原理简介
IPC图像抓拍有两种方法：
- 对RTSP视频流进行视频截图；
- 使用HTTP的GET方式获取图片。
以下介绍第二种方法。
ONVIF协议除了提供RTSP的URL外，其实也给出了抓拍的URL，使用Media模块的GetSnapshotUri接口可获取图像抓拍的URL。
比如，我从IPC获得的抓拍URL为：http://100.100.100.160/onvifsnapshot/media_service/snapshot?channel=1&subtype=0。
那如何通过这个地址获得图片呢？其实在media.wsdl中，该接口的函数功能说明中已经描述的很清楚了：「The URI can be used for acquiring a JPEG image through a HTTP GET operation」，也就是通过HTTP的GET方式获得JPEG图片。
在浏览器上输入抓拍的URL，在浏览器中就会显示出图片，刷新，图片会变化，对于需要验证的IPC，会要求我们输入用户名密码进行HTTP用户认证。
编码流程
- 通过「设备发现」，得到 「设备服务地址」。
- 使用「设备服务地址」调用GetCapabilities接口，得到「媒体服务地址」。
- 使用「媒体服务地址」调用GetProfiles接口，得到主次码流的「媒体配置信息」，其中包含ProfileToken。
- 使用ProfileToken 调用GetSnapshotUri接口，得到主次码图像抓拍的URI地址。
- 根据URI地址，使用HTTP的GET方式获取图片。
- Windows的MFC里有CInternetSession，CHttpConnection，CHttpFile这些类提供通过HTTP获得图像数据。
- Linux可以使用很多开源方案，甚至可以直接使用shell命令wget来下载图像即可，简单高效。比如：
如果需要带认证信息，可以使用：wget -O out.jpeg 'http://100.100.100.5:80/capture/webCapture.jpg?channel=1&FTpsend=0&checkinfo=0'wget -O out.jpeg 'http://username:password@100.100.100.5:80/capture/webCapture.jpg?channel=1&FTpsend=0&checkinfo=0'
示例代码
具体请参见
除了onvif_head.sh修改为：
#!/bin/bash
mkdir onvif_head
cd onvif_head
../bin/wsdl2h -o onvif.h -s -d -x -t ../gsoap/WS/typemap.dat \
http://www.onvif.org/onvif/ver10/network/wsdl/remotediscovery.wsdl \
https://www.onvif.org/onvif/ver10/device/wsdl/devicemgmt.wsdlmain.cpp修改为
#include <assert.h>
#include "soapH.h"
#include "wsdd.nsmap"
#include "soapStub.h"
#include "wsseapi.h"
#include "wsaapi.h"
#include <map>#define SOAP_ASSERT assert
#define SOAP_DBGLOG printf
#define SOAP_DBGERR printf#define SOAP_TO "urn:schemas-xmlsoap-org:ws:2005:04:discovery"
#define SOAP_ACTION "http://schemas.xmlsoap.org/ws/2005/04/discovery/Probe"#define SOAP_MCAST_ADDR "soap.udp://239.255.255.250:3702" // onvif规定的组播地址#define SOAP_ITEM "" // 寻找的设备范围
#define SOAP_TYPES "dn:NetworkVideoTransmitter" // 寻找的设备类型#define SOAP_SOCK_TIMEOUT (10) // socket超时时间（单秒秒）void soap_perror(struct soap *soap, const char *str)
{
if (nullptr == str) {
SOAP_DBGERR("[soap] error: %d, %s, %s\n", soap->error, *soap_faultcode(soap), *soap_faultstring(soap));} else {
SOAP_DBGERR("[soap] %s error: %d, %s, %s\n", str, soap->error, *soap_faultcode(soap), *soap_faultstring(soap));}
}void* ONVIF_soap_malloc(struct soap *soap, unsigned int n)
{
void *p = nullptr;if (n > 0) {
p = soap_malloc(soap, n);SOAP_ASSERT(nullptr != p);memset(p, 0x00 ,n);}return p;
}struct soap *ONVIF_soap_new(int timeout)
{
struct soap *soap = nullptr; // soap环境变量SOAP_ASSERT(nullptr != (soap = soap_new()));soap_set_namespaces(soap, namespaces); // 设置soap的namespacessoap->recv_timeout = timeout; // 设置超时（超过指定时间没有数据就退出）soap->send_timeout = timeout;soap->connect_timeout = timeout;#if defined(__linux__) || defined(__linux) // 参考https://www.genivia.com/dev.html#client-c的修改：soap->socket_flags = MSG_NOSIGNAL; // To prevent connection reset errors
#endifsoap_set_mode(soap, SOAP_C_UTFSTRING); // 设置为UTF-8编码，否则叠加中文OSD会乱码return soap;
}void ONVIF_soap_delete(struct soap *soap)
{
soap_destroy(soap); // remove deserialized class instances (C++ only)soap_end(soap); // Clean up deserialized data (except class instances) and temporary datasoap_done(soap); // Reset, close communications, and remove callbackssoap_free(soap); // Reset and deallocate the context created with soap_new or soap_copy
