pion/webrtc · error

%w: expected(0) got(%d)

Error message

%w: expected(0) got(%d)

What it means

Thrown by parseFileHeader after reading an IVF file header whose version field is not 0. The IVF format defines version 0 as the only valid value; a nonzero version means the file is malformed, corrupted, or not actually IVF despite a matching signature, so the parser rejects it before returning the header to NewWith callers.

Source

Thrown at pkg/media/ivfreader/ivfreader.go:157

	}

	header := &IVFFileHeader{
		signature:           string(buffer[:4]),
		version:             binary.LittleEndian.Uint16(buffer[4:6]),
		headerSize:          binary.LittleEndian.Uint16(buffer[6:8]),
		FourCC:              string(buffer[8:12]),
		Width:               binary.LittleEndian.Uint16(buffer[12:14]),
		Height:              binary.LittleEndian.Uint16(buffer[14:16]),
		TimebaseDenominator: binary.LittleEndian.Uint32(buffer[16:20]),
		TimebaseNumerator:   binary.LittleEndian.Uint32(buffer[20:24]),
		NumFrames:           binary.LittleEndian.Uint32(buffer[24:28]),
		unused:              binary.LittleEndian.Uint32(buffer[28:32]),
	}

	if header.signature != ivfFileHeaderSignature {
		return nil, errSignatureMismatch
	} else if header.version != uint16(0) {
		return nil, fmt.Errorf("%w: expected(0) got(%d)", errUnknownIVFVersion, header.version)
	}

	i.bytesReadSuccesfully += int64(bytesRead)

	return header, nil
}

View on GitHub (pinned to 8c25dc09fa)

Solutions

1. Verify the input file is a genuine IVF container produced by a standard muxer (e.g. ffmpeg's ivf muxer) and not a renamed or truncated file
2. Inspect bytes 4-6 of the file (the version field) with a hex dump to confirm the value being rejected
3. Re-mux the source stream into a fresh IVF file with a known-good tool instead of hand-crafting the header
4. If a nonzero version must be tolerated, patch parseFileHeader to accept it explicitly — but note the reader's field offsets are only validated for version 0

When it happens

Trigger: Thrown at pkg/media/ivfreader/ivfreader.go:157 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of pion/webrtc@8c25dc09fa (2026-09-03). Data as JSON: /api/errors/546cc274980aa782. Report an issue: GitHub.