Instead of having a local cached value for line duration, store it in
the IPASessionConfiguration::sensor structure.
While at it, configure the default analogue gain and shutter speed to
controlled fixed values.
The latter is set to be 10ms as it will in most cases be close to the
one needed, making the AGC faster to converge.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
When the current exposure value is calculated, it is cached and used by
filterExposure(). Use private filteredExposure_ and pass currentExposure
as a parameter.
In order to limit the use of filteredExposure_, return the value from
filterExposure().
While at it, remove a stale comment.
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>
Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Remove the verbose #ifndef/#define/#endif pattern for maintaining
header idempotency, and replace it with a simple #pragma once.
This simplifies the headers, and prevents redundant changes when
header files get moved.
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
The inter-quantile mean is a value that is computed as part of the AGC
run. It doesn't need to be stored in a member variable. Return it from
measureBrightness(), which makes the flow of data easier to follow.
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>
The "current" prefix in the currentYGain variable name is confusing:
- In Agc::estimateLuminance(), the variable contains the gain to be
applied to the image, which is neither a "current" gain nor a "Y"
gain. Rename it to "gain".
- In Agc::computeExposure(), the variable contains the gain computed by
the relative luminance method, so rename it to "yGain".
While at it, rename variables to match the libcamera coding style.
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>
The AGC computes the average relative luminance of the frame and calls
the value "normalized luma", "brightness" or "initialY". The latter is
the most accurate term, as the relative luminance is abbreviated Y, but
the "initial" prefix isn't accurate.
Standardize the vocabulary on "relative luminance" in code and comments,
abbreviating it to Y when needed.
While at it, rename variables to match the libcamera coding style.
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>
The minimum and maximum exposure are stored in lines. Replace it by
values in time to simplify the calculations.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Previously, the exposure value was calculated based on the estimated
shutter time and gain applied. Now that we have the real values for the
current frame, use those before estimating the next one and rename the
variable accordingly.
As the exposure value is updated in the beginning of the computation,
there is no need to initialize effectiveExposureValue anymore in the
configure call, and it can be a local variable and not a class variable
anymore.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
When an image is partially saturated, its brightness is not increasing
linearly when the shutter time or gain increases. It is a big issue with
a backlight as the algorithm is fading to darkness right now.
Introduce a function to estimate the brightness of the frame, based on
the current exposure/gain and loop on it several times to estimate it
again and approach the non linear function.
Inspired-by: 7de5506c30 ("libcamera: src: ipa: raspberrypi: agc: Improve gain update calculation for partly saturated images")
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Now that we have the real exposure applied at each frame, remove the
early return based on a frame counter and compute the gain for each
frame.
Introduce a number of startup frames during which the filter speed is
1.0, meaning we apply instantly the exposure value calculated and not a
slower filtered one. This is used to have a faster convergence, and
those frames may be dropped in a future development to hide the
convergance process from the viewer.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
The pipeline handler populates the new sensorControls ControlList, to
have the effective exposure and gain values for the current frame. This
is done when a statistics buffer is received.
Make those values the frameContext::sensor values for the frame when the
EventStatReady event is received.
AGC also needs to use frameContext.sensor as its input values and
frameContext.agc as its output values. Modify computeExposure by passing
it the frameContext instead of individual exposure and gain values.
Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@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>
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 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>
"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>
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>
