PureBasic Forums - English

Posted: **Mon Jul 17, 2006 1:20 pm**

With the help of some nice people on here, i have managed to make a small app to display my webcam. Is it as simple to pass the captured image through a video compressor then through a video decompressor? I want to stream this over the internet like MSN Messenger does. Im not expecting it to be straight forward but is it pretty feasable?

Posted: **Mon Jul 17, 2006 5:00 pm**

@AndyMk,

I see no reason why not, MSN does it!! Oke it will not be simple to write but yes very possible.

You need some kind of server on your side and the client logs into your server (which has to run 24h a day). See the manual for the network instructions there is even an server.pb and client.pb in the example section.

Let your (web-) camera app put a bmp file into a directory. And let the server send it to the client who can put this onto his (or Here) screen. It works have done it before, we got very easy some 15 frames a second, but needed one shot every 1 sec to keep an eye onto a nest of Husky dogs.

Hope this helps. Ask if you need more assistance.

Jan V.

Posted: **Mon Jul 17, 2006 5:18 pm**

Sounds good but isnt 320x240@15fps bmp gonna be way too much for an average broadband outbound connection to handle? It works out to around 3MB/sec.. even @5fps its gonna be a wopping 1MB/sec! I read a post regarding "PBSOL" libraries and some way of doing it with that and not having to save the file first but do it straight from memory. Problem is, the site is in German. Is there no frame compression/decompression with avicap?

Posted: **Mon Jul 17, 2006 7:10 pm**

Is there any way you could post the german link to this reference to PBOSL reference? Im interested in doing something fairly similar.

Another option is to be instead of using BMP, use JPG compression or some other compression that will keep the image small and can be shown on the other end from memory.

Posted: **Mon Jul 17, 2006 7:35 pm**

http://www.purebasic.fr/english/viewtop ... ight=pbosl

I just found this link so i might still have a chance

Posted: **Mon Jul 17, 2006 7:50 pm**

My apologies, I thought you meant a german thread that contains info on how to transmit a continous stream of images from one comp to another

my bad.

(edit): Nevermind, the BriefL_Z test in the PBOSL library contains a client/server example. Though the desktop res must be the same on both for the image to turn out correctly, I believe.

Posted: **Mon Jul 17, 2006 9:51 pm**

Well im new to this language but none of these examples work straight off... brieflz_test.pb complains about the Lof() command .. im not even going to try at this point in time with my limited knoledge. I may as well compress to jpeg and send the file over the network.

Posted: **Tue Jul 18, 2006 12:26 am**

Let your (web-) camera app put a bmp file into a directory. And let the server send it to the client who can put this onto his (or Here) screen.

Bether try with a jpg, since bmp files is just too big!

Posted: **Tue Jul 18, 2006 12:54 am**

The code below works for displaying a webcam preview.

Code: Select all

#WM_CAP_START = #WM_USER 
#WM_CAP_DRIVER_CONNECT = #WM_CAP_START + 10 
#WM_CAP_DRIVER_DISCONNECT = #WM_CAP_START + 11 
#WM_CAP_DRIVER_GET_CAPS = #WM_CAP_START + 14
#WM_CAP_EDIT_COPY = #WM_CAP_START + 30 
#WM_CAP_SET_PREVIEW = #WM_CAP_START + 50 
#WM_CAP_SET_PREVIEWRATE = #WM_CAP_START + 52 
#WM_CAP_STOP = #WM_CAP_START + 68 
#WM_CAP_SET_SCALE = #WM_CAP_START + 53

