EasyDarwin开源流媒体云平台之语音对讲功能设计与实现

本文由EasyDarwin开源团队成员Alex贡献：http://blog.csdn.net/cai6811376/article/details/52006958

EasyDarwin云平台一直在稳步的升级迭代中，近日，EasyDarwin云平台实现了语音对讲的功能。对讲功能的加入，标志着EasyDarwin云平台进一步的完善。

• 流程设计

  1. 客户端使用POST的方式在body中携带协议报文向云平台发送开始对讲命令；

  2. 云平台组织协议报文向指定的设备发送；

  3. 设备执行开始对讲命令后向云平台返回相应报文；

  4. 云平台将响应报文返回给客户端；

  5. 客户端请求开始对讲成功后，开始向云平台发送采集的音频数据；

  6. 云平台将音频数据转发给设备；

  7. 设备将音频数据播放出来；

  8. 客户端需要停止对讲时，向云平台发送停止对讲命令；

  9. 云平台转发给设备；

  10. 设备执行停止对讲后返回执行结果给云平台；

  11. 云平台将结果返回给客户端。

• 协议设计

//客户端向云平台发送对讲报文
{
   "EasyDarwin": {
      "Body": {
         "Channel": "0",
         "Command": "START",
         "AudioType": "G711A",
         "Protocol": "ONVIF",
         "Reserve": "1",
         "Serial": "001001000058",
         "Preset": "3",
         "AudioData": "BASE64DATA",
         "Pts": "20"
      },
      "Header": {
         "CSeq": "1",
         "MessageType": "MSG_CS_TALKBACK_CONTROL_REQ",
         "Version": "1.0"
      }
   }
}

格式说明：
Serial：设备序列号；
Channel：摄像机通道号；
Protocol：指定预置位控制方式，ONVIF协议或者设备SDK；
Command：对讲控制命令，包括启动对讲、停止对讲、发送对讲数据(START/STOP/SENDDATA)；
AudioType：音频数据类型，包括G711A/G726；
AudioData：音频数据，将音频数据通过Base64编码发送；
Pts：音频时间戳，开始为0，每20ms增加20；
Reserve:预留。

//云平台响应客户端请求
{
    "EasyDarwin": {
        "Body": {
            "Channel": "0",
            "Protocol": "ONVIF",
            "Reserve": "1",
            "Serial": "001001000058"
        },
        "Header": {
            "CSeq": "1",
            "ErrorNum": "200",
            "ErrorString": "Success OK",
            "MessageType": "MSG_SC_TALKBACK_CONTROL_ACK",
            "Version": "1.0"
        }
    }
}

//云平台向设备发送对讲命令
{
   "EasyDarwin": {
      "Body": {
         "Channel": "0",
         "Command": "SENDDATA",
         "AudioType": "G711A",
         "AudioData": "BASE64DATA",
         "Pts": "20",
         "From": "f6a221eec46b47dea8ae1a2bd11f8d02",
         "Protocol": "ONVIF",
         "Reserve": "1",
         "Serial": "001001000058",
         "To": "245d6ec33cd247b7b7524219552db4d8",
         "Via": "27823d2e8b6b4032b453d435a16b7be8"
      },
      "Header": {
         "CSeq": "1",
         "MessageType": "MSG_SD_CONTROL_TALKBACK_REQ",
         "Version": "1.0"
      }
   }
}

格式说明：
From: EasyCMS接收Client访问的SessionID；
To: EasyCMS向Device发送报文的SessionID；
Via: EasyCMS的ServiceID；

//设备向云平台响应对讲命令
{
   "EasyDarwin": {
      "Body": {
         "Channel": "0",
         "From": "245d6ec33cd247b7b7524219552db4d8",
         "Protocol": "ONVIF",
         "Reserve": "1",
         "Serial": "001001000058",
         "To": "f6a221eec46b47dea8ae1a2bd11f8d02",
         "Via": "27823d2e8b6b4032b453d435a16b7be8"
      },
      "Header": {
         "CSeq": "1",
         "ErrorNum": "200",
         "ErrorString": "Success OK",
         "MessageType": "MSG_DS_CONTROL_TALKBACK_ACK",
         "Version": "1.0"
      }
   }
}

• 实现

//EasyCMS HTTPSession.cpp execNetMsgCSTalkbackControlReq
QTSS_Error HTTPSession::execNetMsgCSTalkbackControlReq(const char* json)
{
    if (!fAuthenticated)//没有进行认证请求
        return httpUnAuthorized;

