Android平台GB28181设备接入端如何支持跨网段语音对讲？

s=Talk
............
t=0 0
m=audio 端口 RTP/AVP 8
a=rtpmap:8 PCMA/8000
a=sendrecv
y=xxxx.......

s=Play
............
t=0 0
m=audio 端口号 RTP/AVP 96
a=rtpmap:96 PS/90000
a=sendrecv
y=xxxxxxxx....

// Github: https://github.com/daniulive/SmarterStreaming
// Contract: 89030985@qq.com
 
public interface GBSIPAgentTalkListener {
    /*
     *收到语音对讲INVITE
     */
    void ntsOnInviteTalk(String deviceId, SessionDescription sessionDescription);
 
    /*
     *发送talk invite response 异常
     */
    void ntsOnTalkInviteResponseException(String deviceId, int statusCode, String errorInfo);
 
    /*
     * 收到CANCEL Talk INVITE请求
     */
    void ntsOnCancelTalk(String deviceId);
 
    /*
     * 收到Ack
     */
    void ntsOnAckTalk(String deviceId);
 
    /*
     * 收到Bye
     */
    void ntsOnByeTalk(String deviceId);
 
    /*
     * 不是在收到BYE Message情况下，终止Talk
     */
    void ntsOnTerminateTalk(String deviceId);
 
 
    void ntsOnTalkDialogTerminated(String deviceId);
}
 
 
public interface GBSIPAgent {
 
   // 其他接口省略......
 
   void addTalkListener(GBSIPAgentTalkListener talkListener);
   
   /*
     *响应Invite Talk 200 OK
     */
    boolean respondTalkInviteOK(String deviceId, String addressType, String localAddress,
                                MediaSessionDescription mainLocalAudioDescription, MediaSessionDescription subLocalAudioDescription);
 
    /*
     *响应Invite Talk 其他状态码
     */
    boolean respondTalkInvite(int statusCode, String deviceId);
 
 
    /*
     *终止Talk会话
     */
    void terminateTalk(String deviceId, boolean isSendBYE);
 
    /*
     *终止所有Talk会话
     */
    void terminateAllTalks(boolean isSendBYE);
}

@Override
public void ntsOnInviteTalk(String deviceId, SessionDescription sessionDescription) {
    handler_.postDelayed(new Runnable() {
        @Override
        public void run() {

            gb28181_agent_.respondTalkInvite(180, device_id_);

            MediaSessionDescription audio_description = null;
            SDPRtpMapAttribute rtp_map_attribute = null;

            Vector<MediaSessionDescription> audio_des_list = session_description_.getAudioDescriptions();
            if (audio_des_list != null && !audio_des_list.isEmpty()) {

                for(MediaSessionDescription m : audio_des_list) {
                    if (m != null && m.isValidAddressType() && m.isHasAddress()) {
                        rtp_map_attribute = m.getRtpMapAttribute(SDPRtpMapAttribute.PCMA_ENCODING_NAME);
                        if (rtp_map_attribute != null) {
                            audio_description = m;
                            break;
                        }
                    }
                }

                if (null == rtp_map_attribute) {
                    for(MediaSessionDescription m : audio_des_list) {
                        if (m != null && m.isValidAddressType() && m.isHasAddress()) {
                            rtp_map_attribute = m.getRtpMapAttribute(SDPRtpMapAttribute.PS_ENCODING_NAME);
                            if (rtp_map_attribute != null) {
                                audio_description = m;
                                break;
                            }
                        }
                    }
                }
            }

            if (null == audio_description) {
                gb28181_agent_.respondTalkInvite(488, device_id_);
                Log.i(TAG, "ntsOnInviteTalk get audio description is null, response 488, device_id:" + device_id_);
                return;
            }

            if (null == rtp_map_attribute ) {
                gb28181_agent_.respondTalkInvite(488, device_id_);
                Log.i(TAG, "ntsOnInviteTalk get rtp map attribute is null, response 488, device_id:" + device_id_);
                return;
            }

            Log.i(TAG,"ntsOnInviteTalk, device_id:" +device_id_+", is_tcp:" + audio_description.isRTPOverTCP()
                  + " rtp_port:" + audio_description.getPort() + " ssrc:" + audio_description.getSSRC()
                  + " address_type:" + audio_description.getAddressType() + " address:" + audio_description.getAddress()
                  + " payload_type:" +   rtp_map_attribute.getPayloadType() + " encoding_name:" + rtp_map_attribute.getEncodingName());

            long rtp_sender_handle = libPublisher.CreateRTPSender(0);
            if (0 == rtp_sender_handle) {
                gb28181_agent_.respondTalkInvite(488, device_id_);
                Log.i(TAG, "ntsOnInviteTalk CreateRTPSender failed, response 488, device_id:" + device_id_);
                return;
            }

            gb_talk_rtp_payload_type_  = rtp_map_attribute.getPayloadType();
            gb_talk_rtp_encoding_name_ = rtp_map_attribute.getEncodingName();

