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

[Umang Jain]

Hi Paul,

On 9/23/21 1:10 PM, paul.elder at ideasonboard.com wrote:
> Hi Umang,
>
> On Thu, Sep 23, 2021 at 12:54:53PM +0530, Umang Jain wrote:
>> 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) {
> Since you're incrementing j by 2, shouldn't the limit be entry.count?


My understanding is 2 entries make 1 size, no? 
ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES be like for e.g.

     {0, 0, w1, h1, w2, h2}

So entry.count is 6 but sizes are 3

To go to next Size, incremement by 2 so, j += 2

Does it make sense?


>
>> +		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);
> iirc adding an entry that already exists causes weird problems...


Ah crap, this should be outside the loop. I am re-assigning it here. 
Sorry, rebase fiasco it seems.

>
>
> Paul
>
>> +
>>   	uint8_t aeMode = ANDROID_CONTROL_AE_MODE_ON;
>>   	requestTemplate->addEntry(ANDROID_CONTROL_AE_MODE, aeMode);
>>   
>> -- 
>> 2.31.0
>>