}/************************************************************************ **函数：ONVIF_init_header **功能：初始化soap描述消息头 **参数：[in] soap - soap环境变量 **返回：无 **备注：1). 在本函数内部通过ONVIF_soap_malloc分配的内存，将在ONVIF_soap_delete中被释放 ************************************************************************/
void ONVIF_init_header(struct soap *soap)
{
struct SOAP_ENV__Header *header = nullptr;SOAP_ASSERT(nullptr != soap);header = (struct SOAP_ENV__Header *)ONVIF_soap_malloc(soap, sizeof(struct SOAP_ENV__Header));soap_default_SOAP_ENV__Header(soap, header);header->wsa__MessageID = (char*)soap_wsa_rand_uuid(soap);header->wsa__To = (char*)ONVIF_soap_malloc(soap, strlen(SOAP_TO) + 1);header->wsa__Action = (char*)ONVIF_soap_malloc(soap, strlen(SOAP_ACTION) + 1);strcpy(header->wsa__To, SOAP_TO);strcpy(header->wsa__Action, SOAP_ACTION);soap->header = header;
}/************************************************************************ **函数：ONVIF_init_ProbeType **功能：初始化探测设备的范围和类型 **参数：[in] soap - soap环境变量[out] probe - 填充要探测的设备范围和类型 **返回：0表明探测到，非0表明未探测到 **备注：1). 在本函数内部通过ONVIF_soap_malloc分配的内存，将在ONVIF_soap_delete中被释放 ************************************************************************/
void ONVIF_init_ProbeType(struct soap *soap, struct wsdd__ProbeType *probe)
{
struct wsdd__ScopesType *scope = nullptr; // 用于描述查找哪类的Web服务SOAP_ASSERT(nullptr != soap);SOAP_ASSERT(nullptr != probe);scope = (struct wsdd__ScopesType *)ONVIF_soap_malloc(soap, sizeof(struct wsdd__ScopesType));soap_default_wsdd__ScopesType(soap, scope); // 设置寻找设备的范围scope->__item = (char*)ONVIF_soap_malloc(soap, strlen(SOAP_ITEM) + 1);strcpy(scope->__item, SOAP_ITEM);memset(probe, 0x00, sizeof(struct wsdd__ProbeType));soap_default_wsdd__ProbeType(soap, probe);probe->Scopes = scope;probe->Types = (char*)ONVIF_soap_malloc(soap, strlen(SOAP_TYPES) + 1); // 设置寻找设备的类型strcpy(probe->Types, SOAP_TYPES);
}void ONVIF_DetectDevice(void (*cb)(char *DeviceXAddr))
{
int i;int result = 0;unsigned int count = 0; // 搜索到的设备个数struct soap *soap = nullptr; // soap环境变量struct wsdd__ProbeType req; // 用于发送Probe消息struct __wsdd__ProbeMatches rep; // 用于接收Probe应答struct wsdd__ProbeMatchType *probeMatch;SOAP_ASSERT(nullptr != (soap = ONVIF_soap_new(SOAP_SOCK_TIMEOUT)));ONVIF_init_header(soap); // 设置消息头描述ONVIF_init_ProbeType(soap, &req); // 设置寻找的设备的范围和类型result = soap_send___wsdd__Probe(soap, SOAP_MCAST_ADDR, nullptr, &req); // 向组播地址广播Probe消息while (SOAP_OK == result) // 开始循环接收设备发送过来的消息{
memset(&rep, 0x00, sizeof(rep));result = soap_recv___wsdd__ProbeMatches(soap, &rep);if (SOAP_OK == result) {
if (soap->error) {
soap_perror(soap, "ProbeMatches");} else {
// 成功接收到设备的应答消息// printf("__sizeProbeMatch:%d\n",rep.wsdd__ProbeMatches->__sizeProbeMatch);if (nullptr != rep.wsdd__ProbeMatches) {
count += rep.wsdd__ProbeMatches->__sizeProbeMatch;for(i = 0; i < rep.wsdd__ProbeMatches->__sizeProbeMatch; i++) {
probeMatch = rep.wsdd__ProbeMatches->ProbeMatch + i;if (nullptr != cb ) {
std::string url = probeMatch->XAddrs;if(url == "http://192.168.0.116/onvif/device_service"){
cb(probeMatch->XAddrs); // 使用设备服务地址执行函数回调}}}}}} else if (soap->error) {
break;}}SOAP_DBGLOG("\ndetect end! It has detected %d devices!\n", count);if (nullptr != soap) {
