cam_helper - gain depending on bit mode #286
Description
Hello,
I'm working on a v4l driver where I have the following modes:
8 bit, gain 1 up to 16x, in fine steps
10 bit, gain 1 up to 4x, in fine steps
12 bit, gain 1 and gain 2x, no intermediate steps.
I've created some cam_helper functions to convert actual gain to driver gain codes.
the cam_helper looks something like this:
Now the problem is - when changing modes - the gain codes seem to lag 1 mode behind.
uint32_t CamHelperMira016::gainCode(double gain) const
{
if (mode_.bitdepth == 12) {
return std::log2(gain);
} else if (mode_.bitdepth == 10) {
uint32_t sizeLut = sizeof(gainLut10bit) / sizeof(gainLut10bit[0]);
uint32_t gainCode = 0;
if (gain <= gainLut10bit[0]) {
gainCode = 0;
} else if (gain >= gainLut10bit[sizeLut - 1]) {
gainCode = (sizeLut - 1);
} else {
while (gainCode < sizeLut - 1) {
if (gain >= gainLut10bit[gainCode] && gain < gainLut10bit[gainCode+1]) {
break;
}
gainCode++;
}
}
LOG(IPARPI, Debug) << "gain: " << gain << " gainCode: " << gainCode;
return gainCode;
} else if (mode_.bitdepth == 8) {
uint32_t sizeLut = sizeof(gainLut8bit) / sizeof(gainLut8bit[0]);
uint32_t gainCode = 0;
if (gain <= gainLut8bit[0]) {
gainCode = 0;
} else if (gain >= gainLut8bit[sizeLut - 1]) {
gainCode = (sizeLut - 1);
} else {
while (gainCode < sizeLut - 1) {
if (gain >= gainLut8bit[gainCode] && gain < gainLut8bit[gainCode+1]) {
break;
}
gainCode++;
}
}
LOG(IPARPI, Debug) << "gain: " << gain << " gainCode: " << gainCode;
return gainCode;
} else {
return (uint32_t)(gain);
}
}
double CamHelperMira016::gain(uint32_t gainCode) const
{
if (mode_.bitdepth == 12) {
return std::exp2(gainCode);
} else if (mode_.bitdepth == 10){
uint32_t sizeLut = sizeof(gainLut10bit) / sizeof(gainLut10bit[0]);
if (gainCode >= sizeLut) {
gainCode = sizeLut - 1;
}
return (double)(gainLut10bit[gainCode]);
} else if (mode_.bitdepth == 8){
uint32_t sizeLut = sizeof(gainLut8bit) / sizeof(gainLut8bit[0]);
if (gainCode >= sizeLut) {
gainCode = sizeLut - 1;
}
return (double)(gainLut8bit[gainCode]);
} else {
return (double)(gainCode);
}
}