@@ -154,6 +154,36 @@ double CameraSensorHelper::quantizeGain(double _gain, double *quantizationGain)
return g;
}
+/**
+ * \brief Compute the maximum shutter time given the maximum frame duration
+ * \param[in] maxFrameDuration The maximum frame duration
+ * \param[in] lineDuration The current sensor line duration
+ *
+ * This function returns the maximum achievable shutter time by subtracting to
+ * \a maxFrameDuration the difference between the frame length and the maximum
+ * achievable integration time.
+ *
+ * \todo The line duration should be a property of the CameraSensorHelper class
+ * instead of being provided by the IPA.
+ *
+ * \return The maximum achievable shutter time for the current sensor
+ * configuration
+ */
+utils::Duration CameraSensorHelper::maxShutterTime(utils::Duration maxFrameDuration,
+ utils::Duration lineDuration) const
+{
+ /* Use a static to rate-limit the error message. */
+ static uint32_t exposureMargin = exposureMargin_.has_value()
+ ? exposureMargin_.value() : 0;
+ if (!exposureMargin_.has_value() && !exposureMargin) {
+ LOG(CameraSensorHelper, Warning)
+ << "Exposure margin not known. Default to 4";
+ exposureMargin = 4;
+ }
+
+ return maxFrameDuration - exposureMargin * lineDuration;
+}
+
/**
* \struct CameraSensorHelper::AnalogueGainLinear
* \brief Analogue gain constants for the linear gain model
@@ -229,6 +259,13 @@ double CameraSensorHelper::quantizeGain(double _gain, double *quantizationGain)
* sensor specific. Use this variable to store the values at init time.
*/
+/**
+ * \var CameraSensorHelper::exposureMargin_
+ * \brief The smallest margin between the integration time and the frame lenght
+ * in lines
+ * \sa CameraSensorHelper::maxShutterTime()
+ */
+
/**
* \class CameraSensorHelperFactoryBase
* \brief Base class for camera sensor helper factories
@@ -385,6 +422,7 @@ public:
{
/* Power-on default value: 168 at 12bits. */
blackLevel_ = 2688;
+ exposureMargin_ = 4;
}
uint32_t gainCode(double gain) const override
@@ -474,6 +512,11 @@ REGISTER_CAMERA_SENSOR_HELPER("ar0144", CameraSensorHelperAr0144)
class CameraSensorHelperAr0521 : public CameraSensorHelper
{
public:
+ CameraSensorHelperAr0521()
+ {
+ exposureMargin_ = 4;
+ }
+
uint32_t gainCode(double gain) const override
{
gain = std::clamp(gain, 1.0, 15.5);
@@ -504,6 +547,7 @@ public:
/* From datasheet: 64 at 10bits. */
blackLevel_ = 4096;
gain_ = AnalogueGainLinear{ 100, 0, 0, 1024 };
+ exposureMargin_ = 4;
}
};
REGISTER_CAMERA_SENSOR_HELPER("gc05a2", CameraSensorHelperGc05a2)
@@ -516,6 +560,7 @@ public:
/* From datasheet: 64 at 10bits. */
blackLevel_ = 4096;
gain_ = AnalogueGainLinear{ 100, 0, 0, 1024 };
+ exposureMargin_ = 16;
}
};
REGISTER_CAMERA_SENSOR_HELPER("gc08a3", CameraSensorHelperGc08a3)
@@ -526,6 +571,7 @@ public:
CameraSensorHelperHm1246()
{
gain_ = AnalogueGainLinear{ 1, 16, 0, 16 };
+ exposureMargin_ = 2;
}
};
REGISTER_CAMERA_SENSOR_HELPER("hm1246", CameraSensorHelperHm1246)
@@ -538,6 +584,7 @@ public:
