partOfSpeech: PartOfSpeech.noun,
+          isMerged: false,
+          isKnown: false,
+          isNPlusOneTarget: false,
+        },
+        {
+          headword: "です",
+          surface: "です",
+          reading: "デス",
+          startPos: 1,
+          endPos: 2,
+          partOfSpeech: PartOfSpeech.bound_auxiliary,
+          isMerged: false,
+          isKnown: false,
+          isNPlusOneTarget: false,
+        },
+      ],
+      getFrequencyRank: (text) => (text === "猫" ? 23 : 1200),
+    }),
+  );
+
+  assert.equal(result.tokens?.length, 2);
+  assert.equal(result.tokens?.[0]?.frequencyRank, 23);
+  assert.equal(result.tokens?.[1]?.frequencyRank, 1200);
+});
+
+test("tokenizeSubtitleService skips frequency lookups when disabled", async () => {
+  let frequencyCalls = 0;
+  const result = await tokenizeSubtitleService(
+    "猫",
+    makeDeps({
+      getFrequencyDictionaryEnabled: () => false,
+      tokenizeWithMecab: async () => [
+        {
+          headword: "猫",
+          surface: "猫",
+          reading: "ネコ",
+          startPos: 0,
+          endPos: 1,
+          partOfSpeech: PartOfSpeech.noun,
+          isMerged: false,
+          isKnown: false,
+          isNPlusOneTarget: false,
+        },
+      ],
+      getFrequencyRank: () => {
+        frequencyCalls += 1;
+        return 10;
+      },
+    }),
+  );
+
+  assert.equal(result.tokens?.length, 1);
+  assert.equal(result.tokens?.[0]?.frequencyRank, undefined);
+  assert.equal(frequencyCalls, 0);
+});
+
 test("tokenizeSubtitleService skips JLPT level for excluded demonstratives", async () => {
   const result = await tokenizeSubtitleService(
     "この",

src/core/services/tokenizer-service.ts

@@ -7,6 +7,7 @@ import {
   PartOfSpeech,
   SubtitleData,
   Token,
+  FrequencyDictionaryLookup,
 } from "../../types";
 import {
   shouldIgnoreJlptForMecabPos1,
@@ -35,11 +36,16 @@ const KATAKANA_TO_HIRAGANA_OFFSET = 0x60;
 const KATAKANA_CODEPOINT_START = 0x30a1;
 const KATAKANA_CODEPOINT_END = 0x30f6;
 const JLPT_LEVEL_LOOKUP_CACHE_LIMIT = 2048;
+const FREQUENCY_RANK_LOOKUP_CACHE_LIMIT = 2048;
 
 const jlptLevelLookupCaches = new WeakMap<
   (text: string) => JlptLevel | null,
   Map<string, JlptLevel | null>
 >();
+const frequencyRankLookupCaches = new WeakMap<
+  FrequencyDictionaryLookup,
+  Map<string, number | null>
+>();
 
 function isObject(value: unknown): value is Record<string, unknown> {
   return Boolean(value && typeof value === "object");
@@ -61,6 +67,8 @@ export interface TokenizerServiceDeps {
   getKnownWordMatchMode: () => NPlusOneMatchMode;
   getJlptLevel: (text: string) => JlptLevel | null;
   getJlptEnabled?: () => boolean;
+  getFrequencyDictionaryEnabled?: () => boolean;
+  getFrequencyRank?: FrequencyDictionaryLookup;
   getMinSentenceWordsForNPlusOne?: () => number;
   tokenizeWithMecab: (text: string) => Promise<MergedToken[] | null>;
 }
@@ -81,6 +89,8 @@ export interface TokenizerDepsRuntimeOptions {
   getKnownWordMatchMode: () => NPlusOneMatchMode;
   getJlptLevel: (text: string) => JlptLevel | null;
   getJlptEnabled?: () => boolean;
+  getFrequencyDictionaryEnabled?: () => boolean;
+  getFrequencyRank?: FrequencyDictionaryLookup;
   getMinSentenceWordsForNPlusOne?: () => number;
   getMecabTokenizer: () => MecabTokenizerLike | null;
 }
@@ -122,6 +132,47 @@ function getCachedJlptLevel(
   return level;
 }
 
+function normalizeFrequencyLookupText(rawText: string): string {
+  return rawText.trim().toLowerCase();
+}
+
+function getCachedFrequencyRank(
+  lookupText: string,
+  getFrequencyRank: FrequencyDictionaryLookup,
+): number | null {
+  const normalizedText = normalizeFrequencyLookupText(lookupText);
+  if (!normalizedText) {
+    return null;
+  }
+
+  let cache = frequencyRankLookupCaches.get(getFrequencyRank);
+  if (!cache) {
+    cache = new Map<string, number | null>();
+    frequencyRankLookupCaches.set(getFrequencyRank, cache);
+  }
+
+  if (cache.has(normalizedText)) {
+    return cache.get(normalizedText) ?? null;
+  }
+
+  let rank: number | null;
+  try {
+    rank = getFrequencyRank(normalizedText);
+  } catch {
+    rank = null;
+  }
+
+  cache.set(normalizedText, rank);
+  while (cache.size > FREQUENCY_RANK_LOOKUP_CACHE_LIMIT) {
+    const firstKey = cache.keys().next().value;
+    if (firstKey !== undefined) {
+      cache.delete(firstKey);
+    }
+  }
+
+  return rank;
+}
+
 export function createTokenizerDepsRuntimeService(
   options: TokenizerDepsRuntimeOptions,
 ): TokenizerServiceDeps {
@@ -137,6 +188,8 @@ export function createTokenizerDepsRuntimeService(
     getKnownWordMatchMode: options.getKnownWordMatchMode,
     getJlptLevel: options.getJlptLevel,
     getJlptEnabled: options.getJlptEnabled,
+    getFrequencyDictionaryEnabled: options.getFrequencyDictionaryEnabled,
+    getFrequencyRank: options.getFrequencyRank,
     getMinSentenceWordsForNPlusOne:
       options.getMinSentenceWordsForNPlusOne ?? (() => 3),
     tokenizeWithMecab: async (text) => {
@@ -184,6 +237,34 @@ function applyKnownWordMarking(
   });
 }
 
