1. 增加配置持久化

2. 完善细节

internal/config/extract.go

@@ -0,0 +1,83 @@
+package config
+
+import (
+	"archive/zip"
+	"bytes"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// ExtractBin copies an embedded binary to the bin directory if not already present.
+func (c *Config) ExtractBin(name string, embedded []byte) string {
+	dest := filepath.Join(c.BinDir(), name)
+	if _, err := os.Stat(dest); err == nil {
+		return dest
+	}
+	log.Printf("[config] extracting %s ...", name)
+	if err := os.WriteFile(dest, embedded, 0755); err != nil {
+		log.Printf("[config] extract %s failed: %v", name, err)
+		return ""
+	}
+	return dest
+}
+
+// ExtractZip extracts an embedded zip file to the bin directory.
+// Extracts ffmpeg.exe and ffprobe.exe from the zip, skipping if already present.
+func (c *Config) ExtractZip(embedded []byte) (ffmpegPath, ffprobePath string) {
+	dir := c.BinDir()
+	ffmpegPath = filepath.Join(dir, "ffmpeg.exe")
+	ffprobePath = filepath.Join(dir, "ffprobe.exe")
+
+	// If both exist, skip extraction
+	if fileExists(ffmpegPath) && fileExists(ffprobePath) {
+		return
+	}
+
+	reader, err := zip.NewReader(bytes.NewReader(embedded), int64(len(embedded)))
+	if err != nil {
+		log.Printf("[config] zip open failed: %v", err)
+		return
+	}
+
+	for _, f := range reader.File {
+		name := strings.ToLower(f.Name)
+		name = filepath.Base(name)
+		if name != "ffmpeg.exe" && name != "ffprobe.exe" {
+			continue
+		}
+
+		dest := filepath.Join(dir, name)
+		if fileExists(dest) {
+			continue
+		}
+
+		log.Printf("[config] extracting %s (%d bytes)...", name, f.UncompressedSize64)
+		rc, err := f.Open()
+		if err != nil {
+			log.Printf("[config] zip open %s: %v", name, err)
+			continue
+		}
+		out, err := os.Create(dest)
+		if err != nil {
+			rc.Close()
+			continue
+		}
+		_, err = io.Copy(out, rc)
+		rc.Close()
+		out.Close()
+		if err != nil {
+			os.Remove(dest)
+			log.Printf("[config] extract %s failed: %v", name, err)
+		}
+	}
+
+	return
+}
+
+func fileExists(path string) bool {
+	_, err := os.Stat(path)
+	return err == nil
+}