If OpenWindow(0, 0, 0, 640, 480, "Video Preview", #PB_Window_SystemMenu|#PB_Window_ScreenCentered) 
  If OpenLibrary(0, "avicap32.dll") 
    *capAddress = GetFunction(0, "capCreateCaptureWindowA") 
      
  hWndC.l = CallFunctionFast(*capAddress, "My Capture Window", #WS_CHILD | #WS_VISIBLE, 0, 0, 640, 480, WindowID(0),0) 
SendMessage_(hWndC, #WM_CAP_DRIVER_CONNECT, 0, 0) 
SendMessage_(hWndC, #WM_CAP_SET_PREVIEW, #True, 0) 
SendMessage_(hWndC, #WM_CAP_SET_PREVIEWRATE, 1, 0) 
SendMessage_(HWndC, #WM_CAP_SET_SCALE, #True, 0) 

    
  
  EndIf 
EndIf 

;SendMessage_(hWndC, #WM_CAP_EDIT_COPY, 0, 0) 
;img.l = GetClipboardImage(#PB_Any) 
;reult.l=SaveImage(img.l,"c:\test.jpg",#PB_ImagePlugin_JPEG,10)

Repeat 
  Event = WaitWindowEvent() 
Until Event = #PB_Event_CloseWindow 

SendMessage_(hWndC, #WM_CAP_STOP, 0, 0) 
SendMessage_(hWndC, #WM_CAP_DRIVER_DISCONNECT, 0, 0) 
DestroyWindow_(hWndC) 
CloseLibrary(0) 

End

I am trying to copy frames to the clipboard where i can convert them to a jpeg file ready for sending over the network. As you can see i have had a go but been unsuccessful due to my total lack of PB syntax understanding. Can anyone give me a few pointers?

Posted: **Tue Jul 18, 2006 2:27 am**

Joakim Christiansen wrote:
Let your (web-) camera app put a bmp file into a directory. And let the server send it to the client who can put this onto his (or Here) screen.
Bether try with a jpg, since bmp files is just too big!

You are right but the webcam (through AviCap) can in default write in BMP format. I figured it out to use JPG (some 2 years ago). Must first update to PB4 before i can post the code. Will try tomorrow (it is 03:30 (AM) herer at night.

@AndyMk,
I have found (old) code to view webcam images on remote computers will check tomorrow and post it, but again need conversion to PB4 first.

night night

Jan V.

(PS have found code to see webcam images on remote computers will check tomorrow and post)

Posted: **Wed Jul 19, 2006 1:21 am**

As promised yesterday the 'code' to view a remote webcam.

It is in two parts since the original code used 'urldownloadtofile()' which is not very accurate (the least).

Looking on the board found (old) code by ElChiconi modified it an hé presto a 'talking' download, now at least we now why we can not download a 'camera'.

As you van see very simple (i think).

First the download.pb

Code: Select all


#INTERNET_FLAG_RELOAD = $80000000
#INTERNET_DEFAULT_HTTP_PORT = 80
#INTERNET_SERVICE_HTTP = 3
#HTTP_QUERY_FLAG_NUMBER = $20000000
#HTTP_QUERY_CONTENT_LENGTH = 5
#HTTP_QUERY_STATUS_CODE = 19
#HTTP_STATUS_OK = 200
#INTERNET_OPEN_TYPE_DIRECT = 1

Enumeration 1
  #dl_noInet
  #dl_Urlfail
  #dl_NoConn
  #dl_HTTPfail
  #dl_HTTPsend
  #dl_HTTPqry
  #dl_STATfail
  #dl_CLENfail
  #dl_NOmem
  #dl_NOfile
  #dl_FAIL
EndEnumeration

Dim  dl_Errors.s( 20)

dl_Errors( #dl_noInet)   = "Internet connection not available."
dl_Errors( #dl_Urlfail)  = "InternetOpenUrl_() failed"
dl_Errors( #dl_NoConn)   = "Unable to connect to "
dl_Errors( #dl_HTTPfail) = "Http open failed to "
dl_Errors( #dl_HTTPsend) = "Http send request failed to "
dl_Errors( #dl_HTTPqry)  = "Http query failed."
dl_Errors( #dl_STATfail) = "Status code query failed."
dl_Errors( #dl_CLENfail) = "CONTENT_LENGTH query failed."
dl_Errors( #dl_NOmem)    = "Not enough memory."
dl_Errors( #dl_NOfile)   = "Unable to create file: "
dl_Errors( #dl_FAIL)     = "Download failed."
; dl_Errors( ) =

