[libcamera-devel] [PATCH] android: Check exposure time range for manual sensor capability

[paul.elder at ideasonboard.com]

Hi Jacopo,

On Wed, Aug 25, 2021 at 11:02:22AM +0200, Jacopo Mondi wrote:
> Hi Paul,
> 
> On Mon, Aug 23, 2021 at 07:32:58PM +0900, Paul Elder wrote:
> > In the manual sensor capability validator, add a check for the exposure
> > time range.
> >
> > Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
> > ---
> >  src/android/camera_capabilities.cpp | 22 ++++++++++++++++++++++
> >  1 file changed, 22 insertions(+)
> >
> > diff --git a/src/android/camera_capabilities.cpp b/src/android/camera_capabilities.cpp
> > index bd661675..5b560b4f 100644
> > --- a/src/android/camera_capabilities.cpp
> > +++ b/src/android/camera_capabilities.cpp
> > @@ -217,6 +217,8 @@ std::vector<U> setMetadata(CameraMetadata *metadata, uint32_t tag,
> >
> >  bool CameraCapabilities::validateManualSensorCapability()
> >  {
> > +	camera_metadata_ro_entry_t entry;
> > +
> >  	const char *noMode = "Manual sensor capability unavailable: ";
> >
> >  	if (!staticMetadata_->entryContains<uint8_t>(ANDROID_CONTROL_AE_AVAILABLE_MODES,
> > @@ -231,6 +233,26 @@ bool CameraCapabilities::validateManualSensorCapability()
> >  		return false;
> >  	}
> >
> > +	if (!staticMetadata_->hasEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE)) {
> > +		LOG(HAL, Info) << noMode << "missing exposure time range";
> > +		return false;
> > +	}
> > +
> > +	staticMetadata_->getEntry(ANDROID_SENSOR_INFO_EXPOSURE_TIME_RANGE, &entry);
> > +	if (100000 < entry.data.i32[0]) {
> > +		LOG(HAL, Info)
> > +			<< noMode
> > +			<< "exposure time range minimum must be no larger than 100us";
> > +		return false;
> > +	}
> > +
> > +	if (entry.data.i32[1] < 100000000) {
> > +		LOG(HAL, Info)
> > +			<< noMode
> > +			<< "exposure time range maximum must be no smaller than 100ms";
> > +		return false;
> > +	}
> > +
> 
> Why I don't see such requirement for MANUAL_SENSOR capability
> description, but rather in the FULL level description only ?
> 
> android.sensor.info.exposureTimeRange:
> For FULL capability devices (android.info.supportedHardwareLevel ==
> FULL),The maximum of the range SHOULD be at least 1 second (1e9), MUST
> be at least 100ms.

>From what I saw [1], the first is an overall requirement, while the
second is only a FULL requirement.

The minimum exposure time will be less than 100 us. For FULL capability
devices (android.info.supportedHardwareLevel == FULL), the maximum
exposure time will be greater than 100

So can I assume that the first is satisfied? Or should we check it when
it's set in the static metadata and reject it there?

Also I guess the checks should be "or equal to" :)

[1] https://developer.android.com/reference/android/hardware/camera2/CameraCharacteristics#SENSOR_INFO_EXPOSURE_TIME_RANGE


Thanks,

Paul

> 
> >  	/*
> >  	 * \todo Return true here after we satisfy all the requirements:
> >  	 * https://developer.android.com/reference/android/hardware/camera2/CameraMetadata#REQUEST_AVAILABLE_CAPABILITIES_MANUAL_SENSOR
> > --
> > 2.27.0
> >