C Specification
When calling vkGetPhysicalDeviceVideoCapabilitiesKHR to query the
capabilities for an H.264 encode profile, the
VkVideoCapabilitiesKHR::pNext chain must include a
VkVideoEncodeH264CapabilitiesKHR structure that will be filled with
the profile-specific capabilities.
The VkVideoEncodeH264CapabilitiesKHR structure is defined as:
// Provided by VK_KHR_video_encode_h264
typedef struct VkVideoEncodeH264CapabilitiesKHR {
VkStructureType sType;
void* pNext;
VkVideoEncodeH264CapabilityFlagsKHR flags;
StdVideoH264LevelIdc maxLevelIdc;
uint32_t maxSliceCount;
uint32_t maxPPictureL0ReferenceCount;
uint32_t maxBPictureL0ReferenceCount;
uint32_t maxL1ReferenceCount;
uint32_t maxTemporalLayerCount;
VkBool32 expectDyadicTemporalLayerPattern;
int32_t minQp;
int32_t maxQp;
VkBool32 prefersGopRemainingFrames;
VkBool32 requiresGopRemainingFrames;
VkVideoEncodeH264StdFlagsKHR stdSyntaxFlags;
} VkVideoEncodeH264CapabilitiesKHR;
Members
-
sTypeis a VkStructureType value identifying this structure. -
pNextisNULLor a pointer to a structure extending this structure. -
flagsis a bitmask of VkVideoEncodeH264CapabilityFlagBitsKHR indicating supported H.264 encoding capabilities. -
maxLevelIdcis aStdVideoH264LevelIdcvalue indicating the maximum H.264 level supported by the profile, where enum constantSTD_VIDEO_H264_LEVEL_IDC_<major>_<minor>identifies H.264 level<major>.<minor>as defined in section A.3 of the ITU-T H.264 Specification. -
maxSliceCountindicates the maximum number of slices that can be encoded for a single picture. Further restrictions may apply to the number of slices that can be encoded for a single picture depending on other capabilities and codec-specific rules. -
maxPPictureL0ReferenceCountindicates the maximum number of reference pictures the implementation supports in the reference list L0 for P pictures.NoteAs implementations may override the reference lists,
maxPPictureL0ReferenceCountdoes not limit the number of elements that the application can specify in the L0 reference list for P pictures. However, ifmaxPPictureL0ReferenceCountis zero, then the use of P pictures is not allowed. -
maxBPictureL0ReferenceCountindicates the maximum number of reference pictures the implementation supports in the reference list L0 for B pictures. -
maxL1ReferenceCountindicates the maximum number of reference pictures the implementation supports in the reference list L1 if encoding of B pictures is supported.NoteAs implementations may override the reference lists,
maxBPictureL0ReferenceCountandmaxL1ReferenceCountdoes not limit the number of elements that the application can specify in the L0 and L1 reference lists for B pictures. However, ifmaxBPictureL0ReferenceCountandmaxL1ReferenceCountare both zero, then the use of B pictures is not allowed. -
maxTemporalLayerCountindicates the maximum number of H.264 temporal layers supported by the implementation. -
expectDyadicTemporalLayerPatternindicates that the implementation’s rate control algorithms expect the application to use a dyadic temporal layer pattern when encoding multiple temporal layers. -
minQpindicates the minimum QP value supported. -
maxQpindicates the maximum QP value supported. -
prefersGopRemainingFramesindicates that the implementation’s rate control algorithm prefers the application to specify the number of frames of each type remaining in the current group of pictures when beginning a video coding scope. -
requiresGopRemainingFramesindicates that the implementation’s rate control algorithm requires the application to specify the number of frames of each type remaining in the current group of pictures when beginning a video coding scope. -
stdSyntaxFlagsis a bitmask of VkVideoEncodeH264StdFlagBitsKHR indicating capabilities related to H.264 syntax elements.
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.