Procedure CheckError( value.l, message.l, terminate.l, mess.s = "")
Shared dl_Errors.s()

	If value=0
		MessageRequester("Error", dl_Errors.s( message.l)+mess.s)
		If terminate
			End
		EndIf
	EndIf
EndProcedure


Procedure Download(URL$, LocalFile$)
	Domain$   = RemoveString(Left(URL$, FindString(URL$, "/", 8)-1), "http://")
	dwordSize = 4
	
	hInet = InternetOpen_("Mozilla/5.0 (Windows; U; Windows NT 5.1; es-ES; rv:1.7.8) Gecko/20050511 Firefox/1.0.4", #INTERNET_OPEN_TYPE_DIRECT, #Null, #Null, 0)
	CheckError(hInet, #dl_noInet, #True)
	
	hURL = InternetOpenUrl_(hInet, URL$, #Null, 0, #INTERNET_FLAG_RELOAD, 0)
	CheckError(hURL, #dl_Urlfail, #True, URL$)
	
	hInetCon = InternetConnect_(hInet, Domain$, #INTERNET_DEFAULT_HTTP_PORT, #Null, #Null, #INTERNET_SERVICE_HTTP, 0, 0)
	CheckError(hInetCon, #dl_NoConn, #True, Domain$)
	
	hHttpOpenRequest = HttpOpenRequest_(hInetCon, "HEAD", RemoveString(URL$, "http://"+Domain$+"/"), "http/1.0", #Null, 0, #INTERNET_FLAG_RELOAD, 0)
	CheckError(hHttpOpenRequest, #dl_HTTPfail, #True, Domain$)
	
	CheckError(HttpSendRequest_(hHttpOpenRequest, #Null, 0, 0, 0), #dl_HTTPsend, #True, Domain$)
	
	CheckError(HttpQueryInfo_(hHttpOpenRequest, #HTTP_QUERY_FLAG_NUMBER|#HTTP_QUERY_STATUS_CODE, @sCode, @dwordSize, @lpdwIndex), #dl_HTTPqry, #False)
	
	CheckError(sCode=#HTTP_STATUS_OK, #dl_STATfail, #False)
  
	CheckError(HttpQueryInfo_(hHttpOpenRequest, #HTTP_QUERY_FLAG_NUMBER|#HTTP_QUERY_CONTENT_LENGTH, @sCode, @dwordSize, @lpdwIndex), #dl_CLENfail, #False)
	
	If sCode
		DataBufferLength = sCode
	Else
		DataBufferLength = 4096
	EndIf
	
	*DataBuffer = AllocateMemory(DataBufferLength)
	CheckError(*DataBuffer, #dl_NOmem, #True)
  
	CheckError( CreateFile(0, LocalFile$), #dl_NOfile, #True, localFile$)
	Repeat
		CheckError( InternetReadFile_(hURL, *DataBuffer, DataBufferLength, @Bytes), #dl_FAIL, #True)
		If Bytes
			WriteData( 0, *DataBuffer, Bytes)
		EndIf
	Until Bytes=0
	
	CloseFile(0)
	FreeMemory(*DataBuffer)
	InternetCloseHandle_(hInetCon)
	InternetCloseHandle_(hURL)
	InternetCloseHandle_(hInet)
EndProcedure

; Download("http://xoap.weather.com/weather/local/USNY0181?cc=*&dayf=1", "c:\sources\purebasic\webcam\weather.xml")

second the 'camera' program:

Code: Select all

;
; ------------------------------------------------------------
; Purebasic Webcam viewer by midebor (mdb@skynet.be)

