[RFC PATCH 5/6] libcamera: converter_v4l2_m2m: Add helper to apply controls

[Laurent Pinchart]

On Wed, Jul 24, 2024 at 03:30:22PM +0200, Jacopo Mondi wrote:
> On Fri, Jul 12, 2024 at 10:59:19AM GMT, Umang Jain wrote:
> > Add applyControls() helper to apply controls for a stream.
> 
> This assumes controls are applied on the capture queue. Isn't there a
> use case for applying controls to the output queue ?

Controls are applied on a video device, not a queue, it won't make a
difference.

> > Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
> > ---
> >  .../internal/converter/converter_v4l2_m2m.h    |  5 +++++
> >  src/libcamera/converter/converter_v4l2_m2m.cpp | 18 ++++++++++++++++++
> >  2 files changed, 23 insertions(+)
> >
> > diff --git a/include/libcamera/internal/converter/converter_v4l2_m2m.h b/include/libcamera/internal/converter/converter_v4l2_m2m.h
> > index f61beef8..9d3d62d6 100644
> > --- a/include/libcamera/internal/converter/converter_v4l2_m2m.h
> > +++ b/include/libcamera/internal/converter/converter_v4l2_m2m.h
> > @@ -24,6 +24,7 @@
> >
> >  namespace libcamera {
> >
> > +class ControlList;
> >  class FrameBuffer;
> >  class MediaDevice;
> >  class Size;
> > @@ -61,6 +62,8 @@ public:
> >  	int setCrop(const Stream *stream, Rectangle *rect);
> >  	std::pair<Rectangle, Rectangle> getCropBounds(const Stream *stream);
> >
> > +	int applyControls(const Stream *stream, ControlList &ctrls);

Unless I'm mistaken, the M2M framework doesn't support per-file handle
controls, so you can't have per-stream controls.

> > +
> >  protected:
> >  	class Mapping
> >  	{
> > @@ -97,6 +100,8 @@ private:
> >  		int start();
> >  		void stop();
> >
> > +		int applyControls(ControlList &ctrls);
> > +
> >  		int queueBuffers(FrameBuffer *input, FrameBuffer *output);
> >
> >  		int setSelection(unsigned int target, Rectangle *rect);
> > diff --git a/src/libcamera/converter/converter_v4l2_m2m.cpp b/src/libcamera/converter/converter_v4l2_m2m.cpp
> > index 9752a23e..9ff5102a 100644
> > --- a/src/libcamera/converter/converter_v4l2_m2m.cpp
> > +++ b/src/libcamera/converter/converter_v4l2_m2m.cpp
> > @@ -15,6 +15,7 @@
> >  #include <libcamera/base/signal.h>
> >  #include <libcamera/base/utils.h>
> >
> > +#include <libcamera/controls.h>
> >  #include <libcamera/framebuffer.h>
> >  #include <libcamera/geometry.h>
> >  #include <libcamera/stream.h>
> > @@ -186,6 +187,11 @@ void V4L2M2MConverter::V4L2M2MStream::captureBufferReady(FrameBuffer *buffer)
> >  	converter_->outputBufferReady.emit(buffer);
> >  }
> >
> > +int V4L2M2MConverter::V4L2M2MStream::applyControls(ControlList &ctrls)
> > +{
> > +	return m2m_->capture()->setControls(&ctrls);
> > +};
> > +
> >  /* -----------------------------------------------------------------------------
> >   * V4L2M2MConverter
> >   */
> > @@ -532,6 +538,18 @@ int V4L2M2MConverter::queueBuffers(FrameBuffer *input,
> >  	return 0;
> >  }
> >
> > +/**
> > + * libcamera::Converter::applyControls
> > + */
> > +int V4L2M2MConverter::applyControls(const Stream *stream, ControlList &ctrls)
> > +{
> > +	auto iter = streams_.find(stream);
> > +	if (iter == streams_.end())
> > +		return -EINVAL;
> > +
> > +	return iter->second->applyControls(ctrls);
> > +}
> > +
> >  /*
> >   * \todo: This should be extended to include Feature::Flag to denote
> >   * what each converter supports feature-wise.

-- 
Regards,

Laurent Pinchart