MPEG2_B
The MPEG2_B restricted profile contains a set of features required for support of MPEG-2 video Main Profile and an associated DVD subpicture using front-end buffer-to-buffer subpicture blending. Alpha-blending source and destination surfaces are supported with width and height of at least 720 and 576, respectively. Support of this profile is currently encouraged, but not required.
Because the MPEG2_A restricted profile is defined by a relaxation of the accelerator requirements of the MPEG2_B profile, all accelerators that support the MPEG2_B profile must support the MPEG2_A profile.
The restrictions for MPEG2_B are defined by the restrictions listed for MPEG2_A, except for the following additional restrictions.
Restrictions on DXVA_ConnectMode
These values of the bDXVA_Func variable must be supported: 1 (picture decoding), 2 (alpha-blend data loading), or 3 (alpha-blend combination).
| Structure Member | Value |
|---|---|
wRestrictedMode |
DXVA_RESTRICTED_MODE_MPEG2_B |
Restrictions on DXVA_ConfigAlphaLoad and DXVA_ConfigAlphaCombine
| Structure Member | Value |
|---|---|
bConfigBlendType (DXVA_ConfigAlphaCombine) |
Zero (front-end buffer-to-buffer blending) |
bConfigDataType (DXVA_ConfigAlphaLoad) |
Zero, 1, or 3 (at the accelerator's discretion) |