VkVideoEncodeH264CapabilityFlagBitsKHR

Bits which may be set in VkVideoEncodeH264CapabilitiesKHR::flags, indicating the H.264 encoding capabilities supported, are:

typedef enum VkVideoEncodeH264CapabilityFlagBitsKHR {
    VK_VIDEO_ENCODE_H264_CAPABILITY_HRD_COMPLIANCE_BIT_KHR = 0x00000001,
    VK_VIDEO_ENCODE_H264_CAPABILITY_PREDICTION_WEIGHT_TABLE_GENERATED_BIT_KHR = 0x00000002,
    VK_VIDEO_ENCODE_H264_CAPABILITY_ROW_UNALIGNED_SLICE_BIT_KHR = 0x00000004,
    VK_VIDEO_ENCODE_H264_CAPABILITY_DIFFERENT_SLICE_TYPE_BIT_KHR = 0x00000008,
    VK_VIDEO_ENCODE_H264_CAPABILITY_B_FRAME_IN_L0_LIST_BIT_KHR = 0x00000010,
    VK_VIDEO_ENCODE_H264_CAPABILITY_B_FRAME_IN_L1_LIST_BIT_KHR = 0x00000020,
    VK_VIDEO_ENCODE_H264_CAPABILITY_PER_PICTURE_TYPE_MIN_MAX_QP_BIT_KHR = 0x00000040,
    VK_VIDEO_ENCODE_H264_CAPABILITY_PER_SLICE_CONSTANT_QP_BIT_KHR = 0x00000080,
    VK_VIDEO_ENCODE_H264_CAPABILITY_GENERATE_PREFIX_NALU_BIT_KHR = 0x00000100,
} VkVideoEncodeH264CapabilityFlagBitsKHR;

pub struct VideoEncodeH264CapabilityFlagBitsKHR(u32);
impl VideoEncodeH264CapabilityFlagBitsKHR {
    pub const HRD_COMPLIANCE: Self = 0x00000001;
    pub const PREDICTION_WEIGHT_TABLE_GENERATED: Self = 0x00000002;
    pub const ROW_UNALIGNED_SLICE: Self = 0x00000004;
    pub const DIFFERENT_SLICE_TYPE: Self = 0x00000008;
    pub const B_FRAME_IN_L0_LIST: Self = 0x00000010;
    pub const B_FRAME_IN_L1_LIST: Self = 0x00000020;
    pub const PER_PICTURE_TYPE_MIN_MAX_QP: Self = 0x00000040;
    pub const PER_SLICE_CONSTANT_QP: Self = 0x00000080;
    pub const GENERATE_PREFIX_NALU: Self = 0x00000100;
}

• VK_VIDEO_ENCODE_H264_CAPABILITY_HRD_COMPLIANCE_BIT_KHR specifies whether the implementation may be able to generate HRD compliant bitstreams if any of the nal_hrd_parameters_present_flag or vcl_hrd_parameters_present_flag members of StdVideoH264SpsVuiFlags are set to 1 in the active SPS.
• VK_VIDEO_ENCODE_H264_CAPABILITY_PREDICTION_WEIGHT_TABLE_GENERATED_BIT_KHR specifies that if StdVideoH264PpsFlags::weighted_pred_flag is set to 1 or StdVideoH264PictureParameterSet::weighted_bipred_idc is set to STD_VIDEO_H264_WEIGHTED_BIPRED_IDC_EXPLICIT in the active PPS when encoding a P picture or B picture, respectively, then the implementation is able to internally decide syntax for pred_weight_table, as defined in section 7.4.3.2 of the ITU-T H.264 Specification, and the application is not required to provide a weight table in the H.264 slice header parameters.
• VK_VIDEO_ENCODE_H264_CAPABILITY_ROW_UNALIGNED_SLICE_BIT_KHR specifies that each slice in a frame with multiple slices may begin or finish at any offset in a macroblock row. If not supported, all slices in the frame must begin at the start of a macroblock row (and hence each slice must finish at the end of a macroblock row). When a picture is encoded with intra refresh, encoding non-rectangular slices also requires: support for the VkVideoEncodeIntraRefreshCapabilitiesKHR::nonRectangularIntraRefreshRegions capability.
• VK_VIDEO_ENCODE_H264_CAPABILITY_DIFFERENT_SLICE_TYPE_BIT_KHR specifies that when a frame is encoded with multiple slices, the implementation allows encoding each slice with a different StdVideoEncodeH264SliceHeader::slice_type specified in the H.264 slice header parameters. If not supported, all slices of the frame must be encoded with the same slice_type which corresponds to the picture type of the frame. There is one exception to this rule: if the picture is encoded with the intra refresh mode
  VK_VIDEO_ENCODE_INTRA_REFRESH_MODE_PER_PICTURE_PARTITION_BIT_KHR, then the currently refreshed slice must specify the slice_type
STD_VIDEO_H264_SLICE_TYPE_I and can differ from the slice_type of the other slices regardless of whether VK_VIDEO_ENCODE_H264_CAPABILITY_DIFFERENT_SLICE_TYPE_BIT_KHR is supported.
• VK_VIDEO_ENCODE_H264_CAPABILITY_B_FRAME_IN_L0_LIST_BIT_KHR specifies support for using a B frame as L0 reference, as specified in StdVideoEncodeH264ReferenceListsInfo::RefPicList0 in the H.264 picture information.
• VK_VIDEO_ENCODE_H264_CAPABILITY_B_FRAME_IN_L1_LIST_BIT_KHR specifies support for using a B frame as L1 reference, as specified in StdVideoEncodeH264ReferenceListsInfo::RefPicList1 in the H.264 picture information.
• VK_VIDEO_ENCODE_H264_CAPABILITY_PER_PICTURE_TYPE_MIN_MAX_QP_BIT_KHR specifies support for specifying different QP values in the members of VkVideoEncodeH264QpKHR.
• VK_VIDEO_ENCODE_H264_CAPABILITY_PER_SLICE_CONSTANT_QP_BIT_KHR specifies support for specifying different constant QP values for each slice.
• VK_VIDEO_ENCODE_H264_CAPABILITY_GENERATE_PREFIX_NALU_BIT_KHR specifies support for generating prefix NAL units by setting VkVideoEncodeH264PictureInfoKHR::generatePrefixNalu to VK_TRUE.
• ENCODE H264 MB QP DELTA WRAPAROUND
  VK_VIDEO_ENCODE_H264_CAPABILITY_MB_QP_DIFF_WRAPAROUND_BIT_KHR indicates support for wraparound during the calculation of the QP values of subsequently encoded macroblocks, as defined in equation 7-37 of the ITU-T H.264 Specification. If not supported, equation 7-37 of the ITU-T H.264 Specification is effectively reduced to the following:
  QP_Y = QP_Y,PREV + mb_qp_delta
  The effect of this is that the maximum QP difference across subsequent macroblocks is limited to the [-(26 + QpBdOffset_Y / 2), 25 + QpBdOffset_Y / 2] range.
• VK_VIDEO_ENCODE_H264_CAPABILITY_B_PICTURE_INTRA_REFRESH_BIT_KHR indicates support for encoding B pictures with intra refresh enabled.