+function resolveFrequencyLookupText(token: MergedToken): string {
+  if (token.headword && token.headword.length > 0) {
+    return token.headword;
+  }
+  if (token.reading && token.reading.length > 0) {
+    return token.reading;
+  }
+  return token.surface;
+}
+
+function applyFrequencyMarking(
+  tokens: MergedToken[],
+  getFrequencyRank: FrequencyDictionaryLookup,
+): MergedToken[] {
+  return tokens.map((token) => {
+    const lookupText = resolveFrequencyLookupText(token);
+    if (!lookupText) {
+      return { ...token, frequencyRank: undefined };
+    }
+
+    const rank = getCachedFrequencyRank(lookupText, getFrequencyRank);
+    return {
+      ...token,
+      frequencyRank: rank ?? undefined,
+    };
+  });
+}
+
 function resolveJlptLookupText(token: MergedToken): string {
   if (token.headword && token.headword.length > 0) {
     return token.headword;
@@ -753,6 +834,8 @@ export async function tokenizeSubtitleService(
     .replace(/\s+/g, " ")
     .trim();
   const jlptEnabled = deps.getJlptEnabled?.() !== false;
+  const frequencyEnabled = deps.getFrequencyDictionaryEnabled?.() !== false;
+  const frequencyLookup = deps.getFrequencyRank;
 
   const yomitanTokens = await parseWithYomitanInternalParser(tokenizeText, deps);
   if (yomitanTokens && yomitanTokens.length > 0) {
@@ -761,9 +844,16 @@ export async function tokenizeSubtitleService(
       deps.isKnownWord,
       deps.getKnownWordMatchMode(),
     );
-      const jlptMarkedTokens = jlptEnabled
-        ? applyJlptMarking(knownMarkedTokens, deps.getJlptLevel)
-        : knownMarkedTokens.map((token) => ({ ...token, jlptLevel: undefined }));
+    const frequencyMarkedTokens =
+      frequencyEnabled && frequencyLookup
+        ? applyFrequencyMarking(knownMarkedTokens, frequencyLookup)
+        : knownMarkedTokens.map((token) => ({
+          ...token,
+          frequencyRank: undefined,
+        }));
+    const jlptMarkedTokens = jlptEnabled
+      ? applyJlptMarking(frequencyMarkedTokens, deps.getJlptLevel)
+      : frequencyMarkedTokens.map((token) => ({ ...token, jlptLevel: undefined }));
     return {
       text: displayText,
       tokens: markNPlusOneTargets(
@@ -781,9 +871,16 @@ export async function tokenizeSubtitleService(
         deps.isKnownWord,
         deps.getKnownWordMatchMode(),
       );
+      const frequencyMarkedTokens =
+        frequencyEnabled && frequencyLookup
+          ? applyFrequencyMarking(knownMarkedTokens, frequencyLookup)
+          : knownMarkedTokens.map((token) => ({
+            ...token,
+            frequencyRank: undefined,
+          }));
       const jlptMarkedTokens = jlptEnabled
-        ? applyJlptMarking(knownMarkedTokens, deps.getJlptLevel)
-        : knownMarkedTokens.map((token) => ({ ...token, jlptLevel: undefined }));
+        ? applyJlptMarking(frequencyMarkedTokens, deps.getJlptLevel)
+        : frequencyMarkedTokens.map((token) => ({ ...token, jlptLevel: undefined }));
       return {
         text: displayText,
         tokens: markNPlusOneTargets(

src/main.ts

@@ -162,6 +162,10 @@ import {
   createJlptDictionaryRuntimeService,
   getJlptDictionarySearchPaths,
 } from "./main/jlpt-runtime";
+import {
+  createFrequencyDictionaryRuntimeService,
+  getFrequencyDictionarySearchPaths,
+} from "./main/frequency-dictionary-runtime";
 import { createMediaRuntimeService } from "./main/media-runtime";
 import { createOverlayVisibilityRuntimeService } from "./main/overlay-visibility-runtime";
 import {
@@ -353,6 +357,39 @@ const jlptDictionaryRuntime = createJlptDictionaryRuntimeService({
   },
 });
 
