python3 大华IP摄像头使用 SDK DLL 添加动态文字叠加

#! usr/bin/python#coding=utf-8from ctypes.wintypes import DWORDfrom ctypes import *import timeimport ctypes import ctypes.utilimport jsonObjdll = WinDLL("d:/python/dhnetsdk.dll") def DisConnectFunc( lLoginID, a, nDVRPort, dwUser):printf("Device disconn, IP=%s \n");class msginf(Structure): _fields_ = [ ('bEnable', c_bool), ('dwPosition', DWORD * 6), ('szStrings', c_char_p *6 )]def ctypes_alloc_aligned(size, alignment): buf_size = size (alignment - 1) #?bytearray?? raw_memory = bytearray(buf_size) #?raw_memory?ctypes ctypes_raw_type = (ctypes.c_char * buf_size) ctypes_raw_memory = ctypes_raw_type.from_buffer(raw_memory) #?ctypesaddressof??? raw_address = ctypes.addressof(ctypes_raw_memory) offset = raw_address % alignment #????ó?? offset_to_aligned = (alignment - offset) % alignment ctypes_aligned_type = (ctypes.c_char * (buf_size - offset_to_aligned)) #????ctype ctypes_aligned_memory = ctypes_aligned_type.from_buffer(raw_memory, offset_to_aligned) return ctypes_aligned_memorylibc = ctypes.CDLL(ctypes.util.find_library('c')) #?4k? CMPFUNC = CFUNCTYPE(c_int64, POINTER(c_char),c_int64, DWORD)CMPFUNC = CFUNCTYPE(c_int64, POINTER(c_char),c_int64, DWORD)_callback = CMPFUNC( DisConnectFunc)Objdll.CLIENT_Init(_callback, 0); #如果没有这句就不能登录. 这个函数,是凑合注册和定义的..参数是按照文档要求的Objdll.CLIENT_SetAutoReconnect(_callback, 0);#// 豸????#CLIENT_NET_API void CALL_METHOD CLIENT_SetConnectTime(int nWaitTime, int nTryTimes);Objdll.CLIENT_SetConnectTime(3000,3) i=c_int(13)ipcamID=c_long()ipcamID= Objdll.CLIENT_Login(b"10.71.12.62",37777,b"admin",b"admin",0, byref(i))print ("出错代码",i)print( 'handle',ipcamID)#i成功返回０，否则是错误码，比如密码错1 文档中有说明,, 成功返回一个大数，是handle. ,失败则是0 #这个buf的内存函数很关键，有了它才有了后面的一切。对于python ,调用来说。需要传递一个合适的引用。可读可写。注释被我切换代码时干掉了。buf=ctypes_alloc_aligned(32*1024,4096)CMD_STR=b"VideoWidget" # b"ChannelTitle" #re =Objdll.CLIENT_GetNewDevConfig(ipcamID,CMD_STR,0,byref(buf),32*1024,byref(i),5000) print ("取参数:",re,i)ff=open("d:/python/json12.py","w ")ss=buf.value.strip().decode()if re and ss: oo=json.loads(ss) print("\r\n返回长度:", len(ss)) if len(ss)<200: print(ss,"\r\n\r\n",oo,"\r\n\r\n") ff.write(ss "\r\n") ff.close() print (oo["params"]["table"]['CustomTitle'] ) Custom= oo["params"]["table"]['CustomTitle'] Custom[0]["PreviewBlend"]= True # Custom[0]["EncodeBlend"] Custom[0]["EncodeBlend"]= True # Custom[0]["PreviewBlend"] Custom[0]["Text"]= "eTrue" #这里是占位符了。 param=Custom [0] # 做为utf-8字符，json模块打包会改称　‘\uec98\uef88’这样四个字节的样子。而dll接口要求中文是三字节。测试发现，发现这样可以。 #json 可以指定参数。那时就简单了。目前这是显示中文的笨方法。 param=json.dumps(param) .replace('eTrue','条目测试 ') .encode() param=(param b',' )*5 param #由于结尾如果多出一个‘’，‘’。摄像头不支持。所以，这样制作了６个相同的字符。做测试用。 param =b'{"CustomTitle": [' param b'] }' #它要在参数只有这一项。　所以改写其他参数可以参考这样实现。bytes类型的。 # print( param) # update=json.dumps({"Name":oo["params"] }) # update=json.dumps({"Name" :r'\xe6\x89\x93\xe5\xbc\x80' }) # update["table"]["CustomTitle"][0]["Text"]="654321" re =Objdll.CLIENT_SetNewDevConfig(ipcamID,CMD_STR,0,param, 32*1024,byref(i),i,5000) print ("设置参数",re,i)print(Objdll.CLIENT_GetLastError())Objdll.CLIENT_Logout(ipcamID)Objdll.CLIENT_Cleanup()a=str(input("-:"))