C Specification
When calling vkGetPhysicalDeviceVideoCapabilitiesKHR with
pVideoProfile->videoCodecOperation
specified as
VK_VIDEO_CODEC_OPERATION_ENCODE_H264_BIT_EXT
, the
VkVideoEncodeH264CapabilitiesEXT structure must be included in the
pNext
chain of the VkVideoCapabilitiesKHR structure to retrieve
more capabilities specific to H.264 video encoding.
The VkVideoEncodeH264CapabilitiesEXT structure is defined as:
// Provided by VK_EXT_video_encode_h264
typedef struct VkVideoEncodeH264CapabilitiesEXT {
VkStructureType sType;
void* pNext;
VkVideoEncodeH264CapabilityFlagsEXT 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;
VkVideoEncodeH264StdFlagsEXT stdSyntaxFlags;
} VkVideoEncodeH264CapabilitiesEXT;
Members
-
sType
is a VkStructureType value identifying this structure. -
pNext
isNULL
or a pointer to a structure extending this structure. -
flags
is a bitmask of VkVideoEncodeH264CapabilityFlagBitsEXT indicating supported H.264 encoding capabilities. -
maxLevelIdc
is aStdVideoH264LevelIdc
value indicating the maximum H.264 level supported. -
maxSliceCount
indicates 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. -
maxPPictureL0ReferenceCount
indicates the maximum number of reference pictures the implementation supports in the reference list L0 for P pictures. -
maxBPictureL0ReferenceCount
indicates the maximum number of reference pictures the implementation supports in the reference list L0 for B pictures. The reported value is0
if encoding of B pictures is not supported. -
maxL1ReferenceCount
reports the maximum number of reference pictures the implementation supports in the reference list L1 if encoding of B pictures is supported. The reported value is0
if encoding of B pictures is not supported. -
maxTemporalLayerCount
indicates the maximum number of H.264 temporal layers supported by the implementation. -
expectDyadicTemporalLayerPattern
indicates that the implementation’s rate control algorithms expect the application to use a dyadic temporal layer pattern when encoding multiple temporal layers. -
minQp
indicates the minimum QP value supported. -
maxQp
indicates the maximum QP value supported. -
prefersGopRemainingFrames
indicates 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. -
requiresGopRemainingFrames
indicates 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. -
stdSyntaxFlags
is a bitmask of VkVideoEncodeH264StdFlagBitsEXT indicating capabilities related to H.264 syntax elements.
Description
When vkGetPhysicalDeviceVideoCapabilitiesKHR is called to query the
capabilities with parameter videoCodecOperation
specified as
VK_VIDEO_CODEC_OPERATION_ENCODE_H264_BIT_EXT
, a
VkVideoEncodeH264CapabilitiesEXT
structure can be chained to
VkVideoCapabilitiesKHR to retrieve H.264 extension specific
capabilities.
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.