+const frequencyDictionaryRuntime = createFrequencyDictionaryRuntimeService({
+  isFrequencyDictionaryEnabled: () =>
+    getResolvedConfig().subtitleStyle.frequencyDictionary.enabled,
+  getSearchPaths: () =>
+    getFrequencyDictionarySearchPaths({
+      getDictionaryRoots: () => [
+        path.join(__dirname, "..", "..", "vendor", "jiten_freq_global"),
+        path.join(__dirname, "..", "..", "vendor", "frequency-dictionary"),
+        path.join(app.getAppPath(), "vendor", "jiten_freq_global"),
+        path.join(app.getAppPath(), "vendor", "frequency-dictionary"),
+        path.join(process.resourcesPath, "jiten_freq_global"),
+        path.join(process.resourcesPath, "frequency-dictionary"),
+        path.join(process.resourcesPath, "app.asar", "vendor", "jiten_freq_global"),
+        path.join(process.resourcesPath, "app.asar", "vendor", "frequency-dictionary"),
+        USER_DATA_PATH,
+        app.getPath("userData"),
+        path.join(os.homedir(), ".config", "SubMiner"),
+        path.join(os.homedir(), ".config", "subminer"),
+        path.join(os.homedir(), "Library", "Application Support", "SubMiner"),
+        path.join(os.homedir(), "Library", "Application Support", "subminer"),
+        process.cwd(),
+      ].filter((dictionaryRoot) => dictionaryRoot),
+      getSourcePath: () =>
+        getResolvedConfig().subtitleStyle.frequencyDictionary.sourcePath,
+    }),
+  setFrequencyRankLookup: (lookup) => {
+    appState.frequencyRankLookup = lookup;
+  },
+  log: (message) => {
+    logger.info(`[Frequency] ${message}`);
+  },
+});
+
 function getFieldGroupingResolver(): ((choice: KikuFieldGroupingChoice) => void) | null {
   return appState.fieldGroupingResolver;
 }
@@ -844,6 +881,7 @@ function updateMpvSubtitleRenderMetrics(
 
 async function tokenizeSubtitle(text: string): Promise<SubtitleData> {
   await jlptDictionaryRuntime.ensureJlptDictionaryLookup();
+  await frequencyDictionaryRuntime.ensureFrequencyDictionaryLookup();
   return tokenizeSubtitleService(
     text,
     createTokenizerDepsRuntimeService({
@@ -870,6 +908,9 @@ async function tokenizeSubtitle(text: string): Promise<SubtitleData> {
       getJlptLevel: (text) => appState.jlptLevelLookup(text),
       getJlptEnabled: () =>
         getResolvedConfig().subtitleStyle.enableJlpt,
+      getFrequencyDictionaryEnabled: () =>
+        getResolvedConfig().subtitleStyle.frequencyDictionary.enabled,
+      getFrequencyRank: (text) => appState.frequencyRankLookup(text),
       getMecabTokenizer: () => appState.mecabTokenizer,
     }),
   );
@@ -1345,6 +1386,8 @@ registerIpcRuntimeServices({
           nPlusOneColor: resolvedConfig.ankiConnect.nPlusOne.nPlusOne,
           knownWordColor: resolvedConfig.ankiConnect.nPlusOne.knownWord,
           enableJlpt: resolvedConfig.subtitleStyle.enableJlpt,
+          frequencyDictionary:
+            resolvedConfig.subtitleStyle.frequencyDictionary,
         };
       },
     saveSubtitlePosition: (position: unknown) =>

src/main/frequency-dictionary-runtime.ts

@@ -0,0 +1,80 @@
+import * as path from "path";
+import type { FrequencyDictionaryLookup } from "../types";
+import { createFrequencyDictionaryLookupService } from "../core/services";
+
+export interface FrequencyDictionarySearchPathDeps {
+  getDictionaryRoots: () => string[];
+  getSourcePath?: () => string | undefined;
+}
+
+export interface FrequencyDictionaryRuntimeDeps {
+  isFrequencyDictionaryEnabled: () => boolean;
+  getSearchPaths: () => string[];
+  setFrequencyRankLookup: (lookup: FrequencyDictionaryLookup) => void;
+  log: (message: string) => void;
+}
+
+let frequencyDictionaryLookupInitialized = false;
+let frequencyDictionaryLookupInitialization: Promise<void> | null = null;
+
+export function getFrequencyDictionarySearchPaths(
+  deps: FrequencyDictionarySearchPathDeps,
+): string[] {
+  const dictionaryRoots = deps.getDictionaryRoots();
+  const sourcePath = deps.getSourcePath?.();
+
+  const rawSearchPaths: string[] = [];
+  if (sourcePath && sourcePath.trim()) {
+    rawSearchPaths.push(sourcePath.trim());
+    rawSearchPaths.push(path.join(sourcePath.trim(), "frequency-dictionary"));
+    rawSearchPaths.push(path.join(sourcePath.trim(), "vendor", "frequency-dictionary"));
+  }
+
+  for (const dictionaryRoot of dictionaryRoots) {
+    rawSearchPaths.push(dictionaryRoot);
+    rawSearchPaths.push(path.join(dictionaryRoot, "frequency-dictionary"));
+    rawSearchPaths.push(path.join(dictionaryRoot, "vendor", "frequency-dictionary"));
+  }
+
+  return [...new Set(rawSearchPaths)];
+}
+
+export async function initializeFrequencyDictionaryLookup(
+  deps: FrequencyDictionaryRuntimeDeps,
+): Promise<void> {
+  const lookup = await createFrequencyDictionaryLookupService({
+    searchPaths: deps.getSearchPaths(),
+    log: deps.log,
+  });
+  deps.setFrequencyRankLookup(lookup);
+}
+
+export async function ensureFrequencyDictionaryLookup(
+  deps: FrequencyDictionaryRuntimeDeps,
+): Promise<void> {
+  if (!deps.isFrequencyDictionaryEnabled()) {
+    return;
+  }
+  if (frequencyDictionaryLookupInitialized) {
+    return;
+  }
+  if (!frequencyDictionaryLookupInitialization) {
+    frequencyDictionaryLookupInitialization = initializeFrequencyDictionaryLookup(deps)
+      .then(() => {
+        frequencyDictionaryLookupInitialized = true;
+      })
+      .catch((error) => {
+        frequencyDictionaryLookupInitialization = null;
+        throw error;
+      });
+  }
+  await frequencyDictionaryLookupInitialization;
+}
+
+export function createFrequencyDictionaryRuntimeService(
+  deps: FrequencyDictionaryRuntimeDeps,
+): { ensureFrequencyDictionaryLookup: () => Promise<void> } {
+  return {
+    ensureFrequencyDictionaryLookup: () => ensureFrequencyDictionaryLookup(deps),
+  };
+}