; The programm uses URLDownloadToFile Api to download Webcam images
; to temp.jpg file and displays them using the UseJPEGImageDecoder()
; function.
; The program assumes you are already connected To the Internet
; Has only been tested with ADSL connection
; ------------------------------------------------------------
; 18jul2006
; Modified by Jan J. Vooijs (jan.vooijs@wanadoo.nl)
; - No more array but a linked list if a cam no longer works you can shut it down by one ';' character.
; - It uses Download.pb as the downloader, now we get a verbal warning what is wrong.
;     Download code by ElChiconi (thanks)..
; - Much simpler loading of the image into a screen.
; 


XIncludeFile "download.pb"

UseJPEGImageDecoder() ; to decode the "temp.jpg" file


; ------------------ List of camera's ------------------------
NewList slCams.s()

AddElement( slCams()) : slCams() = "Antwerpen Zeevaartschool           ! http://www.hzs.be/antwerp/schelde.jpg"
; AddElement( slCams()) : slCams() = "Bad Godesberg                      ! http://www.general-anzeiger-bonn.de/images/neteye/stadthaus.jpg"
AddElement( slCams()) : slCams() = "Berlin - Podsdammerplatz           ! http://www.cityscope.de/pp/panos/cityscope.jpg"
; AddElement( slCams()) : slCams() = "Bruxelles Avenue de Terveuren      ! http://camera.viking.be/images/ispy.jpg"
AddElement( slCams()) : slCams() = "CFN WebCam                         ! http://www.spiretech.com/~leonard/cfn/webcam/webcam.jpg"
; AddElement( slCams()) : slCams() = "DAX                                ! http://deutsche-boerse.com/parkett/parkett2.jpg"
; AddElement( slCams()) : slCams() = "De Haan Belgium                    ! http://www.dehaan.be/webcam/Video01.jpg"
; AddElement( slCams()) : slCams() = "Del Mar Beach Cam                  ! http://os1.prod.camzone.com/camzone-ie?delmar:1:1025193280125:0"
; AddElement( slCams()) : slCams() = "Dome of Cologne                    ! http://www.wdr.de/domcam.jpg"
; AddElement( slCams()) : slCams() = "Essen-Kupferdreh                   ! http://www.kupferdreh.de/cam.jpg"
AddElement( slCams()) : slCams() = "Europe Weather Satelite            ! http://www.usatoday.com/weather/twc_images/europesat_440x297.jpg"
; AddElement( slCams()) : slCams() = "GameStar Online-Webcam             ! http://www.gamestar.de/aktuell/webcam/cam.jpg"
AddElement( slCams()) : slCams() = "Ground Zero                        ! http://65.200.140.25/ec_metros/ourcams/johnst.jpg"
AddElement( slCams()) : slCams() = "Iowa State University              ! http://www.iastate.edu/webcam/hugesize.jpg"
AddElement( slCams()) : slCams() = "Jericho Beach, Vancouver           ! http://www.jericho.ca/webcam/images/webcam.jpg"
; AddElement( slCams()) : slCams() = "Kauai, Hawaii                      ! http://hawaiiweathertoday.com/images/webcam_kauai.jpg"
AddElement( slCams()) : slCams() = "Knokke, Belgium                    ! http://www.quiksilver.be/beachcam/live/beach.jpg"
AddElement( slCams()) : slCams() = "Koenigssee, Germany                ! http://www.koenigssee.com/rodelbahn/fsc4.jpg"
; AddElement( slCams()) : slCams() = "La Tour Eifel                      ! http://www.images-abcparislive.com/eiffel1.jpg?1011467343523"
AddElement( slCams()) : slCams() = "La Tour Eifel (2)                  ! http://www.images2-abcparislive.com/eiffelcam1.jpg?1153262971609"
AddElement( slCams()) : slCams() = "Louvain La Neuve, Belgium          ! http://www.sri.ucl.ac.be/SRI/webcam/universite.jpg"
