| Microsoft DirectX 8.1 (C++) |
The following table describes the line 21 closed captioning media subtypes.
| GUID | Description |
| MEDIASUBTYPE_Line21_BytePair | Line 21 data as byte pairs |
| MEDIASUBTYPE_Line21_GOPPacket | Line 21 data in DVD GOP Packet |
| MEDIASUBTYPE_Line21_VBIRawData | Line 21 data in raw VBI format |