AlexxIT/go2rtc · error

xiaomi: unsupported encryption

Error message

xiaomi: unsupported encryption

What it means

DecodeVideo can decrypt the standard encryption variant (data[8]==1) and pass through unencrypted frames, but frames with some other encryption byte are not supported. The library explicitly notes support could be added but such cameras are rare.

Solutions

1. Update camera firmware to a version using the supported encryption scheme
2. Patch DecodeVideo in pkg/xiaomi/legacy/client.go to implement the additional variant (data[8] values other than 0/1)
3. Use a model/firmware combination known to produce standard frames
4. Fall back to the camera's non-TUTK stream if available

// inspect frame encryption byte before decoding
if len(frame) > 8 && frame[8] != 0 && frame[8] != 1 {
    return errors.New("unsupported frame encryption variant")
}

When it happens

Trigger: Calling DecodeVideo (directly or via ReadPacket) on a video frame whose 9th byte is neither 0 nor 1, indicating an unknown encryption variant.

Common situations: Using the library with a camera firmware that encrypts video with a different scheme; decoding streams recorded from a non-standard camera model.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• v4l2: invalid video_size
• v4l2: invalid input_format
• res.Status
• xiaomi
• y4m: unsupported format

AI-assisted analysis of AlexxIT/go2rtc@c245815e75 (2026-09-07). Data as JSON: /api/errors/40438d5ff66f1f47. Report an issue: GitHub.

Appendix: source

Thrown at pkg/xiaomi/legacy/client.go:233

	return fmt.Errorf("xiaomi: unsupported model: %s", c.model)
}

func (c *Client) StopMedia() error {
	return errors.Join(
		c.WriteCommandJSON(cmdVideoStop, `{}`),
		c.WriteCommand(cmdVideoStop, make([]byte, 8)),
	)
}

func DecodeVideo(data, key []byte) ([]byte, error) {
	if string(data[:4]) == "\x00\x00\x00\x01" || data[8] == 0 {
		return data, nil
	}

	if data[8] != 1 {
		// Support could be added, but I haven't seen such cameras.
		return nil, fmt.Errorf("xiaomi: unsupported encryption")
	}

	nonce8 := data[:8]
	i1 := binary.LittleEndian.Uint32(data[9:])
	i2 := binary.LittleEndian.Uint32(data[13:])
	data = data[17:]
	src := data[i1 : i1+i2]

	for i := 32; i+16 < len(src); i += 160 {
		dst, err := crypto.DecodeNonce(src[i:i+16], nonce8, key)
		if err != nil {
			return nil, err
		}
		copy(src[i:], dst) // copy result in same place
	}

	return data, nil
}

View on GitHub (pinned to c245815e75)