Feat/custom language support (#12)

* feat: custom language support

* chore: log format

* feat: i18n

* chore: rollback test

* chore: bump version

* chore: readme en

Author: helloint

README.md

@@ -1,21 +1,49 @@
-# 一键批量提取流媒体视频的中英字幕，并自动合并为双语字幕。
+# dual-subtitle
+
+Extract two embedded subtitle tracks from video files and merge them into a single dual-language subtitle file. Supports batch processing for `.mp4` and `.mkv`.
+
+**[简体中文](README.zh-CN.md)**
+
 [![NPM](https://nodei.co/npm/dual-subtitle.png?downloads=true)](https://www.npmjs.com/package/dual-subtitle)
 
-## 依赖
-需要本地有`Node.js`环境(包括`npm`)
+## Requirements
+
+- **Node.js** (with npm): [nodejs.org](https://nodejs.org/)
+- The CLI prefers your system **ffmpeg** and **ffprobe**; if missing, it falls back to bundled installers.
+
+## Usage
+
+```bash
+# Process all .mp4 and .mkv in the current directory
+npx dual-subtitle
+
+# Or specify a directory (with or without trailing /)
+npx dual-subtitle /path/to/videos
+```
+
+> Without `npx` (e.g. some Synology setups):  
+> `node /path/to/dual-subtitle/index.js [directory]`
+
+### Output
+
+- Merged subtitle file: `<basename>.<lang1>-<lang2>.srt`  
+  Example: `movie.chi-eng.srt` when auto-detecting Simplified Chinese + English.
 
-* 安装【[Node.js/npm环境](https://nodejs.org/zh-cn/)】
+## Flow
 
-## 使用
+1. For **each video**, the tool scans embedded subtitle streams.
+2. **Before running**, there is a **3-second countdown**:
+   - **Do nothing**: It auto-selects **Simplified Chinese (chi)** and **English (eng)** and merges them. If either is missing, it lists tracks and asks you to enter the two **stream indices** to merge.
+   - **Press any key**: Skip auto-detect; it lists all subtitle tracks and asks you to enter the two indices to merge.
+3. **Batch**: If you **manually choose indices** for any file in the run, **all following files** in that run also use manual selection (no countdown, no chi/eng auto-detect).
 
-1. 进入视频所在目录
-2. 命令行执行：`npx dual-subtitle`
+## UI language
 
-   注：有些环境（比如群晖）如果没有`npx`，可以用`npm exec`代替。
+- **Default**: English. If the system or environment suggests Chinese (e.g. `LANG`, `LC_ALL`, or on macOS the primary system language), the UI switches to Chinese.
+- **Override**: Set `DUAL_SUBTITLE_LANG=zh` or `DUAL_SUBTITLE_LANG=en` to force the language.
 
-生成的字幕文件会以`.chs-eng.srt`结尾。
+## About
 
-## 介绍
-此工具主要是为了满足在Infuse上看流媒体视频时，能够显示双语字幕的需求。Infuse本身并不支持同时显示2条不同语言的字幕。
+Useful for players like Infuse that don’t support showing two subtitle tracks at once: merge two embedded tracks (e.g. Chinese + English) into one dual subtitle file.
 
-更多介绍，可以访问知乎文章：https://zhuanlan.zhihu.com/p/1915534266130997832
+More background (Chinese): [Zhihu](https://zhuanlan.zhihu.com/p/1915534266130997832)

README.zh-CN.md

@@ -0,0 +1,47 @@
+# dual-subtitle
+
+一键批量提取视频内嵌字幕中的两条轨道，并合并为双语字幕文件。
+
+[![NPM](https://nodei.co/npm/dual-subtitle.png?downloads=true)](https://www.npmjs.com/package/dual-subtitle)
+
+## 依赖
+
+- 需要本地安装 **Node.js**（含 npm）：[Node.js 官网](https://nodejs.org/zh-cn/)
+- 本工具会优先使用系统自带的 `ffmpeg` / `ffprobe`；若未安装，会通过依赖包自动使用内置版本。
+
+## 使用
+
+```bash
+# 在当前目录下处理所有 .mp4 / .mkv
+npx dual-subtitle
+
+# 指定目录（末尾可带或不带 /）
+npx dual-subtitle /path/to/videos
+```
+
+> 若无 `npx`（如部分群晖环境），可用：`node /path/to/dual-subtitle/index.js [目录]`
+
+### 输出文件
+
+- 合并后的字幕文件名为：`<原文件名>.<语言1>-<语言2>.srt`
+- 例如自动匹配到简体中文 + 英语时，生成：`movie.chi-eng.srt`
+
+## 运行流程
+
+1. **每个视频文件**会先扫描内嵌字幕轨道。
+2. **启动前有 3 秒倒计时**：  
+   - 不按键：自动按「简体中文(chi) + 英语(eng)」查找并合成；若缺某一条，会列出字幕并提示输入要合并的两条**索引**。  
+   - **按任意键**：跳过自动查找，直接列出所有字幕，由你依次输入两条要合并的字幕索引。
+3. **批量处理**：若在**第一个**（或任意一个）文件中进行了「手动选择索引」，则**本轮后续所有文件**都会直接进入手动选择流程，不再倒计时、也不再自动匹配 chi/eng。
+
+## 界面语言
+
+- **默认**：根据系统语言自动选择中文或英文（会读取环境变量 `LANG` / `LC_ALL` 等；在 macOS 上还会读取系统首选语言）。
+- **强制指定**：  
+  `DUAL_SUBTITLE_LANG=zh` 或 `DUAL_SUBTITLE_LANG=en` 可覆盖自动检测。
+
+## 简介
+
+主要用于在 Infuse 等播放器上观看流媒体时，将两条内嵌字幕（如中英）合并成一条双语字幕轨道，以解决播放器无法同时显示两条字幕的问题。
+
+更多说明见知乎文章：<https://zhuanlan.zhihu.com/p/1915534266130997832>

