D3DMLOCKED_RECT (Windows Embedded CE 6.0)
Pitch of surface, in bytes.
The pitch for DXTn formats, see D3DMFORMAT, refers to a row of blocks. For example, if you have a width of 16, then you will have a pitch of 4 blocks (4*8 for DXT1, 4*16 for DXT2-5.)
Pointer to the locked bits. If a RECTL was provided to the LockRect call, pBits will be appropriately offset from the start of the surface.