src/main/state.ts

@@ -7,6 +7,7 @@ import type {
   SubtitlePosition,
   KikuFieldGroupingChoice,
   JlptLevel,
+  FrequencyDictionaryLookup,
 } from "../types";
 import type { CliArgs } from "../cli/args";
 import type { SubtitleTimingTracker } from "../subtitle-timing-tracker";
@@ -55,6 +56,7 @@ export interface AppState {
   autoStartOverlay: boolean;
   texthookerOnlyMode: boolean;
   jlptLevelLookup: (term: string) => JlptLevel | null;
+  frequencyRankLookup: FrequencyDictionaryLookup;
 }
 
 export interface AppStateInitialValues {
@@ -115,6 +117,7 @@ export function createAppState(values: AppStateInitialValues): AppState {
     autoStartOverlay: values.autoStartOverlay ?? false,
     texthookerOnlyMode: values.texthookerOnlyMode ?? false,
     jlptLevelLookup: () => null,
+    frequencyRankLookup: () => null,
   };
 }
 

src/renderer/state.ts

@@ -76,6 +76,15 @@ export type RendererState = {
   jlptN3Color: string;
   jlptN4Color: string;
   jlptN5Color: string;
+  frequencyDictionaryEnabled: boolean;
+  frequencyDictionaryTopX: number;
+  frequencyDictionaryMode: "single" | "banded";
+  frequencyDictionarySingleColor: string;
+  frequencyDictionaryBand1Color: string;
+  frequencyDictionaryBand2Color: string;
+  frequencyDictionaryBand3Color: string;
+  frequencyDictionaryBand4Color: string;
+  frequencyDictionaryBand5Color: string;
 
   keybindingsMap: Map<string, (string | number)[]>;
   chordPending: boolean;
@@ -140,6 +149,15 @@ export function createRendererState(): RendererState {
     jlptN3Color: "#f9e2af",
     jlptN4Color: "#a6e3a1",
     jlptN5Color: "#8aadf4",
+    frequencyDictionaryEnabled: false,
+    frequencyDictionaryTopX: 1000,
+    frequencyDictionaryMode: "single",
+    frequencyDictionarySingleColor: "#f5a97f",
+    frequencyDictionaryBand1Color: "#ed8796",
+    frequencyDictionaryBand2Color: "#f5a97f",
+    frequencyDictionaryBand3Color: "#f9e2af",
+    frequencyDictionaryBand4Color: "#a6e3a1",
+    frequencyDictionaryBand5Color: "#8aadf4",
 
     keybindingsMap: new Map(),
     chordPending: false,

src/renderer/style.css

@@ -255,6 +255,12 @@ body {
   --subtitle-jlpt-n3-color: #f9e2af;
   --subtitle-jlpt-n4-color: #a6e3a1;
   --subtitle-jlpt-n5-color: #8aadf4;
+  --subtitle-frequency-single-color: #f5a97f;
+  --subtitle-frequency-band-1-color: #ed8796;
+  --subtitle-frequency-band-2-color: #f5a97f;
+  --subtitle-frequency-band-3-color: #f9e2af;
+  --subtitle-frequency-band-4-color: #a6e3a1;
+  --subtitle-frequency-band-5-color: #8aadf4;
   text-shadow:
     2px 2px 4px rgba(0, 0, 0, 0.8),
     -1px -1px 2px rgba(0, 0, 0, 0.5);
@@ -346,6 +352,39 @@ body.settings-modal-open #subtitleContainer {
   text-decoration-style: solid;
 }
 
