In case the maximum exposure received from the sensor is very high, we
can have a very high shutter speed with a small analogue gain, and it
may result in very slow framerate. We are not really supporting it for
the moment, so clamp the shutter speed to an arbitrary value of 60ms.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Tested-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
The AGC class was not documented while developing. Extend that to
reference the origins of the implementation, and improve the
descriptions on how the algorithm operates internally.
While at it, rename the functions which have bad names.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Instead of using constants for the analogue gains limits, use the
minimum and maximum from the configured sensor.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
We currently control the exposure value by the shutter speed and the
analogue gain. We can't use the digital gain to have more than the
maximum exposure value calculated because we are not controlling it.
Remove unused code associated with this digital gain.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Simplify the reading by removing one level of indentation to return
early when the change is small between two calls.
Reword the LOG() message when we are correctly exposed, and move the
lastFrame_ variable to update it even if the change is small.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
We need to calculate the gain on the previous exposure value calculated.
Now that we initialise the exposure and gain values in configure(), we
know the initial exposure value, and we can set it before any loop is
running.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
We have mixed terms between gain, analogue gain and the exposure value
gain.
Make it clear when we are using the analogue gain from the sensor, and
when we are using the calculated gain to be applied to the exposure
value to reach the target.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Until now, the algorithm makes complex assumptions when dividing the
exposure and analogue gain values. Instead, use a simpler clamping of
the shutter speed first, and then of the analogue gain, based on the
limits configured.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
We are filtering the exposure value to limit the gain to apply, but we
are not using the result.
Fix it.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The gains are currently set as a uint32_t while the analogue gain is
passed as a double. We also have a default maximum analogue gain of 15
which is quite high for a number of sensors.
Use a maximum value of 8 which should really be configured by the IPA
and not fixed as it is now. While at it make it a double.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
We are using arbitrary constants for the exposure limit in a number of
lines.
Instead of using static constants for those, use the limits of the
sensor passed in IPASessionConfiguration and cache those.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The exposure value is filtered in filterExposure() using the
currentExposure_ and setting a prevExposure_ variable. This is misnamed
as it is not the previous exposure, but a filtered value.
Rename it accordingly.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The AGC frame context needs to be initialised correctly for the first
iteration. Until now, the IPA uses the minimum exposure and gain values
and caches those in local variables.
In order to give the sensor limits to AGC, create a new structure in
IPASessionConfiguration. Store the exposure in time (and not line
duration) and the analogue gain after CameraSensorHelper conversion.
Set the gain and exposure appropriately to the current values known to
the IPA and remove the setting of exposure and gain in IPAIPU3 as those
are now fully controlled by IPU3Agc.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
"using" directives are harmful in headers, as they propagate the
namespace short-circuit to all files that include the header, directly
or indirectly. Drop the directive from agc.h, and use utils::Duration
explicitly. While at it, shorten the namespace qualifier from
libcamera::utils:: to utils:: in agc.cpp for Duration.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
The intel-ipu3.h public interface from the kernel does not define how to
parse the statistics for a cell. This had to be identified by a process
of reverse engineering, and later identifying the structures from [0]
leading to our custom definition of struct Ipu3AwbCell.
[0]
https://chromium.googlesource.com/chromiumos/platform/arc-camera/+/refs/heads/master/hal/intel/include/ia_imaging/awb_public.h
To improve the kernel interface, a proposal has been made to the
linux-kernel [1] to incorporate the memory layout for each cell into the
intel-ipu3 header directly.
[1]
https://lore.kernel.org/linux-media/20211005202019.253353-1-jeanmichel.hautbois@ideasonboard.com/
Update our local copy of the intel-ipu3.h to match the proposal and
change the AGC and AWB algorithms to reference that structure directly,
allowing us to remove the deprecated custom Ipu3AwbCell definition.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Now that we know how the AWB statistics are formatted, use a simplified
loop in processBrightness() to parse the green values and get the
histogram.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The IPASessionConfiguration now has the grid configuration stored. Use
it at process() call in AGC and pass it as a reference to the private
functions when needed.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Now that the interface is properly used by the AGC class, move it into
ipa::ipu3::algorithms and let the loops do the calls.
As we need to exchange the exposure_ and gain_ by passing them through the
FrameContext, use the calculated values in setControls() function to
ease the reading.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
