• numpy中,从一片c_void_p指向的区域里获取数据


    以前采用的数据拷贝的笨办法:

    1 bitmap_size = (1080, 1920, 3)
    2 buf = create_string_buffer(bitmap_size[0]*bitmap_size[1]*bitmap_size[2])
    3 pointer_data = c_void_p(addressof(xxxx))
    4 memmove(buf, pointer_data, bitmap_size[0]*bitmap_size[1]*bitmap_size[2])
    5 #
    6 np_arr = np.frombuffer(buf, dtype=np.uint8, count=bitmap_size[0]*bitmap_size[1]*bitmap_size[2])
    7 np_arr = np_arr.reshape(bitmap_size)

    现在找到了更好的办法,不用拷贝数据:

    1 bitmap_size = (1080, 1920, 3)
    2 bytes_count = bitmap_size[0]*bitmap_size[1]*bitmap_size[2]
    3 pointer_data = c_void_p(addressof(xxxx))
    4 #定义一个指向数组的指针
    5 array_pointer = cast(pointer_data, POINTER(c_char*bytes_count)))
    6 np_arr = np.frombuffer(array_pointer.contents, dtype=np.uint8, count=bytes_count)
    7 np_arr = np_arr.reshape(bitmap_size)
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  • 原文地址:https://www.cnblogs.com/ahfuzhang/p/10920095.html
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