[libcamera-devel] [RFC PATCH 4/5] QCam: Set a read control on each request to get Gain value

[Laurent Pinchart]

Hi Kieran,

Thank you for the patch.

On Thu, Jun 06, 2019 at 09:56:53PM +0100, Kieran Bingham wrote:
> ---
>  src/qcam/main_window.cpp | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
> index c0ab865b46ff..8dbe597e7aa2 100644
> --- a/src/qcam/main_window.cpp
> +++ b/src/qcam/main_window.cpp
> @@ -210,6 +210,10 @@ int MainWindow::startCapture()
>  	}
>  
>  	for (Request *request : requests) {
> +
> +		/* Add a read request for ManualGain */
> +		request->controls().emplace(ManualBrightness);
> +

I had envisioned that libcamera would report all control values
unconditionally. I'd like to discuss the pros and cons of specifying
them explicitly. I wonder in particular if applications won't just end
up adding all possible controls, which would defeat the purpose.

>  		ret = camera_->queueRequest(request);
>  		if (ret < 0) {
>  			std::cerr << "Can't queue request" << std::endl;
> @@ -266,12 +270,18 @@ void MainWindow::requestComplete(Request *request,
>  
>  	display(buffer);
>  
> +	/* Parse completed controls */
> +	for (Control c : request->controls())
> +		std::cout << c << std::endl;
> +
> +	/* Create a new request */
>  	request = camera_->createRequest();
>  	if (!request) {
>  		std::cerr << "Can't create request" << std::endl;
>  		return;
>  	}
>  
> +
>  	request->setBuffers(buffers);
>  	camera_->queueRequest(request);
>  }

-- 
Regards,

Laurent Pinchart