[libcamera-devel] [PATCH v3 4/6] libcamera: camera: extend camera object to support streams
Niklas Söderlund
niklas.soderlund at ragnatech.se
Tue Jan 29 00:00:15 CET 2019
Hi Kieran,
Thanks for your feedback.
On 2019-01-28 11:34:23 +0000, Kieran Bingham wrote:
> Hi Niklas,
>
> On 27/01/2019 00:22, Niklas Söderlund wrote:
> > A camera consist of one or more video streams origination from the same
>
> A camera *consists* of one or more video streams *originating* from ...
>
> > video source. The different streams could for example have access to
> > different hardware blocks in the video pipeline and therefor be able to
>
> therefore
>
> > process the video source in different ways.
> >
> > All static information describing each streams needs to be recorded at
>
>
> describing each stream
>
Thanks!
>
> > camera creation. After a camera is created an application can retrieve
> > the static information about its stream at any time.
> >
> > Update all pipeline handlers to register one stream per camera, this
> > might be extended in the future for some of the pipelines.
> >
> > Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> > ---
> > include/libcamera/camera.h | 10 ++++-
> > src/libcamera/camera.cpp | 55 ++++++++++++++++++++++++++--
> > src/libcamera/pipeline/ipu3/ipu3.cpp | 4 +-
> > src/libcamera/pipeline/uvcvideo.cpp | 4 +-
> > src/libcamera/pipeline/vimc.cpp | 4 +-
> > 5 files changed, 69 insertions(+), 8 deletions(-)
> >
> > diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h
> > index 7e358f8c0aa093cf..786d4d7d66bed5b2 100644
> > --- a/include/libcamera/camera.h
> > +++ b/include/libcamera/camera.h
> > @@ -15,12 +15,14 @@
> > namespace libcamera {
> >
> > class PipelineHandler;
> > +class Stream;
> >
> > class Camera final
> > {
> > public:
> > static std::shared_ptr<Camera> create(PipelineHandler *pipe,
> > - const std::string &name);
> > + const std::string &name,
> > + const std::vector<Stream> &streams);
> >
> > Camera(const Camera &) = delete;
> > void operator=(const Camera &) = delete;
> > @@ -32,6 +34,8 @@ public:
> > int acquire();
> > void release();
> >
> > + std::vector<Stream> streams() const;
> > +
> > private:
> > Camera(PipelineHandler *pipe, const std::string &name);
> > ~Camera();
> > @@ -39,10 +43,14 @@ private:
> > friend class PipelineHandler;
> > void disconnect();
> >
> > + bool haveStreamID(unsigned int id) const;
>
> have? should this be 'hasStreamID()' ?
>
> Looking at the implementation, Yes - I think so.
I have renamed this hasStreamId merging your and Laurents comments on
this.
>
> > +
> > std::shared_ptr<PipelineHandler> pipe_;
> > std::string name_;
> > + std::vector<Stream> streams_;
> >
> > bool acquired_;
> > + bool disconnected_;
>
> Is this related to streams?
Yes, if a camera is disconnected operations should not be forwarded to
the pipeline handler. Laurent thinks streams information should still be
available after a disconnect so I have moved this to the first patch who
adds operations which needs a connected camera.
>
> > };
> >
> > } /* namespace libcamera */
> > diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
> > index 500976b237bcbd2d..3b2c00d0a4bb45d1 100644
> > --- a/src/libcamera/camera.cpp
> > +++ b/src/libcamera/camera.cpp
> > @@ -6,6 +6,7 @@
> > */
> >
> > #include <libcamera/camera.h>
> > +#include <libcamera/stream.h>
> >
> > #include "log.h"
> > #include "pipeline_handler.h"
> > @@ -56,13 +57,15 @@ LOG_DECLARE_CATEGORY(Camera)
> > * \brief Create a camera instance
> > * \param[in] name The name of the camera device
> > * \param[in] pipe The pipeline handler responsible for the camera device
> > + * \param[in] streams Array of streams the camera shall provide
> > *
> > * The caller is responsible for guaranteeing unicity of the camera name.
> > *
> > * \return A shared pointer to the newly created camera object
> > */
> > std::shared_ptr<Camera> Camera::create(PipelineHandler *pipe,
> > - const std::string &name)
> > + const std::string &name,
> > + const std::vector<Stream> &streams)
> > {
> > struct Allocator : std::allocator<Camera> {
> > void construct(void *p, PipelineHandler *pipe,
> > @@ -76,7 +79,19 @@ std::shared_ptr<Camera> Camera::create(PipelineHandler *pipe,
> > }
> > };
> >
> > - return std::allocate_shared<Camera>(Allocator(), pipe, name);
> > + std::shared_ptr<Camera> camera =
> > + std::allocate_shared<Camera>(Allocator(), pipe, name);
> > +
> > + for (const Stream &stream : streams) {
> > + if (camera->haveStreamID(stream.id())) {
> > + LOG(Camera, Error) << "Duplication of stream ID";
>
> What about the pipeline adding a stream to a camera instead, and the ID
> being allocated by the camera device?
For the ID to have any real meaning the pipeline needs to assign the id
as it is the real user of it. When configuring a camera the pipeline
handler needs to know which streams are to be used and it currently do
this by the use of the id. This might change in the future as the API
evolve.
>
> Or does this make things the wrong way around?
>
> I guess it would also have to be a function which only the Pipeline was
> able to call somehow...
>
> (we wouldn't want a public Camera API that could arbitrarily add streams!)..
