feat(local): add thumbnail for video with ffmpeg (#3556)

* feat(local): add ffmpeg

* fix: missed `+`

---------

Co-authored-by: Andy Hsu <i@nn.ci>

drivers/local/driver.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"github.com/alist-org/alist/v3/server/common"
 	"io"
 	"io/ioutil"
 	"net/http"
@@ -20,7 +21,6 @@ import (
 	"github.com/alist-org/alist/v3/internal/model"
 	"github.com/alist-org/alist/v3/internal/sign"
 	"github.com/alist-org/alist/v3/pkg/utils"
-	"github.com/alist-org/alist/v3/server/common"
 	"github.com/disintegration/imaging"
 	_ "golang.org/x/image/webp"
 )
@@ -71,10 +71,13 @@ func (d *Local) List(ctx context.Context, dir model.Obj, args model.ListArgs) ([
 			continue
 		}
 		thumb := ""
-		if d.Thumbnail && utils.GetFileType(f.Name()) == conf.IMAGE {
-			thumb = common.GetApiUrl(nil) + stdpath.Join("/d", args.ReqPath, f.Name())
-			thumb = utils.EncodePath(thumb, true)
-			thumb += "?type=thumb&sign=" + sign.Sign(stdpath.Join(args.ReqPath, f.Name()))
+		if d.Thumbnail {
+			typeName := utils.GetFileType(f.Name())
+			if typeName == conf.IMAGE || typeName == conf.VIDEO {
+				thumb = common.GetApiUrl(nil) + stdpath.Join("/d", args.ReqPath, f.Name())
+				thumb = utils.EncodePath(thumb, true)
+				thumb += "?type=thumb&sign=" + sign.Sign(stdpath.Join(args.ReqPath, f.Name()))
+			}
 		}
 		isFolder := f.IsDir() || isSymlinkDir(f, fullPath)
 		var size int64
@@ -126,11 +129,22 @@ func (d *Local) Link(ctx context.Context, file model.Obj, args model.LinkArgs) (
 	fullPath := file.GetPath()
 	var link model.Link
 	if args.Type == "thumb" && utils.Ext(file.GetName()) != "svg" {
-		imgData, err := ioutil.ReadFile(fullPath)
-		if err != nil {
-			return nil, err
+		var srcBuf *bytes.Buffer
+		if utils.GetFileType(file.GetName()) == conf.VIDEO {
+			videoBuf, err := GetSnapshot(fullPath, 10)
+			if err != nil {
+				return nil, err
+			}
+			srcBuf = videoBuf
+		} else {
+			imgData, err := ioutil.ReadFile(fullPath)
+			if err != nil {
+				return nil, err
+			}
+			imgBuf := bytes.NewBuffer(imgData)
+			srcBuf = imgBuf
 		}
-		srcBuf := bytes.NewBuffer(imgData)
+
 		image, err := imaging.Decode(srcBuf)
 		if err != nil {
 			return nil, err

drivers/local/util.go

@@ -1,6 +1,9 @@
 package local
 
 import (
+	"bytes"
+	"fmt"
+	ffmpeg "github.com/u2takey/ffmpeg-go"
 	"io/fs"
 	"os"
 	"path/filepath"
@@ -23,3 +26,16 @@ func isSymlinkDir(f fs.FileInfo, path string) bool {
 	}
 	return false
 }
+
+func GetSnapshot(videoPath string, frameNum int) (imgData *bytes.Buffer, err error) {
+	srcBuf := bytes.NewBuffer(nil)
+	err = ffmpeg.Input(videoPath).Filter("select", ffmpeg.Args{fmt.Sprintf("gte(n,%d)", frameNum)}).
+		Output("pipe:", ffmpeg.KwArgs{"vframes": 1, "format": "image2", "vcodec": "mjpeg"}).
+		WithOutput(srcBuf, os.Stdout).
+		Run()
+
+	if err != nil {
+		return nil, err
+	}
+	return srcBuf, nil
+}