SubtitleEdit/subtitleedit · error · FileNotFoundException

BinaryOCR database not found: {dbPath}. Use --ocr-db to poin

Error message

BinaryOCR database not found: {dbPath}. Use --ocr-db to point to a .db file (typically %AppData%\Subtitle Edit\OCR\Latin.db or similar).

What it means

FileNotFoundException from the BinaryOcrOcrEngine constructor: the dbPath argument does not point to an existing file. The message names the path and suggests using --ocr-db to point at a .db (typically %AppData%\Subtitle Edit\OCR\Latin.db).

Source

Thrown at src/seconv/Core/BinaryOcrOcrEngine.cs:25

/// In-process OCR via Subtitle Edit's BinaryOCR matcher. Requires a <c>.db</c>
/// database file (typically shipped with SE under <c>%AppData%\Subtitle Edit\OCR\</c>;
/// pass the path via <c>--ocr-db</c>). BinaryOCR uses fast bitmap-hash matching and
/// is a useful alternative to nOCR — different accuracy profile, similar speed.
/// </summary>
internal sealed class BinaryOcrOcrEngine : IOcrEngine
{
    public string Name => "binaryocr";

    private readonly BinaryOcrDb _db;
    private readonly BinaryOcrMatcher _matcher;
    private const int PixelsAreSpaceDefault = 12;
    private const double MaxErrorPercent = 0.5;

    public BinaryOcrOcrEngine(string dbPath)
    {
        if (!File.Exists(dbPath))
        {
            throw new FileNotFoundException(
                $"BinaryOCR database not found: {dbPath}. Use --ocr-db to point to a .db file " +
                "(typically %AppData%\\Subtitle Edit\\OCR\\Latin.db or similar).", dbPath);
        }
        _db = new BinaryOcrDb(dbPath, loadCompareImages: true);
        if (_db.AllCompareImages.Count == 0)
        {
            throw new InvalidOperationException($"BinaryOCR database is empty: {dbPath}");
        }
        _matcher = new BinaryOcrMatcher
        {
            IsLatinDb = Path.GetFileNameWithoutExtension(dbPath).Contains("Latin", StringComparison.OrdinalIgnoreCase),
        };
    }

    public string Recognize(SKBitmap bitmap)
    {
        if (bitmap is null || bitmap.Width == 0 || bitmap.Height == 0)
        {

View on GitHub (pinned to 17a9f07487)

Solutions

1. Run Binary/OCR in the SE GUI once to generate Latin.db, then point --ocr-db at it.
2. Pass --ocr-db:<absolute path to .db> explicitly.
3. Confirm the path resolves under the current user profile (the %AppData% placeholder must be expanded).

Example fix

// before
if (!File.Exists(dbPath))
    throw new FileNotFoundException($"BinaryOCR database not found: {dbPath}. ...", dbPath);

// after
var resolved = Environment.ExpandEnvironmentVariables(dbPath);
if (!File.Exists(resolved))
    throw new FileNotFoundException($"BinaryOCR database not found: '{resolved}'. Use --ocr-db:<path.db>.", resolved);

var resolved = Environment.ExpandEnvironmentVariables(dbPath);
if (!File.Exists(resolved))
    throw new FileNotFoundException($"BinaryOCR db not found: '{resolved}'. Pass --ocr-db:<path.db>.", resolved);

static bool IsExistingOcrDb(string path) => File.Exists(Environment.ExpandEnvironmentVariables(path));

null

When it happens

Trigger: Constructing BinaryOcrOcrEngine with a dbPath whose file does not exist; default OCR-db lookup returned a path that was never populated.

Common situations: First-time use before any BinaryOCR db was created in the SE GUI; moved SE to a new machine; user pointed --ocr-db at the wrong file.

Related errors

• nOCR database not found: {nOcrDbPath}. Use --ocr-db to point
• BinaryOCR database is empty: {dbPath}
• OCR engine '{options.OcrEngine}' is not supported. Use one o
• {engineName} engine requires --ocr-db=<path-to-Latin{require
• Settings file not found: {path}

AI-assisted analysis of SubtitleEdit/subtitleedit@17a9f07487 (2026-08-13). Data as JSON: /api/errors/7ad564d666f24665. Report an issue: GitHub.