+#subtitleRoot .word.word-frequency-single,
+#subtitleRoot .word.word-frequency-band-1,
+#subtitleRoot .word.word-frequency-band-2,
+#subtitleRoot .word.word-frequency-band-3,
+#subtitleRoot .word.word-frequency-band-4,
+#subtitleRoot .word.word-frequency-band-5 {
+  text-shadow: 0 0 6px rgba(255, 255, 255, 0.3);
+}
+
+#subtitleRoot .word.word-frequency-single {
+  color: var(--subtitle-frequency-single-color, #f5a97f);
+}
+
+#subtitleRoot .word.word-frequency-band-1 {
+  color: var(--subtitle-frequency-band-1-color, #ed8796);
+}
+
+#subtitleRoot .word.word-frequency-band-2 {
+  color: var(--subtitle-frequency-band-2-color, #f5a97f);
+}
+
+#subtitleRoot .word.word-frequency-band-3 {
+  color: var(--subtitle-frequency-band-3-color, #f9e2af);
+}
+
+#subtitleRoot .word.word-frequency-band-4 {
+  color: var(--subtitle-frequency-band-4-color, #a6e3a1);
+}
+
+#subtitleRoot .word.word-frequency-band-5 {
+  color: var(--subtitle-frequency-band-5-color, #8aadf4);
+}
+
 #subtitleRoot .word:hover {
   background: rgba(255, 255, 255, 0.2);
   border-radius: 3px;

src/renderer/subtitle-render.test.ts

@@ -22,8 +22,7 @@ function createToken(overrides: Partial<MergedToken>): MergedToken {
   };
 }
 
-function extractClassBlock(cssText: string, level: number): string {
-  const selector = `#subtitleRoot .word.word-jlpt-n${level}`;
+function extractClassBlock(cssText: string, selector: string): string {
   const start = cssText.indexOf(selector);
   if (start < 0) return "";
 
@@ -54,6 +53,87 @@ test("computeWordClass preserves known and n+1 classes while adding JLPT classes
   );
 });
 
+test("computeWordClass adds frequency class for single mode when rank is within topX", () => {
+  const token = createToken({
+    surface: "猫",
+    frequencyRank: 50,
+  });
+
+  const actual = computeWordClass(
+    token,
+    {
+      enabled: true,
+      topX: 100,
+      mode: "single",
+      singleColor: "#000000",
+      bandedColors: ["#000000", "#000000", "#000000", "#000000", "#000000"] as const,
+    },
+  );
+
+  assert.equal(actual, "word word-frequency-single");
+});
+
+test("computeWordClass adds frequency class when rank equals topX", () => {
+  const token = createToken({
+    surface: "水",
+    frequencyRank: 100,
+  });
+
+  const actual = computeWordClass(
+    token,
+    {
+      enabled: true,
+      topX: 100,
+      mode: "single",
+      singleColor: "#000000",
+      bandedColors: ["#000000", "#000000", "#000000", "#000000", "#000000"] as const,
+    },
+  );
+
+  assert.equal(actual, "word word-frequency-single");
+});
+
+test("computeWordClass adds frequency class for banded mode", () => {
+  const token = createToken({
+    surface: "犬",
+    frequencyRank: 250,
+  });
+
+  const actual = computeWordClass(
+    token,
+    {
+      enabled: true,
+      topX: 1000,
+      mode: "banded",
+      singleColor: "#000000",
+      bandedColors:
+        ["#111111", "#222222", "#333333", "#444444", "#555555"] as const,
+    },
+  );
+
+  assert.equal(actual, "word word-frequency-band-2");
+});
+
+test("computeWordClass skips frequency class when rank is out of topX", () => {
+  const token = createToken({
+    surface: "犬",
+    frequencyRank: 1200,
+  });
+
+  const actual = computeWordClass(
+    token,
+    {
+      enabled: true,
+      topX: 1000,
+      mode: "single",
+      singleColor: "#000000",
+      bandedColors: ["#000000", "#000000", "#000000", "#000000", "#000000"] as const,
+    },
+  );
+
+  assert.equal(actual, "word");
+});
+
 test("JLPT CSS rules use underline-only styling in renderer stylesheet", () => {
   const distCssPath = path.join(process.cwd(), "dist", "renderer", "style.css");
   const srcCssPath = path.join(process.cwd(), "src", "renderer", "style.css");
@@ -70,11 +150,25 @@ test("JLPT CSS rules use underline-only styling in renderer stylesheet", () => {
   const cssText = fs.readFileSync(cssPath, "utf-8");
 
   for (let level = 1; level <= 5; level += 1) {
-    const block = extractClassBlock(cssText, level);
+    const block = extractClassBlock(
+      cssText,
+      `#subtitleRoot .word.word-jlpt-n${level}`,
+    );
     assert.ok(block.length > 0, `word-jlpt-n${level} class should exist`);
     assert.match(block, /text-decoration-line:\s*underline;/);
     assert.match(block, /text-decoration-thickness:\s*2px;/);
     assert.match(block, /text-underline-offset:\s*4px;/);
     assert.match(block, /color:\s*inherit;/);
   }
+
+  for (let band = 1; band <= 5; band += 1) {
+    const block = extractClassBlock(
+      cssText,
+      band === 1
+        ? "#subtitleRoot .word.word-frequency-single"
+        : `#subtitleRoot .word.word-frequency-band-${band}`,
+    );
+    assert.ok(block.length > 0, `frequency class word-frequency-${band === 1 ? "single" : `band-${band}`} should exist`);
+    assert.match(block, /color:\s*var\(/);
+  }
 });

src/renderer/subtitle-render.ts

@@ -6,6 +6,14 @@ import type {
 } from "../types";
 import type { RendererContext } from "./context";
 
+type FrequencyRenderSettings = {
+  enabled: boolean;
+  topX: number;
+  mode: "single" | "banded";
+  singleColor: string;
+  bandedColors: [string, string, string, string, string];
+};
+
 function normalizeSubtitle(text: string, trim = true): string {
   if (!text) return "";
 
