我用API的方式显示摄像头的图像,但是画面不是很流畅,画面图像和实际有0.5秒的延迟,有谁知道解决的方法呢?

[liuxiang]

API的方法如下:
用 api 调用 摄像头 源码
//定义变量
uint lhand



//定义常数
long WM_USER=1024
long WM_CAP_START = WM_USER
long WM_CAP_STOP = WM_CAP_START + 68
long WM_CAP_DRIVER_CONNECT = WM_CAP_START + 10
long WM_CAP_DRIVER_DISCONNECT = WM_CAP_START + 11
long WM_CAP_SAVEDIB = WM_CAP_START + 25
long WM_CAP_GRAB_FRAME = WM_CAP_START + 60
long WM_CAP_SEQUENCE = WM_CAP_START + 62
long WM_CAP_FILE_SET_CAPTURE_FILEA = WM_CAP_START + 20
long WM_CAP_SEQUENCE_NOFILE =WM_CAP_START+ 63
long WM_CAP_SET_OVERLAY =WM_CAP_START+ 51
long WM_CAP_SET_PREVIEW =WM_CAP_START+ 50
long WM_CAP_SET_CALLBACK_VIDEOSTREAM = WM_CAP_START +6
long WM_CAP_SET_CALLBACK_ERROR=WM_CAP_START +2
long WM_CAP_SET_CALLBACK_STATUSA= WM_CAP_START +3
long WM_CAP_SET_CALLBACK_FRAME= WM_CAP_START +5
long WM_CAP_SET_SCALE=WM_CAP_START+ 53
long WM_CAP_SET_PREVIEWRATE=WM_CAP_START+ 52



//定义api
function ulong capCreateCaptureWindowA(string lpszWindowName,ulong dwStyle,long x ,long y ,long nWidth ,long nHeight ,ulong ParentWin ,long nId ) LIBRARY 'AVICAP32.DLL'



//初始化代码
string lpszName
ulong l1
l1=handle(w_main)



lpszName='摄像头界面...'
lhand=capCreateCaptureWindowA(lpszName,262144+12582912+1073741824 + 268435456 ,0,0,200,200,l1,0)
if lhand <> 0 then
send(lhand, WM_CAP_SET_CALLBACK_VIDEOSTREAM, 0, 0)
send(lhand, WM_CAP_SET_CALLBACK_ERROR, 0, 0)
send(lhand, WM_CAP_SET_CALLBACK_STATUSA, 0, 0)
send(lhand, WM_CAP_DRIVER_CONNECT, 0, 0)
send(lhand, WM_CAP_SET_SCALE, 1, 0)
send(lhand, WM_CAP_SET_PREVIEWRATE, 66, 0)
send(lhand, WM_CAP_SET_OVERLAY, 1, 0)
send(lhand, WM_CAP_SET_PREVIEW, 1, 0)
end if



//保存到文件
string s
s='c:\save.avi'
if lhand<>0 then
Send(lhand,WM_CAP_FILE_SET_CAPTURE_FILEA,0, s);
Send(lhand,WM_CAP_SEQUENCE, 0, 0) //开始捕捉
end if



//停止保存
send(lhand, WM_CAP_STOP, 0, 0)



//保存为图片
string s
s='c:\save.bmp'
if lhand <> 0 then
Send(lhand,WM_CAP_SAVEDIB,0,s);
end if

[liuxiang]

ding

[baitao79]

我为什么保存不了图片？请教！谢谢！

[lzheng2001]

查一下lhand的值是否正确! 及send返回的值是否正确,如果是-1证明,send失败

[ruky9988]

慢也算正常 ^-^

[zylt]

可能和摄像头的质量有关，建议更换摄像头。

[ybkenan]

幫頂。順便學習﹗﹗﹕）