AddElement( slCams()) : slCams() = "MGM Grand (Las Vegas)              ! http://images.earthcam.com/ec_metros/ourcams/mgm.jpg"
; AddElement( slCams()) : slCams() = "Midvale Hill (Highway 95)          ! http://www.ruralnetwork.net/~rnsmvlcm/midvalehill.jpg"
AddElement( slCams()) : slCams() = "MOBOTIX M1 PreParkCam              ! http://preparkcam.mobotixserver.de/record/current.jpg"
AddElement( slCams()) : slCams() = "New York Times Square Cam 1        ! http://images.earthcam.com/ec_metros/ourcams/lindys.jpg"
AddElement( slCams()) : slCams() = "New York Times Square Cam 2        ! http://images.earthcam.com/ec_metros/ourcams/lennon.jpg"
AddElement( slCams()) : slCams() = "Niagara Falls                      ! http://www.fallsview.com/fallsmain.jpg"
AddElement( slCams()) : slCams() = "Nieuwpoort, Belgium                ! http://www.vvwnieuwpoort.be/webcam/images/webcam.jpg"
AddElement( slCams()) : slCams() = "Oostende aan zee, Belgium          ! http://aanzee.be/images/groot.jpg"
; AddElement( slCams()) : slCams() = "Oostende Camera radioamateurs      ! http://www.flanderswebhost.com/webcams/radiocam/radiocam.jpg"
; AddElement( slCams()) : slCams() = "Oostende Webcam, Belgium           ! http://www.oostende.net/webcam/oostendecam.jpg"
AddElement( slCams()) : slCams() = "Panama Canal, Miraflores Locks     ! http://www.pancanal.com/miraflores/miraflores.jpg"
; AddElement( slCams()) : slCams() = "Poppies Pool, Bali                 ! http://www.poppies.net/webcam.jpg"
; AddElement( slCams()) : slCams() = "Poppies Restaurant, Bali           ! http://www.poppies.net/webcam1.jpg"
; AddElement( slCams()) : slCams() = "Prague                             ! http://193.165.174.197/fullsize.jpg"
AddElement( slCams()) : slCams() = "PSC/EET Weather Station (New York) ! http://www.paulsmiths.edu/aai/eet/aaicam.jpg"
; AddElement( slCams()) : slCams() = "San Diego Zoo Panda Cam            ! http://outstream.camzone.com/camzone-ie?zoo:2:1020871595627:0"
; AddElement( slCams()) : slCams() = "World - Shamu Cam                  ! http://outstream.camzone.com/camzone-ie?shamu:13:1023798289913"
AddElement( slCams()) : slCams() = "Seattle                            ! http://images.earthcam.com/ec_metros/washingtonst/seattle/marqueen.jpg"
AddElement( slCams()) : slCams() = "Stadt Neuburg, Germany             ! http://www.neuburg-donau.de/donaucam/donaukai.jpg"
; AddElement( slCams()) : slCams() = "Trafalgar Square, London           ! http://www.webviews.co.uk/liveimages/trafalgarsq.jpg"
AddElement( slCams()) : slCams() = "University of Arizona              ! http://www.cs.arizona.edu/camera/view.jpg"
AddElement( slCams()) : slCams() = "University of Iowa                 ! http://www.iihr.uiowa.edu/webcam/cam.jpg"
AddElement( slCams()) : slCams() = "USS Intrepid Cam (New York City)   ! http://65.200.140.25/ec_metros/ourcams/intrepid.jpg"
AddElement( slCams()) : slCams() = "Waikiki in Honolulu                ! http://images.earthcam.com/ec_metros/hawaii/waikiki.jpg"
AddElement( slCams()) : slCams() = "Washington Memorial                ! http://images.earthcam.com/ec_metros/washington/metrosquare.jpg"
AddElement( slCams()) : slCams() = "Weimar                             ! http://www.thueringer-webcams.de/weimar/theaterplatz/fullsize.jpg"
AddElement( slCams()) : slCams() = "WorldTradeAftermath.com            ! http://worldtradeaftermath.com/capture0.jpg"
AddElement( slCams()) : slCams() = "Zeebrugge, Belgium                 ! http://www.rustyhouse.com/beachcam/beachcam.jpg"

