Don't generate new thumbnails if they already exist

media/video.go

@@ -79,11 +79,14 @@ func ParseVideo(p *Path, name string) (*Video, error) {
 		v.Thumb = pic.Data
 		v.ThumbType = pic.MIMEType
 	} else if utils.CmdExists("mt") {
+		thumbFn := fmt.Sprintf("%s.jpg", strings.TrimSuffix(pth, filepath.Ext(pth)))
+		if !utils.FileExists(thumbFn) {
 			if err := utils.RunCmd(10, "mt", "-s", "-n", "1", pth); err != nil {
 				err := fmt.Errorf("error generating thumbnail: %w", err)
 				log.Error(err.Error())
 				return nil, err
 			}
+		}
 		data, err := ioutil.ReadFile(fmt.Sprintf("%s.jpg", strings.TrimSuffix(pth, filepath.Ext(pth))))
 		if err != nil {
 			return nil, err

utils/utils.go

@@ -3,10 +3,21 @@ package utils
 import (
 	"context"
 	"fmt"
+	"os"
 	"os/exec"
 	"time"
 )
 
+// FileExists ...
+func FileExists(name string) bool {
+	if _, err := os.Stat(name); err != nil {
+		if os.IsNotExist(err) {
+			return false
+		}
+	}
+	return true
+}
+
 // CmdExists ...
 func CmdExists(cmd string) bool {
 	_, err := exec.LookPath(cmd)