NV_stream_fifo_next

EGL_NV_stream_fifo_next

Daniel Kartch
Miguel A. Vico

Daniel Kartch, NVIDIA (dkartch 'at' nvidia.com)

Draft

Version 3 - October 27, 2016

EGL Extension #110

EGL display extension

Requires EGL_KHR_stream_fifo

When operating on a FIFO stream, a consumer may need to know the
timestamp associated with the next frame in the stream before
deciding whether to acquire it or reuse the previous frame. In the
case of a FIFO size of 1, the EGL_STREAM_TIME_PRODUCER_KHR attribute
is sufficient to determine this. However, when the size is greater
than 1, there may be frames available with earlier time stamps than
the one most recently inserted by the producer. This extension
enables querying of the next pending frame in a stream.

None

None

Accepted as the <attribute> parameter of eglQueryStreamu64KHR

    EGL_PENDING_FRAME_NV                        0x3329

Accepted as the <attribute> parameter of eglQueryStreamTimeKHR

    EGL_STREAM_TIME_PENDING_NV                  0x332A

    Attribute                  Read/Write Type         Section
    -------------------------- ---------- ------------ --------
    EGL_PENDING_FRAME_NV           ro     EGLuint64KHR 3.10.4.x
    EGL_STREAM_TIME_PENDING_NV     ro     EGLTimeKHR   3.10.4.y

3.10.4.x EGL_PENDING_FRAME_NV Attribute

The EGL_PENDING_FRAME_NV attribute indicates the frame number of the
image frame that would be obtained if an acquire operation were
performed at the time of the query. This is the value that
EGL_PRODUCER_FRAME_KHR contained just after this image frame was
inserted into the stream.

3.10.4.y EGL_STREAM_TIME_PENDING_NV Attribute

The EGL_STREAM_TIME_PENDING_NV attribute indicates the timestamp of
the image frame that would be obtained if an acquire operation were
performed at the time of the query.

None

#3  (October 27, 2016) Daniel Kartch
    - Clean up for publication

#2  (April 2nd, 2015) Miguel A. Vico
    - Assigned enumerated values for constants.

#1  (March 20th, 2015) Daniel Kartch
    - Initial draft