InterfaceDemo.py

Enumerate and Control Frame Grabber(s)

It shows how to enumerate one or more frame grabbers via enumeration APIs and perform operations such as turning on frame grabbers and setting attributes.

# -- coding: utf-8 --

import sys
import threading
import platform
import os
from ctypes import *


# Compatible with different operating systems to load DDL
currentsystem = platform.system()
if currentsystem == 'Windows':
    sys.path.append(os.path.join(os.getenv('MVCAM_COMMON_RUNENV'), "Samples", "Python", "MvImport"))
else:
    sys.path.append(os.path.join("..", "..", "MvImport"))

from MvCameraControl_class import *


# Compatible with input processing of Python 2.X and 3.X
if sys.version_info[0] < 3:
    # Python 2.x
    input_func = raw_input
else: 
    # Python 3.x
    input_func = input

# Decoding Characters
def decoding_char(ctypes_char_array):
    """
    Safely decode a string from a ctypes character array.
    Compatible with Python 2.x and 3.x, as well as 32-bit and 64-bit environments.
    """
    byte_str = memoryview(ctypes_char_array).tobytes()
    
    # Truncate at the first null character
    null_index = byte_str.find(b'\x00')
    if null_index != -1:
        byte_str = byte_str[:null_index]
    
    # Attempt to decode using multiple encodings
    for encoding in ['gbk', 'utf-8', 'latin-1']:
        try:
            return byte_str.decode(encoding)
        except UnicodeDecodeError:
            continue
    
    # If all encodings fail, use a replacement strategy
    return byte_str.decode('latin-1', errors='replace')


if __name__ == "__main__":
    
    try:
        # Initialize SDK resources
        MvCamera.MV_CC_Initialize()
        
        SDKVersion = MvCamera.MV_CC_GetSDKVersion()
        print ("SDKVersion[0x%x]" % SDKVersion)
            
        interfaceList = MV_INTERFACE_INFO_LIST()
        transportLayerType = MV_GIGE_INTERFACE | MV_CAMERALINK_INTERFACE | MV_CXP_INTERFACE | MV_XOF_INTERFACE
        
        # Enumerate frame grabbers
        ret = MvCamera.MV_CC_EnumInterfaces(transportLayerType, interfaceList)
        if ret != 0:
            print("enum interfaces fail! ret[0x%x]" % ret)
            sys.exit()

        if interfaceList.nInterfaceNum == 0:
            print("find no interface!")
            sys.exit()

        print("Find %d interfaces!" % interfaceList.nInterfaceNum)

        for i in range(0, interfaceList.nInterfaceNum):
            interfaceInfo = cast(interfaceList.pInterfaceInfos[i], POINTER(MV_INTERFACE_INFO)).contents
            print("interface: [%d]" % i)
            
            displayName = decoding_char(interfaceInfo.chDisplayName)
            print("display name: %s" % displayName)

            serialNumber = decoding_char(interfaceInfo.chSerialNumber)
            print("serial number: %s" % serialNumber)

            modelName = decoding_char(interfaceInfo.chModelName)
            print("model name: %s" % modelName)

            interfaceId = decoding_char(interfaceInfo.chInterfaceID)
            print("interface id: %s" % interfaceId)
            
        nConnectionNum = input_func("please input the number of the interface to connect:")

        if int(nConnectionNum) >= interfaceList.nInterfaceNum:
            print("input error!")
            sys.exit()

        # Create a camera instance
        cam = MvCamera()
        
        # Select the frame grabber, and create a handle
        curInterface = cast(interfaceList.pInterfaceInfos[int(nConnectionNum)], POINTER(MV_INTERFACE_INFO)).contents

        ret = cam.MV_CC_CreateInterface(curInterface)
        if ret != 0:
            raise Exception("create interface handle fail! ret[0x%x]" % ret)
        # Turn on the device
        ret = cam.MV_CC_OpenInterface()
        if ret != 0:
            raise Exception("open interface fail! ret[0x%x]" % ret)
        else:
            print("open interface success")

        # Get features
        stEnumValue = MVCC_ENUMVALUE()
        ret =cam.MV_CC_GetEnumValue("StreamSelector", stEnumValue)
        if ret != 0:
            raise Exception("get StreamSelector fail! ret[0x%x]" % ret)

        # Set features
        ret = cam.MV_CC_SetEnumValue("StreamSelector", stEnumValue.nCurValue)
        if ret != 0:
            raise Exception("set StreamSelector fail! ret[0x%x]" % ret)
        else:
            print("set StreamSelector [%d] success" % stEnumValue.nCurValue)

        # Turn off the frame grabber
        ret = cam.MV_CC_CloseInterface()
        if ret != 0:
            raise Exception("close interface fail! ret[0x%x]" % ret)
        else:
            print("close interface success")

        # Destroy frame grabber handle
        cam.MV_CC_DestroyInterface()

    except Exception as e:
        print(e)
        cam.MV_CC_CloseDevice()
        cam.MV_CC_DestroyInterface()
    finally:
        # Release SDK resources
        MvCamera.MV_CC_Finalize()