[libcamera-devel] [PATCH v5 3/3] libcamera: Add exportFrameBuffers in HeapAllocator

[Jacopo Mondi]

Hello Harvey

On Mon, May 22, 2023 at 04:36:32PM +0800, Cheng-Hao Yang via libcamera-devel wrote:
> Thanks Jacopo.
>
> On Tue, May 16, 2023 at 6:32 PM Jacopo Mondi <jacopo.mondi at ideasonboard.com>
> wrote:
>
> > Hi Harvey
> >
> > On Tue, May 16, 2023 at 08:03:19AM +0000, Harvey Yang via libcamera-devel
> > wrote:
> > > From: Cheng-Hao Yang <chenghaoyang at chromium.org>
> > >
> > > Add a helper function exportFrameBuffers in HeapAllocator to make it
> > > easier to use.
> > >
> > > Signed-off-by: Harvey Yang <chenghaoyang at chromium.org>
> > > ---
> > >  include/libcamera/internal/heap_allocator.h |  9 +++
> > >  src/libcamera/heap_allocator.cpp            | 61 +++++++++++++++++++++
> > >  2 files changed, 70 insertions(+)
> > >
> > > diff --git a/include/libcamera/internal/heap_allocator.h
> > b/include/libcamera/internal/heap_allocator.h
> > > index d061fdce..b6488fbc 100644
> > > --- a/include/libcamera/internal/heap_allocator.h
> > > +++ b/include/libcamera/internal/heap_allocator.h
> > > @@ -8,12 +8,16 @@
> > >  #pragma once
> > >
> > >  #include <stddef.h>
> > > +#include <vector>
> > >
> > >  #include <libcamera/base/unique_fd.h>
> > >
> > >  namespace libcamera {
> > >
> > > +class Camera;
> > > +class FrameBuffer;
> > >  class Heap;
> > > +class Stream;
> > >
> > >  class HeapAllocator
> > >  {
> > > @@ -23,7 +27,12 @@ public:
> > >       bool isValid() const;
> > >       UniqueFD alloc(const char *name, std::size_t size);
> > >
> > > +     int exportFrameBuffers(Camera *camera, Stream *stream,
> > > +                            std::vector<std::unique_ptr<FrameBuffer>>
> > *buffers);
> > > +
> > >  private:
> > > +     std::unique_ptr<FrameBuffer> createBuffer(Stream *stream);
> > > +
> > >       std::unique_ptr<Heap> heap_;
> > >  };
> > >
> > > diff --git a/src/libcamera/heap_allocator.cpp
> > b/src/libcamera/heap_allocator.cpp
> > > index 682a7e01..ce3a815d 100644
> > > --- a/src/libcamera/heap_allocator.cpp
> > > +++ b/src/libcamera/heap_allocator.cpp
> > > @@ -21,6 +21,12 @@
> > >
> > >  #include <libcamera/base/log.h>
> > >
> > > +#include <libcamera/camera.h>
> > > +#include <libcamera/framebuffer.h>
> > > +#include <libcamera/stream.h>
> > > +
> > > +#include "libcamera/internal/formats.h"
> > > +
> > >  namespace libcamera {
> > >
> > >  /*
> > > @@ -231,4 +237,59 @@ UniqueFD HeapAllocator::alloc(const char *name,
> > std::size_t size)
> > >       return heap_->alloc(name, size);
> > >  }
> > >
> > > +int HeapAllocator::exportFrameBuffers([[maybe_unused]] Camera *camera,
> > Stream *stream,
> > > +
> >  std::vector<std::unique_ptr<FrameBuffer>> *buffers)
> > > +{
> > > +     unsigned int count = stream->configuration().bufferCount;
> > > +
> > > +     /** \todo Support multiplanar allocations */
> > > +
> > > +     for (unsigned i = 0; i < count; ++i) {
> > > +             std::unique_ptr<FrameBuffer> buffer = createBuffer(stream);
> > > +             if (!buffer) {
> > > +                     LOG(HeapAllocator, Error) << "Unable to create
> > buffer";
> > > +
> > > +                     buffers->clear();
> > > +                     return -EINVAL;
> > > +             }
> > > +
> > > +             buffers->push_back(std::move(buffer));
> > > +     }
> > > +
> > > +     return count;
> > > +}
> > > +
> > > +std::unique_ptr<FrameBuffer> HeapAllocator::createBuffer(Stream *stream)
> > > +{
> > > +     std::vector<FrameBuffer::Plane> planes;
> > > +
> > > +     unsigned int frameSize = stream->configuration().frameSize;
> > > +     int pageSize = getpagesize();
> > > +     // Allocation size need to be a direct multiple of |pageSize|.
> >
> > no c++ style comments, please
> >
> >
> You mean to use "/**" and "*/", right?
>

/** is (one of the) doxygen markers

/* is the single line comment stlye. */

/*
 * while this one is a multi line comment
 * split on multiple lines.
 */

>
> > > +     unsigned int numPage = (frameSize + pageSize - 1) / pageSize;
> > > +
> > > +     UniqueFD fd = alloc("FrameBuffer", numPage * pageSize);
> > > +     if (!fd.isValid())
> > > +             return nullptr;
> > > +
> >
> > And I would add here a comment as reported in the review of v4
> >
> > Can be fixed when applying
> >
>
> You mean the todo of the dedicated fd for each plane, right?
>

If I recall correctly, yes :)

>
> > Reviewed-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>
> >
> > Thanks
> >   j
> >
> > > +     auto info =
> > PixelFormatInfo::info(stream->configuration().pixelFormat);
> > > +     SharedFD shared_fd(std::move(fd));
> > > +     unsigned int offset = 0;
> > > +     for (size_t i = 0; i < info.planes.size(); ++i) {
> > > +             unsigned int planeSize =
> > info.planeSize(stream->configuration().size, i);
> > > +             if (planeSize == 0)
> > > +                     continue;
> > > +
> > > +             FrameBuffer::Plane plane;
> > > +             plane.fd = shared_fd;
> > > +             plane.offset = offset;
> > > +             plane.length = planeSize;
> > > +             planes.push_back(std::move(plane));
> > > +
> > > +             offset += planeSize;
> > > +     }
> > > +
> > > +     return std::make_unique<FrameBuffer>(planes);
> > > +}
> > > +
> > >  } /* namespace libcamera */
> > > --
> > > 2.40.1.606.ga4b1b128d6-goog
> > >
> >