To enable processing of Closed Captions data for input and output you should specify additional properties for MLive (MFLive) and MRenderer (MFRenderer) objects. The properties are different for different vendors.
Blackmagic Design
Input
HKEY_CURRENT_USER\Software\Medialooks\MFormats\MFLive\BMD
vanc.capture = true
vanc.capture_cc = true
vanc.capture_anc = true
Output
Closed Captions data is processed by default.
Aja
Input
HKEY_CURRENT_USER\Software\Medialooks\MFormats\MFLive\AJA2
capture_cc = true
capture_hanc = true
capture_vanc = true
Output
HKEY_CURRENT_USER\Software\Medialooks\MFormats\MFRenderer\AJA2
output.vanc = true
Bluefish444
Input
Closed Captions data is processed by default.
Output
HKEY_CURRENT_USER\Software\Medialooks\MFormats\MFRenderer\BF
output.vanc = true
Deltacast
Input
Closed Captions data is processed by default.
Output
HKEY_CURRENT_USER\Software\Medialooks\MFormats\MFRenderer\DC
output.vanc = true
NDI
Closed Captions data is processed by default.