form XSTR2TAB tables ET_DATA
               using I_XSTR   type xstring
                     E_LENGTH type i.
  data:
    l_times type i,
    l_pos type i value 0,
    l_last_line_len type i,
    l_tab_line_len type i,
    lr_type_descr type ref to cl_abap_typedescr,
    lr_tab_descr type ref to cl_abap_tabledescr.
  field-symbols:
    <ls_data> type any,
    <ls_line> type any.

  e_length = xstrlen( i_xstr ).

  lr_type_descr = cl_abap_typedescr=>describe_by_data( et_data ).
  lr_tab_descr ?= lr_type_descr.
  lr_type_descr = lr_tab_descr->GET_TABLE_LINE_TYPE( ).
  l_tab_line_len = lr_type_descr->length.

  l_times = e_length div l_tab_line_len.
  l_last_line_len = e_length mod l_tab_line_len.

  do l_times times.
    append initial line to et_data.
    read table et_data assigning <ls_data> index sy-tabix.
    assign component 1 of structure <ls_data> to <ls_line>.
    <ls_line> = i_xstr+l_pos(l_tab_line_len).
    l_pos = l_pos + l_tab_line_len.
  enddo.

  if l_last_line_len <> 0.
    append initial line to et_data.
    read table et_data assigning <ls_data> index sy-tabix.
    assign component 1 of structure <ls_data> to <ls_line>.
    <ls_line> = i_xstr+l_pos(l_last_line_len).
  endif.
endform.



В место

  CALL METHOD cl_umc_ostream=>xstr2tab
    EXPORTING
      i_xstr   = xstrt
    IMPORTING
      et_data  = blob[]
      e_length = blob_length.



Напиши

Perform XSTR2TAB tables blob using xstrt blob_length.



form TAB2XSTR tables IT_DATA
               using I_LENGTH type i
                     E_XSTR   type XSTRING.
  data:
    l_length type i,
    l_xstr type xstring.
  field-symbols:
    <ls_data> type any,
    <ls_line> type any.

  loop at it_data assigning <ls_data>.
    assign component 1 of structure <ls_data> to <ls_line>.
    concatenate l_xstr <ls_line> into l_xstr in byte mode.
  endloop.

  l_length = xstrlen( l_xstr ).
  if l_length > i_length.
    e_xstr = l_xstr(i_length).
  else.
    e_xstr = l_xstr.
  endif.
endform.