使用大华SDK对接视频监控实时播放和回放示例

以下是一个使用大华SDK对接视频监控实时播放和回放的示例，供参考：

import time
import sys
import os
from ctypes import *
from datetime import datetime
import threading

# 大华SDK库文件路径
SDK_PATH = 'C:\\dahua\\SDK\\DHNetSDK.dll'

# 初始化SDK
NET_DVR_Init = windll.DHNetSDK.NET_DVR_Init
NET_DVR_Init.argtypes = None
NET_DVR_Init.restype = c_bool
NET_DVR_Init()

# 登录设备
NET_DVR_Login_V40 = windll.DHNetSDK.NET_DVR_Login_V40
NET_DVR_Login_V40.argtypes = [POINTER(c_int), POINTER(wchar_t), POINTER(c_int), POINTER(wchar_t), \
    POINTER(wchar_t), POINTER(c_int), POINTER(c_int), POINTER(NET_DVR_DEVICEINFO_V40)]
NET_DVR_Login_V40.restype = c_long

lUserID = c_long(-1)
deviceIP = '192.168.1.64'
devicePort = 8000
userName = 'admin'
password = 'admin123'
DeviceInfo = NET_DVR_DEVICEINFO_V40()
ret = NET_DVR_Login_V40(byref(lUserID), deviceIP.encode('utf-8'), devicePort, userName.encode('utf-8'), \
    password.encode('utf-8'), None, None, byref(DeviceInfo))
if ret < 0:
    print('登录失败，错误码：{}'.format(NET_DVR_GetLastError()))
else:
    print('登录成功')

# 实时预览
NET_DVR_RealPlay_V40 = windll.DHNetSDK.NET_DVR_RealPlay_V40
NET_DVR_RealPlay_V40.argtypes = [c_long, POINTER(NET_DVR_PREVIEWINFO), c_void_p, c_void_p]
NET_DVR_RealPlay_V40.restype = c_long

NET_DVR_PREVIEWINFO = struct_net_dvr_previewinfo()

class struct_net_dvr_previewinfo(Structure):
    _fields_ = [('lChannel', c_long),
                ('dwStreamType', c_ulong),
                ('dwLinkMode', c_ulong),
                ('hPlayWnd', c_void_p),
                ('bBlocked', c_bool),
                ('bPassbackRecord', c_bool),
                ('byPreviewMode', c_byte),
                ('byProtoType', c_byte * 3),
                ('byRes', c_byte * 2),
                ('union', c_ulong * 2)]

lRealPlayHandle = c_long(-1)
PreviewInfo = NET_DVR_PREVIEWINFO()
PreviewInfo.lChannel = 1
PreviewInfo.dwStreamType = 0
PreviewInfo.dwLinkMode = 0
PreviewInfo.hPlayWnd = None
PreviewInfo.bBlocked = 1
lRealPlayHandle = NET_DVR_RealPlay_V40(lUserID, byref(PreviewInfo), None, None)
if lRealPlayHandle < 0:
    print('实时预览失败，错误码：{}'.format(NET_DVR_GetLastError()))
else:
    print('实时预览成功')

# 回放
NET_DVR_FindFile_V30 = windll.DHNetSDK.NET_DVR_FindFile_V30
NET_DVR_FindFile_V30.argtypes = [c_long, POINTER(NET_DVR_FILECOND),]
NET_DVR_FindFile_V30.restype = c_long

NET_DVR_FILECOND = struct_net_dvr_filecond()

class struct_net_dvr_filecond(Structure):
    _fields_ = [('lChannel', c_long),
                ('dwFileType', c_ulong),
                ('dwIsLocked', c_ulong),
                ('dwUseCardNo', c_ulong),
                ('struStartTime', NET_DVR_TIME),
                ('struStopTime', NET_DVR_TIME),
                ('sCardNumber', c_byte * 32),
                ('dwFileSize', c_ulong)]

NET_DVR_TIME = struct_net_dvr_time()

class struct_net_dvr_time(Structure):
    _fields_ = [('dwYear', c_ulong),
                ('dwMonth', c_ulong),
                ('dwDay', c_ulong),
                ('dwHour', c_ulong),
                ('dwMinute', c_ulong),
                ('dwSecond', c_ulong)]

NET_DVR_FindNextFile_V30 = windll.DHNetSDK.NET_DVR_FindNextFile_V30
NET_DVR_FindNextFile_V30.argtypes = [c_long, POINTER(NET_DVR_FINDDATA_V30)]
NET_DVR_FindNextFile_V30.restype = c_bool

NET_DVR_FINDDATA_V30 = struct_net_dvr_finddata_v30()

class struct_net_dvr_finddata_v30(Structure):
    _fields_ = [('sFileName', c_byte * 100),
                ('struStartTime', NET_DVR_TIME),
                ('struStopTime', NET_DVR_TIME),
                ('dwFileSize', c_ulong),
                ('sCardNum', c_byte * 32),
                ('byLocked', c_byte),
                ('byFileType', c_byte),
                ('byQuickSearch', c_byte),
                ('byRes', c_byte * 2)]