ONVIF_soap_delete(soap);}}#define SOAP_CHECK_ERROR(result, soap, str) \do { \if (SOAP_OK != (result) || SOAP_OK != (soap)->error) { \soap_perror((soap), (str)); \if (SOAP_OK == (result)) { \(result) = (soap)->error; \} \goto EXIT; \} \ } while (0)/************************************************************************ **函数：ONVIF_SetAuthInfo **功能：设置认证信息 **参数：[in] soap - soap环境变量[in] username - 用户名[in] password - 密码 **返回：0表明成功，非0表明失败 **备注： ************************************************************************/
static int ONVIF_SetAuthInfo(struct soap *soap, const char *username, const char *password)
{
int result = 0;SOAP_ASSERT(nullptr != username);SOAP_ASSERT(nullptr != password);result = soap_wsse_add_UsernameTokenDigest(soap, NULL, username, password);SOAP_CHECK_ERROR(result, soap, "add_UsernameTokenDigest");EXIT:return result;
}#define USERNAME "admin"
#define PASSWORD "hik12345"
/************************************************************************ **函数：ONVIF_GetDeviceInformation **功能：获取设备基本信息 **参数：[in] DeviceXAddr - 设备服务地址 **返回：0表明成功，非0表明失败 **备注： ************************************************************************/
int ONVIF_GetDeviceInformation(const char *DeviceXAddr)
{
int result = 0;struct soap *soap = nullptr;_tds__GetDeviceInformation devinfo_req;_tds__GetDeviceInformationResponse devinfo_resp;SOAP_ASSERT(nullptr != DeviceXAddr);SOAP_ASSERT(nullptr != (soap = ONVIF_soap_new(SOAP_SOCK_TIMEOUT)));ONVIF_SetAuthInfo(soap, USERNAME, PASSWORD);result = soap_call___tds__GetDeviceInformation(soap, DeviceXAddr, nullptr, &devinfo_req, devinfo_resp);SOAP_CHECK_ERROR(result, soap, "GetDeviceInformation");std::cout << " Manufacturer:\t" << devinfo_resp.Manufacturer << "\n";std::cout << " Model:\t" << devinfo_resp.Model << "\n";std::cout << " FirmwareVersion:\t" << devinfo_resp.FirmwareVersion << "\n";std::cout << " SerialNumber:\t" << devinfo_resp.SerialNumber << "\n";std::cout << " HardwareId:\t" << devinfo_resp.HardwareId << "\n";EXIT:if (nullptr != soap) {
ONVIF_soap_delete(soap);}return result;
}/************************************************************************ **函数：ONVIF_GetSnapshotUri **功能：获取设备图像抓拍地址(HTTP) **参数：[in] MediaXAddr - 媒体服务地址[in] ProfileToken - the media profile token[out] uri - 返回的地址[in] sizeuri - 地址缓存大小 **返回：0表明成功，非0表明失败 **备注：1). 并非所有的ProfileToken都支持图像抓拍地址。举例：XXX品牌的IPC有如下三个配置profile0/profile1/TestMediaProfile，其中TestMediaProfile返回的图像抓拍地址就是空指针。 ************************************************************************/
int ONVIF_GetSnapshotUri(const std::string& MediaXAddr, const std::string& ProfileToken, std::string * snapUri)
{
int result = 0;struct soap *soap = nullptr;_trt__GetSnapshotUri req;_trt__GetSnapshotUriResponse rep;SOAP_ASSERT(!MediaXAddr.empty() && !ProfileToken.empty());SOAP_ASSERT(nullptr != (soap = ONVIF_soap_new(SOAP_SOCK_TIMEOUT)));ONVIF_SetAuthInfo(soap, USERNAME, PASSWORD);req.ProfileToken = const_cast<char *>(ProfileToken.c_str());result = soap_call___trt__GetSnapshotUri(soap, MediaXAddr.c_str(), NULL, &req, rep);SOAP_CHECK_ERROR(result, soap, "GetSnapshotUri");if (nullptr != rep.MediaUri && nullptr != rep.MediaUri->Uri) {
*snapUri = rep.MediaUri->Uri;}EXIT:if (NULL != soap) {
