Functions

buffer_add_gl_sync_meta (context, buffer)

buffer_add_gl_sync_meta_full (context, buffer, data)

buffer_pool_config_get_gl_allocation_params (config)

buffer_pool_config_get_gl_min_free_queue_size (config)

buffer_pool_config_set_gl_allocation_params (config, params)

buffer_pool_config_set_gl_min_free_queue_size (config, queue_size)

context_get_gl_display (context)

context_set_gl_display (context, display)

gl_api_from_string (api_s)

gl_api_to_string (api)

gl_base_memory_alloc (allocator, params)

gl_base_memory_error_quark ()

gl_base_memory_init_once ()

gl_buffer_init_once ()

gl_check_extension (name, ext)

gl_config_caveat_to_string (caveat)

gl_config_surface_type_to_string (surface_type)

gl_context_error_quark ()

gl_element_propagate_display_context (element, display)

gl_ensure_element_data (element, display_ptr, other_context_ptr)

gl_format_from_video_info (context, vinfo, plane)

gl_format_is_supported (context, format)

gl_format_n_components (gl_format)

gl_format_type_from_sized_gl_format (format)

gl_format_type_n_bytes (format, type)

gl_get_affine_transformation_meta_as_ndc (meta)

gl_get_plane_data_size (info, align, plane)

gl_get_plane_start (info, valign, plane)

gl_handle_context_query (element, query, display, context, other_context)

gl_handle_set_context (element, context)

gl_memory_init_once ()

gl_memory_pbo_init_once ()

gl_multiply_matrix4 (a, b)

gl_platform_from_string (platform_s)

gl_platform_to_string (platform)

gl_query_local_gl_context (element, direction, context_ptr)

gl_renderbuffer_init_once ()

gl_set_affine_transformation_meta_from_ndc (meta, matrix)

gl_sized_gl_format_from_gl_format_type (context, format, type)

gl_stereo_downmix_mode_get_type ()

gl_swizzle_invert (swizzle)

gl_sync_meta_api_get_type ()

gl_sync_meta_get_info ()

gl_texture_target_from_gl (target)

gl_texture_target_from_string (str)

gl_texture_target_to_buffer_pool_option (target)

gl_texture_target_to_gl (target)

gl_texture_target_to_string (target)

gl_value_get_texture_target_mask (value)

gl_value_set_texture_target (value, target)

gl_value_set_texture_target_from_mask (value, target_mask)

gl_version_to_glsl_version (gl_api, maj, min)

gl_video_format_swizzle (video_format)

gl_window_error_quark ()

glsl_error_quark ()

glsl_profile_from_string (string)

glsl_profile_to_string (profile)

glsl_string_get_version_profile (s)

glsl_version_from_string (string)

glsl_version_profile_from_string (string)

glsl_version_profile_to_string (version, profile)

glsl_version_to_string (version)

is_gl_base_memory (mem)

is_gl_buffer (mem)

is_gl_memory (mem)

is_gl_memory_pbo (mem)

is_gl_renderbuffer (mem)

Details

GstGL.buffer_add_gl_sync_meta(context, buffer)[source]
Parameters:
Returns:

the GstGL.GLSyncMeta added to Gst.Buffer

Return type:

GstGL.GLSyncMeta

New in version 1.6.

GstGL.buffer_add_gl_sync_meta_full(context, buffer, data)[source]
Parameters:
Returns:

the GstGL.GLSyncMeta added to Gst.Buffer

Return type:

GstGL.GLSyncMeta

New in version 1.8.

GstGL.buffer_pool_config_get_gl_allocation_params(config)[source]
Parameters:

config (Gst.Structure) – a buffer pool config

Returns:

the currently set GstGL.GLAllocationParams or None

Return type:

GstGL.GLAllocationParams or None

GstGL.buffer_pool_config_get_gl_min_free_queue_size(config)[source]
Parameters:

config (Gst.Structure) – a buffer pool config

Returns:

then number of buffers configured the free queue

Return type:

int

See GstGL.buffer_pool_config_set_gl_min_free_queue_size().

New in version 1.24.

GstGL.buffer_pool_config_set_gl_allocation_params(config, params)[source]
Parameters:

Sets params on config

GstGL.buffer_pool_config_set_gl_min_free_queue_size(config, queue_size)[source]
Parameters:

  • config (Gst.Structure) – a buffer pool config

  • queue_size (int) – the number of buffers

Instructs the GstGL.GLBufferPool to keep queue_size amount of buffers around before allowing them for reuse.

