[libcamera-devel] [PATCH v3 5/6] libcamera: pipeline: extend pipelines to support stream configuration

Laurent Pinchart laurent.pinchart at ideasonboard.com
Mon Jan 28 01:09:10 CET 2019


Hi Niklas,

Thank you for the patch.

On Sun, Jan 27, 2019 at 01:22:07AM +0100, Niklas Söderlund wrote:
> All streams which are to be used for capture needs to be configured at

s/needs/need/

> the same time. This allows the pipeline handler to take any dependences

s/dependences/dependencies/

> between the different streams and there configuration into account when

s/there configuration/their configurations/

> setting up the hardware.
> 
> Extend the pipeline API and all pipeline implementations with two new
> functions, one to read the configuration and one to update it. Both
> functions operate on a group of streams which the pipeline handler
> should consider when performing the operations.

I don't think we should have a function to read the current
configuration, and if we did, it shouldn't be virtual, but implemented
in PipelineHandler using a cache.

What we need is a function for a pipeline handler to return a default
configuration for a set of streams, in order for applications not to
have to create a configuration from scratch but start from a known to
work (and recommended) config.

> In the current implemented pipelines this is rather easy as they only
> have one stream each per camera. Furthermore as there is yet no way for
> the pipeline handlers to interact with the hardware all they do is log
> that the format have been read or updated. Future work based on more
> components are needed to make the pipelines actually interact with the
> hardware.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> ---
>  src/libcamera/include/pipeline_handler.h |  8 ++++++
>  src/libcamera/pipeline/ipu3/ipu3.cpp     | 32 ++++++++++++++++++++++
>  src/libcamera/pipeline/uvcvideo.cpp      | 35 ++++++++++++++++++++++++
>  src/libcamera/pipeline/vimc.cpp          | 35 ++++++++++++++++++++++++
>  src/libcamera/pipeline_handler.cpp       | 34 +++++++++++++++++++++++
>  5 files changed, 144 insertions(+)
> 
> diff --git a/src/libcamera/include/pipeline_handler.h b/src/libcamera/include/pipeline_handler.h
> index ca77a40b96e69b66..c19eb9b73ede8720 100644
> --- a/src/libcamera/include/pipeline_handler.h
> +++ b/src/libcamera/include/pipeline_handler.h
> @@ -17,6 +17,8 @@ namespace libcamera {
>  class CameraManager;
>  class DeviceEnumerator;
>  class MediaDevice;
> +class Stream;
> +class StreamConfiguration;
>  
>  class Camera;
>  class CameraData
> @@ -38,6 +40,12 @@ public:
>  	PipelineHandler(CameraManager *manager);
>  	virtual ~PipelineHandler();
>  
> +	virtual std::map<unsigned int, StreamConfiguration>
> +	streamConfiguration(const Camera *camera,
> +			    const std::vector<Stream> &streams) const = 0;
> +	virtual int configureStreams(const Camera *camera,

Even if you don't need to modify the state of the Camera object now, you
may need that later. Beside, this method is called by the Camera class
from a non-cost instance, so that won't be a problem.