    EasyProtocol req(json);

    string strDeviceSerial = req.GetBodyValue(EASY_TAG_SERIAL);
    string strChannel = req.GetBodyValue(EASY_TAG_CHANNEL);
    string strProtocol = req.GetBodyValue(EASY_TAG_PROTOCOL);
    string strReserve = req.GetBodyValue(EASY_TAG_RESERVE);
    string strCmd = req.GetBodyValue(EASY_TAG_CMD);
    string strAudioType = req.GetBodyValue(EASY_TAG_AUDIO_TYPE);
    string strAudioData = req.GetBodyValue(EASY_TAG_AUDIO_DATA);
    string strPts = req.GetBodyValue(EASY_TAG_PTS);

    string strCSeq = req.GetHeaderValue(EASY_TAG_CSEQ);//这个是关键字

    if (strChannel.empty())
        strChannel = "0";
    if (strReserve.empty())
        strReserve = "1";

    OSRefTableEx* deviceMap = QTSServerInterface::GetServer()->GetDeviceSessionMap();
    OSRefTableEx::OSRefEx* theDevRef = deviceMap->Resolve(strDeviceSerial);
    if (theDevRef == NULL)//找不到指定设备
        return EASY_ERROR_DEVICE_NOT_FOUND;

    OSRefReleaserEx releaser(deviceMap, strDeviceSerial);
    //走到这说明存在指定设备
    HTTPSession* pDevSession = static_cast<HTTPSession *>(theDevRef->GetObjectPtr());//获得当前设备回话

    string errNo, errString;
    if (strCmd == "SENDDATA")
    {
        if (!pDevSession->GetTalkbackSession().empty() && pDevSession->GetTalkbackSession() == fSessionID)
        {
            EasyProtocolACK reqreq(MSG_SD_CONTROL_TALKBACK_REQ);
            EasyJsonValue headerheader, bodybody;

            char chTemp[16] = { 0 };
            UInt32 uDevCseq = pDevSession->GetCSeq();
            sprintf(chTemp, "%d", uDevCseq);
            headerheader[EASY_TAG_CSEQ] = string(chTemp);//注意这个地方不能直接将UINT32->int,因为会造成数据失真
            headerheader[EASY_TAG_VERSION] = EASY_PROTOCOL_VERSION;

            bodybody[EASY_TAG_SERIAL] = strDeviceSerial;
            bodybody[EASY_TAG_CHANNEL] = strChannel;
            bodybody[EASY_TAG_PROTOCOL] = strProtocol;
            bodybody[EASY_TAG_RESERVE] = strReserve;
            bodybody[EASY_TAG_CMD] = strCmd;
            bodybody[EASY_TAG_AUDIO_TYPE] = strAudioType;
            bodybody[EASY_TAG_AUDIO_DATA] = strAudioData;
            bodybody[EASY_TAG_PTS] = strPts;
            bodybody[EASY_TAG_FROM] = fSessionID;
            bodybody[EASY_TAG_TO] = pDevSession->GetValue(EasyHTTPSessionID)->GetAsCString();
            bodybody[EASY_TAG_VIA] = QTSServerInterface::GetServer()->GetCloudServiceNodeID();

            reqreq.SetHead(headerheader);
            reqreq.SetBody(bodybody);

            string buffer = reqreq.GetMsg();
            StrPtrLen theValue(const_cast<char*>(buffer.c_str()), buffer.size());
            pDevSession->SendHTTPPacket(&theValue, false, false);

            errNo = EASY_ERROR_SUCCESS_OK;
            errString = EasyProtocol::GetErrorString(EASY_ERROR_SUCCESS_OK);
        }
        else
        {
            errNo = EASY_ERROR_CLIENT_BAD_REQUEST;
            errString = EasyProtocol::GetErrorString(EASY_ERROR_CLIENT_BAD_REQUEST);
            goto ACK;
        }
    }
    else
    {
        if (strCmd == "START")
        {
            if (pDevSession->GetTalkbackSession().empty())
            {
                pDevSession->SetTalkbackSession(fSessionID);
                errNo = EASY_ERROR_SUCCESS_OK;
                errString = EasyProtocol::GetErrorString(EASY_ERROR_SUCCESS_OK);
            }
            else
            {
                errNo = EASY_ERROR_CLIENT_BAD_REQUEST;
                errString = EasyProtocol::GetErrorString(EASY_ERROR_CLIENT_BAD_REQUEST);
                goto ACK;
            }
        }
        else if (strCmd == "STOP")
        {
            if (pDevSession->GetTalkbackSession().empty() || pDevSession->GetTalkbackSession() != fSessionID)
            {
                errNo = EASY_ERROR_CLIENT_BAD_REQUEST;
                errString = EasyProtocol::GetErrorString(EASY_ERROR_CLIENT_BAD_REQUEST);
                goto ACK;
            }
            else
            {
                pDevSession->SetTalkbackSession("");
                errNo = EASY_ERROR_SUCCESS_OK;
                errString = EasyProtocol::GetErrorString(EASY_ERROR_SUCCESS_OK);
            }
        }


