[PATCH v5 2/5] libcamera: converter: Add interface to support cropping capability
Jacopo Mondi
jacopo.mondi at ideasonboard.com
Thu Jul 18 12:06:12 CEST 2024
Hi Umang
On Wed, Jul 17, 2024 at 04:34:34PM GMT, Umang Jain wrote:
> Hi Jacopo
>
> On 17/07/24 3:32 pm, Jacopo Mondi wrote:
> > Hi Umang
> >
> > On Wed, Jul 10, 2024 at 01:51:48AM GMT, Umang Jain wrote:
> > > If the converter has cropping capability, the interface should support it
> > > by providing appropriate virtual functions. Provide Feature::Crop in
> > > Feature enumeration for the same.
> > >
> > > Provide virtual setCrop() and getCropBounds() interfaces so that
> > > the converter can implement their own cropping functionality.
> > >
> > > The V4L2M2MConverter implements these interfaces of the Converter
> > > interface. Not all V4L2M2M converters will have cropping capability,
> > > hence Feature::Crop should be set while construction for all those
> > > converters.
> > >
> > > Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> > > ---
> > > include/libcamera/internal/converter.h | 5 ++
> > > .../internal/converter/converter_v4l2_m2m.h | 6 ++
> > > src/libcamera/converter.cpp | 51 +++++++++++
> > > .../converter/converter_v4l2_m2m.cpp | 88 +++++++++++++++++++
> > > 4 files changed, 150 insertions(+)
> > >
> > > diff --git a/include/libcamera/internal/converter.h b/include/libcamera/internal/converter.h
> > > index 7e478356..9b1223fd 100644
> > > --- a/include/libcamera/internal/converter.h
> > > +++ b/include/libcamera/internal/converter.h
> > > @@ -14,6 +14,7 @@
> > > #include <memory>
> > > #include <string>
> > > #include <tuple>
> > > +#include <utility>
> > > #include <vector>
> > >
> > > #include <libcamera/base/class.h>
> > > @@ -35,6 +36,7 @@ class Converter
> > > public:
> > > enum class Feature {
> > > None = 0,
> > > + Crop = (1 << 0),
> > > };
> > >
> > > using Features = Flags<Feature>;
> > > @@ -63,6 +65,9 @@ public:
> > > virtual int queueBuffers(FrameBuffer *input,
> > > const std::map<const Stream *, FrameBuffer *> &outputs) = 0;
> > >
> > > + virtual int setCrop(const Stream *stream, Rectangle *rect);
> > "crop" is loosely defined as a concept.
> > A converter has an input and an output and I presume it scales.
> >
> > Where is the crop rectangle applied ?
>
> A converter is a processing block - outside of ISP. Hence there is a input
> and output, and the crop is applied at/w.r.t input. The resultant should be
> obtained/visible on the output.
>
And where is the assumption that crop is applied to the input
documented ? Aren't there converter that allow to crop on the output
maybe -after- scaling ?
Cropping before or after scaling (or, if you want to put it different,
cropping on the input or on the output) are both possible options, and
this interface doesn't allow you to specify that.
You have wired the V4L2 converter to apply selection on the TGT_CROP
target on the input queue (aka on the 'output' video device, oh funny
names)
int V4L2M2MConverter::setCrop(const Stream *stream, Rectangle *rect)
{
return iter->second->setSelection(V4L2_SEL_TGT_CROP, rect);
}
int V4L2M2MConverter::V4L2M2MStream::setSelection(unsigned int target, Rectangle *rect)
{
int ret = m2m_->output()->setSelection(target, rect);
if (ret < 0)
return ret;
return 0;
}
Can't a converter expose a TGT_CROP target on the capture device to allow
userspace to apply a crop on the "final" image before returning it to
applications ?
> >
> > Does this need to be part of the base class interface ? Or should only
> > derived classes that support it implement it ? (it's reasonable for a
> > V4L2 M2M device to support this, once better specified the interface
> > where the crop rectangle has to be applied).
>
> I think so. Atleast that's what Laurent initally asked for. Converter
> interface should dictate the features supported, the implementation left to
> the derived converter classes. No implementation specific details should be
> handled by the interface itself, only the "feature" part
>
Yes, but concepts like 'crop' and 'selection' might only apply to
certain types of converter, like the v4l2 m2m ones. I wonder if it is
better to provide a stub implementation in the whole hierarcy or only
expose such methods in the classes derived from, in example,
V4L2M2MConverter.