> +				     std::map<unsigned int, StreamConfiguration> &config) = 0;
> +
>  	virtual bool match(DeviceEnumerator *enumerator) = 0;
>  
>  protected:
> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> index dbb2a89163c36cbc..ff4d73f947a683ca 100644
> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> @@ -28,6 +28,12 @@ public:
>  	PipelineHandlerIPU3(CameraManager *manager);
>  	~PipelineHandlerIPU3();
>  
> +	std::map<unsigned int, StreamConfiguration>
> +	streamConfiguration(const Camera *camera,
> +			    const std::vector<Stream> &streams) const;
> +	int configureStreams(const Camera *camera,
> +			     std::map<unsigned int, StreamConfiguration> &config);
> +
>  	bool match(DeviceEnumerator *enumerator);
>  
>  private:
> @@ -61,6 +67,32 @@ PipelineHandlerIPU3::~PipelineHandlerIPU3()
>  		imgu_->release();
>  }
>  
> +std::map<unsigned int, StreamConfiguration>
> +PipelineHandlerIPU3::streamConfiguration(const Camera *camera,
> +					 const std::vector<Stream> &streams) const
> +{
> +	std::map<unsigned int, StreamConfiguration> configs;
> +
> +	StreamConfiguration config;
> +
> +	LOG(IPU3, Info) << "TODO: Fetch stream configuration";
> +
> +	configs[0] = config;
> +
> +	return configs;
> +}
> +
> +int PipelineHandlerIPU3::configureStreams(const Camera *camera,
> +					  std::map<unsigned int, StreamConfiguration> &config)
> +{
> +	StreamConfiguration *cfg = &config[0];
> +
> +	LOG(IPU3, Info) << "TODO: Configure the camera for resolution " <<
> +		cfg->width << "x" << cfg->height;
> +
> +	return 0;
> +}
> +
>  bool PipelineHandlerIPU3::match(DeviceEnumerator *enumerator)
>  {
>  	DeviceMatch cio2_dm("ipu3-cio2");
> diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
> index bc4a8d7236be589d..bba4655a0a26b622 100644
> --- a/src/libcamera/pipeline/uvcvideo.cpp
> +++ b/src/libcamera/pipeline/uvcvideo.cpp
> @@ -9,18 +9,27 @@
>  #include <libcamera/stream.h>
>  
>  #include "device_enumerator.h"
> +#include "log.h"
>  #include "media_device.h"
>  #include "pipeline_handler.h"
>  #include "v4l2_device.h"
>  
>  namespace libcamera {
>  
> +LOG_DEFINE_CATEGORY(UVC)
> +
>  class PipelineHandlerUVC : public PipelineHandler
>  {
>  public:
>  	PipelineHandlerUVC(CameraManager *manager);
>  	~PipelineHandlerUVC();
>  
> +	std::map<unsigned int, StreamConfiguration>
> +	streamConfiguration(const Camera *camera,
> +			    const std::vector<Stream> &streams) const;
> +	int configureStreams(const Camera *camera,
> +			     std::map<unsigned int, StreamConfiguration> &config);
> +
>  	bool match(DeviceEnumerator *enumerator);
>  
>  private:
> @@ -42,6 +51,32 @@ PipelineHandlerUVC::~PipelineHandlerUVC()
>  		media_->release();
>  }
>  
> +std::map<unsigned int, StreamConfiguration>
> +PipelineHandlerUVC::streamConfiguration(const Camera *camera,
> +					const std::vector<Stream> &streams) const
> +{
> +	std::map<unsigned int, StreamConfiguration> configs;
> +
> +	StreamConfiguration config;
> +
> +	LOG(UVC, Info) << "TODO: Fetch stream configuration";
> +
> +	configs[0] = config;
> +
> +	return configs;
> +}
> +
> +int PipelineHandlerUVC::configureStreams(const Camera *camera,
> +					 std::map<unsigned int, StreamConfiguration> &config)
> +{
> +	StreamConfiguration *cfg = &config[0];
> +
> +	LOG(UVC, Info) << "TODO: Configure the camera for resolution " <<
> +		cfg->width << "x" << cfg->height;
> +
> +	return 0;
> +}
> +
>  bool PipelineHandlerUVC::match(DeviceEnumerator *enumerator)
>  {
>  	DeviceMatch dm("uvcvideo");
> diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
> index c426a953aea1b3dd..c9810a8e192ac68b 100644
> --- a/src/libcamera/pipeline/vimc.cpp
> +++ b/src/libcamera/pipeline/vimc.cpp
> @@ -9,17 +9,26 @@
>  #include <libcamera/stream.h>
>  
>  #include "device_enumerator.h"
> +#include "log.h"
>  #include "media_device.h"
>  #include "pipeline_handler.h"
>  
>  namespace libcamera {
>  
> +LOG_DEFINE_CATEGORY(VIMC)
> +
>  class PipeHandlerVimc : public PipelineHandler
>  {
>  public:
>  	PipeHandlerVimc(CameraManager *manager);
>  	~PipeHandlerVimc();
>  
> +	std::map<unsigned int, StreamConfiguration>
> +	streamConfiguration(const Camera *camera,
> +			    const std::vector<Stream> &streams) const;
> +	int configureStreams(const Camera *camera,
> +			     std::map<unsigned int, StreamConfiguration> &config);
> +
>  	bool match(DeviceEnumerator *enumerator);
>  
>  private:
> @@ -37,6 +46,32 @@ PipeHandlerVimc::~PipeHandlerVimc()
>  		media_->release();
>  }
>  
> +std::map<unsigned int, StreamConfiguration>
> +PipeHandlerVimc::streamConfiguration(const Camera *camera,
> +				     const std::vector<Stream> &streams) const
> +{
> +	std::map<unsigned int, StreamConfiguration> configs;
> +
> +	StreamConfiguration config;
> +
> +	LOG(VIMC, Info) << "TODO: Fetch stream configuration";
> +
> +	configs[0] = config;
> +
> +	return configs;
> +}
> +
> +int PipeHandlerVimc::configureStreams(const Camera *camera,
> +				      std::map<unsigned int, StreamConfiguration> &config)
> +{
> +	StreamConfiguration *cfg = &config[0];
> +
> +	LOG(VIMC, Info) << "TODO: Configure the camera for resolution " <<
> +		cfg->width << "x" << cfg->height;
> +
> +	return 0;
> +}
> +
>  bool PipeHandlerVimc::match(DeviceEnumerator *enumerator)
>  {
>  	DeviceMatch dm("vimc");
> diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
> index 1c8640799f714686..ee6d80908f67d564 100644
> --- a/src/libcamera/pipeline_handler.cpp
> +++ b/src/libcamera/pipeline_handler.cpp
> @@ -75,6 +75,40 @@ PipelineHandler::~PipelineHandler()
>  {
>  };
>  
> +
> +/**
> + * \fn PipelineHandler::streamConfiguration(const Camera *camera, * const std::vector<Stream> &streams)

