Release OpenCL memory objects that have been created from media surfaces.
command_queue
A valid command-queue.
num_objects
The number of memory objects to be released in mem_objects
.
mem_objects
A pointer to a list of OpenCL memory objects that were created from media surfaces.
num_events_in_wait_list
, event_wait_list
Specify events that need to complete before this particular
command can be executed. If event_wait_list
is NULL, then this particular command does not wait on any
event to complete. If event_wait_list
is
NULL, num_events_in_wait_list
must be 0. If
event_wait_list
is not NULL, the list of events
pointed to by event_wait_list
must be valid and
num_events_in_wait_list
must be greater than 0.
The events specified in event
returns an event object
that identifies this particular command and can be used to query or queue a
wait for this particular command to complete. event
can
be NULL in which case it will not be possible for the application to query
the status of this command or queue a wait for this command to complete.
If the event_wait_list
and the event arguments are not
NULL, the event
argument should not refer to an element
of the event_wait_list
array.
Used to release OpenCL memory objects that have been created from media
surfaces. The media surfaces are released by the OpenCL context associated with
command_queue
.
OpenCL memory objects created from media surfaces which have been acquired by OpenCL must be released by OpenCL before they may be accessed by the media adapter API. Accessing a media surface while its corresponding OpenCL memory object is acquired is in error and will result in undefined behavior, including but not limited to possible OpenCL errors, data corruption, and program termination.
If CL_CONTEXT_INTEROP_USER_SYNC
is not
specified as CL_TRUE
during context creation,
clEnqueueReleaseDX9MediaSurfacesKHR
provides the
synchronization guarantee that any calls to media adapter APIs involving
the interop device(s) used in the OpenCL context made after the call to
clEnqueueReleaseDX9MediaSurfacesKHR
will not start executing until
after all events in event_wait_list
are complete and all work already
submitted to command_queue
completes execution. If the context was
created with properties specifying CL_CONTEXT_INTEROP_USER_SYNC
as CL_TRUE
, the user is responsible for guaranteeing that any
media adapter API calls involving the interop device(s) used in the OpenCL context made
after clEnqueueReleaseDX9MediaSurfacesKHR
will not start executing
until after event returned by clEnqueueReleaseDX9MediaSurfacesKHR
reports completion.
The goal of this extension is to allow applications to use media surfaces as OpenCL memory objects. This allows efficient sharing of data between OpenCL and selected adapter APIs (only DX9 for now). If this extension is supported, an OpenCL image object can be created from a media surface and the OpenCL API can be used to execute kernels that read and/or write memory objects that are media surfaces. Note that OpenCL memory objects may be created from the adapter media surface if and only if the OpenCL context has been created from that adapter.
If this extension is supported by
an implementation, the string "cl_khr_media_sharing" will be present in the
CL_PLATFORM_EXTENSIONS
or CL_DEVICE_EXTENSIONS
string described in the table of allowed values for param_name
for
clGetDeviceInfo.
As currently proposed the interfaces for this
extension would be provided in cl_dx9_media_sharing.h
.
This section includes the D3D surface formats that are supported when the adapter type is one of the Direct 3D lineage . Using a D3D surface format not listed here is an error. To extend the use of this extension to support media adapters beyond DirectX9 tables similar to the ones in this section will need to be defined for the surface formats supported by the new media adapter. All implementations that support this extension are required to support the NV12 surface format, the other surface formats supported are the same surface formats that the adapter you are sharing with supports as long as they are listed in the two tables below.
FOUR CC code | CL image format (channel order, channel data type) |
---|---|
FOURCC('N', 'V', '1', '2'), Plane 0 |
CL_R, CL_UNORM_INT8
|
FOURCC('N', 'V', '1', '2'), Plane 1 |
CL_RG, CL_UNORM_INT8
|
FOURCC('Y', 'V', '1', '2'), Plane 0 |
CL_R, CL_UNORM_INT8
|
FOURCC('Y', 'V', '1', '2'), Plane 1 |
CL_R, CL_UNORM_INT8
|
FOURCC('Y', 'V', '1', '2'), Plane 2 |
CL_R, CL_UNORM_INT8
|
In the table above, NV12 Plane 0 corresponds to the luminance (Y) channel and Plane 1
corresponds to the UV channels. The YV12 Plane 0 corresponds to the Y channel, Plane
1 to the U channel and Plane 2 to the V channel. Note that the YUV formats map to
CL_R
and CL_RG
but do not perform any YUV to
RGB conversion and vice-versa.
