there is a way to save parameter but we can't save the state machine. this is usefull for suspend/resume mechanism. for exemple imagine your are creating a super_long_film_compressed_with_the_last_super_hea vy_codec
and there is an electricty failure. imagine that all devices you're using are not time dependent (ie they can recreate the same state on different times) but that some of your transcoder have internal state that are dependent of previous processed frames (for exemple a codec with keyframe mechanism) if you save the buffer, the controls states, you can't resume from a specified point since the internal state is missing.... and you can't guess the frame start of the state so.... you must redo all the job..... not really efficient