第一次使用VFW,请教大侠几个问题，

Question

调用笔记本摄像头，图像没有显示
drawdibdraw(hd,bitmap.canvas.handle,0,0,bmpinfo.bmiheader.biwidth div 2 ,bmpinfo.bmiheader.biheight div 2,@bmpinfo.bmiheader,lpvhdr^.lpdata,0,0,bmpinfo.bmiheader.biwidth div 2,bmpinfo.bmiheader.biheight div 2,0);
。
把bitmap.canvas.handle换成capwnd2（panel2.handle），可以显示.几分钟后出错。‘out of memory’.procedure TForm1.Button3Click(Sender: TObject);
begin
capwnd2:=getdc(panel2.Handle;)
end;急等解决。。，请大侠指点

Answer 1

这个程序function framecallback(hwnd: hwnd; lpvhdr: pvideohdr): longint;stdcall;
var hd:thandle;
jpg:tjpegimage;
memstream :tmemorystream;
bitmap:tbitmap;
begin bitmap:=tbitmap.create;
bitmap.width :=bmpinfo.bmiheader.biwidth;
 // new size of bitmap
bitmap.height:=bmpinfo.bmiheader.biheight;
hd:= drawdibopen;
//drawdibdraw(hd,bitmap.canvas.handle,0,0,bmpinfo.bmiheader.biwidth div 2 ,bmpinfo.bmiheader.biheight div 2,@bmpinfo.bmiheader,lpvhdr^.lpdata,0,0,bmpinfo.bmiheader.biwidth div 2,bmpinfo.bmiheader.biheight div 2,0);
drawdibdraw(hd,capwnd2,0,0,bmpinfo.bmiheader.biwidth,bmpinfo.bmiheader.biheight,@bmpinfo.bmiheader,lpvhdr^.lpdata,0,0,bmpinfo.bmiheader.biwidth,bmpinfo.bmiheader.biheight,0);
drawdibclose(hd);
//deletedc(capwnd2);
//releasedc(capwnd2,capwnd22);
//·¢ËÍÊý¾Ý
{memstream := tmemorystream.create;
jpg := tjpegimage.create; jpg.assign(bitmap);
jpg.compressionquality := 10;
jpg.jpegneeded;
jpg.compress;
jpg.savetostream(memstream);
jpg.free;
form1.idudpclient1.broadcastenabled:=true；
if memstream.size>form1.idudpclient1.buffersize then
form1.idudpclient1.sendbuffer('192.168.0.255',9001,memstream.memory^,form1.idudpclient1.buffersize)
else
form1.idudpclient1.sendbuffer('192.168.0.255',9001,memstream.memory^,memstream.size);
memstream.free;  }
bitmap.free;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
capwnd := capcreatecapturewindow('MY', ws_visible or ws_child,//
0, //
0, //
panel1.width, //
panel1.height, //
panel1.handle, //
0); //
if capwnd = 0 then exit; 
capsetcallbackonframe(capwnd,@framecallback);
capparms.dwrequestmicrosecperframe:=1;
capparms.flimitenabled:=false;
capparms.fcaptureaudio:=false;
capparms.fmcicontrol:=false;
capparms.fyield:=true;
capparms.vkeyabort:=vk_escape;
capparms.fabortleftmouse:=false;
capparms.fabortrightmouse:=false; //
capcapturesetsetup(capwnd,@capparms,sizeof(tcaptureparms));
cappreviewrate(capwnd,33); //
capcapturesequencenofile(capwnd); //
capdriverconnect(capwnd,0); //
capgetvideoformat(capwnd, @bmpinfo,sizeof(tbitmapinfo)); 
cappreviewscale(capwnd,true); 
capoverlay(capwnd,true); //
cappreview(capwnd,true);
end;procedure TForm1.Button2Click(Sender: TObject);
begin
capcaptureabort(capwnd); //
capdriverdisconnect(capwnd); //
end;procedure TForm1.Button3Click(Sender: TObject);
begin
capwnd2:=getdc(panel2.Handle;)
end;

Answer 2

drawdibdraw(hd,bitmap.canvas.handle,0,0,bmpinfo.bmiheader.biwidth div 2 ,bmpinfo.bmiheader.biheight div 2,@bmpinfo.bmiheader,lpvhdr^.lpdata,0,0,bmpinfo.bmiheader.biwidth div 2,bmpinfo.bmiheader.biheight div 2,0);
 这个怎么显示不笔记本自带的摄像头图像呢