GstCodecParsers.AV1MetadataScalability

Fields

Name	Type	Access	Description
scalability_mode_idc	GstCodecParsers.AV1ScalabilityModes	r/w	indicates the picture prediction structure of the bitstream.
spatial_layer_description_present_flag	bool	r/w	indicates when set to 1 that the spatial_layer_ref_id is present for each of the (spatial_layers_cnt_minus_1 + 1) layers, or that it is not present when set to 0.
spatial_layer_dimensions_present_flag	bool	r/w	indicates when set to 1 that the spatial_layer_max_width and spatial_layer_max_height parameters are present for each of the (spatial_layers_cnt_minus_1 + 1) layers, or that it they are not present when set to 0.
spatial_layer_max_height	[int]	r/w	specifies the maximum frame height for the frames with spatial_id equal to i. This number must not be larger than max_frame_height_minus_1 + 1.
spatial_layer_max_width	[int]	r/w	specifies the maximum frame width for the frames with spatial_id equal to i. This number must not be larger than max_frame_width_minus_1 + 1.
spatial_layer_ref_id	bytes	r/w	specifies the spatial_id value of the frame within the current temporal unit that the frame of layer i uses for reference. If no frame within the current temporal unit is used for reference the value must be equal to 255.
spatial_layers_cnt_minus_1	int	r/w	indicates the number of spatial layers present in the video sequence minus one.
temporal_group_description_present_flag	bool	r/w	indicates when set to 1 that the temporal dependency information is present, or that it is not when set to 0.
temporal_group_ref_cnt	bytes	r/w	indicates the number of reference pictures used by the i-th picture in the temporal group.
temporal_group_ref_pic_diff	bytes	r/w	indicates, for the i-th picture in the temporal group, the temporal distance between the i-th picture and the j-th reference picture used by the i-th picture. The temporal distance is measured in frames, counting only frames of identical spatial_id values.
temporal_group_size	int	r/w	indicates the number of pictures in a temporal picture group. If the temporal_group_size is greater than 0, then the scalability structure data allows the inter-picture temporal dependency structure of the video sequence to be specified. If the temporal_group_size is greater than 0, then for temporal_group_size pictures in the temporal group, each picture’s temporal layer id (temporal_id), switch up points (temporal_group_temporal_switching_up_point_flag and temporal_group_spatial_switching_up_point_flag), and the reference picture indices (temporal_group_ref_pic_diff) are specified. The first picture specified in a temporal group must have temporal_id equal to 0. If the parameter temporal_group_size is not present or set to 0, then either there is only one temporal layer or there is no fixed inter-picture temporal dependency present going forward in the video sequence. Note that for a given picture, all frames follow the same inter-picture temporal dependency structure. However, the frame rate of each layer can be different from each other. The specified dependency structure in the scalability structure data must be for the highest frame rate layer.
temporal_group_spatial_switching_up_point_flag	bytes	r/w	is set to 1 if spatial layers of the current picture in the temporal group (i.e., pictures with a spatial_id higher than zero) do not depend on any picture preceding the current picture in the temporal group.
temporal_group_temporal_id	bytes	r/w	specifies the temporal_id value for the i-th picture in the temporal group.
temporal_group_temporal_switching_up_point_flag	bytes	r/w	is set to 1 if subsequent (in decoding order) pictures with a temporal_id higher than temporal_group_temporal_id[i] do not depend on any picture preceding the current picture (in coding order) with temporal_id higher than temporal_group_temporal_id[ i ].

Methods

None

Details

class GstCodecParsers.AV1MetadataScalability

The scalability metadata OBU is intended for use by intermediate processing entities that may perform selective layer elimination.