[libcamera-devel,2/2] qcam: main_window: Prefer stream formats that don't require conversion

3296 diff mbox series

Query the viewfinder for the formats it supports natively, and select
one of them for the stream if possible.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 src/qcam/main_window.cpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Hi Laurent,

On 24/03/2020 10:30, Laurent Pinchart wrote:
> Query the viewfinder for the formats it supports natively, and select
> one of them for the stream if possible.

This should help improve performances indeed!

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  src/qcam/main_window.cpp | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
> index b13660bccb25..565732698a5e 100644
> --- a/src/qcam/main_window.cpp
> +++ b/src/qcam/main_window.cpp
> @@ -297,6 +297,19 @@ int MainWindow::startCapture()
>  		}
>  	}
>  
> +	/* Use a format supported by the viewfinder if available. */
> +	std::vector<PixelFormat> formats = cfg.formats().pixelformats();

That's just a reference right? Not a full copy of the pixelformats() table?

> +	for (const PixelFormat &format : viewfinder_->nativeFormats()) {
> +		auto match = std::find_if(formats.begin(), formats.end(),
> +					  [&](const PixelFormat &f) {
> +						  return f == format;
> +					  });
> +		if (match != formats.end()) {
> +			cfg.pixelFormat = format;
> +			break;
> +		}
> +	}
> +
>  	CameraConfiguration::Status validation = config_->validate();
>  	if (validation == CameraConfiguration::Invalid) {
>  		qWarning() << "Failed to create valid camera configuration";
>

Hi Kieran,

On Tue, Mar 24, 2020 at 12:41:13PM +0000, Kieran Bingham wrote:
> On 24/03/2020 10:30, Laurent Pinchart wrote:
> > Query the viewfinder for the formats it supports natively, and select
> > one of them for the stream if possible.
> 
> This should help improve performances indeed!
> 
> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
> 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> >  src/qcam/main_window.cpp | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> > 
> > diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
> > index b13660bccb25..565732698a5e 100644
> > --- a/src/qcam/main_window.cpp
> > +++ b/src/qcam/main_window.cpp
> > @@ -297,6 +297,19 @@ int MainWindow::startCapture()
> >  		}
> >  	}
> >  
> > +	/* Use a format supported by the viewfinder if available. */
> > +	std::vector<PixelFormat> formats = cfg.formats().pixelformats();
> 
> That's just a reference right? Not a full copy of the pixelformats() table?

No, it's a copy, as StreamFormats doesn't store a vector of
PixelFormats, but a map. The vector is constructed at runtime.

> > +	for (const PixelFormat &format : viewfinder_->nativeFormats()) {
> > +		auto match = std::find_if(formats.begin(), formats.end(),
> > +					  [&](const PixelFormat &f) {
> > +						  return f == format;
> > +					  });
> > +		if (match != formats.end()) {
> > +			cfg.pixelFormat = format;
> > +			break;
> > +		}
> > +	}
> > +
> >  	CameraConfiguration::Status validation = config_->validate();
> >  	if (validation == CameraConfiguration::Invalid) {
> >  		qWarning() << "Failed to create valid camera configuration";