[libcamera-devel] [PATCH v2] android: camera_device: Generate JPEG thumbnail sizes

[Jacopo Mondi]

Hi me,

On Thu, Feb 04, 2021 at 04:08:20PM +0100, Jacopo Mondi wrote:
> The list of the available thumbnail sizes is generated from the
> list of available JPEG resolution, one for each aspect ratio.
>
> This change fixes the CTS test
> android.hardware.cts.CameraTest#testJpegThumbnailSize
>
> Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> ---
>  src/android/camera_device.cpp | 39 ++++++++++++++++++++++++++++++-----
>  1 file changed, 34 insertions(+), 5 deletions(-)
>
> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> index df5e295656d7..cdb28f1f2d28 100644
> --- a/src/android/camera_device.cpp
> +++ b/src/android/camera_device.cpp
> @@ -871,12 +871,41 @@ const camera_metadata_t *CameraDevice::getStaticMetadata()
>  				  &availableControlModes, 1);
>
>  	/* JPEG static metadata. */
> -	std::vector<int32_t> availableThumbnailSizes = {
> -		0, 0,
> -	};
> +
> +	/*
> +	 * Create the list of supported thumbnail sizes by inspecting the
> +	 * available JPEG resolutions collected in streamConfigurations_ and
> +	 * generate one entry for each aspect ratio.
> +	 *
> +	 * The JPEG thumbnailer can freely scale, so pick an arbitrary
> +	 * (160, 160) size as designated thumbnail size.
> +	 */
> +	constexpr Size maxJpegThumbnail(160, 160);
> +	std::vector<Size> thumbnailSizes;
> +	thumbnailSizes.push_back({ 0, 0 });
> +	for (const auto &entry : streamConfigurations_) {
> +		if (entry.androidFormat != HAL_PIXEL_FORMAT_BLOB)
> +			continue;
> +
> +		Size thumbnailSize = maxJpegThumbnail
> +				     .boundedToAspectRatio({ entry.resolution.width,
> +							     entry.resolution.height });
> +		thumbnailSizes.push_back(thumbnailSize);
> +	}
> +
> +	std::sort(thumbnailSizes.begin(), thumbnailSizes.end());
> +	auto last = std::unique(thumbnailSizes.begin(), thumbnailSizes.end());
> +	thumbnailSizes.erase(last, thumbnailSizes.end());
> +
> +	/* Transform sizes in to a list of integers that can be consumed. */
> +	std::vector<int32_t> thumbnailEntries;
> +	thumbnailEntries.reserve(thumbnailSizes.size() * 2);
> +	for (const auto &size : thumbnailSizes) {
> +		thumbnailEntries.push_back(size.width);
> +		thumbnailEntries.push_back(size.height);
> +	}
>  	staticMetadata_->addEntry(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> -				  availableThumbnailSizes.data(),
> -				  availableThumbnailSizes.size());
> +				  thumbnailEntries.data(), thumbnailEntries.size());

I just realized space for the additional entries have to reserved in
the staticMetadata_ pack, as we have more sizes than the single {} we
had before.

I'll go for the better-safe-then-sorry approach and reserve 8
additional bytes for each JPEG size to accommodate the worst case
scenario where they all have a different aspect ratio.

>
>  	/*
>  	 * \todo Calculate the maximum JPEG buffer size by asking the encoder
> --
> 2.30.0
>
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