gstvideometa: GStreamer Base Plugins 1.0 Library Reference Manual

gstvideometa

Functions

gboolean	gst_video_meta_map ()
gboolean	gst_video_meta_unmap ()
const GstMetaInfo *	gst_video_meta_get_info ()
GstVideoMeta *	gst_buffer_add_video_meta ()
GstVideoMeta *	gst_buffer_add_video_meta_full ()
GstVideoMeta *	gst_buffer_get_video_meta ()
GstVideoMeta *	gst_buffer_get_video_meta_id ()
#define	gst_buffer_add_video_crop_meta()
#define	gst_buffer_get_video_crop_meta()
GstVideoRegionOfInterestMeta *	gst_buffer_add_video_region_of_interest_meta ()
GstVideoRegionOfInterestMeta *	gst_buffer_add_video_region_of_interest_meta_id ()
#define	gst_buffer_get_video_region_of_interest_meta()
GstVideoRegionOfInterestMeta *	gst_buffer_get_video_region_of_interest_meta_id ()
gboolean	(*GstVideoGLTextureUpload) ()
GstVideoGLTextureUploadMeta *	gst_buffer_add_video_gl_texture_upload_meta ()
#define	gst_buffer_get_video_gl_texture_upload_meta()
gboolean	gst_video_gl_texture_upload_meta_upload ()
GstVideoTimeCodeMeta *	gst_buffer_add_video_time_code_meta ()
GstVideoTimeCodeMeta *	gst_buffer_add_video_time_code_meta_full ()
#define	gst_buffer_get_video_time_code_meta()

Types and Values

struct	GstVideoMeta
	GstVideoMetaTransform
struct	GstVideoCropMeta
	GstVideoRegionOfInterestMeta
#define	GST_BUFFER_POOL_OPTION_VIDEO_GL_TEXTURE_UPLOAD_META
struct	GstVideoGLTextureUploadMeta
	GstVideoTimeCodeMeta

Includes

#include <gst/video/gstvideometa.h>

Description

Functions

gst_video_meta_map ()

gboolean
gst_video_meta_map (GstVideoMeta *meta,
                    guint plane,
                    GstMapInfo *info,
                    gpointer *data,
                    gint *stride,
                    GstMapFlags flags);

Map the video plane with index plane in meta and return a pointer to the first byte of the plane and the stride of the plane.

Parameters

meta	a GstVideoMeta
plane	a plane
info	a GstMapInfo
data	the data of `plane`
stride	the stride of `plane`
flags	`GstMapFlags`

Returns

TRUE if the map operation was successful.

gst_video_meta_unmap ()

gboolean
gst_video_meta_unmap (GstVideoMeta *meta,
                      guint plane,
                      GstMapInfo *info);

Unmap a previously mapped plane with gst_video_meta_map().

Parameters

meta	a GstVideoMeta
plane	a plane
info	a GstMapInfo

Returns

TRUE if the memory was successfully unmapped.

gst_video_meta_get_info ()

const GstMetaInfo *
gst_video_meta_get_info (void);

gst_buffer_add_video_meta ()

GstVideoMeta *
gst_buffer_add_video_meta (GstBuffer *buffer,
                           GstVideoFrameFlags flags,
                           GstVideoFormat format,
                           guint width,
                           guint height);

Attaches GstVideoMeta metadata to buffer with the given parameters and the default offsets and strides for format and width x height .

This function calculates the default offsets and strides and then calls gst_buffer_add_video_meta_full() with them.

Parameters

buffer	a GstBuffer
flags	GstVideoFrameFlags
format	a GstVideoFormat
width	the width
height	the height

Returns

the GstVideoMeta on buffer .

[transfer none]

gst_buffer_add_video_meta_full ()

GstVideoMeta *
gst_buffer_add_video_meta_full (GstBuffer *buffer,
                                GstVideoFrameFlags flags,
                                GstVideoFormat format,
                                guint width,
                                guint height,
                                guint n_planes,
                                gsize offset[GST_VIDEO_MAX_PLANES],
                                gint stride[GST_VIDEO_MAX_PLANES]);

Attaches GstVideoMeta metadata to buffer with the given parameters.