 
ForEach slCams.s()
	Nam.s = Trim( StringField( slCams(), 1, "!"))
	Url.s = Trim( StringField( slCams(), 2, "!"))
	Debug "Nam = " + Nam.s + " Url: "+ Url.s
	Download( Url.s, "temp.jpg")
	
	If OpenWindow(0, 0, 0, 800, 600, "PB - Webcam " + Nam.s, #PB_Window_SystemMenu | #PB_Window_ScreenCentered) And CreateGadgetList(WindowID(0))
		Result.l = LoadImage( #PB_Any, "temp.jpg")		; change 2nd parameter to the path/filename of your image..
		If Result.l
			ImageGadget(0,  10, 10, ImageWidth( Result.l), ImageHeight( Result.l), ImageID( Result.l))                      ; imagegadget standard
			; ImageGadget(1, 130, 10, 100, 83, ImageID(0), #PB_Image_Border)     ; imagegadget with border
		EndIf
		
		Repeat
			
		Until WaitWindowEvent() = #PB_Event_CloseWindow
	Else
		MessageRequester("Error", "Can't load the image...", 0)
	EndIf
Next

End

All very simple and working it is code for PB4.0 (but it worked originaly for 3.94).

As you can see some cameras are no longer functional those are commented out.

Have fun with it!!

Jan V.

Posted: **Wed Jul 19, 2006 8:44 pm**

Very nice.

Posted: **Thu Jul 20, 2006 10:16 am**

Nice work Jan.
Just wondering if anybody here has had any experience with mpeg4 technologies and maybe knows of a good lib or (freebie)sdk I can get hold of to do a bit of streaming experiementing with?

Posted: **Thu Jul 20, 2006 10:48 am**

Thank you very much for this code. I will experiment over the weekend. I must say, coming from a Blitzbasic/DBpro environment, the people on this forum is so much more helpfull.

Posted: **Thu Jul 20, 2006 1:19 pm**

AndyMK wrote:Thank you very much for this code. I will experiment over the weekend. I must say, coming from a Blitzbasic/DBpro environment, the people on this forum is so much more helpfull.

Your'e welcom. And YES the people here are amazing!! So much code to play with like above the cam program original by Midebor and the original download prog is from ElChiconi, modified both (mostly to PB4) and hey presto a webcan viewer program (well very simple).

Have you read my tip about images and freeimage() in the Tips and tricks section?

Btw. because of this forum i stick with PureBasic 4.0 it rocks!

It is SO easy to try (little) bits of code being windows apps or good old plain console programs! Copy & paste, press F5 and we have liftoff!!!

There is NO other programming language (and IDE) like it!! The rest all need loads of setup (at least 40 lines of code) or produce programs which do not fit on 1 (one) CD!! Here if a programs exe is above 100k i start to worry

and keep slimming it down

Or compiling linking recompile other parts for long periodes than to discover there is a tiny litte error somewhere and the process starts over and over.

My motto here on the forum is "Help where you can and be helped" and with the execption of two other boards there is NO comparissing. And yes i own a legal copy of BlitzBasic but there forum eeks!! No code to speak of or it does not work or... But that is MY opinion not that of others. I did stop usinfg Blitz now for a year.

No here i feel at home among peers. Nobody yells (oke exept me sometimes, yes i have a big mouth

) everybody helps or give meaning full ideas that helps you further.

No PureBasic a day helps to keep the docter at bay (something to do with an apples original i think, no real appels!!)

Anytime,

Jan V.

PureBasic Forums - English

Another Video Capture question

Another Video Capture question