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Hi All:
I referred the AN75779 document to achieve the UVC device, and it works!
However, I met a trouble to define the Camera Terminal - Exposure Time (Absolute) Control.
I don’t know how to define that... It’s more difficult than the Processing Unit, such as Brightness Control.
I also refer the “USB Device Class Definition for Video Devices v1.5.pdf” for the control function, but it don’t describe the rule detailed.
Now I just know the Exposure Time (Absolute) Control is defined by “2 to the power of n”, and the resolution(one step) is to change the “n”.
[Goat]
Total Step: 10(-10 ~ -1)
Max value: 1024
Min value: 1
Default value: 256
[My Setting]
[My Result]
It’s strange... (Checked the actual setting value by UART)
The slider range: -13 ~ -3
Max value: 1024
Min value: 1
Each step value
Hope somebody could provide me some suggestions, or provide an example by my [Goat].
Thank you so much!
Hughes
Solved! Go to Solution.
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hello,
Windows using log2() second to get/set exposure time.
Your max/min value (4/2) means 0.4ms and 0.2ms,
and
log2(0.0004) = -11.28771,
log2(0.0002) = -12.28771.
so the result is -11 and -12.
KSPROPERTY\_CAMERACONTROL\_EXPOSURE - Windows drivers | Microsoft Docs
Hope this helps.
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Hello Hughes,
It is defined as follows in one of the reference firmware.
VideoControl_uint8_t aeModeCam = {0x2,0x2,0x4,0x2,0x2,0x2};
typedef struct VideoControl_uint8
{
uint8_t CurrentVal; /*Current Value of the feature*/
uint8_t MinVal; /*Minimum Value supported by the feature*/
uint8_t MaxVal; /*Maximum Value supported by the feature*/
uint8_t Res; /*Resolution supported by the feature*/
uint8_t DefaultVal; /*Default Value of the feature*/
uint8_t SetVal; /*Set Value sent by the host application*/
} VideoControl_uint8_t;
I will check with the respective sensor and get back to you.
Regards,
Sridhar
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Dear Sridhar:
Thanks for your reply!
I experimented the setting you provided, and the slider range is -12 & -11 on the UVC AP:
Could you explain why the Maximum:0x4 & Minimum:0x2 will caused the slider which shows -11 & -12 respectively?
The following figure is the introduction from “USB Device Class Definition for Video Devices v1.5.pdf”, but I cannot understand still...
Thank you!
Hughes
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hello,
Windows using log2() second to get/set exposure time.
Your max/min value (4/2) means 0.4ms and 0.2ms,
and
log2(0.0004) = -11.28771,
log2(0.0002) = -12.28771.
so the result is -11 and -12.
KSPROPERTY\_CAMERACONTROL\_EXPOSURE - Windows drivers | Microsoft Docs
Hope this helps.