AlexxIT/go2rtc · error

rtmp: unknown command:

Error message

rtmp: unknown command: 

What it means

After handling CommandPlay and CommandPublish, the RTMP server's tcpHandle treats any other rtmpConn.Intent as unsupported and returns "rtmp: unknown command: <intent>". The library only implements play and publish for incoming RTMP connections.

Solutions

1. Use a standard RTMP client that issues only play or publish commands
2. Update the client library to a conforming RTMP implementation
3. Inspect the intent value in the error to identify the offending client
4. If you need more commands, patch the RTMP server handler to support them

// Go
if err := tcpHandle(conn); err != nil {
    if strings.HasPrefix(err.Error(), "rtmp: unknown command") {
        log.Warn().Msg("client sent unsupported RTMP intent; dropping connection")
        conn.Close()
    }
}

When it happens

Trigger: An RTMP client sends an intent/command other than play or publish (custom or malformed handshake state), so the switch statement falls through to the default error return at internal/rtmp/rtmp.go:124.

Common situations: Non-standard RTMP clients or fuzzers sending unexpected commands, a client library setting a custom intent value, or protocol-level misbehavior after handshake.

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

• stream not found:
• wrong auth response
• wrong start byte
• read error
• eseecloud: wrong start byte

AI-assisted analysis of AlexxIT/go2rtc@c245815e75 (2026-09-07). Data as JSON: /api/errors/cc1be5e36986556d. Report an issue: GitHub.

Appendix: source

Thrown at internal/rtmp/rtmp.go:124

		if err = rtmpConn.WriteStart(); err != nil {
			return err
		}

		prod, err := rtmpConn.Producer()
		if err != nil {
			return err
		}

		stream.AddProducer(prod)

		defer stream.RemoveProducer(prod)

		_ = prod.Start()

		return nil
	}

	return errors.New("rtmp: unknown command: " + rtmpConn.Intent)
}

var log zerolog.Logger

func streamsHandle(url string) (core.Producer, error) {
	return rtmp.DialPlay(url)
}

func streamsConsumerHandle(url string) (core.Consumer, func(), error) {
	cons := flv.NewConsumer()
	run := func() {
		wr, err := rtmp.DialPublish(url, cons)
		if err != nil {
			return
		}
		_, err = cons.WriteTo(wr)
	}

View on GitHub (pinned to c245815e75)