[libcamera-devel] [PATCH v2 4/5] android: camera_device: Use YUV post-processor

[Laurent Pinchart]

Hi Paul and Hiro,

Thank you for the patch.

On Fri, May 27, 2022 at 06:34:39PM +0900, Paul Elder via libcamera-devel wrote:
> From: Hirokazu Honda <hiroh at chromium.org>
> 
> When creating the list of StreamConfiguration to be requested to the camera,
> map NV12 streams of equal size and format together, so that they will be
> generated by using the YUV post-processor.
> 
> Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
>  src/android/camera_device.cpp | 32 +++++++++++++++++++++++++++++---
>  1 file changed, 29 insertions(+), 3 deletions(-)
> 
> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> index 95c14f60..9ee34b93 100644
> --- a/src/android/camera_device.cpp
> +++ b/src/android/camera_device.cpp
> @@ -605,14 +605,40 @@ int CameraDevice::configureStreams(camera3_stream_configuration_t *stream_list)
>  			continue;
>  		}
>  
> +		/*
> +		 * While gralloc usage flags are supposed to report usage
> +		 * patterns to select a suitable buffer allocation strategy, in
> +		 * practice they're also used to make other decisions, such as
> +		 * selecting the actual format for the IMPLEMENTATION_DEFINED
> +		 * HAL pixel format. To avoid issues, we thus have to set the
> +		 * GRALLOC_USAGE_HW_CAMERA_WRITE flag unconditionally, even for
> +		 * streams that will be produced in software.
> +		 */
> +		stream->usage |= GRALLOC_USAGE_HW_CAMERA_WRITE;
> +
> +		/*
> +		 * If a CameraStream with the same size and format of the

s/of the/as the/

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

> +		 * current stream has already been requested, associate the two.
> +		 */
> +		auto iter = std::find_if(
> +			streamConfigs.begin(), streamConfigs.end(),
> +			[&size, &format](const Camera3StreamConfig &streamConfig) {
> +				return streamConfig.config.size == size &&
> +				       streamConfig.config.pixelFormat == format;
> +			});
> +		if (iter != streamConfigs.end()) {
> +			/* Add usage to copy the buffer in streams[0] to stream. */
> +			iter->streams[0].stream->usage |= GRALLOC_USAGE_SW_READ_OFTEN;
> +			stream->usage |= GRALLOC_USAGE_SW_WRITE_OFTEN;
> +			iter->streams.push_back({ stream, CameraStream::Type::Mapped });
> +			continue;
> +		}
> +
>  		Camera3StreamConfig streamConfig;
>  		streamConfig.streams = { { stream, CameraStream::Type::Direct } };
>  		streamConfig.config.size = size;
>  		streamConfig.config.pixelFormat = format;
>  		streamConfigs.push_back(std::move(streamConfig));
> -
> -		/* This stream will be produced by hardware. */
> -		stream->usage |= GRALLOC_USAGE_HW_CAMERA_WRITE;
>  	}
>  
>  	/* Now handle the MJPEG streams, adding a new stream if required. */

-- 
Regards,

Laurent Pinchart