NET_DVR_PlayBackByTime_V40 = windll.DHNetSDK.NET_DVR_PlayBackByTime_V40
NET_DVR_PlayBackByTime_V40.argtypes = [c_long, POINTER(NET_DVR_VOD_PARA), c_void_p]
NET_DVR_PlayBackByTime_V40.restype = c_long

NET_DVR_VOD_PARA = struct_net_dvr_vod_para()

class struct_net_dvr_vod_para(Structure):
    _fields_ = [('dwSize', c_ulong),
                ('struIDInfo', NET_DVR_STREAM_INFO),
                ('hWnd', c_void_p),
                ('lpUserData', c_void_p),
                ('struBeginTime', NET_DVR_TIME),
                ('struEndTime', NET_DVR_TIME),
                ('byDrawFrame', c_byte),
                ('byVolumeType', c_byte),
                ('byVolumeNum', c_byte),
                ('byStreamType', c_byte),
                ('byAudioType', c_byte),
                ('byVideoEncType', c_byte),
                ('byAudioEncType', c_byte),
                ('byVideoResolution', c_byte),
                ('byNetType', c_byte),
                ('dwEngineVersion', c_ulong),
                ('bySupportStreamEncrypt', c_byte),
                ('byRes', c_byte * 7)]

NET_DVR_STREAM_INFO = struct_net_dvr_stream_info()

class struct_net_dvr_stream_info(Structure):
    _fields_ = [('dwSize', c_ulong),
                ('byID', c_byte * 48),
                ('byRes', c_byte * 4),
                ('dwChannel', c_ulong),
                ('byRes1', c_byte * 16)]

lPlaybackHandle = c_long(-1)
FileCond = NET_DVR_FILECOND()
FileCond.lChannel = 1
FileCond.dwFileType = 0xff
FileCond.struStartTime.dwYear = 2021
FileCond.struStartTime.dwMonth = 7
FileCond.struStartTime.dwDay = 1
FileCond.struStartTime.dwHour = 0
FileCond.struStartTime.dwMinute = 0
FileCond.struStartTime.dwSecond = 0
FileCond.struStopTime.dwYear = 2021
FileCond.struStopTime.dwMonth = 7
FileCond.struStopTime.dwDay = 1
FileCond.struStopTime.dwHour = 23
FileCond.struStopTime.dwMinute = 59
FileCond.struStopTime.dwSecond = 59
FileHandle = NET_DVR_FindFile_V30(lUserID, byref(FileCond))
if FileHandle >= 0:
    FindData = NET_DVR_FINDDATA_V30()
    while NET_DVR_FindNextFile_V30(FileHandle, byref(FindData)):
        PlaybackInfo = NET_DVR_VOD_PARA()
        PlaybackInfo.struIDInfo.dwChannel = FileCond.lChannel
        PlaybackInfo.struBeginTime = FindData.struStartTime
        PlaybackInfo.struEndTime = FindData.struStopTime
        lPlaybackHandle = NET_DVR_PlayBackByTime_V40(lUserID, byref(PlaybackInfo), None)
        if lPlaybackHandle < 0:
            print('回放失败，错误码：{}'.format(NET_DVR_GetLastError()))
        else:
            print('回放成功')
            time.sleep(10)
            NET_DVR_StopPlayBack = windll.DHNetSDK.NET_DVR_StopPlayBack
            NET_DVR_StopPlayBack.argtypes = [c_long]
            NET_DVR_StopPlayBack.restype = c_bool
            NET_DVR_StopPlayBack(lPlaybackHandle)
    NET_DVR_FindClose = windll.DHNetSDK.NET_DVR_FindClose
    NET_DVR_FindClose.argtypes = [c_long]
    NET_DVR_FindClose(FileHandle)

# 释放SDK资源
NET_DVR_Logout = windll.DHNetSDK.NET_DVR_Logout
NET_DVR_Logout.argtypes = [c_long]
NET_DVR_Logout.restype = c_bool
NET_DVR_Logout(lUserID)

NET_DVR_Cleanup = windll.DHNetSDK.NET_DVR_Cleanup
NET_DVR_Cleanup.argtypes = None
NET_DVR_Cleanup.restype = c_bool
NET_DVR_Cleanup()

需要注意的是，以上示例代码中使用的`NET_DVR_PREVIEWINFO`和`NET_DVR_VOD_PARA`结构体以及相关的字段定义均来自于大华SDK文档，具体可根据实际应用场景进行调整。此外，因为回放需要先查找可用的录像文件，因此在回放示例中还使用了`NET_DVR_FindFile_V30`和`NET_DVR_FindNextFile_V30`函数来查找录像文件。