> > > + virtual std::pair<Rectangle, Rectangle> getCropBounds(const Stream *stream);
> > not "get" in getters
>
> ah yes
> >
> > > +
> > > Signal<FrameBuffer *> inputBufferReady;
> > > Signal<FrameBuffer *> outputBufferReady;
> > >
> > > diff --git a/include/libcamera/internal/converter/converter_v4l2_m2m.h b/include/libcamera/internal/converter/converter_v4l2_m2m.h
> > > index 91701dbe..2697eed9 100644
> > > --- a/include/libcamera/internal/converter/converter_v4l2_m2m.h
> > > +++ b/include/libcamera/internal/converter/converter_v4l2_m2m.h
> > > @@ -30,6 +30,7 @@ class Size;
> > > class SizeRange;
> > > class Stream;
> > > struct StreamConfiguration;
> > > +class Rectangle;
> > > class V4L2M2MDevice;
> > >
> > > class V4L2M2MConverter : public Converter
> > > @@ -57,6 +58,9 @@ public:
> > > int queueBuffers(FrameBuffer *input,
> > > const std::map<const Stream *, FrameBuffer *> &outputs);
> > >
> > > + int setCrop(const Stream *stream, Rectangle *rect);
> > > + std::pair<Rectangle, Rectangle> getCropBounds(const Stream *stream);
> > > +
> > > private:
> > > class V4L2M2MStream : protected Loggable
> > > {
> > > @@ -75,6 +79,8 @@ private:
> > >
> > > int queueBuffers(FrameBuffer *input, FrameBuffer *output);
> > >
> > > + int setSelection(unsigned int target, Rectangle *rect);
> > > +
> > > protected:
> > > std::string logPrefix() const override;
> > >
> > > diff --git a/src/libcamera/converter.cpp b/src/libcamera/converter.cpp
> > > index 2c3da6d4..d51e77a0 100644
> > > --- a/src/libcamera/converter.cpp
> > > +++ b/src/libcamera/converter.cpp
> > > @@ -11,6 +11,8 @@
> > >
> > > #include <libcamera/base/log.h>
> > >
> > > +#include <libcamera/stream.h>
> > > +
> > > #include "libcamera/internal/media_device.h"
> > >
> > > /**
> > > @@ -39,6 +41,8 @@ LOG_DEFINE_CATEGORY(Converter)
> > > * \brief Specify the features supported by the converter
> > > * \var Converter::Feature::None
> > > * \brief No extra features supported by the converter
> > > + * \var Converter::Feature::Crop
> > > + * \brief Cropping capability is supported by the converter
> > > */
> > >
> > > /**
> > > @@ -161,6 +165,53 @@ Converter::~Converter()
> > > * \return 0 on success or a negative error code otherwise
> > > */
> > >
> > > +/**
> > > + * \brief Set the crop rectangle \a rect for \a stream
> > > + * \param[in] stream Pointer to output stream
> > > + * \param[inout] rect The crop rectangle to be applied
> > > + *
> > > + * Set the crop rectangle \a rect for \a stream provided the converter supports
> > > + * cropping. The converter should have the Feature::Crop flag in this case.
> > > + *
> > > + * \return 0 on success or a negative error code otherwise
> > > + */
> > > +int Converter::setCrop([[maybe_unused]] const Stream *stream, [[maybe_unused]] Rectangle *rect)
> > > +{
> > > + if (!(getFeatures() & Feature::Crop)) {
> > > + LOG(Converter, Error) << "Converter doesn't support cropping capabilities";
> > > + return -ENOTSUP;
> > > + }
> > > +
> > > + return 0;
> > > +}
> > > +
> > > +/**
> > > + * \brief Get the crop bounds \a stream
> > > + * \param[in] stream Pointer to output stream
> > > + *
> > > + * Get the minimum and maximum crop bounds for \a stream. The converter
> > > + * should supporting cropping (Feature::Crop).
> > > + *
> > > + * \return A std::pair<Rectangle, Rectangle> containining minimum and maximum
> > > + * crop bound respectively.
> > > + */
> > > +std::pair<Rectangle, Rectangle> Converter::getCropBounds([[maybe_unused]] const Stream *stream)
> > > +{
> > > + const StreamConfiguration &config = stream->configuration();
> > > + Rectangle rect;
> > > +
> > > + if (!(getFeatures() & Feature::Crop))
> > > + LOG(Converter, Error) << "Converter doesn't support cropping capabilities";
> > > +
> > > + /*
> > > + * This is base implementation for the Converter class, so just return
> > > + * the stream configured size as minimum and maximum crop bounds.
> > > + */
> > > + rect.size() = config.size;
> > > +
> > > + return { rect, rect };
> > I would rather not make it part of the base class interface
>
> no? If the crop is a feature, getting the supported bounds would be
> something callers would like to know. Do you think this should be left only
> to derived converter classes ?
Only to the hierarchy of derived classes that supports it, like the
classes derived from V4L2M2MConverter (and the class itself). For some
other "converters" cropping and scaling might not make sense at all.