        EasyProtocolACK reqreq(MSG_SD_CONTROL_TALKBACK_REQ);
        EasyJsonValue headerheader, bodybody;

        char chTemp[16] = { 0 };
        UInt32 uDevCseq = pDevSession->GetCSeq();
        sprintf(chTemp, "%d", uDevCseq);
        headerheader[EASY_TAG_CSEQ] = string(chTemp);//注意这个地方不能直接将UINT32->int,因为会造成数据失真
        headerheader[EASY_TAG_VERSION] = EASY_PROTOCOL_VERSION;

        bodybody[EASY_TAG_SERIAL] = strDeviceSerial;
        bodybody[EASY_TAG_CHANNEL] = strChannel;
        bodybody[EASY_TAG_PROTOCOL] = strProtocol;
        bodybody[EASY_TAG_RESERVE] = strReserve;
        bodybody[EASY_TAG_CMD] = strCmd;
        bodybody[EASY_TAG_AUDIO_TYPE] = strAudioType;
        bodybody[EASY_TAG_AUDIO_DATA] = strAudioData;
        bodybody[EASY_TAG_PTS] = strPts;
        bodybody[EASY_TAG_FROM] = fSessionID;
        bodybody[EASY_TAG_TO] = pDevSession->GetValue(EasyHTTPSessionID)->GetAsCString();
        bodybody[EASY_TAG_VIA] = QTSServerInterface::GetServer()->GetCloudServiceNodeID();

        reqreq.SetHead(headerheader);
        reqreq.SetBody(bodybody);

        string buffer = reqreq.GetMsg();
        StrPtrLen theValue(const_cast<char*>(buffer.c_str()), buffer.size());
        pDevSession->SendHTTPPacket(&theValue, false, false);
    }

ACK:
    char chTemp[16] = { 0 };
    UInt32 uDevCseq = pDevSession->GetCSeq();
    sprintf(chTemp, "%d", uDevCseq);

    EasyProtocolACK rsp(MSG_SC_TALKBACK_CONTROL_ACK);
    EasyJsonValue header, body;
    body[EASY_TAG_SERIAL] = strDeviceSerial;
    body[EASY_TAG_CHANNEL] = strChannel;
    body[EASY_TAG_PROTOCOL] = strProtocol;
    body[EASY_TAG_RESERVE] = strReserve;

    header[EASY_TAG_VERSION] = EASY_PROTOCOL_VERSION;
    header[EASY_TAG_CSEQ] = string(chTemp);;
    header[EASY_TAG_ERROR_NUM] = errNo;
    header[EASY_TAG_ERROR_STRING] = errString;

    rsp.SetHead(header);
    rsp.SetBody(body);
    string msg = rsp.GetMsg();
    StrPtrLen theValueAck(const_cast<char*>(msg.c_str()), msg.size());
    this->SendHTTPPacket(&theValueAck, false, false);

    return QTSS_NoErr;
}

//EasyCamera EasyCameraSource.cpp ControlTalkback
QTSS_Error EasyCameraSource::ControlTalkback(Easy_CameraTalkback_Params* params)
{
    QTSS_Error result = QTSS_RequestFailed;

    if (cameraLogin())
    {
        HI_S32 error = HI_SUCCESS;
        switch (params->inCommand)
        {
        case EASY_TALKBACK_CMD_TYPE_START:
            {
                int type = 1;
                if (params->inType == EASY_TALKBACK_AUDIO_TYPE_G711A)
                    type = 1;
                else if (params->inType == EASY_TALKBACK_AUDIO_TYPE_G726)
                    type = 4;
                error = HI_NET_DEV_StartVoice(m_u32Handle, type);
            }
            break;
        case EASY_TALKBACK_CMD_TYPE_SENDDATA:
            {
                if (params->inBuff == NULL || params->inBuffLen == 0)
                {
                    result = QTSS_BadArgument;
                    break;
                }
                int len = params->inBuffLen;
                int offset = 0;
                int pts = params->inPts;
                while (len >= BUFFLEN)
                {
                    AddHead(fTalkbackBuff, (char*)params->inBuff + offset, BUFFLEN);
                    error = HI_NET_DEV_SendVoiceData(m_u32Handle, fTalkbackBuff, HSBUFFLEN, pts);
                    offset += BUFFLEN;
                    len -= BUFFLEN;
                    pts += PTSPER;
                }
            }
            break;
        case EASY_TALKBACK_CMD_TYPE_STOP:
            error = HI_NET_DEV_StopVoice(m_u32Handle);
            break;
        default:
            result = QTSS_RequestFailed;
            break;
        }

        if (error == HI_SUCCESS)
        {
            result = QTSS_NoErr;
        }
        else
        {
            result = QTSS_RequestFailed;
        }
    }

    return result;
}

代码与文档

EasyDarwin Github：https://github.com/easydarwin

EasyDarwin开源流媒体云平台协议文档：https://github.com/EasyDarwin/EasyDarwin/blob/master/Doc/EasyDarwin%20Protocol.pdf

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