[PATCH v2 4/4] apps: cam: sdl_sink: Support more single-plane formats

[Laurent Pinchart]

Hi Barnabás,

Thank you for the patch.

On Fri, Apr 25, 2025 at 12:47:03PM +0200, Barnabás Pőcze wrote:
> With the newly introduced `SDLTexture1Plane` it is easy to handle
> any single-plane format that has an SDL equivalent. So use it for
> more YUV and RGB formats.
> 
> The mapping of RGB formats is not entirely straightforward because
> `SDL_PIXELFORMAT_ZZZ...888...` defines a format where the order of
> the components is endian dependent, while libcamera's `ZZZ...888...`
> formats are derived from the matching DRM formats, and the RGB formats
> in question are defined to be little-endian there. So the
> endian-independent `SDL_PIXELFORMAT_{ZZZ24,ZZZZ32}` are used.

Format mapping is always painful :-(

> Signed-off-by: Barnabás Pőcze <barnabas.pocze at ideasonboard.com>
> ---
>  src/apps/cam/sdl_sink.cpp | 36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/src/apps/cam/sdl_sink.cpp b/src/apps/cam/sdl_sink.cpp
> index b295675dc..2edbb523d 100644
> --- a/src/apps/cam/sdl_sink.cpp
> +++ b/src/apps/cam/sdl_sink.cpp
> @@ -77,6 +77,42 @@ int SDLSink::configure(const libcamera::CameraConfiguration &config)
>  	case libcamera::formats::YUYV:
>  		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_YUY2, cfg.stride);
>  		break;
> +	case libcamera::formats::UYVY:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_UYVY, cfg.stride);
> +		break;
> +	case libcamera::formats::YVYU:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_YVYU, cfg.stride);
> +		break;
> +	case libcamera::formats::ARGB8888:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_BGRA32, cfg.stride);
> +		break;
> +	case libcamera::formats::XRGB8888:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_BGRX32, cfg.stride);
> +		break;
> +	case libcamera::formats::RGBA8888:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_ABGR32, cfg.stride);
> +		break;
> +	case libcamera::formats::RGBX8888:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_XBGR32, cfg.stride);
> +		break;
> +	case libcamera::formats::ABGR8888:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_RGBA32, cfg.stride);
> +		break;
> +	case libcamera::formats::XBGR8888:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_RGBX32, cfg.stride);
> +		break;
> +	case libcamera::formats::BGRA8888:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_ARGB32, cfg.stride);
> +		break;
> +	case libcamera::formats::BGRX8888:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_XRGB32, cfg.stride);
> +		break;
> +	case libcamera::formats::RGB888:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_BGR24, cfg.stride);
> +		break;
> +	case libcamera::formats::BGR888:
> +		texture_ = std::make_unique<SDLTexture1Plane>(rect_, SDL_PIXELFORMAT_RGB24, cfg.stride);
> +		break;

I'm tempted to avoid all the constructor calls by instead adding a
sdlFormat variable and filling it in the switch, and then creating the
texture after the switch.

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

>  	default:
>  		std::cerr << "Unsupported pixel format "
>  			  << cfg.pixelFormat.toString() << std::endl;

-- 
Regards,

Laurent Pinchart