> > > +}
> > > +
> > > /**
> > > * \var Converter::inputBufferReady
> > > * \brief A signal emitted when the input frame buffer completes
> > > diff --git a/src/libcamera/converter/converter_v4l2_m2m.cpp b/src/libcamera/converter/converter_v4l2_m2m.cpp
> > > index 4aeb7dd9..eaae3528 100644
> > > --- a/src/libcamera/converter/converter_v4l2_m2m.cpp
> > > +++ b/src/libcamera/converter/converter_v4l2_m2m.cpp
> > > @@ -155,6 +155,15 @@ int V4L2M2MConverter::V4L2M2MStream::queueBuffers(FrameBuffer *input, FrameBuffe
> > > return 0;
> > > }
> > >
> > > +int V4L2M2MConverter::V4L2M2MStream::setSelection(unsigned int target, Rectangle *rect)
> > > +{
> > > + int ret = m2m_->output()->setSelection(target, rect);
> > > + if (ret < 0)
> > > + return ret;
> > > +
> > > + return 0;
> > > +}
> > > +
> > > std::string V4L2M2MConverter::V4L2M2MStream::logPrefix() const
> > > {
> > > return stream_->configuration().toString();
> > > @@ -375,6 +384,81 @@ int V4L2M2MConverter::exportBuffers(const Stream *stream, unsigned int count,
> > > return iter->second->exportBuffers(count, buffers);
> > > }
> > >
> > > +/**
> > > + * \copydoc libcamera::Converter::setCrop
> > > + */
> > > +int V4L2M2MConverter::setCrop(const Stream *stream, Rectangle *rect)
> > > +{
> > > + if (!(getFeatures() & Feature::Crop))
> > > + return -ENOTSUP;
> > > +
> > > + auto iter = streams_.find(stream);
> > > + if (iter == streams_.end())
> > > + return -EINVAL;
> > > +
> > > + return iter->second->setSelection(V4L2_SEL_TGT_CROP, rect);
> > > +}
> > > +
> > > +/**
> > > + * \copydoc libcamera::Converter::getCropBounds
> > > + */
> > > +std::pair<Rectangle, Rectangle>
> > > +V4L2M2MConverter::getCropBounds(const Stream *stream)
> > > +{
> > > + Rectangle minCrop;
> > > + Rectangle maxCrop;
> > > + int ret;
> > > +
> > > + minCrop.width = 1;
> > > + minCrop.height = 1;
> > > + maxCrop.width = UINT_MAX;
> > > + maxCrop.height = UINT_MAX;
> > You can move all of this after the check for the feature support
> >
> > > +
> > > + if (!(getFeatures() & Feature::Crop)) {
> > > + LOG(Converter, Error) << "Crop functionality is not supported";
> > > + return {};
> > > + }
> > > +
> > > + auto iter = streams_.find(stream);
> > > + if (iter == streams_.end()) {
> > > + /*
> > > + * No streams configured, return minimum and maximum crop
> > > + * bounds at initialization.
> > > + */
> > > + ret = m2m_->output()->setSelection(V4L2_SEL_TGT_CROP, &minCrop);
> > > + if (ret) {
> > > + LOG(Converter, Error) << "Failed to query minimum crop bound";
> > > + return {};
> > > + }
> > > +
> > > + ret = m2m_->output()->setSelection(V4L2_SEL_TGT_CROP, &maxCrop);
> > > + if (ret) {
> > > + LOG(Converter, Error) << "Failed to query maximum crop bound";
> > > + return {};
> > > + }
> > > +
> > > + return { minCrop, maxCrop };
> > > + }
> > > +
> > > + /*
> > > + * If the streams are configured, return bounds from according to
> > > + * stream configuration.
> > > + */
> > > + ret = setCrop(stream, &minCrop);
> > > + if (ret) {
> > > + LOG(Converter, Error) << "Failed to query minimum crop bound";
> > > + return {};
> > > + }
> > > +
> > > + ret = setCrop(stream, &maxCrop);
> > > + if (ret) {
> > > + LOG(Converter, Error) << "Failed to query maximum crop bound";
> > > + return {};
> > > + }
> > > +
> > > + return { minCrop, maxCrop };
> > > +}
> > > +
> > > /**
> > > * \copydoc libcamera::Converter::start
> > > */
> > > @@ -448,6 +532,10 @@ int V4L2M2MConverter::queueBuffers(FrameBuffer *input,
> > > return 0;
> > > }
> > >
> > > +/*
> > > + * \todo: This should be extended to include Feature::Flag to denote
> > > + * what each converter supports feature-wise.
> > > + */
> > That's another option.
> >
> > I'll send to the list the patches I have on top of your series that
> > makes it possible to specify features at registration time for a
> > comparison.
>
> Right , this bit is something I have to develop once I get a testing setup.
>
> The compatibles below are currently used for simple pipeline handler only.
> >
> > > static std::initializer_list<std::string> compatibles = {
> > > "mtk-mdp",
> > > "pxp",
> > > --
> > > 2.45.2
> > >
>
More information about the libcamera-devel
mailing list