ONVIF_soap_delete(soap);}return result;
}bool ONVIF_GetProfiles(const std::string& mediaXAddr, std::string * profilesToken)
{
int result = 0;struct soap *soap = nullptr;_trt__GetProfiles devinfo_req;_trt__GetProfilesResponse devinfo_resp;SOAP_ASSERT(!mediaXAddr.empty());SOAP_ASSERT(nullptr != (soap = ONVIF_soap_new(SOAP_SOCK_TIMEOUT)));ONVIF_SetAuthInfo(soap, USERNAME, PASSWORD);result = soap_call___trt__GetProfiles(soap, mediaXAddr.c_str(), nullptr, &devinfo_req, devinfo_resp);SOAP_CHECK_ERROR(result, soap, "ONVIF_GetProfiles");SOAP_ASSERT(devinfo_resp.__sizeProfiles > 0);*profilesToken = (*devinfo_resp.Profiles)->token;EXIT:if (nullptr != soap) {
ONVIF_soap_delete(soap);}return result;
}/************************************************************************ **函数：ONVIF_GetCapabilities **功能：获取设备能力信息 **参数：[in] DeviceXAddr - 设备服务地址[in] **返回：0表明成功，非0表明失败 **备注：1). 其中最主要的参数之一是媒体服务地址 ************************************************************************/
int ONVIF_GetCapabilities(const std::string& deviceXAddr, std::string * mediaXAddr)
{
int result = 0;struct soap *soap = nullptr;_tds__GetCapabilities devinfo_req;_tds__GetCapabilitiesResponse devinfo_resp;SOAP_ASSERT(!deviceXAddr.empty());SOAP_ASSERT(nullptr != (soap = ONVIF_soap_new(SOAP_SOCK_TIMEOUT)));result = soap_call___tds__GetCapabilities(soap, deviceXAddr.c_str(), NULL, &devinfo_req, devinfo_resp);SOAP_CHECK_ERROR(result, soap, "GetCapabilities");if(devinfo_resp.Capabilities->Media != nullptr){
*mediaXAddr = devinfo_resp.Capabilities->Media->XAddr;}EXIT:if (nullptr != soap) {
ONVIF_soap_delete(soap);}return result;
}/************************************************************************ **函数：make_uri_withauth **功能：构造带有认证信息的URI地址 **参数：[in] src_uri - 未带认证信息的URI地址[in] username - 用户名[in] password - 密码[out] dest_uri - 返回的带认证信息的URI地址[in] size_dest_uri - dest_uri缓存大小 **返回：0成功，非0失败 **备注：1). 例子：无认证信息的uri：rtsp://100.100.100.140:554/av0_0带认证信息的uri：rtsp://username:password@100.100.100.140:554/av0_0 ************************************************************************/
static int make_uri_withauth(const std::string& src_uri, const std::string&username, const std::string&password, std::string *dest_uri)
{
int result = 0;SOAP_ASSERT(!src_uri.empty());if (username.empty() &&password.empty()) {
// 生成新的uri地址*dest_uri = src_uri;} else {
std::string::size_type position = src_uri.find("//");if (std::string::npos == position) {
SOAP_DBGERR("can't found '//', src uri is: %s.\n", src_uri.c_str());result = -1;return result;}position += 2;dest_uri->append(src_uri,0, position) ;dest_uri->append(username + ":" + password + "@");dest_uri->append(src_uri,position, std::string::npos) ;}return result;
}void cb_discovery(char *deviceXAddr)
{
std::string mediaXAddr, profilesToken, snapUri, snapAuthUri;ONVIF_GetCapabilities(deviceXAddr, &mediaXAddr);ONVIF_GetProfiles(mediaXAddr, &profilesToken);ONVIF_GetSnapshotUri(mediaXAddr, profilesToken, &snapUri);make_uri_withauth(snapUri, USERNAME, PASSWORD, &snapAuthUri);char cmd[256];sprintf(cmd, "wget -O %s '%s'", "out.jpeg", snapAuthUri.c_str()); // 使用wget下载图片system(cmd);
}int main(int argc, char **argv)
{
ONVIF_DetectDevice(cb_discovery);return 0;
}