Faster thumbnail image preview of video files

[ReGdj50]

Is your feature request related to a problem? Please describe.
I recently started using TUI file managers, and the image preview feature is something I use often since I work with a lot of image and video files, but the image generation seems a bit slow to me.

Describe the solution you'd like
Looking at other options I came to yazi which has specific support for certain terminal applications, in my case, kitty, which has a built-in image previewer (icat) and I wonder if that could be possible here too, I love how it looks and I want to continue using spf and with these changes speed up the workflow.

Describe alternatives you've considered
Perhaps precaching the images from a directory before entering and ensuring that the previews load faster with these changes or loading an x amount of files before loading another x amount allowing the previews to load as they are used.

Additional context

recording_2026-02-13_21.14.14.mp4

[github-actions]

👋 Hi there, and welcome to superfile!

Thanks for opening your first issue. We really appreciate your interest and involvement.

A maintainer might ask you for more details or clarification to better understand the issue.
That’s totally normal and helps us solve the problem more effectively.

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[lazysegtree]

I think that the delay comes in generating the thumbnail image and then resizing it, rather than displaying the image.

Using icat won't likely speed up, but it can be explored.

We can switch to a persistent cache, and improve the way we use ffmpeg to generate thumbnails

• Make thumbnail cache persistent across superfile launches #1200

current code for preview generation

func (g *VideoGenerator) generateThumbnail(inputPath string, outputPathWithoutExt string) (string, error) {
	ctx, cancel := context.WithTimeout(context.Background(), thumbGenerationTimeout)
	defer cancel()
	outputPath := outputPathWithoutExt + thumbOutputExt

	// 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", maxVideoFileSizeForThumb, // limit the max file size to match image previewer limit
		"-y", outputPath, // set the outputFile and overwrite it without confirmation if already exists
	)

	err := ffmpeg.Run()
	if err != nil {
		return "", fmt.Errorf("error generating video thumbnail, outputPath: %s : %w", outputPath, err)
	}

	return outputPath, nil
}

[lazysegtree]

Limitations in our implementation

We generate thumbnail in highest quality and then scale down for preview.
We don't cancel old tasks
We don't debounce when user scroll too fast.

We could look at the implementation of yazi for more ideas.

[ReGdj50]

Limitations in our implementation

We generate thumbnail in highest quality and then scale down for preview. We don't cancel old tasks We don't debounce when user scroll too fast.

We could look at the implementation of yazi for more ideas.

I understand and thanks for responding!