Parameters

buffer	a GstBuffer
flags	GstVideoFrameFlags
format	a GstVideoFormat
width	the width
height	the height
n_planes	number of planes
offset	offset of each plane
stride	stride of each plane

Returns

the GstVideoMeta on buffer .

[transfer none]

gst_buffer_get_video_meta ()

GstVideoMeta *
gst_buffer_get_video_meta (GstBuffer *buffer);

Find the GstVideoMeta on buffer with the lowest id .

Buffers can contain multiple GstVideoMeta metadata items when dealing with multiview buffers.

Parameters

buffer

a GstBuffer

Returns

the GstVideoMeta with lowest id (usually 0) or NULL when there is no such metadata on buffer .

[transfer none]

gst_buffer_get_video_meta_id ()

GstVideoMeta *
gst_buffer_get_video_meta_id (GstBuffer *buffer,
                              gint id);

Find the GstVideoMeta on buffer with the given id .

Buffers can contain multiple GstVideoMeta metadata items when dealing with multiview buffers.

Parameters

buffer	a GstBuffer
id	a metadata id

Returns

the GstVideoMeta with id or NULL when there is no such metadata on buffer .

[transfer none]

gst_buffer_add_video_crop_meta()

#define gst_buffer_add_video_crop_meta(b) ((GstVideoCropMeta*)gst_buffer_add_meta((b),GST_VIDEO_CROP_META_INFO, NULL))

gst_buffer_get_video_crop_meta()

#define gst_buffer_get_video_crop_meta(b) ((GstVideoCropMeta*)gst_buffer_get_meta((b),GST_VIDEO_CROP_META_API_TYPE))

gst_buffer_add_video_region_of_interest_meta ()

GstVideoRegionOfInterestMeta *
gst_buffer_add_video_region_of_interest_meta
                               (GstBuffer *buffer,
                                const gchar *roi_type,
                                guint x,
                                guint y,
                                guint w,
                                guint h);

Attaches GstVideoRegionOfInterestMeta metadata to buffer with the given parameters.

Parameters

buffer	a GstBuffer
roi_type	Type of the region of interest (e.g. "face")
x	X position
y	Y position
w	width
h	height

Returns

the GstVideoRegionOfInterestMeta on buffer .

[transfer none]

gst_buffer_add_video_region_of_interest_meta_id ()

GstVideoRegionOfInterestMeta *
gst_buffer_add_video_region_of_interest_meta_id
                               (GstBuffer *buffer,
                                GQuark roi_type,
                                guint x,
                                guint y,
                                guint w,
                                guint h);

Attaches GstVideoRegionOfInterestMeta metadata to buffer with the given parameters.

Parameters

buffer	a GstBuffer
roi_type	Type of the region of interest (e.g. "face")
x	X position
y	Y position
w	width
h	height

Returns

the GstVideoRegionOfInterestMeta on buffer .

[transfer none]

gst_buffer_get_video_region_of_interest_meta()

#define             gst_buffer_get_video_region_of_interest_meta(b)

gst_buffer_get_video_region_of_interest_meta_id ()

GstVideoRegionOfInterestMeta *
gst_buffer_get_video_region_of_interest_meta_id
                               (GstBuffer *buffer,
                                gint id);

Find the GstVideoRegionOfInterestMeta on buffer with the given id .

Buffers can contain multiple GstVideoRegionOfInterestMeta metadata items if multiple regions of interests are marked on a frame.

Parameters

buffer	a GstBuffer
id	a metadata id

Returns

the GstVideoRegionOfInterestMeta with id or NULL when there is no such metadata on buffer .

