tc2sc_sub.lua

-- tc2sc_sub.lua
-- 快捷键: Ctrl+t
-- 依赖: opencc (必须), ffmpeg (仅提取内封字幕时需要)

local mp = require 'mp'
local utils = require 'mp.utils'
local msg = require 'mp.msg'

-- OpenCC 配置文件，默认为繁转简 (Traditional to Simplified)
local OPENCC_CONFIG = "t2s.json"

-- 获取文件扩展名
local function get_extension(path)
    return path:match("^.+(%..+)$") or ""
end

-- 获取去除了扩展名的文件名
local function strip_extension(path)
    return path:match("^(.+)%..+$") or path
end

-- 核心转换函数
local function convert_sub()
    local sid = mp.get_property_number("sid")
    if not sid then
        mp.osd_message("没有选择任何字幕 (No subtitle selected)")
        return
    end

    local track_list = mp.get_property_native("track-list")
    local current_sub = nil

    -- 找到当前的字幕轨道
    for _, track in ipairs(track_list) do
        if track.type == "sub" and track.id == sid then
            current_sub = track
            break
        end
    end

    if not current_sub then
        mp.osd_message("未找到字幕轨道信息")
        return
    end

    local is_external = current_sub.external
    local in_file = current_sub["external-filename"]
    local out_file = ""
    
    local video_path = mp.get_property("path")
    local dir, filename = utils.split_path(video_path)
    
    if is_external and in_file then
        -- ========== 处理外封字幕 ==========
        local in_dir, in_name = utils.split_path(in_file)
        local base_name = strip_extension(in_name)
        local ext = get_extension(in_name)
        
        -- 重命名逻辑：将 .tc 或 .TC 替换为 .tc2sc，如果没有则直接追加 .tc2sc
        if string.match(base_name:lower(), "%.tc$") then
            base_name = string.gsub(base_name, "%.tc$", ".tc2sc")
            base_name = string.gsub(base_name, "%.TC$", ".tc2sc")
        else
            base_name = base_name .. ".tc2sc"
        end
        
        out_file = utils.join_path(in_dir, base_name .. ext)
        
        mp.osd_message("正在使用 OpenCC 转换外封字幕...")
        run_opencc(in_file, out_file)
        
    else
        -- ========== 处理内封字幕 ==========
        local ff_index = current_sub["ff-index"]
        if not ff_index then
            mp.osd_message("无法获取内封字幕的流索引")
            return
        end
        
        -- 判断字幕格式 (ASS 或 SRT)
        local codec = current_sub["codec"]
        local ext = ".ass" 
        if codec == "subrip" then ext = ".srt" end
        
        local base_video_name = strip_extension(filename)
        -- 临时文件和输出文件路径
        local temp_file = utils.join_path(dir, base_video_name .. "_track_" .. tostring(sid) .. "_temp" .. ext)
        out_file = utils.join_path(dir, base_video_name .. ".tc2sc" .. ext)
        
        mp.osd_message("正在使用 FFmpeg 提取内封字幕...")
        
        -- 步骤1: 用 FFmpeg 提取字幕
        local ext_res = mp.command_native({
            name = "subprocess",
            playback_only = false,
            capture_stdout = true,
            capture_stderr = true,
            args = {"ffmpeg", "-y", "-i", video_path, "-map", "0:" .. tostring(ff_index), "-c:s", "copy", temp_file}
        })
        
        if ext_res.status ~= 0 then
            mp.osd_message("提取内封字幕失败！(请确保已安装 FFmpeg)")
            msg.error("FFmpeg error: " .. (ext_res.stderr or ""))
            return
        end
        
        mp.osd_message("正在使用 OpenCC 转换内封字幕...")
        
        -- 步骤2: 用 OpenCC 转换
        run_opencc(temp_file, out_file)
        
        -- 步骤3: 清理提取出的临时文件
        os.remove(temp_file)
    end
end

-- 调用 OpenCC 执行转换并加载字幕
function run_opencc(in_file, out_file)
    local res = mp.command_native({
        name = "subprocess",
        playback_only = false,
        capture_stdout = true,
        capture_stderr = true,
        args = {"opencc", "-i", in_file, "-o", out_file, "-c", OPENCC_CONFIG}
    })
    
    if res.status == 0 then
        mp.osd_message("繁简转换成功！已加载新字幕。")
        -- 挂载新生成的字幕并选中它 ("select" 标志表示立即切换过去)
        mp.commandv("sub-add", out_file, "select")
    else
        mp.osd_message("OpenCC 转换失败！(请确保 opencc 在系统变量中)")
        msg.error("OpenCC error: " .. (res.stderr or ""))
    end
end

-- 绑定快捷键 Ctrl+T
mp.add_key_binding("ctrl+t", "convert_sub_t2s", convert_sub)