mmcv/video/io.py
def get_frame(self, frame_id):
        """Get frame by index.

        Args:
            frame_id (int): Index of the expected frame, 0-based.

        Returns:
            ndarray or None: Return the frame if successful, otherwise None.
        """
        if frame_id < 0 or frame_id >= self._frame_cnt:
            raise IndexError(
                '"frame_id" must be between 0 and {}'.format(self._frame_cnt -
                                                             1))
        if frame_id == self._position:
            return self.read()
        if self._cache:
            img = self._cache.get(frame_id)
            if img is not None:
                self._position = frame_id + 1
                return img
        self._set_real_position(frame_id)
        ret, img = self._vcap.read()
        if ret:
            if self._cache:
                self._cache.put(self._position, img)
            self._position += 1
        return img
def get_frame(self, frame_id):
        if frame_id < 0 or frame_id >= self._frame_cnt:
            raise IndexError(
                '"frame_id" must be between 0 and {}'.format(self._frame_cnt -
                                                             1))
        if frame_id == self._position:
            return self.read()
        if self._cache:
            img = self._cache.get(frame_id)
            if img is not None:
                self._position = frame_id + 1
                return img
        self._set_real_position(frame_id)
        ret, img = self._vcap.read()
        if ret:
            if self._cache:
                self._cache.put(self._position, img)
            self._position += 1
        return img
def get_frame ( self , frame_id ) : if frame_id < 0 or frame_id >= self . _frame_cnt : raise IndexError ( '"frame_id" must be between 0 and {}' . format ( self . _frame_cnt - 1 ) ) if frame_id == self . _position : return self . read ( ) if self . _cache : img = self . _cache . get ( frame_id ) if img is not None : self . _position = frame_id + 1 return img self . _set_real_position ( frame_id ) ret , img = self . _vcap . read ( ) if ret : if self . _cache : self . _cache . put ( self . _position , img ) self . _position += 1 return img
Get frame by index.

        Args:
            frame_id (int): Index of the expected frame, 0-based.

        Returns:
            ndarray or None: Return the frame if successful, otherwise None.
Get frame by index .