[transfer none]

GstVideoGLTextureUpload ()

gboolean
(*GstVideoGLTextureUpload) (GstVideoGLTextureUploadMeta *meta,
                            guint texture_id[4]);

gst_buffer_add_video_gl_texture_upload_meta ()

GstVideoGLTextureUploadMeta *
gst_buffer_add_video_gl_texture_upload_meta
                               (GstBuffer *buffer,
                                GstVideoGLTextureOrientation texture_orientation,
                                guint n_textures,
                                GstVideoGLTextureType texture_type[4],
                                GstVideoGLTextureUpload upload,
                                gpointer user_data,
                                GBoxedCopyFunc user_data_copy,
                                GBoxedFreeFunc user_data_free);

Attaches GstVideoGLTextureUploadMeta metadata to buffer with the given parameters.

Parameters

buffer	a GstBuffer
texture_orientation	the GstVideoGLTextureOrientation
n_textures	the number of textures
texture_type	array of GstVideoGLTextureType
upload	the function to upload the buffer to a specific texture ID.	[scope call]
user_data	user data for the implementor of `upload`
user_data_copy	function to copy `user_data` .	[scope call]
user_data_free	function to free `user_data` .	[scope call]

Returns

the GstVideoGLTextureUploadMeta on buffer .

[transfer none]

gst_buffer_get_video_gl_texture_upload_meta()

#define gst_buffer_get_video_gl_texture_upload_meta(b) ((GstVideoGLTextureUploadMeta*)gst_buffer_get_meta((b),GST_VIDEO_GL_TEXTURE_UPLOAD_META_API_TYPE))

gst_video_gl_texture_upload_meta_upload ()

gboolean
gst_video_gl_texture_upload_meta_upload
                               (GstVideoGLTextureUploadMeta *meta,
                                guint texture_id[4]);

Uploads the buffer which owns the meta to a specific texture ID.

Parameters

meta	a GstVideoGLTextureUploadMeta
texture_id	the texture IDs to upload to

Returns

TRUE if uploading succeeded, FALSE otherwise.

gst_buffer_add_video_time_code_meta ()

GstVideoTimeCodeMeta *
gst_buffer_add_video_time_code_meta (GstBuffer *buffer,
                                     GstVideoTimeCode *tc);

Attaches GstVideoTimeCodeMeta metadata to buffer with the given parameters.

Parameters

buffer	a GstBuffer
tc	a GstVideoTimeCode

Returns

the GstVideoTimeCodeMeta on buffer .

[transfer none]

Since: 1.10

gst_buffer_add_video_time_code_meta_full ()

GstVideoTimeCodeMeta *
gst_buffer_add_video_time_code_meta_full
                               (GstBuffer *buffer,
                                guint fps_n,
                                guint fps_d,
                                GDateTime *latest_daily_jam,
                                GstVideoTimeCodeFlags flags,
                                guint hours,
                                guint minutes,
                                guint seconds,
                                guint frames,
                                guint field_count);

Attaches GstVideoTimeCodeMeta metadata to buffer with the given parameters.

Parameters

buffer	a GstBuffer
fps_n	framerate numerator
fps_d	framerate denominator
latest_daily_jam	a GDateTime for the latest daily jam
flags	a GstVideoTimeCodeFlags
hours	hours since the daily jam
minutes	minutes since the daily jam
seconds	seconds since the daily jam
frames	frames since the daily jam
field_count	fields since the daily jam

Returns

the GstVideoTimeCodeMeta on buffer .

[transfer none]

Since: 1.10

gst_buffer_get_video_time_code_meta()

#define             gst_buffer_get_video_time_code_meta(b)

Types and Values

struct GstVideoMeta

struct GstVideoMeta {
  GstMeta            meta;

  GstBuffer         *buffer;

  GstVideoFrameFlags flags;
  GstVideoFormat     format;
  gint               id;
  guint              width;
  guint              height;

  guint              n_planes;
  gsize              offset[GST_VIDEO_MAX_PLANES];
  gint               stride[GST_VIDEO_MAX_PLANES];

  gboolean (*map)    (GstVideoMeta *meta, guint plane, GstMapInfo *info,
                      gpointer *data, gint * stride, GstMapFlags flags);
  gboolean (*unmap)  (GstVideoMeta *meta, guint plane, GstMapInfo *info);
};