/* From datasheet: 64 at 10bits. */
blackLevel_ = 4096;
gain_ = AnalogueGainLinear{ 0, 512, -1, 512 };
+ exposureMargin_ = 10;
}
};
REGISTER_CAMERA_SENSOR_HELPER("imx214", CameraSensorHelperImx214)
@@ -550,6 +597,7 @@ public:
/* From datasheet: 64 at 10bits. */
blackLevel_ = 4096;
gain_ = AnalogueGainLinear{ 0, 256, -1, 256 };
+ exposureMargin_ = 4;
}
};
REGISTER_CAMERA_SENSOR_HELPER("imx219", CameraSensorHelperImx219)
@@ -562,6 +610,7 @@ public:
/* From datasheet: 0x40 at 10bits. */
blackLevel_ = 4096;
gain_ = AnalogueGainLinear{ 0, 512, -1, 512 };
+ exposureMargin_ = 10;
}
};
REGISTER_CAMERA_SENSOR_HELPER("imx258", CameraSensorHelperImx258)
@@ -574,6 +623,7 @@ public:
/* From datasheet: 0x32 at 10bits. */
blackLevel_ = 3200;
gain_ = AnalogueGainLinear{ 0, 2048, -1, 2048 };
+ exposureMargin_ = 4;
}
};
REGISTER_CAMERA_SENSOR_HELPER("imx283", CameraSensorHelperImx283)
@@ -586,6 +636,7 @@ public:
/* From datasheet: 0xf0 at 12bits. */
blackLevel_ = 3840;
gain_ = AnalogueGainExp{ 1.0, expGainDb(0.3) };
+ exposureMargin_ = 2;
}
};
REGISTER_CAMERA_SENSOR_HELPER("imx290", CameraSensorHelperImx290)
@@ -596,6 +647,11 @@ public:
CameraSensorHelperImx296()
{
gain_ = AnalogueGainExp{ 1.0, expGainDb(0.1) };
+ /*
+ * The driver doesn't apply any margin. Use the value
+ * in RPi's CamHelper.
+ */
+ exposureMargin_ = 4;
}
};
REGISTER_CAMERA_SENSOR_HELPER("imx296", CameraSensorHelperImx296)
@@ -613,6 +669,7 @@ public:
/* From datasheet: 0x32 at 10bits. */
blackLevel_ = 3200;
gain_ = AnalogueGainExp{ 1.0, expGainDb(0.3) };
+ exposureMargin_ = 9;
}
};
REGISTER_CAMERA_SENSOR_HELPER("imx335", CameraSensorHelperImx335)
@@ -623,6 +680,7 @@ public:
CameraSensorHelperImx415()
{
gain_ = AnalogueGainExp{ 1.0, expGainDb(0.3) };
+ exposureMargin_ = 8;
}
};
REGISTER_CAMERA_SENSOR_HELPER("imx415", CameraSensorHelperImx415)
@@ -638,6 +696,7 @@ public:
CameraSensorHelperImx477()
{
gain_ = AnalogueGainLinear{ 0, 1024, -1, 1024 };
+ exposureMargin_ = 22;
}
};
REGISTER_CAMERA_SENSOR_HELPER("imx477", CameraSensorHelperImx477)
@@ -663,6 +722,7 @@ public:
* This has been validated with some empirical testing only.
*/
gain_ = AnalogueGainLinear{ 1, 0, 0, 128 };
+ exposureMargin_ = 4;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov2685", CameraSensorHelperOv2685)
@@ -673,6 +733,7 @@ public:
CameraSensorHelperOv2740()
{
gain_ = AnalogueGainLinear{ 1, 0, 0, 128 };
+ exposureMargin_ = 8;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov2740", CameraSensorHelperOv2740)
@@ -685,6 +746,7 @@ public:
/* From datasheet: 0x40 at 12bits. */
blackLevel_ = 1024;
gain_ = AnalogueGainLinear{ 1, 0, 0, 128 };
+ exposureMargin_ = 4;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov4689", CameraSensorHelperOv4689)
@@ -697,6 +759,14 @@ public:
/* From datasheet: 0x10 at 10bits. */
blackLevel_ = 1024;
gain_ = AnalogueGainLinear{ 1, 0, 0, 16 };
+ /*
+ * Very convoluted in the driver that however applies a margin
+ * of 4 lines when setting vts.
