[libcamera-devel] [PATCH v4 05/32] ipa: libipa: Provide a common base for frame contexts

[Kieran Bingham]

Quoting Laurent Pinchart (2022-09-20 20:12:58)
> On Tue, Sep 20, 2022 at 02:40:28PM +0100, Kieran Bingham wrote:
> > Quoting Laurent Pinchart (2022-09-08 02:41:33)
> > > From: Kieran Bingham <kieran.bingham at ideasonboard.com>
> > > 
> > > Provide a common FrameContext as a base for IPA modules to inherit from.
> > > 
> > > This will allow having a common set of parameters for every frame
> > > context managed by the FCQueue implementation.
> > > 
> > > Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> > 
> > Missing SoB.
> > > ---
> > > Changes since v3:
> > > 
> > > - Rename structure from IPAFrameContext to FrameContext
> > > - Move changes to IPA modules to separate patches
> > > - Make the FrameContext::frame member private
> > > ---
> > >  src/ipa/libipa/fc_queue.cpp | 18 ++++++++++++++++++
> > >  src/ipa/libipa/fc_queue.h   | 10 ++++++++++
> > >  2 files changed, 28 insertions(+)
> > > 
> > > diff --git a/src/ipa/libipa/fc_queue.cpp b/src/ipa/libipa/fc_queue.cpp
> > > index b81d497e255a..8f61c85131c9 100644
> > > --- a/src/ipa/libipa/fc_queue.cpp
> > > +++ b/src/ipa/libipa/fc_queue.cpp
> > > @@ -20,6 +20,24 @@ namespace ipa {
> > >   * \brief Queue to access per-frame Context
> > >   */
> > >  
> > > +/**
> > > + * \struct FrameContext
> > > + * \brief Context for a frame
> > > + *
> > > + * The frame context stores data specific to a single frame processed by the
> > > + * IPA. Each frame processed by the IPA has a context associated with it,
> > > + * accessible through the Frame Context Queue.
> > > + *
> > > + * Fields in the frame context should reflect values and controls associated
> > > + * with the specific frame as requested by the application, and as configured by
> > > + * the hardware. Fields can be read by algorithms to determine if they should
> > > + * update any specific action for this frame, and finally to update the metadata
> > > + * control lists when the frame is fully completed.
> > > + *
> > > + * \var FrameContext::frame
> > > + * \brief The frame number
> > > + */
> > > +
> > >  /**
> > >   * \class FCQueue
> > >   * \brief A support class for queueing FrameContext instances through the IPA
> > > diff --git a/src/ipa/libipa/fc_queue.h b/src/ipa/libipa/fc_queue.h
> > > index 0f3af0f3a189..d8a5b8297a70 100644
> > > --- a/src/ipa/libipa/fc_queue.h
> > > +++ b/src/ipa/libipa/fc_queue.h
> > > @@ -8,6 +8,7 @@
> > >  #pragma once
> > >  
> > >  #include <algorithm>
> > > +#include <stdint.h>
> > >  #include <vector>
> > >  
> > >  #include <libcamera/base/log.h>
> > > @@ -18,6 +19,15 @@ LOG_DECLARE_CATEGORY(FCQueue)
> > >  
> > >  namespace ipa {
> > >  
> > > +template<typename FrameContext>
> > > +class FCQueue;
> > > +
> > > +struct FrameContext {
> > > +private:
> > > +       template<typename T> friend class FCQueue;
> > > +       uint32_t frame;
> > 
> > Seems fine to me.
> > 
> > I'm still not sure what else is going to end up in here. There's a
> > chance that we might need to store the incoming Request ControlList (or
> > a copy of) ... so I still think there's sufficient requirement for the
> > common base type.
> 
> I haven't found a need for storing additional data in the base class in
> the RkISP1 IPA. We'll see.

We should add a 
	ControlList metadata;

here in the base FrameContext. It can certainly be on top of this
series, and it should then get sent to the Pipeline handler to merge in
to the Request::metadata().

That should be common to all algortihms using this design, and the
algorithms can use it to populate the Request metadata at the earliest
opportunity.

--
Kieran


> 
> > Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> > 
> > > +};
> > > +
> > >  template<typename FrameContext>
> > >  class FCQueue
> > >  {
> 
> -- 
> Regards,
> 
> Laurent Pinchart