Extra buffer metadata describing image properties

Members

GstMeta `meta`;	parent GstMeta
GstBuffer *`buffer`;	the buffer this metadata belongs to
GstVideoFrameFlags `flags`;	additional video flags
GstVideoFormat `format`;	the video format
gint `id`;	identifier of the frame
guint `width`;	the video width
guint `height`;	the video height
guint `n_planes`;	the number of planes in the image
gsize `offset`[GST_VIDEO_MAX_PLANES];	array of offsets for the planes. This field might not always be valid, it is used by the default implementation of `map` .
gint `stride`[GST_VIDEO_MAX_PLANES];	array of strides for the planes. This field might not always be valid, it is used by the default implementation of `map` .
`map` ()	map the memory of a plane
`unmap` ()	unmap the memory of a plane

GstVideoMetaTransform

typedef struct {
  GstVideoInfo *in_info;
  GstVideoInfo *out_info;
} GstVideoMetaTransform;

Extra data passed to a video transform GstMetaTransformFunction such as: "gst-video-scale".

Members

GstVideoInfo *`in_info`;	the input GstVideoInfo
GstVideoInfo *`out_info`;	the output GstVideoInfo

struct GstVideoCropMeta

struct GstVideoCropMeta {
  GstMeta       meta;

  guint         x;
  guint         y;
  guint         width;
  guint         height;
};

Extra buffer metadata describing image cropping.

Members

GstMeta `meta`;	parent GstMeta
guint `x`;	the horizontal offset
guint `y`;	the vertical offset
guint `width`;	the cropped width
guint `height`;	the cropped height

GstVideoRegionOfInterestMeta

typedef struct {
  GstMeta meta;

  GQuark roi_type;
  gint id;
  gint parent_id;

  guint x;
  guint y;
  guint w;
  guint h;
} GstVideoRegionOfInterestMeta;

Extra buffer metadata describing an image region of interest

Members

GstMeta `meta`;	parent GstMeta
GQuark `roi_type`;	GQuark describing the semantic of the Roi (f.i. a face, a pedestrian)
gint `id`;	identifier of this particular ROI
gint `parent_id`;	identifier of its parent ROI, used f.i. for ROI hierarchisation.
guint `x`;	x component of upper-left corner
guint `y`;	y component of upper-left corner
guint `w`;	bounding box width
guint `h`;	bounding box height

GST_BUFFER_POOL_OPTION_VIDEO_GL_TEXTURE_UPLOAD_META

#define GST_BUFFER_POOL_OPTION_VIDEO_GL_TEXTURE_UPLOAD_META "GstBufferPoolOptionVideoGLTextureUploadMeta"

An option that can be activated on a bufferpool to request gl texture upload meta on buffers from the pool.

When this option is enabled on the bufferpool, GST_BUFFER_POOL_OPTION_VIDEO_META should also be enabled.

Since: 1.2.2

struct GstVideoGLTextureUploadMeta

struct GstVideoGLTextureUploadMeta {
  GstMeta       meta;

  GstVideoGLTextureOrientation texture_orientation;
  guint n_textures;
  GstVideoGLTextureType texture_type[4];
};

Extra buffer metadata for uploading a buffer to an OpenGL texture ID. The caller of gst_video_gl_texture_upload_meta_upload() must have OpenGL set up and call this from a thread where it is valid to upload something to an OpenGL texture.

Members

GstMeta `meta`;	parent GstMeta
GstVideoGLTextureOrientation `texture_orientation`;	Orientation of the textures
guint `n_textures`;	Number of textures that are generated
GstVideoGLTextureType `texture_type`[4];	Type of each texture

GstVideoTimeCodeMeta

typedef struct {
  GstMeta meta;

  GstVideoTimeCode tc;
} GstVideoTimeCodeMeta;

Extra buffer metadata describing the GstVideoTimeCode of the frame.

Each frame is assumed to have its own timecode, i.e. they are not automatically incremented/interpolated.

Members

GstMeta `meta`;	parent GstMeta
GstVideoTimeCode `tc`;	the GstVideoTimeCode to attach

Since: 1.10