---
name: "clGetDeviceIDsFromDX9MediaAdapterKHR"
section: "3clc"
platform: "linux"
package: "opencl-1.2-man-doc"
version: "1.0~svn33624-5.1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/clGetDeviceIDsFromDX9MediaAdapterKHR"
---

# clGetDeviceIDsFromDX9MediaAdapterKHR(3clc)

Query a media adapter for any associated OpenCL devices.

## NAME

clGetDeviceIDsFromDX9MediaAdapterKHR - Query a media adapter for any associated OpenCL devices.

##

**cl\_int clGetDeviceIDsFromDX9MediaAdapterKHR(cl\_platform\_id** *platform***, cl\_uint** *num\_media\_adapters***, cl\_dx9\_media\_adapter\_type\_khr \****media\_adapters\_type***, void \****media\_adapters***, cl\_dx9\_media\_adapter\_set\_khr** *media\_adapter\_set***, cl\_uint** *num\_entries***, cl\_device\_id \****devices***, cl\_int \****num\_devices***);**

## PARAMETERS

*platform*

Refers to the platform ID returned by [**clGetPlatformIDs**(3clc)](/clGetPlatformIDs/3clc.md).

*num\_media\_adapters*

The number of media adapters.

*media\_adapters\_type*

An array of *num\_media\_adapters* entries. Each entry specifies the type of media adapter and must be one of the values described in the table below.

| | |
| --- | --- |
| **cl\_dx9\_media\_adapter\_type\_khr** | **Type of media adapters** |
| **CL\_ADAPTER\_D3D9\_KHR** | IDirect3DDevice9 \* |
| **CL\_ADAPTER\_D3D9EX\_KHR** | IDirect3DDevice9Ex \* |
| **CL\_ADAPTER\_DXVA\_KHR** | IDXVAHD\_Device \* |

*media\_adapters*

An array of *num\_media\_adapters* entries. Each entry specifies the actual adapter whose type is specified by *media\_adapter\_type*. The *media\_adapters* must be one of the types describes in the table above.

*media\_adapter\_set*

Specifies the set of adapters to return and must be one of the values described in the table below.

| | |
| --- | --- |
| **cl\_dx9\_media\_adapter\_set\_khr** | **Description** |
| **CL\_PREFERRED\_DEVICES\_FOR\_MEDIA\_ADAPTER\_KHR** | The preferred OpenCL devices associated with the media adapter. |
| **CL\_ALL\_DEVICES\_FOR\_MEDIA\_ADAPTER\_KHR** | All OpenCL devices that may interoperate with the media adapter. |

*num\_entries*

The number of cl\_device\_id entries that can be added to *devices*. If *devices* is not NULL, the *num\_entries* must be greater than zero.

*devices*

Returns a list of OpenCL devices found that support the list of media adapters specified. The cl\_device\_id values returned in *devices* can be used to identify a specific OpenCL device. If *devices* argument is NULL, this argument is ignored. The number of OpenCL devices returned is the minimum of the value specified by *num\_entries* or the number of OpenCL devices whose type matches *device\_type*.

*num\_devices*

Returns the number of OpenCL devices. If *num\_devices* is NULL, this argument is ignored.

## DESCRIPTION

Queries a media adapter for any associated OpenCL devices. Adapters with associated OpenCL devices can enable media surface sharing between the two.

## NOTES

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**(3clc)](/clGetDeviceInfo/3clc.md).

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**(3clc)](/clGetMemObjectInfo/3clc.md) and [**clGetImageInfo**(3clc)](/clGetImageInfo/3clc.md) 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**(3clc)](/clGetImageInfo/3clc.md) and in the information below about accessing mapped regions of a memory object. Accessing mapped regions of a memory object.PP 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**(3clc)](/clEnqueueMapBuffer/3clc.md) or [**clEnqueueMapImage**(3clc)](/clEnqueueMapImage/3clc.md)) 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**(3clc)](/clEnqueueCopyBuffer/3clc.md)) 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**(3clc)](/clEnqueueMapBuffer/3clc.md) or [**clEnqueueMapImage**(3clc)](/clEnqueueMapImage/3clc.md).

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**(3clc)](/clEnqueueMapBuffer/3clc.md) or [**clEnqueueMapImage**(3clc)](/clEnqueueMapImage/3clc.md) can be used as *ptr* argument value to [**clEnqueueReadBuffer**(3clc)](/clEnqueueReadBuffer/3clc.md), [**clEnqueueWriteBuffer**(3clc)](/clEnqueueWriteBuffer/3clc.md), [**clEnqueueReadBufferRect**(3clc)](/clEnqueueReadBufferRect/3clc.md), [**clEnqueueWriteBufferRect**(3clc)](/clEnqueueWriteBufferRect/3clc.md), [**clEnqueueReadImage**(3clc)](/clEnqueueReadImage/3clc.md), and [**clEnqueueWriteImage**(3clc)](/clEnqueueWriteImage/3clc.md), provided the rules described above are adhered to.

## ERRORS

Returns CL\_SUCCESS if the function is executed successfully. Otherwise, it returns one of the following errors:

• CL\_INVALID\_PLATFORM if *platform* is not a valid platform.

• CL\_INVALID\_VALUE if *num\_media\_adapters* is zero or if *media\_adapters\_type* is NULL or if *media\_adapters* is NULL.

• CL\_INVALID\_VALUE if any of the entries in *media\_adapters\_type* or *media\_adapters* is not a valid value.

• CL\_INVALID\_VALUE if *media\_adapter\_set* is not a valid value.

• CL\_INVALID\_VALUE if *num\_entries* is equal to zero and *devices* is not NULL or if both *num\_devices* and *devices* are NULL.

• CL\_DEVICE\_NOT\_FOUND if no OpenCL devices that correspond to adapters specified in *media\_adapters* and *media\_adapters\_type* were found.

• CL\_OUT\_OF\_RESOURCES if there is a failure to allocate resources required by the OpenCL implementation on the device.

• CL\_OUT\_OF\_HOST\_MEMORY if there is a failure to allocate resources required by the OpenCL implementation on the host.

## SPECIFICATION

**OpenCL Specification**\[1\]

## SEE ALSO

[**cl\_khr\_dx9\_media\_sharing**(3clc)](/cl_khr_dx9_media_sharing/3clc.md), [**clGetDeviceIDsFromDX9MediaAdapterKHR**(3clc)](/clGetDeviceIDsFromDX9MediaAdapterKHR/3clc.md), [**clCreateFromDX9MediaSurfaceKHR**(3clc)](/clCreateFromDX9MediaSurfaceKHR/3clc.md), [**clEnqueueAcquireDX9MediaSurfacesKHR**(3clc)](/clEnqueueAcquireDX9MediaSurfacesKHR/3clc.md), [**clEnqueueReleaseDX9MediaSurfacesKHR**(3clc)](/clEnqueueReleaseDX9MediaSurfacesKHR/3clc.md),

## AUTHORS

**The Khronos Group**

## COPYRIGHT

Copyright © 2007-2011 The Khronos Group Inc.\
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and/or associated documentation files (the "Materials"), to deal in the Materials without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Materials, and to permit persons to whom the Materials are furnished to do so, subject to the condition that this copyright notice and permission notice shall be included in all copies or substantial portions of the Materials.

## NOTES

- 1\.

  OpenCL Specification

  page 88, section 9.10.7.1 - Querying OpenCL Devices corresponding....