analyzeMedia.js

@@ -1,22 +1,23 @@
 import { execSync } from 'child_process';
 import ffprobe from "ffprobe";
 import ffprobeInstaller from '@ffprobe-installer/ffprobe';
-import {config} from "./config.js";
+import { config } from "./config.js";
+import { t } from './i18n.js';
 
 const getFFprobePath = () => {
     try {
         // 检查系统是否安装了 ffprobe
         execSync('ffprobe -version', { stdio: 'ignore' });
         // 如果能执行到这里，说明系统已安装
-        console.log('使用本地ffprobe');
+        console.log(t('usingLocalFfprobe'));
         return 'ffprobe'; // 返回系统命令
     } catch (e) {
         return ffprobeInstaller.path;
     }
 }
 
 export const analyzeMedia = (file) => {
-    console.log(`获取字幕信息...`);
+    console.log(t('gettingSubtitleInfo'));
     const ffprobePath = getFFprobePath();
 
     /*
@@ -35,7 +36,8 @@ export const analyzeMedia = (file) => {
                     duration: Math.round(stream.duration),
                     frames: Number(stream.tags.NUMBER_OF_FRAMES) || 0
                 }));
-                console.log(`找到 ${subTitles.length} 条字幕。`);
+                // 使用 printf 风格 + 多参数，让编辑器高亮数字
+                console.log(t('foundSubtitleCount'), subTitles.length);
                 resolve(subTitles);
             })
             .catch(function (err) {

config.js

@@ -1,7 +1,6 @@
 const config = {
     workdir: './',
     exts: ['.mp4', '.mkv'],
-    srtTag: 'chs-eng',
 };
 
 if (process.argv.length > 2) {

extractSub.js

@@ -2,15 +2,16 @@ import readline from 'readline';
 import { execSync } from 'child_process';
 import ffmpegInstaller from '@ffmpeg-installer/ffmpeg';
 import ffmpeg from 'fluent-ffmpeg';
-import {config} from "./config.js";
-import {removeExtension} from "./utils.js";
+import { config } from "./config.js";
+import { removeExtension } from "./utils.js";
+import { t } from './i18n.js';
 
 const getFFmpegPath = () => {
     try {
         // 检查系统是否安装了 ffprobe
         execSync('ffmpeg -version', { stdio: 'ignore' });
         // 如果能执行到这里，说明系统已安装
-        console.log('使用本地ffmpeg');
+        console.log(t('usingLocalFfmpeg'));
         return 'ffmpeg'; // 返回系统命令
     } catch (e) {
         return ffmpegInstaller.path;
@@ -39,8 +40,11 @@ const timemarkToSeconds = (timemark) => {
 
 export const extractSub = (filename, targetSubs) => {
     return new Promise((resolve, reject) => {
-        const mainSrt = `${removeExtension(filename)}.chs.srt`;
-        const secondarySrt = `${removeExtension(filename)}.eng.srt`;
+        // 使用字幕的 code 或 index 来生成文件名
+        const code1 = targetSubs[0].code || `sub${targetSubs[0].index}`;
+        const code2 = targetSubs[1].code || `sub${targetSubs[1].index}`;
+        const mainSrt = `${removeExtension(filename)}.${code1}.srt`;
+        const secondarySrt = `${removeExtension(filename)}.${code2}.srt`;
         const duration = targetSubs[0].duration;
         let startTs = 0;
 
@@ -52,7 +56,7 @@ export const extractSub = (filename, targetSubs) => {
             .outputOptions(['-map', `0:${targetSubs[1].index}`, '-c', 'copy'])
             .run()
             .on('start', function (str) {
-                console.log('正在提取字幕文件...', str);
+                console.log(t('extractingStart'), str);
                 startTs = Date.now();
             })
             .on('progress', function (progress) {
@@ -61,14 +65,19 @@ export const extractSub = (filename, targetSubs) => {
                 const elapsedSec = startTs ? (Date.now() - startTs) / 1000 : 0;
                 const remainingSec = fraction > 0 ? elapsedSec * (1 - fraction) / fraction : 0;
                 readline.cursorTo(process.stdout, 0);
-                process.stdout.write(`字幕提取中，进度：${(progressPercent || 0)}% | 预计剩余：${formatSeconds(remainingSec)}`);
+                process.stdout.write(
+                    t('extractingProgress', {
+                        progressPercent,
+                        remaining: formatSeconds(remainingSec),
+                    }),
+                );
             })
             .on('end', function (str) {
-                console.log('\n字幕提取完成。');
+                console.log(t('extractingDone'));
                 resolve([mainSrt, secondarySrt]);
             })
             .on('error', function (err) {
-                console.log('字幕提取出错：', err);
+                console.log(t('extractingError', { err }));
                 reject(err);
             });
     });