C Specification
The VkVideoDecodeH264DpbSlotInfoKHR structure is defined as:
// Provided by VK_KHR_video_decode_h264
typedef struct VkVideoDecodeH264DpbSlotInfoKHR {
VkStructureType sType;
const void* pNext;
const StdVideoDecodeH264ReferenceInfo* pStdReferenceInfo;
} VkVideoDecodeH264DpbSlotInfoKHR;
Members
-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
pStdReferenceInfois a pointer to aStdVideoDecodeH264ReferenceInfostructure specifying H.264 reference information.
Description
This structure is specified in the pNext chain of
VkVideoDecodeInfoKHR::pSetupReferenceSlot, if not NULL, and
the pNext chain of the elements of
VkVideoDecodeInfoKHR::pReferenceSlots to specify the
codec-specific reference picture information for an H.264
decode operation.
- Active Reference Picture Information
-
When this structure is specified in the
pNextchain of the elements of VkVideoDecodeInfoKHR::pReferenceSlots, one or two elements are added to the list of active reference pictures used by the video decode operation for each element of VkVideoDecodeInfoKHR::pReferenceSlotsas follows:-
If neither
pStdReferenceInfo->flags.top_field_flagnorpStdReferenceInfo->flags.bottom_field_flagis set, then the picture is added as a frame reference to the list of active reference pictures. -
If
pStdReferenceInfo->flags.top_field_flagis set, then the picture is added as a top field reference to the list of active reference pictures. -
If
pStdReferenceInfo->flags.bottom_field_flagis set, then the picture is added as a bottom field reference to the list of active reference pictures. -
For each added reference picture, the corresponding image subregion used is determined according to the H.264 Decode Picture Data Access section.
-
Each added reference picture is associated with the DPB slot index specified in the
slotIndexmember of the corresponding element of VkVideoDecodeInfoKHR::pReferenceSlots. -
Each added reference picture is associated with the H.264 reference information provided in
pStdReferenceInfo.
-
|
Note
When both the top and bottom field of an interlaced frame currently
associated with a DPB slot is intended to be used as an active reference
picture and both fields are stored in the same image subregion (which is the
case when using
|
- Reconstructed Picture Information
-
When this structure is specified in the
pNextchain of VkVideoDecodeInfoKHR::pSetupReferenceSlot, the information related to the reconstructed picture is defined as follows:-
If neither
pStdReferenceInfo->flags.top_field_flagnorpStdReferenceInfo->flags.bottom_field_flagis set, then the picture represents a frame. -
If
pStdReferenceInfo->flags.top_field_flagis set, then the picture represents a field, specifically, the top field of the frame. -
If
pStdReferenceInfo->flags.bottom_field_flagis set, then the picture represents a field, specifically, the bottom field of the frame. -
The image subregion used is determined according to the H.264 Decode Picture Data Access section.
-
If reference picture setup is requested, then the reconstructed picture is used to activate the DPB slot with the index specified in VkVideoDecodeInfoKHR::
pSetupReferenceSlot->slotIndex. -
The reconstructed picture is associated with the H.264 reference information provided in
pStdReferenceInfo.
-
- Std Reference Information
-
The members of the
StdVideoDecodeH264ReferenceInfostructure pointed to bypStdReferenceInfoare interpreted as follows:-
flags.top_field_flagis used to indicate whether the reference is used as top field reference; -
flags.bottom_field_flagis used to indicate whether the reference is used as bottom field reference; -
flags.used_for_long_term_referenceis used to indicate whether the picture is marked as “used for long-term reference” as defined in section 8.2.5.1 of the ITU-T H.264 Specification; -
flags.is_non_existingis used to indicate whether the picture is marked as “non-existing” as defined in section 8.2.5.2 of the ITU-T H.264 Specification; -
all other members are interpreted as defined in section 8.2 of the ITU-T H.264 Specification.
-
Document Notes
For more information, see the Vulkan Specification
This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.