+ *
+ * cap_vts = cap_shutter + 4;
+ * ret = ov5640_set_vts(sensor, cap_vts);
+ */
+ exposureMargin_ = 4;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov5640", CameraSensorHelperOv5640)
@@ -707,6 +777,7 @@ public:
CameraSensorHelperOv5647()
{
gain_ = AnalogueGainLinear{ 1, 0, 0, 16 };
+ exposureMargin_ = 4;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov5647", CameraSensorHelperOv5647)
@@ -717,6 +788,7 @@ public:
CameraSensorHelperOv5670()
{
gain_ = AnalogueGainLinear{ 1, 0, 0, 128 };
+ exposureMargin_ = 8;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov5670", CameraSensorHelperOv5670)
@@ -729,6 +801,7 @@ public:
/* From Linux kernel driver: 0x40 at 10bits. */
blackLevel_ = 4096;
gain_ = AnalogueGainLinear{ 1, 0, 0, 128 };
+ exposureMargin_ = 4;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov5675", CameraSensorHelperOv5675)
@@ -739,6 +812,7 @@ public:
CameraSensorHelperOv5693()
{
gain_ = AnalogueGainLinear{ 1, 0, 0, 16 };
+ exposureMargin_ = 8;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov5693", CameraSensorHelperOv5693)
@@ -749,6 +823,7 @@ public:
CameraSensorHelperOv64a40()
{
gain_ = AnalogueGainLinear{ 1, 0, 0, 128 };
+ exposureMargin_ = 32;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov64a40", CameraSensorHelperOv64a40)
@@ -765,6 +840,7 @@ public:
* See: https://patchwork.linuxtv.org/project/linux-media/patch/20221106171129.166892-2-nicholas@rothemail.net/#142267
*/
gain_ = AnalogueGainLinear{ 1, 0, 0, 128 };
+ exposureMargin_ = 4;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov8858", CameraSensorHelperOv8858)
@@ -775,6 +851,7 @@ public:
CameraSensorHelperOv8865()
{
gain_ = AnalogueGainLinear{ 1, 0, 0, 128 };
+ exposureMargin_ = 8;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov8865", CameraSensorHelperOv8865)
@@ -785,6 +862,7 @@ public:
CameraSensorHelperOv13858()
{
gain_ = AnalogueGainLinear{ 1, 0, 0, 128 };
+ exposureMargin_ = 8;
}
};
REGISTER_CAMERA_SENSOR_HELPER("ov13858", CameraSensorHelperOv13858)
@@ -797,6 +875,7 @@ public:
/* From datasheet: 0x40 at 10bits. */
blackLevel_ = 4096;
gain_ = AnalogueGainLinear{ 0, 32, -1, 32 };
+ exposureMargin_ = 64;
}
};
REGISTER_CAMERA_SENSOR_HELPER("vd55g1", CameraSensorHelperVd55g1)
@@ -809,6 +888,7 @@ public:
/* From datasheet: 0x40 at 10bits. */
blackLevel_ = 4096;
gain_ = AnalogueGainLinear{ 0, 32, -1, 32 };
+ exposureMargin_ = 75;
}
};
REGISTER_CAMERA_SENSOR_HELPER("vd56g3", CameraSensorHelperVd56g3)
@@ -15,6 +15,7 @@
#include <vector>
#include <libcamera/base/class.h>
+#include <libcamera/base/utils.h>
namespace libcamera {
@@ -30,6 +31,8 @@ public:
virtual uint32_t gainCode(double gain) const;
virtual double gain(uint32_t gainCode) const;
double quantizeGain(double gain, double *quantizationGain) const;
+ utils::Duration maxShutterTime(utils::Duration maxFrameDuration,
+ utils::Duration lineDuration) const;
protected:
struct AnalogueGainLinear {
@@ -46,6 +49,7 @@ protected:
std::optional<int16_t> blackLevel_;
std::variant<std::monostate, AnalogueGainLinear, AnalogueGainExp> gain_;
+ std::optional<uint32_t> exposureMargin_;
private:
LIBCAMERA_DISABLE_COPY_AND_MOVE(CameraSensorHelper)
There is a margin between the maximum achievable shutter time and the frame length. The value is sensor-dependent and should be used to adjust the maximum achievable exposure time whenever the frame length changes. Introduce in the CameraSensorHelper the notion of exposureMargin_ as the minimum difference in number of lines between the current frame length and the maximum achievable shutter time and the maxShutterTime() function that returns the maximum achievable shutter time give the current maximum frame length. This feature is already implemented in the RPi CamHelper class hierarchy with the name of frameIntegrationDiff. Populate the CameraSensorHelper instances with an exposureMargin_. The value of the exposure margin comes from the mainline driver version of each sensor, and it has been compared with the frameIntegrationDiff_ value in the rpi camera helpers. Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com> --- src/ipa/libipa/camera_sensor_helper.cpp | 80 +++++++++++++++++++++++++++++++++ src/ipa/libipa/camera_sensor_helper.h | 4 ++ 2 files changed, 84 insertions(+)