[libcamera-devel] [RFC 1/5] cam: Rework how streams configuration is prepared

[Niklas Söderlund]

Hi Laurent,

Thanks for your feedback.

On 2019-04-02 17:16:23 +0300, Laurent Pinchart wrote:
> Hi Niklas,
> 
> Thank you for the patch.
> 
> On Tue, Apr 02, 2019 at 02:53:28AM +0200, Niklas Söderlund wrote:
> > In preparation of reworking how a default configuration is retrieved
> > from a camera separate preparation of stream configuration and applying
> > of it into to different functions. Reason for this is that preparation
> 
> s/into to/into two/
> 
> "applying of it" could also be replaced by "application".
> 
> > of camera configuration will become more complex.
> > 
> > Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> > ---
> >  src/cam/main.cpp | 35 ++++++++++++++++++++---------------
> >  1 file changed, 20 insertions(+), 15 deletions(-)
> > 
> > diff --git a/src/cam/main.cpp b/src/cam/main.cpp
> > index e7490c32f99a01ad..cc5302ca4e72ea6f 100644
> > --- a/src/cam/main.cpp
> > +++ b/src/cam/main.cpp
> > @@ -78,27 +78,27 @@ static int parseOptions(int argc, char *argv[])
> >  	return 0;
> >  }
> >  
> > -static int configureStreams(Camera *camera, std::set<Stream *> &streams)
> > +static int prepare_camera_config(std::map<Stream *, StreamConfiguration> *config)
> >  {
> > -	KeyValueParser::Options format = options[OptFormat];
> > -	Stream *id = *streams.begin();
> > -
> > -	std::map<Stream *, StreamConfiguration> config =
> > -		camera->streamConfiguration(streams);
> > +	std::set<Stream *> streams = camera->streams();
> > +	*config = camera->streamConfiguration(streams);
> > +	Stream *stream = config->begin()->first;
> >  
> >  	if (options.isSet(OptFormat)) {
> > +		KeyValueParser::Options format = options[OptFormat];
> > +
> >  		if (format.isSet("width"))
> > -			config[id].width = format["width"];
> > +			(*config)[stream].width = format["width"];
> >  
> >  		if (format.isSet("height"))
> > -			config[id].height = format["height"];
> > +			(*config)[stream].height = format["height"];
> >  
> >  		/* TODO: Translate 4CC string to ID. */
> >  		if (format.isSet("pixelformat"))
> > -			config[id].pixelFormat = format["pixelformat"];
> > +			(*config)[stream].pixelFormat = format["pixelformat"];
> >  	}
> >  
> > -	return camera->configureStreams(config);
> > +	return 0;
> >  }
> >  
> >  static void requestComplete(Request *request, const std::map<Stream *, Buffer *> &buffers)
> > @@ -136,18 +136,23 @@ static void requestComplete(Request *request, const std::map<Stream *, Buffer *>
> >  
> >  static int capture()
> >  {
> > -	int ret;
> > -
> > -	std::set<Stream *> streams = camera->streams();
> > +	std::map<Stream *, StreamConfiguration> config;
> >  	std::vector<Request *> requests;
> > +	int ret;
> >  
> > -	ret = configureStreams(camera.get(), streams);
> > +	ret = prepare_camera_config(&config);
> 
> Would it make sense to return the map by value instead of passing a
> pointer to it ? Apart from that,

I have done so in the past in other places but I'm starting to dislike 
returning an empty map to indicate an error. I will keep it as is for v1 
but I'm open to change this.

> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> 
> > +	if (ret) {
> > +		std::cout << "Failed to prepare camera configuration" << std::endl;
> > +		return ret;
> > +	}
> > +
> > +	ret = camera->configureStreams(config);
> >  	if (ret < 0) {
> >  		std::cout << "Failed to configure camera" << std::endl;
> >  		return ret;
> >  	}
> >  
> > -	Stream *stream = *streams.begin();
> > +	Stream *stream = config.begin()->first;
> >  
> >  	ret = camera->allocateBuffers();
> >  	if (ret) {
> 
> -- 
> Regards,
> 
> Laurent Pinchart

-- 
Regards,
Niklas Söderlund