@@ -24,7 +32,87 @@ function sanitizeHexColor(value: unknown, fallback: string): string {
     : fallback;
 }
 
-function renderWithTokens(root: HTMLElement, tokens: MergedToken[]): void {
+const DEFAULT_FREQUENCY_RENDER_SETTINGS: FrequencyRenderSettings = {
+  enabled: false,
+  topX: 1000,
+  mode: "single",
+  singleColor: "#f5a97f",
+  bandedColors: ["#ed8796", "#f5a97f", "#f9e2af", "#a6e3a1", "#8aadf4"],
+};
+
+function sanitizeFrequencyTopX(value: unknown, fallback: number): number {
+  if (typeof value !== "number" || !Number.isFinite(value) || value <= 0) {
+    return fallback;
+  }
+  return Math.max(1, Math.floor(value));
+}
+
+function sanitizeFrequencyBandedColors(
+  value: unknown,
+  fallback: FrequencyRenderSettings["bandedColors"],
+): FrequencyRenderSettings["bandedColors"] {
+  if (!Array.isArray(value) || value.length !== 5) {
+    return fallback;
+  }
+
+  return [
+    sanitizeHexColor(value[0], fallback[0]),
+    sanitizeHexColor(value[1], fallback[1]),
+    sanitizeHexColor(value[2], fallback[2]),
+    sanitizeHexColor(value[3], fallback[3]),
+    sanitizeHexColor(value[4], fallback[4]),
+  ];
+}
+
+function getFrequencyDictionaryClass(
+  token: MergedToken,
+  settings: FrequencyRenderSettings,
+): string {
+  if (!settings.enabled) {
+    return "";
+  }
+
+  if (typeof token.frequencyRank !== "number" || !Number.isFinite(token.frequencyRank)) {
+    return "";
+  }
+
+  const rank = Math.max(1, Math.floor(token.frequencyRank));
+  const topX = sanitizeFrequencyTopX(settings.topX, DEFAULT_FREQUENCY_RENDER_SETTINGS.topX);
+  if (rank > topX) {
+    return "";
+  }
+
+  if (settings.mode === "banded") {
+    const normalizedBand = Math.ceil((rank / topX) * 5);
+    const band = Math.min(5, Math.max(1, normalizedBand));
+    return `word-frequency-band-${band}`;
+  }
+
+  return "word-frequency-single";
+}
+
+function renderWithTokens(
+  root: HTMLElement,
+  tokens: MergedToken[],
+  frequencyRenderSettings?: Partial<FrequencyRenderSettings>,
+): void {
+  const resolvedFrequencyRenderSettings = {
+    ...DEFAULT_FREQUENCY_RENDER_SETTINGS,
+    ...frequencyRenderSettings,
+    bandedColors: sanitizeFrequencyBandedColors(
+      frequencyRenderSettings?.bandedColors,
+      DEFAULT_FREQUENCY_RENDER_SETTINGS.bandedColors,
+    ),
+    topX: sanitizeFrequencyTopX(
+      frequencyRenderSettings?.topX,
+      DEFAULT_FREQUENCY_RENDER_SETTINGS.topX,
+    ),
+    singleColor: sanitizeHexColor(
+      frequencyRenderSettings?.singleColor,
+      DEFAULT_FREQUENCY_RENDER_SETTINGS.singleColor,
+    ),
+  };
+
   const fragment = document.createDocumentFragment();
 
   for (const token of tokens) {
@@ -35,7 +123,10 @@ function renderWithTokens(root: HTMLElement, tokens: MergedToken[]): void {
         for (let i = 0; i < parts.length; i += 1) {
           if (parts[i]) {
             const span = document.createElement("span");
-            span.className = computeWordClass(token);
+            span.className = computeWordClass(
+              token,
+              resolvedFrequencyRenderSettings,
+            );
             span.textContent = parts[i];
             if (token.reading) span.dataset.reading = token.reading;
             if (token.headword) span.dataset.headword = token.headword;
@@ -49,7 +140,7 @@ function renderWithTokens(root: HTMLElement, tokens: MergedToken[]): void {
     }
 
     const span = document.createElement("span");
-    span.className = computeWordClass(token);
+    span.className = computeWordClass(token, resolvedFrequencyRenderSettings);
     span.textContent = surface;
     if (token.reading) span.dataset.reading = token.reading;
     if (token.headword) span.dataset.headword = token.headword;
@@ -59,7 +150,27 @@ function renderWithTokens(root: HTMLElement, tokens: MergedToken[]): void {
   root.appendChild(fragment);
 }
 
-export function computeWordClass(token: MergedToken): string {
+export function computeWordClass(
+  token: MergedToken,
+  frequencySettings?: Partial<FrequencyRenderSettings>,
+): string {
+  const resolvedFrequencySettings = {
+    ...DEFAULT_FREQUENCY_RENDER_SETTINGS,
+    ...frequencySettings,
+    bandedColors: sanitizeFrequencyBandedColors(
+      frequencySettings?.bandedColors,
+      DEFAULT_FREQUENCY_RENDER_SETTINGS.bandedColors,
+    ),
+    topX: sanitizeFrequencyTopX(
+      frequencySettings?.topX,
+      DEFAULT_FREQUENCY_RENDER_SETTINGS.topX,
+    ),
+    singleColor: sanitizeHexColor(
+      frequencySettings?.singleColor,
+      DEFAULT_FREQUENCY_RENDER_SETTINGS.singleColor,
+    ),
+  };
+
   const classes = ["word"];
 
   if (token.isNPlusOneTarget) {
@@ -72,6 +183,14 @@ export function computeWordClass(token: MergedToken): string {
     classes.push(`word-jlpt-${token.jlptLevel.toLowerCase()}`);
   }
 
