[libcamera-devel] [PATCH v3 2/2] android: Fix generation of thumbnail for EXIF data

[Umang Jain]

Generation of thumbnail is not occuring currently because
ANDROID_JPEG_THUMBNAIL_SIZE is not set for request metadata passed
to PostProcessorJpeg::process(). The commit 1264628d3c92("android:
jpeg: Configure thumbnailer based on request metadata") introduced
the mechanism to retrieve the thumbanil size from request metadata,
however it didn't add the counterpart i.e. inserting the size in
the request metadata in request metadata template, at the first place.

The patch fixes this issue by setting ANDROID_JPEG_THUMBNAIL_SIZE in
the request metadata template populated by
CameraCapabilities::requestTemplatePreview(). The value for
ANDROID_JPEG_THUMBNAIL_SIZE is set to be the first non-zero size
reported by static metadata ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES.

Fixes: 1264628d3c92("android: jpeg: Configure thumbnailer based on request metadata")
Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh at chromium.org>
---
 src/android/camera_capabilities.cpp | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/android/camera_capabilities.cpp b/src/android/camera_capabilities.cpp
index 238b44db..ba6adf73 100644
--- a/src/android/camera_capabilities.cpp
+++ b/src/android/camera_capabilities.cpp
@@ -1347,7 +1347,7 @@ std::unique_ptr<CameraMetadata> CameraCapabilities::requestTemplatePreview() con
 	 * CameraMetadata is capable to resize the container on the fly, if the
 	 * number of entries get exceeded.
 	 */
-	auto requestTemplate = std::make_unique<CameraMetadata>(21, 36);
+	auto requestTemplate = std::make_unique<CameraMetadata>(22, 38);
 	if (!requestTemplate->isValid()) {
 		return nullptr;
 	}
@@ -1368,6 +1368,28 @@ std::unique_ptr<CameraMetadata> CameraCapabilities::requestTemplatePreview() con
 	requestTemplate->addEntry(ANDROID_CONTROL_AE_TARGET_FPS_RANGE,
 				  entry.data.i32, 2);
 
+	/*
+	 * Get thumbnail sizes from static metadata and add the first non-zero
+	 * size to the template.
+	 */
+	found = staticMetadata_->getEntry(ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
+					  &entry);
+	ASSERT(found && entry.count >= 4);
+	unsigned int j = 0;
+	while (j < entry.count / 2) {
+		if (entry.data.i32[j] == 0 || entry.data.i32[j + 1] == 0) {
+			j += 2;
+			continue;
+		}
+
+		requestTemplate->addEntry(ANDROID_JPEG_THUMBNAIL_SIZE,
+					  entry.data.i32 + j, 2);
+		break;
+	}
+
+	requestTemplate->addEntry(ANDROID_JPEG_THUMBNAIL_SIZE,
+				  entry.data.i32 + 2, 2);
+
 	uint8_t aeMode = ANDROID_CONTROL_AE_MODE_ON;
 	requestTemplate->addEntry(ANDROID_CONTROL_AE_MODE, aeMode);
 
-- 
2.31.0