[libcamera-devel] [PATCH v5 08/19] libcamera: ipu3: Cache the camera sizes

[Laurent Pinchart]

Hi Jacopo,

On Tue, Apr 02, 2019 at 10:26:07AM +0200, Jacopo Mondi wrote:
> On Tue, Apr 02, 2019 at 10:27:17AM +0300, Laurent Pinchart wrote:
> > On Tue, Mar 26, 2019 at 09:38:51AM +0100, Jacopo Mondi wrote:
> >> When creating a camera, make sure a the image sensor provides images in
> >> a format compatible with IPU3 CIO2 unit requirements and cache the
> >> minimum and maximum camera sizes.
> >>
> >> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> >> ---
> >>  src/libcamera/pipeline/ipu3/ipu3.cpp | 56 +++++++++++++++++++++++++++-
> >>  1 file changed, 54 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> >> index 55489c31df2d..d42c81273cc6 100644
> >> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> >> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> >> @@ -8,11 +8,14 @@
> >>  #include <memory>
> >>  #include <vector>
> >>
> >> +#include <linux/media-bus-format.h>
> >> +
> >>  #include <libcamera/camera.h>
> >>  #include <libcamera/request.h>
> >>  #include <libcamera/stream.h>
> >>
> >>  #include "device_enumerator.h"
> >> +#include "geometry.h"
> >>  #include "log.h"
> >>  #include "media_device.h"
> >>  #include "pipeline_handler.h"
> >> @@ -24,6 +27,22 @@ namespace libcamera {
> >>
> >>  LOG_DEFINE_CATEGORY(IPU3)
> >>
> >> +static int mediaBusToCIO2Format(unsigned int code)
> >> +{
> >> +	switch (code) {
> >> +	case MEDIA_BUS_FMT_SBGGR10_1X10:
> >> +		return V4L2_PIX_FMT_IPU3_SBGGR10;
> >> +	case MEDIA_BUS_FMT_SGBRG10_1X10:
> >> +		return V4L2_PIX_FMT_IPU3_SGBRG10;
> >> +	case MEDIA_BUS_FMT_SGRBG10_1X10:
> >> +		return V4L2_PIX_FMT_IPU3_SGRBG10;
> >> +	case MEDIA_BUS_FMT_SRGGB10_1X10:
> >> +		return V4L2_PIX_FMT_IPU3_SRGGB10;
> >> +	default:
> >> +		return -EINVAL;
> >> +	}
> >> +}
> >> +
> >>  class PipelineHandlerIPU3 : public PipelineHandler
> >>  {
> >>  public:
> >> @@ -70,6 +89,9 @@ private:
> >>  		V4L2Subdevice *sensor_;
> >>
> >>  		Stream stream_;
> >> +
> >> +		/* Maximum sizes and the mbus code used to produce them. */
> >> +		std::pair<unsigned int, SizeRange> maxSizes_;
> >
> > The use of std::pair here makes the code below use .first and .second,
> > which are not very readable. I think it would be better to store the
> > pixel format and max size in two separate fields, of unsigned int and
> > SizeRange types respectively. Or, now that I think about it, as you only
> > care about the maximum size, maybe adding a Size structure to geometry.h
> > would be a good idea.
> >
> 
> I see... I'll ponder about it. Adding new stuff it's always a burden
> because of documentation and such, but I get your point...

I know it can be a bit painful :-( A Size structure should hopefully be
simple though.

> >>  	};
> >>
> >>  	IPU3CameraData *cameraData(const Camera *camera)
> >> @@ -404,18 +426,48 @@ void PipelineHandlerIPU3::registerCameras()
> >>  		if (ret)
> >>  			continue;
> >>
> >> -		data->cio2_->bufferReady.connect(data.get(), &IPU3CameraData::bufferReady);
> >> -
> >> +		/*
> >> +		 * Make sure the sensor produces at least one image format
> >> +		 * compatible with IPU3 CIO2 requirements and cache the camera
> >> +		 * maximum sizes.
> >> +		 */
> >>  		data->sensor_ = new V4L2Subdevice(sensor);
> >>  		ret = data->sensor_->open();
> >>  		if (ret)
> >>  			continue;
> >>
> >> +		for (auto it : data->sensor_->formats(0)) {
> >> +			int mbusCode = mediaBusToCIO2Format(it.first);
> >> +			if (mbusCode < 0)
> >> +				continue;
> >> +
> >> +			for (const SizeRange &size : it.second) {
> >> +				SizeRange &maxSize = data->maxSizes_.second;
> >> +
> >> +				if (maxSize.maxWidth < size.maxWidth &&
> >> +				    maxSize.maxHeight < size.maxHeight) {
> >> +					maxSize.maxWidth = size.maxWidth;
> >> +					maxSize.maxHeight = size.maxHeight;
> >> +					data->maxSizes_.first = mbusCode;
> >> +				}
> >> +			}
> >> +		}
> >
> > One blank line ?
> 
> Not sure, as this is an error condition, I like it better without an
> empty line.

There are generally empty lines after a for loop of if block, but it's
your code :-)

> >> +		if (data->maxSizes_.second.maxWidth == 0) {
> >> +			LOG(IPU3, Info)
> >> +				<< "Sensor '" << data->sensor_->entityName()
> >> +				<< "' detected, but no supported image format "
> >> +				<< " found: skip camera creation";
> >> +			continue;
> >> +		}
> >> +
> >>  		data->csi2_ = new V4L2Subdevice(csi2);
> >>  		ret = data->csi2_->open();
> >>  		if (ret)
> >>  			continue;
> >>
> >> +		data->cio2_->bufferReady.connect(data.get(),
> >> +						 &IPU3CameraData::bufferReady);
> >> +
> >
> > This seems unrelated to this patch, is it needed ?
> 
> please see:
> >> -           data->cio2_->bufferReady.connect(data.get(), &IPU3CameraData::bufferReady);
> 
> A few lines above here.

I know, what I meant is that moving the code seems unrelated, as you
don't touch it (apart from wrapping the line).

> >>  		registerCamera(std::move(camera), std::move(data));
> >>
> >>  		LOG(IPU3, Info)

-- 
Regards,

Laurent Pinchart