[libcamera-devel] [PATCH v6 6/6] libcamera: camera: extend camera object to support configuration of streams

[Laurent Pinchart]

Hi Niklas,

Thank you for the patch.

On Thu, Jan 31, 2019 at 07:18:53PM +0100, Niklas Söderlund wrote:
> Extend the camera to support reading and configuring formats for
> groups of streams. The implementation in the Camera are minimalistic as
> the heavy lifting are done by the pipeline handler implementations.
> 
> The most important functionality the camera provides in this context is
> validation of data structures passed to it from the application and
> access control to the pipeline handler.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
>  include/libcamera/camera.h |  6 ++++
>  src/libcamera/camera.cpp   | 66 ++++++++++++++++++++++++++++++++++++--
>  2 files changed, 70 insertions(+), 2 deletions(-)
> 
> diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h
> index d796ce32cc9a6fff..734dbc8e5e7985b5 100644
> --- a/include/libcamera/camera.h
> +++ b/include/libcamera/camera.h
> @@ -7,6 +7,7 @@
>  #ifndef __LIBCAMERA_CAMERA_H__
>  #define __LIBCAMERA_CAMERA_H__
>  
> +#include <map>
>  #include <memory>
>  #include <string>
>  
> @@ -16,6 +17,7 @@ namespace libcamera {
>  
>  class PipelineHandler;
>  class Stream;
> +class StreamConfiguration;
>  
>  class Camera final
>  {
> @@ -35,6 +37,9 @@ public:
>  	void release();
>  
>  	const std::vector<Stream *> &streams() const;
> +	std::map<Stream *, StreamConfiguration>
> +	streamConfiguration(std::vector<Stream *> &streams);
> +	int configureStreams(std::map<Stream *, StreamConfiguration> &config);
>  
>  private:
>  	Camera(PipelineHandler *pipe, const std::string &name);
> @@ -48,6 +53,7 @@ private:
>  	std::vector<Stream *> streams_;
>  
>  	bool acquired_;
> +	bool disconnected_;
>  };
>  
>  } /* namespace libcamera */
> diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
> index 49f49fb71c11e124..b8c6c8b2aa16430a 100644
> --- a/src/libcamera/camera.cpp
> +++ b/src/libcamera/camera.cpp
> @@ -110,7 +110,8 @@ 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)
>  {
>  }
>  
> @@ -133,7 +134,7 @@ void Camera::disconnect()
>  {
>  	LOG(Camera, Debug) << "Disconnecting camera " << name_;
>  
> -	/** \todo Block API calls when they will be implemented. */
> +	disconnected_ = true;
>  	disconnected.emit(this);
>  }
>  
> @@ -186,4 +187,65 @@ const std::vector<Stream *> &Camera::streams() const
>  	return streams_;
>  }
>  
> +/**
> + * \brief Retrieve a group of stream configurations
> + * \param[in] streams A map of stream IDs and configurations to setup
> + *
> + * Retrieve the camera's configuration for a specified group of streams. The
> + * caller can specifies which of the camera's streams to retrieve configuration
> + * from by populating \a streams.
> + *
> + * The easiest way to populate the array of streams to fetch configuration from
> + * is to first retrieve the camera's full array of stream with streams() and
> + * then potentially trim it down to only contain the streams the caller
> + * are interested in.
> + *
> + * \return A map of successfully retrieved stream IDs and configurations or an
> + * empty list on error.
> + */
> +std::map<Stream *, StreamConfiguration>
> +Camera::streamConfiguration(std::vector<Stream *> &streams)
> +{
> +	if (disconnected_ || !streams.size())
> +		std::map<unsigned int, StreamConfiguration> {};
> +
> +	return pipe_->streamConfiguration(this, streams);
> +}
> +
> +/**
> + * \brief Configure the camera's streams prior to capture
> + * \param[in] config A map of stream IDs and configurations to setup
> + *
> + * Prior to starting capture, the camera must be configured to select a
> + * group of streams to be involved in the capture and their configuration.
> + * The caller specifies which streams are to be involved and their configuration
> + * by populating \a config.
> + *
> + * The easiest way to populate the array of config is to fetch an initial
> + * configuration from the camera with streamConfiguration() and then change the
> + * parameters to fit the caller's need and once all the streams parameters are
> + * configured hand that over to configureStreams() to actually setup the camera.
> + *
> + * Exclusive access to the camera shall be ensured by a call to acquire() prior
> + * to calling this function, otherwise an -EACCES error will be returned.
> + *
> + * \return 0 on success or a negative error code on error.
> + * \retval -ENODEV The camera is not connected to any hardware
> + * \retval -EACCES The user has not acquired exclusive access to the camera
> + * \retval -EINVAL The configuration is not valid
> + */
> +int Camera::configureStreams(std::map<Stream *, StreamConfiguration> &config)
> +{
> +	if (disconnected_)
> +		return -ENODEV;
> +
> +	if (!acquired_)
> +		return -EACCES;
> +
> +	if (!config.size())
> +		return -EINVAL;
> +
> +	return pipe_->configureStreams(this, config);
> +}
> +
>  } /* namespace libcamera */
> -- 
> 2.20.1
> 
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-- 
Regards,

Laurent Pinchart