I have not experienced the problem with quicktime. But through the apple forums I found a solution for the Finder preview mode. if you go to finder you can reset preview for some codecs, however I could not find the solution yet for DXV. Maybe someone else knows the solution of this, or can finish mine to make it better?
I had to do this to make my other codecs work in Mavericks
type this is terminal:
qtdefaults write LegacyVideoCodecs ApplePlanarRGB enabled
qtdefaults write LegacyVideoCodecs SorensonVideo enabled
qtdefaults write LegacyVideoCodecs SorensonVideo3 enabled
qtdefaults write LegacyVideoCodecs AppleBMP enabled
qtdefaults write LegacyVideoCodecs AppleCinepak enabled
qtdefaults write LegacyVideoCodecs AppleH261 enabled
qtdefaults write LegacyVideoCodecs AppleH263 enabled
qtdefaults write LegacyVideoCodecs AppleMotionJPEGA enabled
qtdefaults write LegacyVideoCodecs AppleMotionJPEGB enabled
qtdefaults write LegacyVideoCodecs ApplePNG enabled
qtdefaults write LegacyVideoCodecs AppleNone enabled
qtdefaults write LegacyVideoCodecs AppleVideo enabled
qtdefaults write LegacyVideoCodecs AppleGraphics enabled
qtdefaults write LegacyVideoCodecs AppleTGA enabled
qtdefaults write LegacyVideoCodecs AppleTIFF enabled
qtdefaults write LegacyVideoCodecs AppleComponentVideo enabled
qtdefaults write LegacyVideoCodecs AppleJPEG2000 enabled
qtdefaults write LegacyVideoCodecs ApplePixlet enabled
for DXV I do not know the shortcut in Terminal