[libcamera-devel] [RFC PATCH v1 08/12] libcamera: framebuffer: Prevent modifying the number of metadata planes
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Thu Sep 2 20:20:19 CEST 2021
Hi Kieran,
On Thu, Sep 02, 2021 at 11:03:47AM +0100, Kieran Bingham wrote:
> On 02/09/2021 05:22, Laurent Pinchart wrote:
> > The number of metadata planes should always match the number of frame
> > buffer planes. Enforce this by making the vector private and providing
> > accessor functions.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> > include/libcamera/framebuffer.h | 10 +++++++++-
> > src/cam/camera_session.cpp | 4 ++--
> > src/cam/file_sink.cpp | 2 +-
> > src/libcamera/framebuffer.cpp | 12 +++++++++---
> > src/libcamera/v4l2_videodevice.cpp | 14 +++++++-------
> > src/qcam/main_window.cpp | 2 +-
> > src/qcam/viewfinder_gl.cpp | 2 +-
> > src/qcam/viewfinder_qt.cpp | 2 +-
> > src/v4l2/v4l2_camera_proxy.cpp | 2 +-
> > 9 files changed, 32 insertions(+), 18 deletions(-)
> >
> > diff --git a/include/libcamera/framebuffer.h b/include/libcamera/framebuffer.h
> > index fd68ed0a139d..7f2f176af691 100644
> > --- a/include/libcamera/framebuffer.h
> > +++ b/include/libcamera/framebuffer.h
> > @@ -13,6 +13,7 @@
> > #include <vector>
> >
> > #include <libcamera/base/class.h>
> > +#include <libcamera/base/span.h>
> >
> > #include <libcamera/file_descriptor.h>
> >
> > @@ -34,7 +35,14 @@ struct FrameMetadata {
> > Status status;
> > unsigned int sequence;
> > uint64_t timestamp;
> > - std::vector<Plane> planes;
> > +
> > + Span<Plane> planes() { return planes_; }
> > + Span<const Plane> planes() const { return planes_; }
>
> Returning a span here is nice.
>
> This likely causes compile breakage for any external app.
>
> I know we're not ABI/API stable, but I wonder if we should highlight
> when we do cause breakage somehow, perhaps in the commit message at
> least, as we already have external users who we might want to notify.
Most changes to public header files will be ABI/API breakages at this
point, and users will certainly notice when they get a compilation
failure :-) What value do you think this would bring, who would read
those messages ? I think it could be different for things that change
the ABI without breaking compilation and that would require more than a
recompilation to fix, there a warning seems to have more value, but I'm
also sure we'll forget from time to time, if not most of the time.
> > +
> > +private:
> > + friend class FrameBuffer;
> > +
> > + std::vector<Plane> planes_;
> > };
> >
> > class FrameBuffer final : public Extensible
> > diff --git a/src/cam/camera_session.cpp b/src/cam/camera_session.cpp
> > index 60d640f2b15c..32a373a99b72 100644
> > --- a/src/cam/camera_session.cpp
> > +++ b/src/cam/camera_session.cpp
> > @@ -374,9 +374,9 @@ void CameraSession::processRequest(Request *request)
> > << " bytesused: ";
> >
> > unsigned int nplane = 0;
> > - for (const FrameMetadata::Plane &plane : metadata.planes) {
> > + for (const FrameMetadata::Plane &plane : metadata.planes()) {
> > info << plane.bytesused;
> > - if (++nplane < metadata.planes.size())
> > + if (++nplane < metadata.planes().size())
> > info << "/";
> > }
> > }
> > diff --git a/src/cam/file_sink.cpp b/src/cam/file_sink.cpp
> > index 0b529e3eb767..0fc7d621f50b 100644
> > --- a/src/cam/file_sink.cpp
> > +++ b/src/cam/file_sink.cpp
> > @@ -110,7 +110,7 @@ void FileSink::writeBuffer(const Stream *stream, FrameBuffer *buffer)
> >
> > for (unsigned int i = 0; i < buffer->planes().size(); ++i) {
> > const FrameBuffer::Plane &plane = buffer->planes()[i];
> > - const FrameMetadata::Plane &meta = buffer->metadata().planes[i];
> > + const FrameMetadata::Plane &meta = buffer->metadata().planes()[i];
> >
> > uint8_t *data = planeData_[&plane];
> > unsigned int length = std::min(meta.bytesused, plane.length);
> > diff --git a/src/libcamera/framebuffer.cpp b/src/libcamera/framebuffer.cpp
> > index c1529dfb0ad1..83cf7b83d182 100644
> > --- a/src/libcamera/framebuffer.cpp
> > +++ b/src/libcamera/framebuffer.cpp
> > @@ -91,8 +91,14 @@ LOG_DEFINE_CATEGORY(Buffer)
> > */
> >
> > /**
> > - * \var FrameMetadata::planes
> > - * \brief Array of per-plane metadata
> > + * \fn FrameMetadata::planes()
> > + * \copydoc FrameMetadata::planes() const
> > + */
> > +
> > +/**
> > + * \fn FrameMetadata::planes() const
> > + * \brief Retrieve the array of per-plane metadata
> > + * \return The array of per-plane metadata
> > */
> >
> > /**
> > @@ -210,7 +216,7 @@ FrameBuffer::FrameBuffer(const std::vector<Plane> &planes, unsigned int cookie)