You don't need to specify the function parameters when the function
isn't overloaded.

> + * \brief Retrieve a group of stream configurations for a specified camera
> + * \param[in] camera The camera to fetch the configuration from
> + * \param[in] streams An array of streams to fetch information about
> + *
> + * Retrieve the species camera's configuration for a specified group of streams.
> + * The caller shall populate the \a streams array with the streams it wish to
> + * fetch the configuration from. The map of stream IDs and configuration
> + * returned can then be examined by the caller to learn about the parameters for
> + * the specified streams.
> + *
> + * The intended companion to this is \a configureStreams() which can be used to
> + * change the group of streams parameters.
> + *
> + * \return A map of successfully retrieved stream IDs and configurations or an
> + * empty map on error.
> + */
> +
> +/**
> + * \fn PipelineHandler::configureStreams(const Camera *camera, std::map<unsigned int, StreamConfiguration> &config)
> + * \brief Configure a group of streams for capture
> + * \param[in] camera The camera to apply the configuration to

You could simply say "The camera to configure".

> + * \param[in] config A map of stream configurations to apply
> + *
> + * Configure the specified group of streams for \a camera according to the
> + * configuration specified in \a configs. The intended caller of this interface
> + * is the Camera class which will receive configuration to apply from the
> + * application.
> + *
> + * \return 0 on success or a negative error code on error.
> + */
> +
>  /**
>   * \fn PipelineHandler::match(DeviceEnumerator *enumerator)
>   * \brief Match media devices and create camera instances

-- 
Regards,

Laurent Pinchart


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