+ // For each card, the last three frames (or fields), with 0 being the
+ // most recent one. Note that we only need the actual history if we have
+ // interlaced output (for deinterlacing), so if we detect progressive input,
+ // we immediately clear out all history and all entries will point to the same
+ // frame.
+ BufferedFrame buffered_frames[MAX_CARDS][FRAME_HISTORY_LENGTH];