[Elphel-support] linescan mode

[Michael Aschauer]

dear andrey,

it works. however I do not fully understand how to calculate 
frame/scan-line duration and framerate now.

Which measurements/formats are VIRT_WIDTH and VIRT_HEIGHT in ? Pixels? 
(tooltip tells frame duration in scanlines = VIRT_WIDTH * VIRT_HEIGHT. 
so do I need to multiply by pixel clock to get the real readout time?)

best,
m,-



>
> The simplest way to slow down the linescan mode is to use two parameters
> (they appear in parsedit.php links in the camera if you use current
> code), here is the link to the source:
> http://elphel.cvs.sourceforge.net/viewvc/elphel/elphel353-8.0/packages/web/353/php_top/parsedit.php?view=markup
>
> There are two paramteres (with "tooltip" when you hold mouse pointer over)
>
> VIRT_HEIGHT - number of scan lines per each"frame"  (two lines in your case).
> The scan line duration is constant, by default software sets it to a minimal
> value allowed by the sensor, but you may increase it.
>
>
> VIRT_KEEP  - set to 1 to instruct software to keep VIRT_HEIGHT value. When 0 the VIRT_HEIGHT
> is calculated automatically.
> And of course the period of 2 line-stripes (including the invisible to the total of VIRT_HEIGHT)ca
> not be less than exposure time. So if exposure increases, the frame rate goes down.

>