mmcv/video/io.py
def read(self):
        """Read the next frame.

        If the next frame have been decoded before and in the cache, then
        return it directly, otherwise decode, cache and return it.

        Returns:
            ndarray or None: Return the frame if successful, otherwise None.
        """
        # pos = self._position
        if self._cache:
            img = self._cache.get(self._position)
            if img is not None:
                ret = True
            else:
                if self._position != self._get_real_position():
                    self._set_real_position(self._position)
                ret, img = self._vcap.read()
                if ret:
                    self._cache.put(self._position, img)
        else:
            ret, img = self._vcap.read()
        if ret:
            self._position += 1
        return img
def read(self):
        # pos = self._position
        if self._cache:
            img = self._cache.get(self._position)
            if img is not None:
                ret = True
            else:
                if self._position != self._get_real_position():
                    self._set_real_position(self._position)
                ret, img = self._vcap.read()
                if ret:
                    self._cache.put(self._position, img)
        else:
            ret, img = self._vcap.read()
        if ret:
            self._position += 1
        return img
def read ( self ) : # pos = self._position if self . _cache : img = self . _cache . get ( self . _position ) if img is not None : ret = True else : if self . _position != self . _get_real_position ( ) : self . _set_real_position ( self . _position ) ret , img = self . _vcap . read ( ) if ret : self . _cache . put ( self . _position , img ) else : ret , img = self . _vcap . read ( ) if ret : self . _position += 1 return img
Read the next frame.

        If the next frame have been decoded before and in the cache, then
        return it directly, otherwise decode, cache and return it.

        Returns:
            ndarray or None: Return the frame if successful, otherwise None.
Read the next frame .