+  const frequencyClass = getFrequencyDictionaryClass(
+    token,
+    resolvedFrequencySettings,
+  );
+  if (frequencyClass) {
+    classes.push(frequencyClass);
+  }
+
   return classes.join(" ");
 }
 
@@ -139,12 +258,32 @@ export function createSubtitleRenderer(ctx: RendererContext) {
 
     const normalized = normalizeSubtitle(text);
     if (tokens && tokens.length > 0) {
-      renderWithTokens(ctx.dom.subtitleRoot, tokens);
+      renderWithTokens(
+        ctx.dom.subtitleRoot,
+        tokens,
+        getFrequencyRenderSettings(),
+      );
       return;
     }
     renderCharacterLevel(ctx.dom.subtitleRoot, normalized);
   }
 
+  function getFrequencyRenderSettings(): Partial<FrequencyRenderSettings> {
+    return {
+      enabled: ctx.state.frequencyDictionaryEnabled,
+      topX: ctx.state.frequencyDictionaryTopX,
+      mode: ctx.state.frequencyDictionaryMode,
+      singleColor: ctx.state.frequencyDictionarySingleColor,
+      bandedColors: [
+        ctx.state.frequencyDictionaryBand1Color,
+        ctx.state.frequencyDictionaryBand2Color,
+        ctx.state.frequencyDictionaryBand3Color,
+        ctx.state.frequencyDictionaryBand4Color,
+        ctx.state.frequencyDictionaryBand5Color,
+      ] as [string, string, string, string, string],
+    };
+  }
+
   function renderSecondarySub(text: string): void {
     ctx.dom.secondarySubRoot.innerHTML = "";
     if (!text) return;
@@ -236,6 +375,66 @@ export function createSubtitleRenderer(ctx: RendererContext) {
     ctx.dom.subtitleRoot.style.setProperty("--subtitle-jlpt-n3-color", jlptColors.N3);
     ctx.dom.subtitleRoot.style.setProperty("--subtitle-jlpt-n4-color", jlptColors.N4);
     ctx.dom.subtitleRoot.style.setProperty("--subtitle-jlpt-n5-color", jlptColors.N5);
+    const frequencyDictionarySettings = style.frequencyDictionary ?? {};
+    const frequencyEnabled =
+      frequencyDictionarySettings.enabled ?? ctx.state.frequencyDictionaryEnabled;
+    const frequencyTopX = sanitizeFrequencyTopX(
+      frequencyDictionarySettings.topX,
+      ctx.state.frequencyDictionaryTopX,
+    );
+    const frequencyMode = frequencyDictionarySettings.mode
+      ? frequencyDictionarySettings.mode
+      : ctx.state.frequencyDictionaryMode;
+    const frequencySingleColor = sanitizeHexColor(
+      frequencyDictionarySettings.singleColor,
+      ctx.state.frequencyDictionarySingleColor,
+    );
+    const frequencyBandedColors = sanitizeFrequencyBandedColors(
+      frequencyDictionarySettings.bandedColors,
+      [
+        ctx.state.frequencyDictionaryBand1Color,
+        ctx.state.frequencyDictionaryBand2Color,
+        ctx.state.frequencyDictionaryBand3Color,
+        ctx.state.frequencyDictionaryBand4Color,
+        ctx.state.frequencyDictionaryBand5Color,
+      ] as [string, string, string, string, string],
+    );
+
+    ctx.state.frequencyDictionaryEnabled = frequencyEnabled;
+    ctx.state.frequencyDictionaryTopX = frequencyTopX;
+    ctx.state.frequencyDictionaryMode = frequencyMode;
+    ctx.state.frequencyDictionarySingleColor = frequencySingleColor;
+    [
+      ctx.state.frequencyDictionaryBand1Color,
+      ctx.state.frequencyDictionaryBand2Color,
+      ctx.state.frequencyDictionaryBand3Color,
+      ctx.state.frequencyDictionaryBand4Color,
+      ctx.state.frequencyDictionaryBand5Color,
+    ] = frequencyBandedColors;
+    ctx.dom.subtitleRoot.style.setProperty(
+      "--subtitle-frequency-single-color",
+      frequencySingleColor,
+    );
+    ctx.dom.subtitleRoot.style.setProperty(
+      "--subtitle-frequency-band-1-color",
+      frequencyBandedColors[0],
+    );
+    ctx.dom.subtitleRoot.style.setProperty(
+      "--subtitle-frequency-band-2-color",
+      frequencyBandedColors[1],
+    );
+    ctx.dom.subtitleRoot.style.setProperty(
+      "--subtitle-frequency-band-3-color",
+      frequencyBandedColors[2],
+    );
+    ctx.dom.subtitleRoot.style.setProperty(
+      "--subtitle-frequency-band-4-color",
+      frequencyBandedColors[3],
+    );
+    ctx.dom.subtitleRoot.style.setProperty(
+      "--subtitle-frequency-band-5-color",
+      frequencyBandedColors[4],
+    );
 
     const secondaryStyle = style.secondary;
     if (!secondaryStyle) return;

src/types.ts

@@ -55,8 +55,11 @@ export interface MergedToken {
   isKnown: boolean;
   isNPlusOneTarget: boolean;
   jlptLevel?: JlptLevel;
+  frequencyRank?: number;
 }
 
