Name String

    cl_intel_egl_image_yuv

Contributors

    Ben Ashbaugh, Intel
    Pawel Wilma, Intel
    Bartosz Sochacki, Intel

Contact

    Pawel Wilma, Intel (pawel.wilma 'at' intel.com)

Version

    Version 1.0, June 03, 2015

Number

    OpenCL Extension #37

Status

    Final Draft

Extension Type

    OpenCL platform extension

Dependencies

    OpenCL 1.2 is required and cl_khr_egl_image implementation supporting
    sharing of images between EGL and OpenCL is required.  This extension
    is written against revision 26 of the OpenCL 2.0 extension specification
    and revision 26 of OpenCL 2.0 specification.

Overview

    The goal of this extension is to increase interoperability between OpenCL
    and EGL by introducing support for planar YUV images. Specifically, this
    extension adds the ability to create OpenCL memory objects representing
    individual planes of an EGL planar YUV image.


New Tokens

    Accepted as property in <properties> parameter of function clCreateFromEGLImageKHR
    and as <param_name> parameter of function clGetImageInfo

        CL_EGL_YUV_PLANE_INTEL                   0x4107

Additions to Chapter 9 of the OpenCL 2.0 Extension Specification

    In section 9.19.4, replace the description of <properties> under
    clCreateFromEGLImageKHR with:

    "<properties> specifies a list of property names and their corresponding
    values. Each property name is immediately followed by the corresponding
    desired value. The list is terminated with 0. <properties> can be NULL.
    Supported property names and values:

    ----------------------------------------------------------------------------------------
    Property name             Property value     Description
    -----------------------   --------------     -----------
    CL_EGL_YUV_PLANE_INTEL    -1,0,1,...         Defines plane from planar YUV image to be
                                                 used as OpenCL image source. If the value
                                                 specified for this property name is not
                                                 valid the function returns error code
                                                 CL_INVALID_VALUE. Default value is -1 which
                                                 represents all planes of the image.
    ----------------------------------------------------------------------------------------"

    At the end of section 9.19.4 add following description:

    "Supported planar YUV formats

    ------------------------------------------------------------------
    Format    Plane                  cl_channel_order  cl_channel_type
    ------    --------------------   ----------------  ---------------
    NV12      0                      CL_R              CL_UNORM_INT8
    NV12      1                      CL_RG             CL_UNORM_INT8
    ------------------------------------------------------------------
    Table 9.19.4.1: List of planar YUV formats and corresponding OpenCL
    Image Formats.

    For the NV12 surface format, plane 0 corresponds to the Y channel
    data and plane 1 corresponds to the UV channel data.

    In case of creating OpenCL image based on Y-plane from NV12 image
    the <properties> could be defined in following way:

    cl_egl_image_properties_khr properties[]  =
    {
        CL_EGL_YUV_PLANE_INTEL, 0,
        CL_NONE
    };

    cl_mem image = clCreateFromEGLImageKHR( context, display, egl_image,
                                            flags, properties, &error_code );"

Additions to Chapter 5 of the OpenCL2.0 Specification

    Add to the list of errors for clGetImageInfo:
        * CL_INVALID_EGL_OBJECT_KHR if <param_name> is CL_EGL_YUV_PLANE_INTEL
          and <image> was not created by the function clCreateFromEGLImageKHR.

    Extend table 5.10 to include the following entry:

    -------------------------------------------------------------------------
    cl_image_info          Return type    Info. returned in <param_value>
    -------------          -----------    -----------------------------------
    CL_EGL_YUV_PLANE_INTEL cl_int         If <image> was created using
                                          clCreateFromEGLImageKHR, returns
                                          the value of CL_EGL_YUV_PLANE_INTEL
                                          property from <properties> argument
                                          specified when <image> was created.
    -------------------------------------------------------------------------

Issues

    None

Revision History

    Version 1.0 (2015, June 03): First public revision.