> > : Extensible(std::make_unique<Private>()), planes_(planes),
> > cookie_(cookie)
> > {
> > - metadata_.planes.resize(planes_.size());
> > + metadata_.planes_.resize(planes_.size());
> >
> > unsigned int offset = 0;
> >
> > diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
> > index a51971879e75..82ddaed3656f 100644
> > --- a/src/libcamera/v4l2_videodevice.cpp
> > +++ b/src/libcamera/v4l2_videodevice.cpp
> > @@ -1485,14 +1485,14 @@ int V4L2VideoDevice::queueBuffer(FrameBuffer *buffer)
> >
> > if (multiPlanar) {
> > unsigned int nplane = 0;
> > - for (const FrameMetadata::Plane &plane : metadata.planes) {
> > + for (const FrameMetadata::Plane &plane : metadata.planes()) {
> > v4l2Planes[nplane].bytesused = plane.bytesused;
> > v4l2Planes[nplane].length = buffer->planes()[nplane].length;
> > nplane++;
> > }
> > } else {
> > - if (metadata.planes.size())
> > - buf.bytesused = metadata.planes[0].bytesused;
> > + if (metadata.planes().size())
> > + buf.bytesused = metadata.planes()[0].bytesused;
> > }
> >
> > buf.sequence = metadata.sequence;
> > @@ -1587,17 +1587,17 @@ FrameBuffer *V4L2VideoDevice::dequeueBuffer()
> > + buf.timestamp.tv_usec * 1000ULL;
> >
> > if (multiPlanar) {
> > - if (buf.length > buffer->metadata_.planes.size()) {
> > + if (buf.length > buffer->metadata_.planes().size()) {
> > LOG(V4L2, Error)
> > << "Invalid number of planes (" << buf.length
> > - << " != " << buffer->metadata_.planes.size() << ")";
> > + << " != " << buffer->metadata_.planes().size() << ")";
> > return nullptr;
> > }
> >
> > for (unsigned int nplane = 0; nplane < buf.length; nplane++)
> > - buffer->metadata_.planes[nplane].bytesused = planes[nplane].bytesused;
> > + buffer->metadata_.planes()[nplane].bytesused = planes[nplane].bytesused;
> > } else {
> > - buffer->metadata_.planes[0].bytesused = buf.bytesused;
> > + buffer->metadata_.planes()[0].bytesused = buf.bytesused;
> > }
> >
> > return buffer;
> > diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
> > index 1536b2b5bd66..ac853e360aea 100644
> > --- a/src/qcam/main_window.cpp
> > +++ b/src/qcam/main_window.cpp
> > @@ -756,7 +756,7 @@ void MainWindow::processViewfinder(FrameBuffer *buffer)
> >
> > qDebug().noquote()
> > << QString("seq: %1").arg(metadata.sequence, 6, 10, QLatin1Char('0'))
> > - << "bytesused:" << metadata.planes[0].bytesused
> > + << "bytesused:" << metadata.planes()[0].bytesused
> > << "timestamp:" << metadata.timestamp
> > << "fps:" << Qt::fixed << qSetRealNumberPrecision(2) << fps;
> >
> > diff --git a/src/qcam/viewfinder_gl.cpp b/src/qcam/viewfinder_gl.cpp
> > index 40226601f9fd..d2ef036974f4 100644
> > --- a/src/qcam/viewfinder_gl.cpp
> > +++ b/src/qcam/viewfinder_gl.cpp
> > @@ -125,7 +125,7 @@ void ViewFinderGL::render(libcamera::FrameBuffer *buffer,
> > /*
> > * \todo Get the stride from the buffer instead of computing it naively
> > */
> > - stride_ = buffer->metadata().planes[0].bytesused / size_.height();
> > + stride_ = buffer->metadata().planes()[0].bytesused / size_.height();
>
> Can this be obtained from the PixelFormatInfo now ?
> or do we still not expose that to applications...
PixelFormatInfo is still internal. I'm considering exposing it, but then
it would be good to move the V4L2-specific part somewhere else.
> Anyway, that's likely a change on top even if we could to solve the \todo.
>
> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
>
> > update();
> > buffer_ = buffer;
> > }
> > diff --git a/src/qcam/viewfinder_qt.cpp b/src/qcam/viewfinder_qt.cpp
> > index efa1d412584b..a0bf99b0b522 100644
> > --- a/src/qcam/viewfinder_qt.cpp
> > +++ b/src/qcam/viewfinder_qt.cpp
> > @@ -87,7 +87,7 @@ void ViewFinderQt::render(libcamera::FrameBuffer *buffer,
> > }
> >
> > unsigned char *memory = mem.data();
> > - size_t size = buffer->metadata().planes[0].bytesused;
> > + size_t size = buffer->metadata().planes()[0].bytesused;
> >
> > {
> > QMutexLocker locker(&mutex_);
> > diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
> > index 8d8ee395954f..68e47ee81834 100644
> > --- a/src/v4l2/v4l2_camera_proxy.cpp
> > +++ b/src/v4l2/v4l2_camera_proxy.cpp
> > @@ -212,7 +212,7 @@ void V4L2CameraProxy::updateBuffers()
> >
> > switch (fmd.status) {
> > case FrameMetadata::FrameSuccess:
> > - buf.bytesused = fmd.planes[0].bytesused;
> > + buf.bytesused = fmd.planes()[0].bytesused;
> > buf.field = V4L2_FIELD_NONE;
> > buf.timestamp.tv_sec = fmd.timestamp / 1000000000;
> > buf.timestamp.tv_usec = fmd.timestamp % 1000000;
--
Regards,
Laurent Pinchart
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