            libPublisher.SetRTPSenderTransportProtocol(rtp_sender_handle, audio_description.isRTPOverUDP()?0:1);
            libPublisher.SetRTPSenderIPAddressType(rtp_sender_handle, audio_description.isIPv4()?0:1);
            libPublisher.SetRTPSenderLocalPort(rtp_sender_handle, 0);
            libPublisher.SetRTPSenderSSRC(rtp_sender_handle, audio_description.getSSRC());
            libPublisher.SetRTPSenderSocketSendBuffer(rtp_sender_handle, 256*1024); // 音频配置到256KB
            libPublisher.SetRTPSenderClockRate(rtp_sender_handle, rtp_map_attribute.getClockRate());
            libPublisher.SetRTPSenderDestination(rtp_sender_handle, audio_description.getAddress(), audio_description.getPort());

            gb_talk_is_receive_ = audio_description.isHasAttribute("sendrecv");

            if (gb_talk_is_receive_) {
                libPublisher.EnableRTPSenderReceive(rtp_sender_handle, 1);

                // libPublisher.SetRTPSenderReceiveSSRC(rtp_sender_handle, audio_description.getSSRC());

                libPublisher.SetRTPSenderReceivePayloadType(rtp_sender_handle, gb_talk_rtp_payload_type_, gb_talk_rtp_encoding_name_, 2,  rtp_map_attribute.getClockRate());

                // 目前发现某些平台 PS-PCMA 是8000, 不建议设置
                //if (gb_talk_rtp_encoding_name_.equals("PS")) {
                //    libPublisher.SetRTPSenderReceivePSClockFrequency(rtp_sender_handle, 8000);
                // }

                // 如果是PCMA编码, 采样率和通道可以先不设置
                // libPublisher.SetRTPSenderReceiveAudioSamplingRate(rtp_sender_handle, 8000);
                // libPublisher.SetRTPSenderReceiveAudioChannels(rtp_sender_handle, 1);
            }

            if (libPublisher.InitRTPSender(rtp_sender_handle) != 0 ) {
                gb28181_agent_.respondTalkInvite(488, device_id_);
                libPublisher.DestoryRTPSender(rtp_sender_handle);
                return;
            }

            int local_port = libPublisher.GetRTPSenderLocalPort(rtp_sender_handle);
            if (0==local_port) {
                gb28181_agent_.respondTalkInvite(488, device_id_);
                libPublisher.DestoryRTPSender(rtp_sender_handle);
                return;
            }

            Log.i(TAG,"ntsOnInviteTalk get local_port:" + local_port);

            String local_ip_addr = IPAddrUtils.getIpAddress(context_);

            MediaSessionDescription main_local_audio_des = new MediaSessionDescription(audio_description.getType());

            main_local_audio_des.addFormat(String.valueOf(rtp_map_attribute.getPayloadType()));
            main_local_audio_des.addRtpMapAttribute(rtp_map_attribute);

            main_local_audio_des.addAttribute(new SDPAttribute("sendonly"));
            if (audio_description.isRTPOverTCP()) {
                // tcp主动链接服务端
                main_local_audio_des.addAttribute(new SDPAttribute("setup", "active"));
                main_local_audio_des.addAttribute(new SDPAttribute("connection", "new"));
            }

            main_local_audio_des.setPort(local_port);
            main_local_audio_des.setTransportProtocol(audio_description.getTransportProtocol());

            main_local_audio_des.setSSRC(audio_description.getSSRC());

            MediaSessionDescription sub_local_audio_des = null;
            if (gb_talk_is_receive_) {
                sub_local_audio_des = new MediaSessionDescription(audio_description.getType());

                sub_local_audio_des.addFormat(String.valueOf(rtp_map_attribute.getPayloadType()));
                sub_local_audio_des.addRtpMapAttribute(rtp_map_attribute);

                sub_local_audio_des.addAttribute(new SDPAttribute("recvonly"));
                if (audio_description.isRTPOverTCP()) {
                    // tcp主动链接服务端
                    sub_local_audio_des.addAttribute(new SDPAttribute("setup", "active"));
                    sub_local_audio_des.addAttribute(new SDPAttribute("connection", "new"));
                }

                sub_local_audio_des.setPort(local_port);
                sub_local_audio_des.setTransportProtocol(audio_description.getTransportProtocol());

                sub_local_audio_des.setSSRC(audio_description.getSSRC());
            }

            if (!gb28181_agent_.respondTalkInviteOK(device_id_, audio_description.getAddressType(), local_ip_addr, main_local_audio_des, sub_local_audio_des) ) {
                libPublisher.DestoryRTPSender(rtp_sender_handle);
                Log.e(TAG, "ntsOnInviteTalk call respondPlayInviteOK failed.");
                return;
            }

            gb_talk_rtp_sender_handle_ = rtp_sender_handle;
        }

        private String device_id_;
        private SessionDescription session_description_;

        public Runnable set(String device_id, SessionDescription session_des) {
            this.device_id_ = device_id;
            this.session_description_ = session_des;
            return this;
        }
    }.set(deviceId, sessionDescription),0);
}