[libcamera-devel] [PATCH v3 2/4] pipeline: vimc: Allocate mock IPA buffers

[Laurent Pinchart]

Hi Paul,

On Sat, Aug 14, 2021 at 02:36:44PM +0900, paul.elder at ideasonboard.com wrote:
> On Sat, Aug 14, 2021 at 10:39:10AM +0530, Umang Jain wrote:
> > VIMC is a virtual test driver that doesn't have statistics or
> > parameters buffers that are typically passed from a pipeline
> > handler to its platform IPA. To increase the test coverage going
> > forward, we can atleast mimick the typical interaction of how
> > a pipeline handler and IPA interacts, and use it to increase the
> > test coverage.
> > 
> > Hence, create simple (single plane) dmabuf-backed FrameBuffers,
> > which can act as mock IPA buffers and can be memory mapped(mmap)
> > to VIMC IPA. To create these buffers, temporarily hijack the output
> > video node and configure it with a V4L2DeviceFormat. Buffers then
> > can be exported from the output video node using
> > V4L2VideoDevice::exportBuffers(). These buffers will be mimicked as
> > IPA buffers in subsequent commits.
> > 
> > Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> >  src/libcamera/pipeline/vimc/vimc.cpp | 23 +++++++++++++++++++++++
> >  1 file changed, 23 insertions(+)
> > 
> > diff --git a/src/libcamera/pipeline/vimc/vimc.cpp b/src/libcamera/pipeline/vimc/vimc.cpp
> > index 4c92729d..2dfa1418 100644
> > --- a/src/libcamera/pipeline/vimc/vimc.cpp
> > +++ b/src/libcamera/pipeline/vimc/vimc.cpp
> > @@ -50,6 +50,7 @@ public:
> >  	}
> >  
> >  	int init();
> > +	int allocateMockIPABuffers();
> >  	void bufferReady(FrameBuffer *buffer);
> >  
> >  	MediaDevice *media_;
> > @@ -61,6 +62,7 @@ public:
> >  	Stream stream_;
> >  
> >  	std::unique_ptr<ipa::vimc::IPAProxyVimc> ipa_;
> > +	std::vector<std::unique_ptr<FrameBuffer>> mockIPABufs_;
> >  };
> >  
> >  class VimcCameraConfiguration : public CameraConfiguration
> > @@ -500,6 +502,12 @@ int VimcCameraData::init()
> >  	if (raw_->open())
> >  		return -ENODEV;
> >  
> > +	ret = allocateMockIPABuffers();
> > +	if (!ret) {
> > +		LOG(VIMC, Warning) << "Cannot allocate mock IPA buffers";
> > +		return ret;
> > +	}
> > +
> >  	/* Initialise the supported controls. */
> >  	const ControlInfoMap &controls = sensor_->controls();
> >  	ControlInfoMap::Map ctrls;
> > @@ -548,6 +556,21 @@ void VimcCameraData::bufferReady(FrameBuffer *buffer)
> >  	pipe_->completeRequest(request);
> >  }
> >  
> > +int VimcCameraData::allocateMockIPABuffers()
> > +{
> > +	constexpr unsigned int kBufCount = 2;
> > +
> > +	V4L2DeviceFormat format;
> > +	format.fourcc = video_->toV4L2PixelFormat(formats::BGR888);
> > +	format.size = Size (160, 120);
> > +
> > +	int ret = video_->setFormat(&format);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	return video_->exportBuffers(kBufCount, &mockIPABufs_);
> 
> Do we ever need to free these buffers?

It's the beauty of a std::vector<std::unique_ptr<>> :-)

> > +}
> > +
> >  REGISTER_PIPELINE_HANDLER(PipelineHandlerVimc)
> >  
> >  } /* namespace libcamera */

-- 
Regards,

Laurent Pinchart