[libcamera-devel] [RFC PATCH 3/6] android: camera_device: Add ANDROID_JPEG_MAX_SIZE

[Kieran Bingham]

On 22/07/2020 11:35, Jacopo Mondi wrote:
> Hi Kieran
> 
> On Tue, Jul 21, 2020 at 11:01:23PM +0100, Kieran Bingham wrote:
>> Provide a key for ANDROID_JPEG_MAX_SIZE. The value of 13MB is currently
>> arbitrary, but taken from the USB Camera HAL in CrOS platform2:
>>
>>   // android.jpeg
>>   update_static(ANDROID_JPEG_MAX_SIZE, int32_t{13 << 20});
>>   update_request(ANDROID_JPEG_QUALITY, uint8_t{90});
>>   update_request(ANDROID_JPEG_THUMBNAIL_QUALITY, uint8_t{90});
>>   update_request(ANDROID_JPEG_ORIENTATION, int32_t{0});
>>
>> Note: The metadata entries/size updates are probably wrong, and should
>> be automated.
> 
> What does make you think so ?

Because I did it by hand, and when I wrote this I was getting arbitrary
crashes of the whole GUI which I had not been able to pin down.


> 
>>
>> Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
>> ---
>>  src/android/camera_device.cpp | 10 +++++++---
>>  1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
>> index 3f3d7857f0ab..56652ac57676 100644
>> --- a/src/android/camera_device.cpp
>> +++ b/src/android/camera_device.cpp
>> @@ -407,10 +407,10 @@ std::tuple<uint32_t, uint32_t> CameraDevice::calculateStaticMetadataSize()
>>  {
>>  	/*
>>  	 * \todo Keep this in sync with the actual number of entries.
>> -	 * Currently: 50 entries, 647 bytes of static metadata
>> +	 * Currently: 51 entries, 651 bytes of static metadata
>>  	 */
>> -	uint32_t numEntries = 50;
>> -	uint32_t byteSize = 647;
>> +	uint32_t numEntries = 51;
>> +	uint32_t byteSize = 651;
>>
>>  	/*
>>  	 * Calculate space occupation in bytes for dynamically built metadata
>> @@ -567,6 +567,9 @@ const camera_metadata_t *CameraDevice::getStaticMetadata()
>>  				  availableThumbnailSizes.data(),
>>  				  availableThumbnailSizes.size());
>>
>> +	int32_t jpegMaxSize = 13 << 20; /* 13631488 from USB HAL */
>> +	staticMetadata_->addEntry(ANDROID_JPEG_MAX_SIZE, &jpegMaxSize, 1);
>> +
> 
> Makes sense as long as we don't have a more precise value.
> Where should this come from ? By combining the frame size with libjpeg
> features ?


We can ask libjpeg what size it would require, *if* we have the relevant
configuration parameters for libjpeg. So we could construct a
CompressorJPEG and give it a 'maximum' expected configuration, and then
add a function to return the expected/required maximum buffer size from
that.

But it's a bit chicken/egg, as this happens before we configure streams
- so we'd have to have created a temporary compressor object (or just
provide a static function on a compressor that says "given this
configuration, what is the maximum size" ... then the compression object
can do what it likes to return the value.

Ok that makes more sense so that woudl be somethign like:

max_size = myCompressor->maxBufferSize(StreamConfiguration &cfg);

That doesn't seem too outlandish ;-)


>>  	/* Sensor static metadata. */
>>  	int32_t pixelArraySize[] = {
>>  		2592, 1944,
>> @@ -773,6 +776,7 @@ const camera_metadata_t *CameraDevice::getStaticMetadata()
>>  		ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
>>  		ANDROID_CONTROL_AVAILABLE_MODES,
>>  		ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
>> +		ANDROID_JPEG_MAX_SIZE,
>>  		ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
>>  		ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
>>  		ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
>> --
>> 2.25.1
>>
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>> libcamera-devel at lists.libcamera.org
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-- 
Regards
--
Kieran