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

[Barnabás Pőcze]

Hi


2025. 04. 25. 16:41 keltezéssel, Laurent Pinchart írta:
> On Fri, Apr 25, 2025 at 02:58:08PM +0200, Barnabás Pőcze wrote:
>> Hi
>>
>>
>> 2025. 04. 25. 14:45 keltezéssel, Laurent Pinchart írta:
>>> 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.
>>
>> Yes, indeed, and I had thought about that for a bit, but there is also
>> SDLTextureNV12 (conditionally), and I didn't really see a good way to
>> reconcile the two.
> 
> 
> 	switch (cfg.pixelFormat) {
> #ifdef HAVE_LIBJPEG
> 	case libcamera::formats::MJPEG:
> 		texture_ = std::make_unique<SDLTextureMJPG>(rect_);
> 		break;
> #endif
> #if SDL_VERSION_ATLEAST(2, 0, 16)
> 	case libcamera::formats::NV12:
> 		texture_ = std::make_unique<SDLTextureNV12>(rect_, cfg.stride);
> 		break;
> #endif
>   	case libcamera::formats::YUYV:
>   		sdlFormat = SDL_PIXELFORMAT_YUY2;
>   		break;
> 	case libcamera::formats::UYVY:
>   		sdlFormat = SDL_PIXELFORMAT_UYVY;
> 		break;
> ...
> 	default:
> 		std::cerr << "Unsupported pixel format "
> 			  << cfg.pixelFormat.toString() << std::endl;
> 		return -EINVAL;
> 	};
> 
> 	if (sdlFormat)
> 		texture_ = std::make_unique<SDLTexture1Plane>(rect_, sdlFormat, cfg.stride);
> 

I have looked at something like this, but I am not a fan at all. :(


Regards,
Barnabás Pőcze


>>> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
>>>
>>>>    	default:
>>>>    		std::cerr << "Unsupported pixel format "
>>>>    			  << cfg.pixelFormat.toString() << std::endl;
>