This is helpful to allow GPU processing to complete before the CPU operations on the same buffer could start. Particularly useful when uploading or downloading data to/from the GPU.

A value of 0 disabled this functionality.

This value must be less than the configured maximum amount of buffers for this config.

New in version 1.24.

GstGL.context_get_gl_display(context)[source]
Parameters:

context (Gst.Context) – a Gst.Context

Returns:

Whether display was in context

display:

resulting GstGL.GLDisplay

Return type:

(bool, display: GstGL.GLDisplay or None)

New in version 1.4.

GstGL.context_set_gl_display(context, display)[source]
Parameters:

Sets display on context

New in version 1.4.

GstGL.gl_api_from_string(api_s)[source]
Parameters:

api_s (str) – a space separated string of OpenGL apis

Returns:

The GstGL.GLAPI represented by api_s

Return type:

GstGL.GLAPI

GstGL.gl_api_to_string(api)[source]
Parameters:

api (GstGL.GLAPI) – a GstGL.GLAPI to stringify

Returns:

A space separated string of the OpenGL api’s enabled in api

Return type:

str

GstGL.gl_base_memory_alloc(allocator, params)[source]
Parameters:
Returns:

a new GstGL.GLBaseMemory from allocator with the requested params.

Return type:

GstGL.GLBaseMemory or None

New in version 1.8.

GstGL.gl_base_memory_error_quark()[source]
Returns:

the quark used for GstGL.GLBaseMemory in GLib.Error's

Return type:

int

GstGL.gl_base_memory_init_once()[source]

Initializes the GL Base Memory allocator. It is safe to call this function multiple times. This must be called before any other GstGL.GLBaseMemory operation.

New in version 1.8.

GstGL.gl_buffer_init_once()[source]

Initializes the GL Buffer allocator. It is safe to call this function multiple times. This must be called before any other GstGL.GLBuffer operation.

New in version 1.8.

GstGL.gl_check_extension(name, ext)[source]
Parameters:

  • name (str) – the extension to search for

  • ext (str) – the list of possible extensions

Returns:

whether name is in the space separated list of ext

Return type:

bool

GstGL.gl_config_caveat_to_string(caveat)[source]
Parameters:

caveat (GstGL.GLConfigCaveat) – the GstGL.GLConfigCaveat

Returns:

a string version of caveat or None if caveat does not exist.

Return type:

str or None

New in version 1.20.

GstGL.gl_config_surface_type_to_string(surface_type)[source]
Parameters:

surface_type (GstGL.GLConfigSurfaceType) – the GstGL.GLConfigSurfaceType

Returns:

a string version of caveat or None if surface_type does not exist.

Return type:

str or None

New in version 1.20.

GstGL.gl_context_error_quark()[source]
Returns:

the quark used for GstGL.GLContext in GLib.Error's

Return type:

int

GstGL.gl_element_propagate_display_context(element, display)[source]
Parameters:
GstGL.gl_ensure_element_data(element, display_ptr, other_context_ptr)[source]
Parameters:
Returns:

whether a GstGL.GLDisplay exists in display_ptr

display_ptr:

the resulting GstGL.GLDisplay

other_context_ptr:

the resulting GstGL.GLContext

Return type:

(bool, display_ptr: GstGL.GLDisplay, other_context_ptr: GstGL.GLContext)

Perform the steps necessary for retrieving a GstGL.GLDisplay and (optionally) an application provided GstGL.GLContext from the surrounding elements or from the application using the Gst.Context mechanism.

If the contents of display_ptr or other_context_ptr are not None, then no Gst.Context query is necessary for GstGL.GLDisplay or GstGL.GLContext retrieval or is performed.

This performs Gst.Context queries (if necessary) for a winsys display connection with GstGL.GL_DISPLAY_CONTEXT_TYPE, “gst.x11.display.handle”, and “GstWaylandDisplayHandleContextType” stopping after the first successful retrieval.

This also performs a Gst.Context query (if necessary) for an optional application provided GstGL.GLContext using the name “gst.gl.app_context”. The returned GstGL.GLContext will be shared with a GStreamer created OpenGL context.

