feat: add video preview support (#1178)

Author: Yassen-Higazi

src/internal/common/predefined_variable.go

@@ -64,6 +64,30 @@ var (
 
 var (
 	UnsupportedPreviewFormats = []string{".pdf", ".torrent"}
+	ImageExtensions           = map[string]bool{
+		".jpg":  true,
+		".jpeg": true,
+		".png":  true,
+		".gif":  true,
+		".bmp":  true,
+		".tiff": true,
+		".svg":  true,
+		".webp": true,
+		".ico":  true,
+	}
+	VideoExtensions = map[string]bool{
+		".mkv":  true,
+		".mp4":  true,
+		".mov":  true,
+		".avi":  true,
+		".flv":  true,
+		".webm": true,
+		".wmv":  true,
+		".m4v":  true,
+		".mpeg": true,
+		".3gp":  true,
+		".ogv":  true,
+	}
 )
 
 // No dependencies

src/internal/model.go

@@ -771,10 +771,12 @@ func (panel *filePanel) applyTargetFileCursor() {
 // Close superfile application. Cd into the current dir if CdOnQuit on and save
 // the path in state direcotory
 func (m *model) quitSuperfile(cdOnQuit bool) {
-	// close exiftool session
+	// Resource cleanup
 	if common.Config.Metadata && et != nil {
 		et.Close()
 	}
+	m.fileModel.filePreview.CleanUp()
+
 	// cd on quit
 	currentDir := m.fileModel.filePanels[m.filePanelFocusIndex].location
 	variable.SetLastDir(currentDir)

src/internal/ui/preview/model.go

@@ -31,19 +31,26 @@ import (
 )
 
 type Model struct {
-	open           bool
-	width          int
-	height         int
-	location       string
-	content        string
-	imagePreviewer *filepreview.ImagePreviewer
-	batCmd         string
+	open               bool
+	width              int
+	height             int
+	location           string
+	content            string
+	imagePreviewer     *filepreview.ImagePreviewer
+	batCmd             string
+	thumbnailGenerator *filepreview.ThumbnailGenerator
 }
 
 func New() Model {
+	generator, err := filepreview.NewThumbnailGenerator()
+	if err != nil {
+		slog.Error("Could not NewThumbnailGenerator object", "error", err)
+	}
+
 	return Model{
-		open:           common.Config.DefaultOpenFilePreview,
-		imagePreviewer: filepreview.NewImagePreviewer(),
+		open:               common.Config.DefaultOpenFilePreview,
+		imagePreviewer:     filepreview.NewImagePreviewer(),
+		thumbnailGenerator: generator,
 		// TODO:  This is an IO operation, move to async ?
 		batCmd: checkBatCmd(),
 	}
@@ -112,6 +119,15 @@ func (m *Model) ToggleOpen() {
 	m.open = !m.open
 }
 
+func (m *Model) CleanUp() {
+	if m.thumbnailGenerator != nil {
+		err := m.thumbnailGenerator.CleanUp()
+		if err != nil {
+			slog.Error("Error While cleaning up TempDirectory", "Error:", err)
+		}
+	}
+}
+
 func renderFileInfoError(r *rendering.Renderer, err error) string {
 	slog.Error("Error get file info", "error", err)
 	return r.Render()
@@ -164,7 +180,8 @@ func renderDirectoryPreview(r *rendering.Renderer, itemPath string, previewHeigh
 }
 
 func (m *Model) renderImagePreview(box lipgloss.Style, itemPath string, previewWidth,
-	previewHeight int, sideAreaWidth int) string {
+	previewHeight int, sideAreaWidth int,
+) string {
 	if !m.open {
 		return box.Render("\n --- Preview panel is closed ---")
 	}
@@ -197,7 +214,8 @@ func (m *Model) renderImagePreview(box lipgloss.Style, itemPath string, previewW
 }
 
 func (m *Model) renderTextPreview(r *rendering.Renderer, box lipgloss.Style, itemPath string,
-	previewWidth, previewHeight int) string {
+	previewWidth, previewHeight int,
+) string {
 	format := lexers.Match(filepath.Base(itemPath))
 	if format == nil {
 		isText, err := common.IsTextFile(itemPath)
@@ -274,6 +292,18 @@ func (m *Model) RenderWithPath(itemPath string, fullModelWidth int) string {
 		return renderDirectoryPreview(r, itemPath, previewHeight) + clearCmd
 	}
 
+	if isVideoFile(itemPath) {
+		if m.thumbnailGenerator == nil {
+			return renderUnsupportedFormat(box) + clearCmd
+		}
+		thumbnailPath, err := m.thumbnailGenerator.GetThumbnailOrGenerate(itemPath)
+		if err != nil {
+			slog.Error("Error generating thumbnail", "error", err)
+			return renderUnsupportedFormat(box) + clearCmd
+		}
+		return m.renderImagePreview(box, thumbnailPath, previewWidth, previewHeight, fullModelWidth-previewWidth+1)
+	}
+
 	if isImageFile(itemPath) {
 		return m.renderImagePreview(box, itemPath, previewWidth, previewHeight, fullModelWidth-previewWidth+1)
 	}
@@ -333,18 +363,9 @@ func checkBatCmd() string {
 }
 
 func isImageFile(filename string) bool {
-	imageExtensions := map[string]bool{
-		".jpg":  true,
-		".jpeg": true,
-		".png":  true,
-		".gif":  true,
-		".bmp":  true,
-		".tiff": true,
-		".svg":  true,
-		".webp": true,
-		".ico":  true,
-	}
+	return common.ImageExtensions[strings.ToLower(filepath.Ext(filename))]
+}
 
