tree 954a5ac70ef4a30c504a9155147a846b8a342ca1
parent b57dc852ee4364b80450da86868c7cd7db3b8c29
author kongchenrui <kongchenrui@xiaomi.com> 1629169130 +0800
committer chenrui kong <kongchenrui@xiaomi.com> 1629189039 +0000

Fix the problem of excessive sensitivity error

The error mainly comes from the following two aspects:
1. Insufficient precision of the hardware (sensor)
   As the gain increases, the sensor error will also increase. When the
   gain is greater than 31.99..., SENSITIVITY_ERROR_MARGIN_RATE will
   exceed the specified 3%.
2. MaxSensorDigitalGain  =  1
   Since Digital gain will introduce more noise and seriously affect
   the image quality, MaxSensorDigitalGain will be set to 1 during
   actual use, which will cause a part of real gain to be allocated to
   isp Gain, thereby increasing the error.

Solution: According to calculations, when the range of realGain is
[1,64],the range of SENSITIVITY_ERROR_MARGIN_RATE should theoretically
be [0,0.06].

Bug: 196524715

Change-Id: I1724073b81b3f1620eac525e5929224473caf042
Signed-off-by: kongchenrui <kongchenrui@xiaomi.com>