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ipa: ipu3: agc: Change analogue gain limits

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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>
This commit is contained in:
Jean-Michel Hautbois 2021-10-12 16:44:54 +02:00
parent 355503233b
commit a58a784e53
1 changed files with 6 additions and 8 deletions
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14
src/ipa/ipu3/algorithms/agc.cpp
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@ -30,14 +30,10 @@ static constexpr uint32_t kInitialFrameMinAECount = 4;
/* Number of frames to wait between new gain/exposure estimations */
static constexpr uint32_t kFrameSkipCount = 6;
/* Maximum ISO value for analogue gain */
static constexpr uint32_t kMinISO = 100;
static constexpr uint32_t kMaxISO = 1500;
/* Maximum analogue gain value
* \todo grab it from a camera helper */
static constexpr uint32_t kMinGain = kMinISO / 100;
static constexpr uint32_t kMaxGain = kMaxISO / 100;
static constexpr double kMinGain = 1.0;
static constexpr double kMaxGain = 8.0;
/* Histogram constants */
static constexpr uint32_t knumHistogramBins = 256;
@ -166,9 +162,11 @@ void Agc::lockExposureGain(uint32_t &exposure, double &gain)
minExposureLines_,
maxExposureLines_);
newExposure = currentExposure_ / exposure;
gain = std::clamp(static_cast<uint32_t>(gain * currentExposure_ / newExposure), kMinGain, kMaxGain);
gain = std::clamp(gain * currentExposure_ / newExposure,
kMinGain, kMaxGain);
} else {
gain = std::clamp(static_cast<uint32_t>(gain * currentExposure_ / currentExposureNoDg_), kMinGain, kMaxGain);
gain = std::clamp(gain * currentExposure_ / currentExposureNoDg_,
kMinGain, kMaxGain);
newExposure = currentExposure_ / gain;
exposure = std::clamp<uint32_t>(exposure * currentExposure_ / newExposure,
minExposureLines_,