:-)
>
>
> > + camera.reset();
> > + break;
> > + }
> > + camera->streams_.push_back(stream);
> > + }
> > +
> > + return camera;
> > }
> >
> > /**
> > @@ -102,7 +117,8 @@ const std::string &Camera::name() const
> > */
> >
> > Camera::Camera(PipelineHandler *pipe, const std::string &name)
> > - : pipe_(pipe->shared_from_this()), name_(name), acquired_(false)
> > + : pipe_(pipe->shared_from_this()), name_(name), acquired_(false),
> > + disconnected_(false)
> > {
> > }
> >
> > @@ -125,10 +141,24 @@ void Camera::disconnect()
> > {
> > LOG(Camera, Debug) << "Disconnecting camera " << name_;
> >
> > - /** \todo Block API calls when they will be implemented. */
> > + disconnected_ = true;
> > disconnected.emit(this);
> > }
> >
> > +/**
> > + * \brief Check if camera have a stream ID
>
> Check if the camera has a particular stream ID
>
>
> > + * \param[in] id Stream ID to check for
> > + * \return ture if stream ID exists, else false
>
> s/ture/True/
Thanks.
>
>
> > + */
> > +bool Camera::haveStreamID(unsigned int id) const
> > +{
> > + for (const Stream &stream : streams_)
> > + if (stream.id() == id)
> > + return true;
> > +
> > + return false;
> > +}
> > +
> > /**
> > * \brief Acquire the camera device for exclusive access
> > *
> > @@ -164,4 +194,21 @@ void Camera::release()
> > acquired_ = false;
> > }
> >
> > +/**
> > + * \brief Retrieve all the camera's stream information
> > + *
> > + * Retrieve all of the camera's static stream information. The static
> > + * information describes among other things how many streams the camera support
> > + * and each streams capabilities.
> > + *
> > + * \return An array of all the camera's streams or an empty list on error.
>
> Is if(disconnected) an error?
>
> I'd say if a camera is disconnected it has no streams ... I don't think
> that's an error?
>
> Perhaps:
>
> \return An array of all the camera's streams valid streams.
Merging your and Laurents comment a disconnected camera will keep
exposing the static stream information so I have update this to:
\return An array of all the camera's streams.
>
>
> > + */
> > +std::vector<Stream> Camera::streams() const
> > +{
> > + if (disconnected_)
> > + return std::vector<Stream>{};
> > +
> > + return streams_;
> > +}
> > +
> > } /* namespace libcamera */
> > diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> > index d74655d037728feb..dbb2a89163c36cbc 100644
> > --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> > +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> > @@ -9,6 +9,7 @@
> > #include <vector>
> >
> > #include <libcamera/camera.h>
> > +#include <libcamera/stream.h>
> >
> > #include "device_enumerator.h"
> > #include "log.h"
> > @@ -197,7 +198,8 @@ void PipelineHandlerIPU3::registerCameras()
> > continue;
> >
> > std::string cameraName = sensor->name() + " " + std::to_string(id);
> > - std::shared_ptr<Camera> camera = Camera::create(this, cameraName);
> > + std::vector<Stream> streams{ Stream(0) };
> > + std::shared_ptr<Camera> camera = Camera::create(this, cameraName, streams);
> >
> > /*
> > * If V4L2 device creation fails, the Camera instance won't be
> > diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
> > index c51e8bc1f2c2bf25..bc4a8d7236be589d 100644
> > --- a/src/libcamera/pipeline/uvcvideo.cpp
> > +++ b/src/libcamera/pipeline/uvcvideo.cpp
> > @@ -6,6 +6,7 @@
> > */
> >
> > #include <libcamera/camera.h>
> > +#include <libcamera/stream.h>
> >
> > #include "device_enumerator.h"
> > #include "media_device.h"
> > @@ -64,7 +65,8 @@ bool PipelineHandlerUVC::match(DeviceEnumerator *enumerator)
> > return false;
> > }
> >
> > - std::shared_ptr<Camera> camera = Camera::create(this, media_->model());
> > + std::vector<Stream> streams{ Stream(0) };
> > + std::shared_ptr<Camera> camera = Camera::create(this, media_->model(), streams);
> > registerCamera(std::move(camera));
> > hotplugMediaDevice(media_.get());
> >
> > diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
> > index f58a97d51619515d..c426a953aea1b3dd 100644
> > --- a/src/libcamera/pipeline/vimc.cpp
> > +++ b/src/libcamera/pipeline/vimc.cpp
> > @@ -6,6 +6,7 @@
> > */
> >
> > #include <libcamera/camera.h>
> > +#include <libcamera/stream.h>
> >
> > #include "device_enumerator.h"
> > #include "media_device.h"
> > @@ -56,7 +57,8 @@ bool PipeHandlerVimc::match(DeviceEnumerator *enumerator)
> >
> > media_->acquire();
> >
> > - std::shared_ptr<Camera> camera = Camera::create(this, "Dummy VIMC Camera");
> > + std::vector<Stream> streams{ Stream(0) };
> > + std::shared_ptr<Camera> camera = Camera::create(this, "Dummy VIMC Camera", streams);
>
> Out of interest, UVC exposes two video device nodes. One for the video
> data, and one for 'meta' data.
>
> Would we consider this meta data to be a second stream?
Possibly, to be honest I don't know what the second video node is used
for. If it carries meta data maybe it should be used by a 3A sometime in
the future :-)
>
>
> > registerCamera(std::move(camera));
> >
> > return true;
> >
>
> --
> Regards
> --
> Kieran
--
Regards,
Niklas Söderlund
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