Exact loop for second

[OliverA]

Hi community

Sorry if the title isn't explicative, i'd like to make 24 screenshot for second using the screencapture udf( like a video, but with images ) but i have some doubt like:

Is possible to make an exact loop like this?

It will kill my CPU and destroy the world?

Many thanks for the help

[Melba23]

OliverA,

I doubt it will end the world - or even fry your CPU if you only run for 1 second. But I think you might run into problems with the disk writing cache. Give it a go and see.

M23

[OliverA]

Thanks

I don't wont to run it for 1 second, but i want to save 24 frames/screen for second, for underterminate minutes

About the disk writing cache, i think can be a problem and maybe the files can be saved at the end of the process, but i dunno

Edited April 2, 2013 by OliverA

[czardas]

I've never used the UDF, but for accurate timing you might be able to use the AdLib function. I would have thought writing the shots to separate image files would be possible within the small time window available. However I'm not familiar with the UDF so I don't know exactly what it does or how fast it is. I also don't know if this is a practical method: the amount of data would get large very quickly.

Edited April 2, 2013 by czardas

[OliverA]

Mmm maybe the UDF is not fast like i have think:

#include <ScreenCapture.au3>

Global $iCount

$timer = TimerInit()
Do
$iCount += 1
_ScreenCapture_Capture(@ScriptDir & "\Test\" & $iCount & ".jpg")
Until TimerDiff($timer) >= 1000

It saves 13 images on my PC, but it saves everytime in real-temp a screenshot

Maybe using _ScreenCapture_SaveImage at the end of the process it will be more faster, but i don't know if change or not

Edited April 2, 2013 by OliverA

[czardas]

Try different formats. I'm not sure if the UDF is best for the purpose. You could possibly run two processes simultaneously to get more shots, but they would have to be carefully synchronised and that could be tricky. I bet there are free tools available that do this kind of thing.

Edited April 2, 2013 by czardas

[OliverA]

My "goal" was a sort of screen recoding with autoit, and my best idea was to convert screenshot to a video file.

I know how to convert jpeg's to video in autoit, but the result isn't "smooth" because the number of the screen is too low.

Maybe was a bad idea

[czardas]

If it's faster to save bitmaps then you can convert them to jpg and then to video. I imagine there's some conversion taking place with the UDF functions, and the time taken by that process will most likely vary with different formats. This is the reason I suggested you try some different approaches. You might also find something in example scripts that does something similar.

Edited April 2, 2013 by czardas

[OliverA]

The fastes is jpeg, bitmap and png saves only 10 files, i think it depends on the output file size?

Other approach is using the clipboard and PRINT key but was slower then the UDF. I don't have find another example

[czardas]

Okay, here's an idea: Have a master script run a second script to capture each screenshot and then exit. You may need to introduce accurate timed delays before each shot. Then it should be possible with enough RAM available. It's just a thought, but be careful you don't kill your CPU and destroy the world. Run small tests on just a few shots. Monitor the cpu and memory as you go. This might be a possible workaround, but understand that this is not a normal proceedure - so run lots of small tests before the big one - 24 fps. This might not work.

Edited April 2, 2013 by czardas

[jdelaney]

Starting a script has a bit of a delay...you would almost need to use a TCPIP, to one of several running scripts to be more instant...or write to a file, and logically have another running process know when to take the shot...too bad something like this wouldn't work:

$iCounter = 0
$iFramePerSec = 24
$iPause = 1000/$iFramePerSec
While $iCounter < 250
$iStart = TimerInit()
Run(@AutoItExe & " /AutoIt3ExecuteLine #include <ScreenCapture.au3>" & @CRLF & "_ScreenCapture_Capture('C:\testpic" & $iCounter & ".bmp')")
$iPauseLess = TimerDiff($iStart)
Sleep($iPause-$iPauseLess)
$iCounter += 1
WEnd

$start = TimerInit()
Run(@AutoItExe & " /AutoIt3ExecuteLine msgbox(1,'NEW','test')")
WinWait('NEW')
MsgBox(1,1,TimerDiff($start)/1000)

running a single line takes .307 sec

$iCounter = 1
$iFramePerSec = 24
$iPause = 1000/$iFramePerSec
$time = TimerInit()
While $iCounter < 24
$iStart = TimerInit()
_ScreenCapture_Capture(@DesktopDir & "\image\" & $iCounter & '.bmp', 0,0,100,100)
$iPauseLess = TimerDiff($iStart)
$iStart2 = TimerInit()
Sleep(Int($iPause-$iPauseLess))
ConsoleWrite(TimerDiff($iStart2) & "     " & $iPause-$iPauseLess & @CRLF)
$iCounter += 1
WEnd
ConsoleWrite( TimerDiff($time)/1000 & @CRLF)

This one works, within a pretty good tolerance (small screenshots though)...the loop takes .95933 seconds...very small margin(some waits are too short)

Edited April 2, 2013 by jdelaney

[czardas]

What you've written looks good.

I would set the delay according to the computer's clock, wait until it goes a certain number of seconds on the clock, and then begin sequenced delays in several scripts. You could perhaps do it with four scripts, each taking 6 shots per second and each out of phase by a precise number of miliseconds.

Edited April 3, 2013 by czardas