>o kaip tai padaryt?

  Dar kitas būdas: failo pradžioje, pvz.,

0000000000: 52 49 46 46 64 F4 00 1F │ 41 56 49 20 4C 49 53 54  RIFFd. .AVI LIST
0000000010: 7E 22 00 00 68 64 72 6C │ 61 76 69 68 38 00 00 00  ~"  hdrlavih8
0000000020: 40 9C 00 00 00 00 00 00 │ 00 00 00 00 10 01 00 00  @_          ..
0000000030: F0 2F 01 00 00 00 00 00 │ 02 00 00 00 00 00 00 00  š/.     .
0000000040: 80 02 00 00 E0 01 00 00 │ 00 00 00 00 00 00 00 00  _.  ą.
0000000050: 00 00 00 00 00 00 00 00 │ 4C 49 53 54 94 10 00 00          LIST..
0000000060: 73 74 72 6C 73 74 72 68 │ 38 00 00 00 76 69 64 73  strlstrh8   vids
0000000070: 64 69 76 78 00 00 00 00 │ 00 00 00 00 00 00 00 00  divx
0000000080: 01 00 00 00 19 00 00 00 │ 00 00 00 00 F0 2F 01 00  .   .       š/.
0000000090: CE CD 00 00 10 27 00 00 │ 00 00 00 00 00 00 00 00  .Ķ  .'
00000000A0: C0 02 40 02 73 74 72 66 │ 28 00 00 00 28 00 00 00  Ą.@.strf(   (
00000000B0: 80 02 00 00 E0 01 00 00 │ 01 00 0C 00 44 58 35 30  ..  ą.  . . DX50
00000000C0: 00 90 12 00 00 00 00 00 │ 00 00 00 00 00 00 00 00   ..
00000000D0: 00 00 00 00 4A 55 4E 4B │ 18 10 00 00 00 00 00 00      JUNK..

"divx" galima be problemų keisti į "xvid", "DX50" -- į "XVID". Identifikatoriai
(iš 4 raidžių bei skaičių), kiek atsimenu, vis tais pačiais adresais.
   Reikia hex editoriaus. Kurį naudoju pats, to negaliu siūlyti, nes neberandu
instaliatoriaus nei pas save, nei internete.

-- 
  saimhe