The algorithm for generating the current slot index is a simple round robin,
nonetheless it's not assured that the next slot index it's not still used by a
still living encode picture.
This new way holds an array with the still living encode pictures and the next
slot index looks for a released index in the array.
Its downside is deallocating a picture need to be removed from the array, so the
helper has to be passed to the uninit() function
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8007>
In GStreamer that buffer information is decoupled, holding other structures to
describe the stream: GstCaps. So, to keep the GStreamer design this patch
removes these information from GstVulkanEncoderPicture and pass to
gst_vulkan_encoder_encode() a pointer to GstVideoInfo.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8007>
Instead of holding all headers in an external array and add them into the
bitstream buffer before the encoding operation, adding extra memory and extra
copy operations, the encoder picture should specify the offset where the Vulkan
will start to add the bitstream slices/frame, because the element has written
already the headers until that offset.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8007>
That's the number of references that gst_vulkan_encoder_encode() receives to
process, so it has to go as a parameter, because it's part of the reference
list, not of the picture.
This commit also modified unit tests accordingly.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8007>
