SubtitleEdit/subtitleedit · error · InvalidDataException

Cannot read bits per sample of

Error message

Cannot read bits per sample of {Header.BitsPerSample}

What it means

Thrown by GetSampleDataReader when Header.BytesPerSample (derived from BitsPerSample, rounded up to whole bytes) is not 1, 2, 3, or 4. The reader only has implementations for 8/16/24/32-bit PCM samples; any other byte-per-sample value (e.g. 0 from a 0-bit header, or a non-PCM format) has no read path. The message echoes BitsPerSample rather than BytesPerSample, which can be slightly misleading.

Solutions

1. Check Header.BitsPerSample is 8, 16, 24, or 32 before invoking sample-reading APIs.
2. For 32-bit float audio, convert to 16-bit PCM first or extend the reader.
3. Validate Header.AudioFormat == PCM (1) before reading samples.
4. Re-encode the source WAV to a supported PCM bit depth if it is an exotic format.

Example fix

// before
var reader = GetSampleDataReader();

// after
if (Header.BytesPerSample is not (1 or 2 or 3 or 4))
    throw new NotSupportedException($"Unsupported bit depth: {Header.BitsPerSample}-bit");
var reader = GetSampleDataReader();

if (wave.Header.BytesPerSample is not (1 or 2 or 3 or 4))
    throw new NotSupportedException($"Unsupported bit depth: {wave.Header.BitsPerSample}-bit (AudioFormat={wave.Header.AudioFormat})");
if (wave.Header.AudioFormat != WaveHeader2.AudioFormatPcm && wave.Header.AudioFormat != 0xFFFE)
    throw new NotSupportedException("Only PCM WAV is supported for sample reading");

static bool IsSupportedReadBitDepth(WaveHeader2 h) => h.BytesPerSample is 1 or 2 or 3 or 4;

try { var reader = GetSampleDataReader(); }
catch (InvalidDataException ex) when (ex.Message.Contains("Cannot read")) { /* convert to 16-bit PCM */ }

When it happens

Trigger: Calling any sample-reading API (GeneratePeaks, GenerateSpectrogram, GetSamples) on a WAV whose BitsPerSample is 0, 12, an unusual value, or whose AudioFormat is non-PCM (float/compressed) so BitsPerSample does not map to 8/16/24/32.

Common situations: Opening a 32-bit float WAV (AudioFormat 3) where BitsPerSample is 32 but the value semantics differ; a corrupt fmt chunk yielding BitsPerSample 0; a 20-bit file that rounds up but is otherwise mishandled; header corruption.

Related errors

• Cannot write bits per sample of
• Peaks file must be 16 bits per sample.
• Peaks file must have 1 or 2 channels.
• Stream is too small
• A faster-whisper model folder must contain a 'model.bin'…

AI-assisted analysis of SubtitleEdit/subtitleedit@17a9f07487 (2026-08-13). Data as JSON: /api/errors/dbdf8af9f8bf1621. Report an issue: GitHub.

Appendix: source

Thrown at src/ui/Logic/Media/WaveToVisualizer2.cs:914

    private double GetSampleAndChannelScale()
    {
        return GetSampleScale() / Header.NumberOfChannels;
    }

    private ReadSampleDataValue GetSampleDataReader()
    {
        switch (Header.BytesPerSample)
        {
            case 1:
                return ReadValue8Bit;
            case 2:
                return ReadValue16Bit;
            case 3:
                return ReadValue24Bit;
            case 4:
                return ReadValue32Bit;
            default:
                throw new InvalidDataException("Cannot read bits per sample of " + Header.BitsPerSample);
        }
    }

    private WriteSampleDataValue GetSampleDataWriter()
    {
        switch (Header.BytesPerSample)
        {
            case 1:
                return WriteValue8Bit;
            case 2:
                return WriteValue16Bit;
            case 3:
                return WriteValue24Bit;
            case 4:
                return WriteValue32Bit;
            default:
                throw new InvalidDataException("Cannot write bits per sample of " + Header.BitsPerSample);
        }

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