+export type FrequencyDictionaryLookup = (term: string) => number | null;
+
 export type JlptLevel = "N1" | "N2" | "N3" | "N4" | "N5";
 
 export interface WindowGeometry {
@@ -283,6 +286,14 @@ export interface SubtitleStyleConfig {
     N4: string;
     N5: string;
   };
+  frequencyDictionary?: {
+    enabled?: boolean;
+    sourcePath?: string;
+    topX?: number;
+    mode?: FrequencyDictionaryMode;
+    singleColor?: string;
+    bandedColors?: [string, string, string, string, string];
+  };
   secondary?: {
     fontFamily?: string;
     fontSize?: number;
@@ -293,6 +304,8 @@ export interface SubtitleStyleConfig {
   };
 }
 
+export type FrequencyDictionaryMode = "single" | "banded";
+
 export interface ShortcutsConfig {
   toggleVisibleOverlayGlobal?: string | null;
   toggleInvisibleOverlayGlobal?: string | null;
@@ -431,8 +444,18 @@ export interface ResolvedConfig {
   shortcuts: Required<ShortcutsConfig>;
   secondarySub: Required<SecondarySubConfig>;
   subsync: Required<SubsyncConfig>;
-  subtitleStyle: Required<Omit<SubtitleStyleConfig, "secondary">> & {
+  subtitleStyle: Required<
+    Omit<SubtitleStyleConfig, "secondary" | "frequencyDictionary">
+  > & {
     secondary: Required<NonNullable<SubtitleStyleConfig["secondary"]>>;
+    frequencyDictionary: {
+      enabled: boolean;
+      sourcePath: string;
+      topX: number;
+      mode: FrequencyDictionaryMode;
+      singleColor: string;
+      bandedColors: [string, string, string, string, string];
+    };
   };
   auto_start_overlay: boolean;
   bind_visible_overlay_to_mpv_sub_visibility: boolean;

subminer

@@ -705,6 +705,39 @@ function isExecutable(filePath: string): boolean {
   }
 }
 
+function resolveMacAppBinaryCandidate(candidate: string): string {
+  if (process.platform !== "darwin") return "";
+
+  const direct = resolveBinaryPathCandidate(candidate);
+  if (!direct) return "";
+
+  if (isExecutable(direct)) {
+    return direct;
+  }
+
+  const appIndex = direct.indexOf(".app/");
+  const appPath =
+    direct.endsWith(".app") && direct.includes(".app")
+      ? direct
+      : appIndex >= 0
+        ? direct.slice(0, appIndex + ".app".length)
+        : "";
+  if (!appPath) return "";
+
+  const candidates = [
+    path.join(appPath, "Contents", "MacOS", "SubMiner"),
+    path.join(appPath, "Contents", "MacOS", "subminer"),
+  ];
+
+  for (const candidateBinary of candidates) {
+    if (isExecutable(candidateBinary)) {
+      return candidateBinary;
+    }
+  }
+
+  return "";
+}
+
 function commandExists(command: string): boolean {
   const pathEnv = process.env.PATH ?? "";
   for (const dir of pathEnv.split(path.delimiter)) {
@@ -1666,8 +1699,8 @@ function findAppBinary(selfPath: string): string | null {
   ].filter((candidate): candidate is string => Boolean(candidate));
 
   for (const envPath of envPaths) {
-    const resolved = resolveBinaryPathCandidate(envPath);
-    if (resolved && isExecutable(resolved)) {
+    const resolved = resolveMacAppBinaryCandidate(envPath);
+    if (resolved) {
       return resolved;
     }
   }
@@ -2636,6 +2669,7 @@ function startMpv(
   targetKind: "file" | "url",
   args: Args,
   socketPath: string,
+  appPath: string,
   preloadedSubtitles?: { primaryPath?: string; secondaryPath?: string },
 ): void {
   if (
@@ -2692,6 +2726,9 @@ function startMpv(
   if (preloadedSubtitles?.secondaryPath) {
     mpvArgs.push(`--sub-file=${preloadedSubtitles.secondaryPath}`);
   }
+  mpvArgs.push(
+    `--script-opts=subminer-binary_path=${appPath},subminer-socket_path=${socketPath}`,
+  );
   mpvArgs.push(`--log-file=${getMpvLogPath()}`);
 
   try {
@@ -2833,6 +2870,7 @@ async function main(): Promise<void> {
     selectedTarget.kind,
     args,
     mpvSocketPath,
+    appPath,
     preloadedSubtitles,
   );
 

vendor/jiten_freq_global/index.json

@@ -0,0 +1 @@
+{"title":"Jiten","format":3,"revision":"Jiten 26-02-16","isUpdatable":true,"indexUrl":"https://api.jiten.moe/api/frequency-list/index","downloadUrl":"https://api.jiten.moe/api/frequency-list/download","sequenced":false,"frequencyMode":"rank-based","author":"Jiten","url":"https://jiten.moe","description":"Dictionary based on frequency data of all media from jiten.moe"}