GstGL.gl_format_from_video_info(context, vinfo, plane)[source]
Parameters:
Returns:

the GstGL.GLFormat necessary for holding the data in plane of vinfo

Return type:

GstGL.GLFormat

GstGL.gl_format_is_supported(context, format)[source]
Parameters:
Returns:

Whether format is supported by context based on the OpenGL API, version, or available OpenGL extension/s.

Return type:

bool

New in version 1.16.

GstGL.gl_format_n_components(gl_format)[source]
Parameters:

gl_format (GstGL.GLFormat) – the GstGL.GLFormat

Returns:

the number of components in a GstGL.GLFormat

Return type:

int

New in version 1.24.

GstGL.gl_format_type_from_sized_gl_format(format)[source]
Parameters:

format (GstGL.GLFormat) – the sized internal GstGL.GLFormat

Returns:

unsized_format:

location for the resulting unsized GstGL.GLFormat

gl_type:

location for the resulting GL type

Return type:

(unsized_format: GstGL.GLFormat, gl_type: int)

Get the unsized format and type from format for usage in glReadPixels, glTex{Sub}Image*, glTexImage* and similar functions.

New in version 1.16.

GstGL.gl_format_type_n_bytes(format, type)[source]
Parameters:

  • format (int) – the OpenGL format, GL_RGBA, GL_LUMINANCE, etc

  • type (int) – the OpenGL type, GL_UNSIGNED_BYTE, GL_FLOAT, etc

Returns:

the number of bytes the specified format, type combination takes per pixel

Return type:

int

GstGL.gl_get_affine_transformation_meta_as_ndc(meta)[source]
Parameters:

meta (GstVideo.VideoAffineTransformationMeta or None) – a GstVideo.VideoAffineTransformationMeta

Returns:

result of the 4x4 matrix

Return type:

matrix: [float]

Retrieves the stored 4x4 affine transformation matrix stored in meta in NDC coordinates. if meta is None, an identity matrix is returned.

NDC is a left-handed coordinate system

  • x - [-1, 1] - +ve X moves right

  • y - [-1, 1] - +ve Y moves up

  • z - [-1, 1] - +ve Z moves into

New in version 1.20.

GstGL.gl_get_plane_data_size(info, align, plane)[source]
Parameters:
Return type:

int

Retrieve the size in bytes of a video plane of data with a certain alignment

GstGL.gl_get_plane_start(info, valign, plane)[source]
Parameters:
Returns:

difference between the supposed start of the plane from the info and where the data from the previous plane ends.

Return type:

int

GstGL.gl_handle_context_query(element, query, display, context, other_context)[source]
Parameters:
Returns:

Whether the query was successfully responded to from the passed display, context, and other_context.

Return type:

bool

GstGL.gl_handle_set_context(element, context)[source]
Parameters:
Returns:

whether the display or other_context could be set successfully

display:

location of a GstGL.GLDisplay

other_context:

location of a GstGL.GLContext

Return type:

(bool, display: GstGL.GLDisplay, other_context: GstGL.GLContext)

Helper function for implementing Gst.Element.do_set_context() in OpenGL capable elements.

Retrieve’s the GstGL.GLDisplay or GstGL.GLContext in context and places the result in display or other_context respectively.

GstGL.gl_memory_init_once()[source]

Initializes the GL Base Texture allocator. It is safe to call this function multiple times. This must be called before any other GstGL.GLMemory operation.

New in version 1.4.

GstGL.gl_memory_pbo_init_once()[source]
GstGL.gl_multiply_matrix4(a, b)[source]
Parameters:

  • a ([float]) – a 2-dimensional 4x4 array of float

  • b ([float]) – another 2-dimensional 4x4 array of float

Returns:

the result of the multiplication

Return type:

result: [float]

Multiplies two 4x4 matrices, a and b, and stores the result, a 2-dimensional array of float, in result.

New in version 1.20.

