AlistGo/alist · warning

invalid video path: %w

Error message

invalid video path: %w

What it means

GetSnapshot rejects the video path via the same sanitizeFilePath gate used for images: path must be absolute, free of shell metacharacters (;;&|`$<>!\n\r\x00), stat-able, and a regular file. The wrapped error names the failing rule. This runs before ffprobe, so it fires only on path problems, not on media problems.

Source

Thrown at drivers/local/util.go:156

	// outputFormat := imaging.PNG
	// encodeOptions := []imaging.EncodeOption{}

	err = imaging.Encode(&buf, thumbImg, outputFormat, encodeOptions...)
	if err != nil {
		return nil, fmt.Errorf("failed to encode thumbnail: %w", err)
	}

	thumbImg = nil

	return &buf, nil
}

// Get the snapshot of the video
func (d *Local) GetSnapshot(videoPath string) (imgData *bytes.Buffer, err error) {
	sanitized, err := sanitizeFilePath(videoPath)
	if err != nil {
		return nil, fmt.Errorf("invalid video path: %w", err)
	}
	videoPath = sanitized

	// Run ffprobe to get the video duration
	jsonOutput, err := ffmpeg.Probe(videoPath)
	if err != nil {
		return nil, err
	}
	// get format.duration from the json string
	type probeFormat struct {
		Duration string `json:"duration"`
	}
	type probeData struct {
		Format probeFormat `json:"format"`
	}
	var probe probeData
	err = json.Unmarshal([]byte(jsonOutput), &probe)
	if err != nil {

View on GitHub (pinned to 843d9dc814)

Solutions

1. Read the wrapped message to see which rule failed
2. Rename files containing metacharacters, or adjust sanitizeFilePath since ffmpeg-go spawns ffmpeg directly (no shell) and only NUL/newline truly need rejecting
3. Verify the video exists and the process user can stat it

Example fix

// before: every metacharacter rejected, ffmpeg invoked without a shell anyway
if strings.ContainsAny(cleaned, ";&|`$<>!\n\r\x00") {
    return "", fmt.Errorf("file path contains invalid characters: %s", path)
}

// after: only reject characters that cannot appear in a single argv element
if strings.ContainsAny(cleaned, "\n\r\x00") {
    return "", fmt.Errorf("file path contains invalid characters: %s", path)
}

if !filepath.IsAbs(videoPath) { return nil, fmt.Errorf("video path must be absolute") }
if info, err := os.Stat(videoPath); err != nil || !info.Mode().IsRegular() { return nil, nil /* skip snapshot */ }

In getThumb, wrap GetSnapshot; on error return (nil, nil, err-swigged-thumb) so the listing still renders and the failure is only logged.

When it happens

Trigger: Requesting a thumbnail for a video whose path contains '$' or ';' (very common in scene-release filenames), a video behind a broken symlink, or a video that was deleted after the directory listing was cached.

Common situations: Filenames like 'Movie.2023.1080p;$hadow.mp4' or subtitled releases with '!' in the name; symlinked media libraries; thumbnails requested for entries from a stale cache.

Related errors

• invalid input file path: %w
• ffmpeg-go failed to resize image %s to buffer: %w
• ffmpeg-go produced empty buffer for %s
• failed to open image: %w
• directory separator prohibited

AI-assisted analysis of AlistGo/alist@843d9dc814 (2026-08-15). Data as JSON: /api/errors/048691c71daae8c9. Report an issue: GitHub.