CLENQUEUEACQUIREDX9M(3clc)

📦
version 1.0~svn33624 · 3 versions
, in ubuntu jammy, ubuntu noble

✨ CLENQUEUEACQUIREDX9M 💅

okay bestie, settle in, because this one is from the OpenCL Manual (that's the 3clc section, iykyk) and it's literally the glow-up your media surfaces have been waiting for. ✨

🌸 NAME 🌸

clEnqueueAcquireDX9MediaSurfacesKHR — acquire OpenCL memory objects that have been created from a media surface. That's it, that's the whole vibe. 🫶

cl_int
clEnqueueAcquireDX9MediaSurfacesKHR(cl_command_queue command_queue,
                                    cl_uint num_objects,
                                    const cl_mem *mem_objects,
                                    cl_uint num_events_in_wait_list,
                                    const cl_event *event_wait_list,
                                    cl_event *event);

🎀 PARAMETERS 🎀

  • command_queue — a valid command-queue. queen needs a place to sit. 👑
  • num_objects — the number of memory objects to be acquired in mem_objects. count 'em, bestie. 🔢
  • mem_objects — a pointer to a list of OpenCL memory objects that were created from media surfaces. yes, those surfaces. 🦋
  • num_events_in_wait_list, event_wait_list — specify events that need to complete before this particular command can be executed. here's the tea, so listen up:
    • 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. no cap.
    • 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_wait_list act as synchronization points. ⏳
  • 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. so like… you can ghost it, but then you won't know what happened. 🙈

💖 NOTES 💖

Used to acquire OpenCL memory objects that have been created from a media surface. The media surfaces are acquired by the OpenCL context associated with command_queue and can therefore be used by all command-queues associated with the OpenCL context. one context, everybody invited, no drama. 🎉

OpenCL memory objects created from media surfaces must be acquired before they can be used by any OpenCL commands queued to a command-queue. If an OpenCL memory object created from a media surface is used while it is not currently acquired by OpenCL, the call attempting to use that OpenCL memory object will return CL_DX9_MEDIA_SURFACE_NOT_ACQUIRED_KHR. > so like, do the acquire first or the whole thing flops. it's giving unfinished business. 💀

If CL_CONTEXT_INTEROP_USER_SYNC is not specified as CL_TRUE during context creation, clEnqueueAcquireDX9MediaSurfacesKHR provides the synchronization guarantee that any media adapter API calls involving the interop device(s) used in the OpenCL context made before clEnqueueAcquireDX9MediaSurfacesKHR is called will complete executing before event reports completion and before the execution of any subsequent OpenCL work issued in command_queue begins. ✨

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 before clEnqueueAcquireDX9MediaSurfacesKHR is called have completed before calling clEnqueueAcquireDX9MediaSurfacesKHR. > read that again bestie — that one's on you, not on OpenCL. 😭

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). 👑

As currently proposed the interfaces for this extension would be provided in cl_dx9_media_sharing.h. 📁

🦋 the D3D surface format situation 🦋

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. 🌈

  • 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 🍓

that's the whole menu, no substitutions, no swaps. ⭐

okay so looking at that table up there 👆, NV12 Plane 0 is literally the luminance (Y) channel and Plane 1 is the UV channels. For YV12, Plane 0 is the Y channel, Plane 1 is the U channel, and Plane 2 is the V channel. And bestie, note that the YUV formats map to CL_R and CL_RG but they do not do any YUV to RGB conversion or vice-versa. No cap. 💅

                ┌──────────────────────┬───────────────────────────┐
                │      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   │
                └──────────────────────┴───────────────────────────┘

So like, D3D9 format names might seem to imply that the color channel order is switched compared to OpenCL, but bestie that is not the case. For example, the layout of channels for each pixel for D3DFMT_A32FB32FG32FR32F is literally the same as CL_RGBA, CL_FLOAT. Periodt. 💁‍♀️

You can query properties of media surface objects using clGetMemObjectInfo(3clc) and clGetImageInfo(3clc) with param_name set to CL_MEM_MEDIA_ADAPTER_TYPE_KHR, CL_MEM_MEDIA_SURFACE_INFO_KHR, and CL_IMAGE_MEDIA_SURFACE_PLANE_KHR, as described for clGetImageInfo(3clc) and in the info below about accessing mapped regions of a memory object.

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 the map_flags argument to clEnqueueMapBuffer(3clc) or clEnqueueMapImage(3clc)) are considered undefined until this region is unmapped. So don't touch them, bestie! 🚫

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)) executing on a device(s). It's giving shared reading vibes 📚.

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) or clEnqueueMapImage(3clc). So like, don't do it. 🛑

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. Like, undefined is giving chaos 💀.

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. Same energy, bestie. 🙈

Accessing the contents of the memory region referred to by the mapped pointer that has been unmapped is undefined. Like, don't even try it. 💀

The mapped pointer returned by clEnqueueMapBuffer(3clc) or clEnqueueMapImage(3clc) can be used as the ptr argument value to clEnqueueReadBuffer(3clc), clEnqueueWriteBuffer(3clc), clEnqueueReadBufferRect(3clc), clEnqueueWriteBufferRect(3clc), clEnqueueReadImage(3clc), and clEnqueueWriteImage(3clc), provided the rules described above are adhered to. Slay. 💅

🚨 ERRORS 🚨

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 these errors, bestie:

  • CL_INVALID_VALUE — if num_objects is zero and mem_objects is not a NULL value or if num_objects > 0 and mem_objects is NULL.
  • CL_INVALID_MEM_OBJECT — if memory objects in mem_objects are not valid OpenCL memory objects or if memory objects in mem_objects have not been created from media surfaces.
  • CL_INVALID_COMMAND_QUEUE — if command_queue is not a valid command-queue.
  • CL_INVALID_CONTEXT — if context associated with command_queue was not created from a device that can share the media surface referenced by mem_objects.
  • CL_DX9_MEDIA_SURFACE_ALREADY_ACQUIRED_KHR — if memory objects in mem_objects have previously been acquired using clEnqueueAcquireDX9MediaSurfacesKHR but have not been released using clEnqueueReleaseDX9MediaSurfacesKHR(3clc).
  • CL_INVALID_EVENT_WAIT_LIST — if 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_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 👀

💖 AUTHORS 💖

The Khronos Group

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 92, section 9.10.7.4 - Sharing Memory Objects created from Media Surfaces

That's the tea! This page is from The Khronos Group, dated 01/14/2021, and it's for CLENQUEUEACQUIREDX9M(3clc). Stay slay! 💅✨

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