camera.py

# camera.py
import ctypes
from contextlib import contextmanager

# load and configure the shared lib once
_lib = ctypes.CDLL("./libcamera.so")

_lib.capture_frame_cpp.restype  = ctypes.c_char_p
_lib.capture_frame_cpp.argtypes = []          # takes no params

_lib.free_frame_cpp.restype     = None
_lib.free_frame_cpp.argtypes    = [ctypes.c_char_p]

class Camera:
    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.close()

    def capture_frame(self) -> str:
        ptr = _lib.capture_frame_cpp()
        if not ptr:
            raise RuntimeError("capture_frame_cpp returned NULL")
        try:
            # Base64 is ASCII-safe
            return ptr.decode("ascii")
        finally:
            _lib.free_frame_cpp(ptr)

    def close(self):
        # _lib.cleanup_camera()
        pass