[libcamera-devel] [PATCH v3 1/2] android: CameraBuffer: Add a static function to check a buffer validness

[Hirokazu Honda]

On Tue, Apr 13, 2021 at 12:11 PM Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
>
> Hi Hiro,
>
> Thank you for the patch.
>
> On Thu, Apr 08, 2021 at 12:10:39PM +0900, Hirokazu Honda wrote:
> > This adds a static function to CameraBuffer class that checks if
> > a buffer_handle is valid with a platform dependent framework.
> > For example, the function validates a buffer using
> > cros::CameraBufferManager on ChromeOS.
> >
> > Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
> > Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>
> > ---
> >  src/android/camera_buffer.h              |  6 ++++++
> >  src/android/mm/cros_camera_buffer.cpp    | 18 ++++++++++++++++++
> >  src/android/mm/generic_camera_buffer.cpp |  9 +++++++++
> >  3 files changed, 33 insertions(+)
> >
> > diff --git a/src/android/camera_buffer.h b/src/android/camera_buffer.h
> > index 7e8970b4..ade082c3 100644
> > --- a/src/android/camera_buffer.h
> > +++ b/src/android/camera_buffer.h
> > @@ -20,6 +20,8 @@ public:
> >       CameraBuffer(buffer_handle_t camera3Buffer, int flags);
> >       ~CameraBuffer();
> >
> > +     static bool isValidBuffer(buffer_hanlde_t camera3Buffer);
> > +
> >       bool isValid() const;
> >
> >       unsigned int numPlanes() const;
> > @@ -38,6 +40,10 @@ CameraBuffer::CameraBuffer(buffer_handle_t camera3Buffer, int flags)       \
> >  CameraBuffer::~CameraBuffer()                                                \
> >  {                                                                    \
> >  }                                                                    \
> > +bool CameraBuffer::isValidBuffer(buffer_handle_t buffer)             \
> > +{                                                                    \
> > +     return Private::isValidBuffer(buffer)                           \
> > +}                                                                    \
> >  bool CameraBuffer::isValid() const                                   \
> >  {                                                                    \
> >       const Private *const d = LIBCAMERA_D_PTR();                     \
> > diff --git a/src/android/mm/cros_camera_buffer.cpp b/src/android/mm/cros_camera_buffer.cpp
> > index 1a4fd5d1..f8449dfd 100644
> > --- a/src/android/mm/cros_camera_buffer.cpp
> > +++ b/src/android/mm/cros_camera_buffer.cpp
> > @@ -24,6 +24,8 @@ public:
> >               buffer_handle_t camera3Buffer, int flags);
> >       ~Private();
> >
> > +     static bool isValidBuffer(buffer_handle_t camera3Buffer);
> > +
> >       bool isValid() const { return valid_; }
> >
> >       unsigned int numPlanes() const;
> > @@ -133,4 +135,20 @@ size_t CameraBuffer::Private::jpegBufferSize(size_t maxJpegBufferSize) const
> >       return bufferManager_->GetPlaneSize(handle_, 0);
> >  }
> >
> > +/* static */
> > +bool CameraBuffer::Private::isValidBuffer(buffer_handle_t camera3Buffer)
> > +{
> > +     cros::CameraBufferManager *bufferManager =
> > +             cros::CameraBufferManager::GetInstance();
> > +
> > +     int ret = bufferManager->Register(camera3Buffer);
> > +     if (ret) {
> > +             return false;
> > +     }
>
> No need for braces.
>
> > +
> > +     bufferManager->Deregister(camera3Buffer);
>
> This seems quite inefficient, as it will lead to registering all
> buffers, even the ones we don't need to map to the CPU. For buffers that
> we need to map to the CPU, we will register and unregister them here,
> and then register them later.
>
> Could we do better than this ?
>

We may want to add verifyBuffer() to CameraBufferManagerInterface to
do a cheap verification, basically only do
camera_buffer_handle_t::FromBufferHandle().
+Shik Chen +Ricky Liang +Tomasz Figa how do you think?

-Hiro


> > +
> > +     return true;
> > +}
> > +
> >  PUBLIC_CAMERA_BUFFER_IMPLEMENTATION
> > diff --git a/src/android/mm/generic_camera_buffer.cpp b/src/android/mm/generic_camera_buffer.cpp
> > index 929e078a..07a07372 100644
> > --- a/src/android/mm/generic_camera_buffer.cpp
> > +++ b/src/android/mm/generic_camera_buffer.cpp
> > @@ -24,6 +24,8 @@ public:
> >               buffer_handle_t camera3Buffer, int flags);
> >       ~Private();
> >
> > +     static bool isValidBuffer(buffer_handle_t camera3Buffer);
> > +
> >       unsigned int numPlanes() const;
> >
> >       Span<uint8_t> plane(unsigned int plane);
> > @@ -85,4 +87,11 @@ size_t CameraBuffer::Private::jpegBufferSize(size_t maxJpegBufferSize) const
> >                                     maxJpegBufferSize);
> >  }
> >
> > +/* static */
> > +bool CameraBuffer::Private::isValidBuffer(
> > +     [[maybe_unused]] buffer_handle_t camera3Buffer)
> > +{
> > +     return true;
> > +}
> > +
> >  PUBLIC_CAMERA_BUFFER_IMPLEMENTATION
>
> --
> Regards,
>
> Laurent Pinchart