GstVideo.VideoMeta

Fields

Name	Type	Access	Description
alignment	GstVideo.VideoAlignment	r/w	the paddings and alignment constraints of the video buffer. It is up to the caller of gst_buffer_add_video_meta_full() to set it using GstVideo.VideoMeta.set_alignment(), if they did not it defaults to no padding and no alignment.
buffer	Gst.Buffer	r/w	the buffer this metadata belongs to
flags	GstVideo.VideoFrameFlags	r/w	additional video flags
format	GstVideo.VideoFormat	r/w	the video format
height	int	r/w	the video height
id	int	r/w	identifier of the frame
map	object	r	map the memory of a plane
meta	Gst.Meta	r/w	parent Gst.Meta
n_planes	int	r/w	the number of planes in the image
offset	[int]	r/w	array of offsets for the planes. This field might not always be valid, it is used by the default implementation of map.
stride	[int]	r/w	array of strides for the planes. This field might not always be valid, it is used by the default implementation of map.
unmap	object	r	unmap the memory of a plane
width	int	r/w	the video width

Methods

class	get_info ()
	get_plane_height ()
	get_plane_size ()
	set_alignment (alignment)

Details

class GstVideo.VideoMeta

Extra buffer metadata describing image properties

This meta can also be used by downstream elements to specifiy their buffer layout requirements for upstream. Upstream should try to fit those requirements, if possible, in order to prevent buffer copies.

This is done by passing a custom Gst.Structure to Gst.Query.add_allocation_meta() when handling the ALLOCATION query. This structure should be named ‘video-meta’ and can have the following fields:

• padding-top (uint): extra pixels on the top

• padding-bottom (uint): extra pixels on the bottom

• padding-left (uint): extra pixels on the left side

• padding-right (uint): extra pixels on the right side The padding fields have the same semantic as GstVideo.VideoMeta.alignment and so represent the paddings requested on produced video buffers.

Since 1.24 it can be serialized using Gst.Meta.serialize() and Gst.Meta.deserialize().

classmethod get_info()

Return type:

Gst.MetaInfo

get_plane_height()

Returns:

True if self's alignment is valid and plane_height has been updated, False otherwise

plane_height:

array used to store the plane height

Return type:

(bool, plane_height: [int])

Compute the padded height of each plane from self (padded size divided by stride).

It is not valid to call this function with a meta associated to a TILED video format.

New in version 1.18.

get_plane_size()

Returns:

True if self's alignment is valid and plane_size has been updated, False otherwise

plane_size:

array used to store the plane sizes

Return type:

(bool, plane_size: [int])

Compute the size, in bytes, of each video plane described in self including any padding and alignment constraint defined in self->alignment.

New in version 1.18.

set_alignment(alignment)

Parameters:

alignment (GstVideo.VideoAlignment) – a GstVideo.VideoAlignment

Returns:

True if alignment's meta has been updated, False if not

Return type:

bool

Set the alignment of self to alignment. This function checks that the paddings defined in alignment are compatible with the strides defined in self and will fail to update if they are not.

New in version 1.18.