SubtitleEdit/subtitleedit · error · InvalidOperationException

No subtitles recognised in Blu-Ray sup file: {filePath}

Error message

No subtitles recognised in Blu-Ray sup file: {filePath}

What it means

Thrown by LoadBluRaySup when ImageOcrLoader.LoadBluRaySup returned a Subtitle whose Paragraphs list is empty. The .sup was parsed (BluRaySupParser did not throw) but yielded zero presentation composition segments, so there is nothing to convert.

Source

Thrown at src/seconv/Core/ContainerSubtitleLoader.cs:401

    private static List<LoadedTrack> LoadMcc(string filePath)
    {
        var mcc = new MacCaption10();
        if (!mcc.IsMine(null, filePath))
        {
            throw new InvalidOperationException($"File is not a valid MCC subtitle: {filePath}");
        }
        var subtitle = new Subtitle();
        mcc.LoadSubtitle(subtitle, null, filePath);
        subtitle.Renumber();
        return [new LoadedTrack(subtitle, mcc, string.Empty, null)];
    }

    private static List<LoadedTrack> LoadBluRaySup(string filePath, ConversionOptions options)
    {
        var subtitle = ImageOcrLoader.LoadBluRaySup(filePath, options);
        if (subtitle.Paragraphs.Count == 0)
        {
            throw new InvalidOperationException($"No subtitles recognised in Blu-Ray sup file: {filePath}");
        }
        return [new LoadedTrack(subtitle, new SubRip(), string.Empty, null)];
    }

    private static List<LoadedTrack> LoadVobSub(string subPath, string idxPath, ConversionOptions options)
    {
        var subtitle = ImageOcrLoader.LoadVobSub(subPath, idxPath, options);
        if (subtitle.Paragraphs.Count == 0)
        {
            throw new InvalidOperationException($"No subtitles recognised in VobSub file: {subPath}");
        }
        return [new LoadedTrack(subtitle, new SubRip(), string.Empty, null)];
    }

    private static List<LoadedTrack> LoadTransportStream(string filePath, ConversionOptions options)
    {
        var tracks = new List<LoadedTrack>();

View on GitHub (pinned to 17a9f07487)

Solutions

1. Validate the .sup with a BD/PGS tool (BDSup2Sub, ffmpeg) to confirm it has PCS entries.
2. Re-demux the PGS from the original Blu-ray source (MakeMKV/eac3to).
3. If the file is a different image format (.idx/.sub), pass the correct extension.

// Pre-validate the .sup has PCS entries via the parser's log/output.
var log = new StringBuilder();
if (BluRaySupParser.ParseBluRaySup(filePath, log).Count == 0)
    return Error($"No PCS entries in {filePath}");

try { tracks = ContainerSubtitleLoader.TryLoadTracks(filePath, options); }
catch (InvalidOperationException ex) when (ex.Message.Contains("Blu-Ray sup"))
{ Console.Error.WriteLine(ex.Message); return; }

When it happens

Trigger: Passing a .sup file (ContainerSubtitleLoader.cs:74-76 routes .sup here) that BluRaySupParser.ParseBluRaySup reads but finds no valid PCS entries, or where OCR produced no paragraphs; the post-check at line 399 sees Paragraphs.Count == 0.

Common situations: A corrupt/truncated BD .sup; a .sup that is actually another format mis-named; a PGS file with only display/Windows segments and no composition segments; an empty placeholder.

Related errors

• No Blu-Ray sup subtitles found in: {filePath}
• Unable to access bitmap pixel data.
• No PGS subtitles in MKV track #{track.TrackNumber}.
• No Blu-Ray sup subtitles found in: {filePath}
• No subtitle essences found in MXF: {filePath}

AI-assisted analysis of SubtitleEdit/subtitleedit@17a9f07487 (2026-08-13). Data as JSON: /api/errors/ffde4b38c1c7aa37. Report an issue: GitHub.