[libcamera-devel] [PATCH v3 2/8] libcamera: ipu3: imgu: Filter resolutions < IF_CROP_MAX

[Jean-Michel Hautbois]

Hi Jacopo,

On 13/05/2021 17:21, Jacopo Mondi wrote:
> As reported in https://bugs.libcamera.org/show_bug.cgi?id=32
> allowing resolutions < IF_CROP_MAX leads to a not manageable number
> configurations to be tested, slowing down the ImgU pipe configuration
> to a point which is not acceptable for production devices.
> 
> Filter all resolutions < IF_CROP_MAX to maintain the run-time complexity
> acceptable and remove the safety check that was meant to avoid overflows
> when computing the IF rectangle sizes.
> 
> Bug: https://bugs.libcamera.org/show_bug.cgi?id=32
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois at ideasonboard.com>
> ---
>  src/libcamera/pipeline/ipu3/imgu.cpp | 21 +++++++++++++++------
>  1 file changed, 15 insertions(+), 6 deletions(-)
> 
> diff --git a/src/libcamera/pipeline/ipu3/imgu.cpp b/src/libcamera/pipeline/ipu3/imgu.cpp
> index acc625ab0fac..f25f14a71e9e 100644
> --- a/src/libcamera/pipeline/ipu3/imgu.cpp
> +++ b/src/libcamera/pipeline/ipu3/imgu.cpp
> @@ -392,6 +392,17 @@ ImgUDevice::PipeConfig ImgUDevice::calculatePipeConfig(Pipe *pipe)
>  	LOG(IPU3, Debug) << "vf: " << pipe->viewfinder.toString();
>  
>  	const Size &in = pipe->input;
> +
> +	/*
> +	 * \todo Filter out all resolutions < IF_CROP_MAX.
> +	 * See https://bugs.libcamera.org/show_bug.cgi?id=32
> +	 */
> +	if (in.width < IF_CROP_MAX_W || in.height < IF_CROP_MAX_H) {
> +		LOG(IPU3, Error) << "Input resolution " << in.toString()
> +				 << " not supported";
> +		return {};
> +	}
> +
>  	Size gdc = calculateGDC(pipe);
>  
>  	float bdsSF = static_cast<float>(in.width) / gdc.width;
> @@ -400,10 +411,8 @@ ImgUDevice::PipeConfig ImgUDevice::calculatePipeConfig(Pipe *pipe)
>  	/* Populate the configurations vector by scaling width and height. */
>  	unsigned int ifWidth = utils::alignUp(in.width, IF_ALIGN_W);
>  	unsigned int ifHeight = utils::alignUp(in.height, IF_ALIGN_H);
> -	unsigned int minIfWidth = std::min(IF_ALIGN_W,
> -					   in.width - IF_CROP_MAX_W);
> -	unsigned int minIfHeight = std::min(IF_ALIGN_H,
> -					    in.height - IF_CROP_MAX_H);
> +	unsigned int minIfWidth = in.width - IF_CROP_MAX_W;
> +	unsigned int minIfHeight = in.height - IF_CROP_MAX_H;
>  	while (ifWidth >= minIfWidth) {
>  		while (ifHeight >= minIfHeight) {
>  			Size iif{ ifWidth, ifHeight };
> @@ -417,8 +426,8 @@ ImgUDevice::PipeConfig ImgUDevice::calculatePipeConfig(Pipe *pipe)
>  	/* Repeat search by scaling width first. */
>  	ifWidth = utils::alignUp(in.width, IF_ALIGN_W);
>  	ifHeight = utils::alignUp(in.height, IF_ALIGN_H);
> -	minIfWidth = std::min(IF_ALIGN_W, in.width - IF_CROP_MAX_W);
> -	minIfHeight = std::min(IF_ALIGN_H, in.height - IF_CROP_MAX_H);
> +	minIfWidth = in.width - IF_CROP_MAX_W;
> +	minIfHeight = in.height - IF_CROP_MAX_H;
>  	while (ifHeight >= minIfHeight) {
>  		/*
>  		 * \todo This procedure is probably broken:
>