commit 5d20e71220096e281a75536bcd0e754f434110c9
author Jonas Larsson <ljonas@google.com> Wed Sep 25 17:09:51 2019 -0700
committer Jonas Larsson <ljonas@google.com> Wed Oct 02 16:46:12 2019 -0700
tree 2af374c338b8c87862734e6a823e573b9724be57
parent ce6622438e8ad72d1107592e77feddac317662f7

Add glbox plugin

This plugin draws input textures to output textures scaling with
maintained aspect ratio. That means that there will be black borders
around the resulting frame to make it fit, ie the input frame is
'boxed'.

This is mainly useful for preparing input frames for inference. To
make that process even faster glbox can also render straight to an
RGB texture (not just RGBA). Thus with glbox one can do for example

src ! glupload ! glbox ! gldownload ! video/x-raw,format=RGB ! tpu

with a minimized number of GPU operations for maximum throughput.
Source frame (from e.g. camera) is uploaded an converted using
hardware shaders, then it's drawn once scaled with borders to a
RGB texture that's backed by a dmabuf, which can be used by the
CPU and TPU directly.

This replaces all CPU based processing and can therefor support
higher resolutions at maintained speeds.

Change-Id: I8d0dc892db6c81a18b923609224297f0777b2288