GstGL.gl_platform_from_string(platform_s)[source]
Parameters:

platform_s (str) – a space separated string of OpenGL platformss

Returns:

The GstGL.GLPlatform represented by platform_s

Return type:

GstGL.GLPlatform

GstGL.gl_platform_to_string(platform)[source]
Parameters:

platform (GstGL.GLPlatform) – a GstGL.GLPlatform to stringify

Returns:

A space separated string of the OpenGL platforms enabled in platform

Return type:

str

GstGL.gl_query_local_gl_context(element, direction, context_ptr)[source]
Parameters:
Returns:

whether context_ptr contains a GstGL.GLContext

context_ptr:

location containing the current and/or resulting GstGL.GLContext

Return type:

(bool, context_ptr: GstGL.GLContext)

Performs a Gst.QueryType.CONTEXT query of type “gst.gl.local_context” on all Gst.Pads in element of direction for the local OpenGL context used by GStreamer elements.

GstGL.gl_renderbuffer_init_once()[source]

Initializes the GL Base Texture allocator. It is safe to call this function multiple times. This must be called before any other GstGL.GLRenderbuffer operation.

New in version 1.10.

GstGL.gl_set_affine_transformation_meta_from_ndc(meta, matrix)[source]
Parameters:

Set the 4x4 affine transformation matrix stored in meta from the NDC coordinates in matrix.

New in version 1.20.

GstGL.gl_sized_gl_format_from_gl_format_type(context, format, type)[source]
Parameters:
Returns:

the sized internal format specified by format and type that can be used in context

Return type:

int

GstGL.gl_stereo_downmix_mode_get_type()[source]
Return type:

GObject.GType

GstGL.gl_swizzle_invert(swizzle)[source]
Parameters:

swizzle ([int]) – input swizzle

Returns:

resulting inversion

Return type:

inversion: [int]

Given swizzle, produce inversion such that:

swizzle[inversion[i]] == identity[i] where:

  • identity = {0, 1, 2,…}

  • unset fields are marked by -1

New in version 1.24.

GstGL.gl_sync_meta_api_get_type()[source]
Return type:

GObject.GType

GstGL.gl_sync_meta_get_info()[source]
Return type:

Gst.MetaInfo

GstGL.gl_texture_target_from_gl(target)[source]
Parameters:

target (int) – an OpenGL texture binding target

Returns:

the GstGL.GLTextureTarget that’s equiavalant to target or GstGL.GLTextureTarget.NONE

Return type:

GstGL.GLTextureTarget

GstGL.gl_texture_target_from_string(str)[source]
Parameters:

str (str) – a string equivalent to one of the GST_GL_TEXTURE_TARGET_*_STR values

Returns:

the GstGL.GLTextureTarget represented by str or GstGL.GLTextureTarget.NONE

Return type:

GstGL.GLTextureTarget

GstGL.gl_texture_target_to_buffer_pool_option(target)[source]
Parameters:

target (GstGL.GLTextureTarget) – a GstGL.GLTextureTarget

Returns:

a string representing the GstBufferPoolOption specified by target

Return type:

str or None

GstGL.gl_texture_target_to_gl(target)[source]
Parameters:

target (GstGL.GLTextureTarget) – a GstGL.GLTextureTarget

Returns:

the OpenGL value for binding the target with glBindTexture() and similar functions or 0

Return type:

int

GstGL.gl_texture_target_to_string(target)[source]
Parameters:

target (GstGL.GLTextureTarget) – a GstGL.GLTextureTarget

Returns:

the stringified version of target or None

Return type:

str or None

GstGL.gl_value_get_texture_target_mask(value)[source]
Parameters:

value (GObject.Value) – an initialized GObject.Value of type GObject.TYPE_STRING

Returns:

the mask of GstGL.GLTextureTarget's in value or GstGL.GLTextureTarget.NONE on failure

Return type:

GstGL.GLTextureTarget

See GstGL.gl_value_set_texture_target_from_mask() for what entails a mask

GstGL.gl_value_set_texture_target(value, target)[source]
Parameters:
Returns:

whether the target could be set on value

Return type:

bool

GstGL.gl_value_set_texture_target_from_mask(value, target_mask)[source]
Parameters:
Returns:

whether the target_mask could be set on value

Return type:

bool

A mask is a bitwise OR of (1 << target) where target is a valid GstGL.GLTextureTarget

GstGL.gl_version_to_glsl_version(gl_api, maj, min)[source]
Parameters:
Returns:

The minimum supported GstGL.GLSLVersion available for gl_api, maj and min

Return type:

GstGL.GLSLVersion

GstGL.gl_video_format_swizzle(video_format)[source]
Parameters:

video_format (GstVideo.VideoFormat) – the GstVideo.VideoFormat in use

Returns:

whether valid swizzle indices could be found

swizzle:

the returned swizzle indices

Return type:

(bool, swizzle: [int])

Calculates the swizzle indices for video_format and gl_format in order to access a texture such that accessing a texel from a texture through the swizzle index produces values in the order (R, G, B, A) or (Y, U, V, A).