-	ext := strings.ToLower(filepath.Ext(filename))
-	return imageExtensions[ext]
+func isVideoFile(filename string) bool {
+	return common.VideoExtensions[strings.ToLower(filepath.Ext(filename))]
 }

src/pkg/file_preview/thumbnail_generator.go

@@ -0,0 +1,121 @@
+package filepreview
+
+import (
+	"context"
+	"errors"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"sync"
+	"time"
+)
+
+const (
+	maxFileSize       = "104857600" // 100MB limit
+	outputExt         = ".jpg"
+	generationTimeout = 30 * time.Second
+)
+
+type ThumbnailGenerator struct {
+	// This is a cache. Key -> Video file path, Value -> Thumbnail file path
+	// TODO: We can potentially make it persisitent, preventing generation
+	// of thumbnail on every launch or superfile
+	tempFilesCache map[string]string
+	tempDirectory  string
+	mu             sync.Mutex
+}
+
+func NewThumbnailGenerator() (*ThumbnailGenerator, error) {
+	if !isFFmpegInstalled() {
+		return nil, errors.New("ffmpeg is not installed")
+	}
+
+	tmp, err := os.MkdirTemp("", "superfiles-*")
+	if err != nil {
+		return nil, err
+	}
+
+	thumbnailGenerator := &ThumbnailGenerator{
+		tempFilesCache: make(map[string]string),
+		tempDirectory:  tmp,
+	}
+
+	return thumbnailGenerator, nil
+}
+
+func (g *ThumbnailGenerator) GetThumbnailOrGenerate(path string) (string, error) {
+	g.mu.Lock()
+	file, ok := g.tempFilesCache[path]
+	g.mu.Unlock()
+
+	if ok {
+		_, err := os.Stat(file)
+		if err == nil {
+			return file, nil
+		}
+
+		g.mu.Lock()
+		delete(g.tempFilesCache, path)
+		g.mu.Unlock()
+	}
+
+	generatedThumbnailPath, err := g.generateThumbnail(path)
+	if err != nil {
+		return "", err
+	}
+
+	g.mu.Lock()
+	g.tempFilesCache[path] = generatedThumbnailPath
+	g.mu.Unlock()
+
+	return generatedThumbnailPath, nil
+}
+
+func (g *ThumbnailGenerator) generateThumbnail(inputPath string) (string, error) {
+	fileExt := filepath.Ext(inputPath)
+	filename := filepath.Base(inputPath)
+	baseName := filename[:len(filename)-len(fileExt)]
+
+	outputFile, err := os.CreateTemp(g.tempDirectory, "*-"+baseName+outputExt)
+	if err != nil {
+		return "", err
+	}
+	outputFilePath := outputFile.Name()
+	outputFile.Close()
+
+	ctx, cancel := context.WithTimeout(context.Background(), generationTimeout)
+	defer cancel()
+
+	// ffmpeg -v warning -t 60 -hwaccel auto -an -sn -dn -skip_frame nokey -i input.mkv -vf scale='min(1024,iw)':'min(720,ih)':force_original_aspect_ratio=decrease:flags=fast_bilinear -vf "thumbnail" -frames:v 1 -y thumb.jpg
+	ffmpeg := exec.CommandContext(ctx, "ffmpeg",
+		"-v", "warning", // set log level to warning
+		"-an",       // disable Audio stream
+		"-sn",       // disable Subtitle stream
+		"-dn",       // disable data stream
+		"-t", "180", // process maximum 180s of the video (the first 3 min)
+		"-hwaccel", "auto", // Use Hardware Acceleration if available
+		"-skip_frame", "nokey", // skip non-key frames
+		"-i", inputPath, // set input file
+		"-vf", "thumbnail", // use ffmpeg default thumbnail filter
+		"-frames:v", "1", // output only one frame (one image)
+		"-f", "image2", // set format to image2
+		"-fs", maxFileSize, // limit the max file size to match image previewer limit
+		"-y", outputFilePath, // set the outputFile and overwrite it without confirmation if already exists
+	)
+
+	err = ffmpeg.Run()
+	if err != nil {
+		return "", err
+	}
+
+	return outputFilePath, nil
+}
+
+func (g *ThumbnailGenerator) CleanUp() error {
+	return os.RemoveAll(g.tempDirectory)
+}
+
+func isFFmpegInstalled() bool {
+	_, err := exec.LookPath("ffmpeg")
+	return err == nil
+}