D3D format | CL image format (channel order, channel data type) |
---|---|
D3DFMT_R32F |
CL_R, CL_FLOAT
|
D3DFMT_R16F |
CL_R, CL_HALF_FLOAT
|
D3DFMT_L16 |
CL_R, CL_UNORM_INT16
|
D3DFMT_A8 |
CL_A, CL_UNORM_INT8
|
D3DFMT_L8 |
CL_R, CL_UNORM_INT8
|
D3DFMT_G32R32F |
CL_RG, CL_FLOAT
|
D3DFMT_G16R16F |
CL_RG, CL_HALF_FLOAT
|
D3DFMT_G16R16 |
CL_RG, CL_UNORM_INT16
|
D3DFMT_A8L8 |
CL_RG, CL_UNORM_INT8
|
D3DFMT_A32B32G32R32F |
CL_RGBA, CL_FLOAT
|
D3DFMT_A16B16G16R16F |
CL_RGBA, CL_HALF_FLOAT
|
D3DFMT_A16B16G16R16 |
CL_RGBA, CL_UNORM_INT16
|
D3DFMT_A8B8G8R8 |
CL_RGBA, CL_UNORM_INT8
|
D3DFMT_X8B8G8R8 |
CL_RGBA, CL_UNORM_INT8
|
D3DFMT_A8R8G8B8 |
CL_BGRA, CL_UNORM_INT8
|
D3DFMT_X8R8G8B8 |
CL_BGRA, CL_UNORM_INT8
|
Note that D3D9 format names seem to imply that the order of the color channels are switched
relative to OpenCL but this is not the case. For example, layout of channels for each pixel
for D3DFMT_A32FB32FG32FR32F is the same as CL_RGBA
, CL_FLOAT
.
Properties of media surface objects may be queried using
clGetMemObjectInfo
and clGetImageInfo with
param_name
CL_MEM_MEDIA_ADAPTER_TYPE_KHR
,
CL_MEM_MEDIA_SURFACE_INFO_KHR
and
CL_IMAGE_MEDIA_SURFACE_PLANE_KHR
as described for
clGetImageInfo and in the
information below about accessing mapped regions of a memory object.
This section describes the behavior of OpenCL commands that access mapped regions of a memory object.
The contents of the region of a memory object and associated memory objects
(sub-buffer objects or 1D image buffer objects that overlap this region) mapped
for writing (i.e. CL_MAP_WRITE
or
CL_MAP_WRITE_INVALIDATE_REGION
is set in map_flags
argument to clEnqueueMapBuffer
or clEnqueueMapImage) are
considered to be undefined until this region is unmapped.
Multiple commands in command-queues can map a region or overlapping regions of a memory
object and associated memory objects (sub-buffer objects or 1D image buffer objects that
overlap this region) for reading (i.e. map_flags
= CL_MAP_READ
).
The contents of the regions of a memory object mapped for reading can also be read by kernels
and other OpenCL commands (such as
clEnqueueCopyBuffer) executing on a device(s).
Mapping (and unmapping) overlapped regions in a memory object and/or associated memory
objects (sub-buffer objects or 1D image buffer objects that overlap this region) for writing
is an error and will result in CL_INVALID_OPERATION
error returned by
clEnqueueMapBuffer
or clEnqueueMapImage.
If a memory object is currently mapped for writing, the application must ensure that the memory object is unmapped before any enqueued kernels or commands that read from or write to this memory object or any of its associated memory objects (sub-buffer or 1D image buffer objects) or its parent object (if the memory object is a sub-buffer or 1D image buffer object) begin execution; otherwise the behavior is undefined.
If a memory object is currently mapped for reading, the application must ensure that the memory object is unmapped before any enqueued kernels or commands that write to this memory object or any of its associated memory objects (sub-buffer or 1D image buffer objects) or its parent object (if the memory object is a sub-buffer or 1D image buffer object) begin execution; otherwise the behavior is undefined.
Accessing the contents of the memory region referred to by the mapped pointer that has been unmapped is undefined.
The mapped pointer returned by
clEnqueueMapBuffer
or clEnqueueMapImage can be used as
ptr
argument value to
clEnqueueReadBuffer,
clEnqueueWriteBuffer,
clEnqueueReadBufferRect,
clEnqueueWriteBufferRect,
clEnqueueReadImage, and
clEnqueueWriteImage,
provided the rules described above are adhered to.
Returns CL_SUCCESS returns CL_SUCCESS
if the function is executed successfully. If num_objects
is 0 and
<mem_objects
> is NULL then the function does nothing and returns
CL_SUCCESS. Otherwise it returns one of the following errors:
num_objects
is zero and
mem_objects
is not a NULL value or if num_objects
> 0 and mem_objects
is NULL.
mem_objects
are not valid OpenCL memory objects or if memory objects in mem_objects
have
not been created from media surfaces.
command_queue
is not
a valid command-queue.
command_queue
was not created from a media object.
mem_objects
have not been previously been acquired using
clEnqueueAcquireDX9MediaSurfacesKHR
or have been released using
clEnqueueReleaseDX9MediaSurfacesKHR
since the last time that they were acquired.
event_wait_list
is
NULL and num_event_in_wait_list
> 0, or event_wait_list
is not NULL and num_event_in_wait_list
is 0, or if event objects in
event_wait_list
are not valid events.
cl_khr_dx9_media_sharing, clGetDeviceIDsFromDX9MediaAdapterKHR, clCreateFromDX9MediaSurfaceKHR, clEnqueueAcquireDX9MediaSurfacesKHR, clEnqueueReleaseDX9MediaSurfacesKHR