For multi-planer formats, the swizzle index uses the same component order (RGBA/YUVA) and should be applied after combining multiple planes into a single rgba/yuva value. e.g. sampling from a NV12 format would have Y from one texture and UV from another texture into a (Y, U, V) value. Add an Aplha component and then perform swizzling. Sampling from NV21 would produce (Y, V, U) which is then swizzled to (Y, U, V).

New in version 1.24.

GstGL.gl_window_error_quark()[source]
Returns:

the quark used for GstGL.GLWindow in GLib.Error's

Return type:

int

GstGL.glsl_error_quark()[source]
Returns:

the quark used for GstGLSL in GLib.Error's

Return type:

int

GstGL.glsl_profile_from_string(string)[source]
Parameters:

string (str) – a GLSL version string

Returns:

the GstGL.GLSLProfile of string or GstGL.GLSLProfile.NONE on error

Return type:

GstGL.GLSLProfile

GstGL.glsl_profile_to_string(profile)[source]
Parameters:

profile (GstGL.GLSLProfile) – a GstGL.GLSLProfile

Returns:

the name for profile or None on error

Return type:

str or None

GstGL.glsl_string_get_version_profile(s)[source]
Parameters:

s (str) – string to search for a valid #version string

Returns:

True if a valid #version string was found, False otherwise

version:

resulting GstGL.GLSLVersion

profile:

resulting GstGL.GLSLProfile

Return type:

(bool, version: GstGL.GLSLVersion, profile: GstGL.GLSLProfile)

Note: this function first searches the first 1 kilobytes for a #version preprocessor directive and then executes GstGL.GLSLVersion.profile_from_string().

GstGL.glsl_version_from_string(string)[source]
Parameters:

string (str) – a GLSL version string

Returns:

the GstGL.GLSLVersion of string or GstGL.GLSLVersion.NONE on error

Return type:

GstGL.GLSLVersion

GstGL.glsl_version_profile_from_string(string)[source]
Parameters:

string (str) – a valid GLSL #version string

Returns:

True if a valid #version string was found, False otherwise

version_ret:

resulting GstGL.GLSLVersion

profile_ret:

resulting GstGL.GLSLVersion

Return type:

(bool, version_ret: GstGL.GLSLVersion, profile_ret: GstGL.GLSLProfile)

Note: this function expects either a #version GLSL preprocesser directive or a valid GLSL version and/or profile.

GstGL.glsl_version_profile_to_string(version, profile)[source]
Parameters:
Returns:

the combined GLSL #version string for version and profile

Return type:

str or None

GstGL.glsl_version_to_string(version)[source]
Parameters:

version (GstGL.GLSLVersion) – a GstGL.GLSLVersion

Returns:

the name of version or None on error

Return type:

str or None

GstGL.is_gl_base_memory(mem)[source]
Parameters:

mem (Gst.Memory) – a Gst.Memory

Returns:

whether the memory at mem is a GstGL.GLBaseMemory

Return type:

bool

New in version 1.8.

GstGL.is_gl_buffer(mem)[source]
Parameters:

mem (Gst.Memory) – a Gst.Memory

Returns:

whether the memory at mem is a GstGL.GLBuffer

Return type:

bool

New in version 1.8.

GstGL.is_gl_memory(mem)[source]
Parameters:

mem (Gst.Memory) – a Gst.Memory

Returns:

whether the memory at mem is a GstGL.GLMemory

Return type:

bool

New in version 1.4.

GstGL.is_gl_memory_pbo(mem)[source]
Parameters:

mem (Gst.Memory) – a Gst.Memory

Returns:

whether the memory at mem is a GstGL.GLMemoryPBO

Return type:

bool

New in version 1.8.

GstGL.is_gl_renderbuffer(mem)[source]
Parameters:

mem (Gst.Memory) – a Gst.Memory

Returns:

whether the memory at mem is a GstGL.GLRenderbuffer

Return type:

bool

New in version 1.10.