一段提取avi帧图片的代码，保存的图片无法打开，望指出问题，等待回复。。。。。

geonsin 2007-04-18 10:30:40

本人在网上下了一段avi to bmp的代码，但保存后的图片无法打开，数据有问题，不知是何故，望指点：
void CAvi::AVItoBmp(CString strAVIFileName, CString strBmpDir)
{
// TODO: 在此添加控件通知处理程序代码
AVIFileInit();
PAVIFILE avi;
int res=AVIFileOpen(&avi, strAVIFileName, OF_READ, NULL);
int n = GetLastError();
if (res!=AVIERR_OK)
{
//an error occures
if (avi!=NULL)
AVIFileRelease(avi);
return ;
}
AVIFILEINFO avi_info;
AVIFileInfo(avi, &avi_info, sizeof(AVIFILEINFO));
PAVISTREAM pStream;
res=AVIFileGetStream(avi, &pStream, streamtypeVIDEO /*video stream*/,
0 /*first stream*/);
if (res!=AVIERR_OK)
{
if (pStream!=NULL)
AVIStreamRelease(pStream);
AVIFileExit();
return ;
}

//do some task with the stream
int iNumFrames;
int iFirstFrame;
iFirstFrame=AVIStreamStart(pStream);
if (iFirstFrame==-1)
{
//Error getteing the frame inside the stream
if (pStream!=NULL)
AVIStreamRelease(pStream);
AVIFileExit();
return ;
}
iNumFrames=AVIStreamLength(pStream);
if (iNumFrames==-1)
{
//Error getteing the number of frames inside the stream
if (pStream!=NULL)
AVIStreamRelease(pStream);
AVIFileExit();
return ;
}

//getting bitmap from frame
BITMAPINFOHEADER bih;
ZeroMemory(&bih, sizeof(BITMAPINFOHEADER));

bih.biBitCount=24; //24 bit per pixel
bih.biClrImportant=0;
bih.biClrUsed = 0;
bih.biCompression = BI_RGB;
bih.biPlanes = 1;
bih.biSize = 40;
bih.biXPelsPerMeter = 0;
bih.biYPelsPerMeter = 0;
//calculate total size of RGBQUAD scanlines (DWORD aligned)
bih.biSizeImage = (((bih.biWidth * 3) + 3) & 0xFFFC) * bih.biHeight ;
// bih.biSizeImage=avi_info.dwWidth*avi_info.dwHeight*3;
PGETFRAME pFrame;
pFrame=AVIStreamGetFrameOpen(pStream, NULL );

AVISTREAMINFO streaminfo;
AVIStreamInfo(pStream,&streaminfo,sizeof(AVISTREAMINFO));

//Get the first frame
BITMAPINFOHEADER bih2;
long lsize = sizeof(bih2);
int index=0;
for (int i=7000; i<7001; i++)//已修改过，只保存一帧（第7000帧）
{
index= i-iFirstFrame;
BYTE* pDIB = (BYTE*) AVIStreamGetFrame(pFrame, index); //
AVIStreamReadFormat(pStream,index,&bih2,&lsize);
BITMAPFILEHEADER stFileHdr;

BYTE* Bits=new BYTE[bih2.biSizeImage];
AVIStreamRead(pStream,index,1,Bits,bih2.biSizeImage,NULL,NULL);
// RtlMoveMemory(Bits, pDIB + sizeof(BITMAPINFOHEADER), bih2.biSizeImage);
bih2.biClrUsed =0;
stFileHdr.bfOffBits=sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER);
stFileHdr.bfSize=sizeof(BITMAPFILEHEADER);
stFileHdr.bfType=0x4d42;

CString FileName;
FileName.Format("Frame-%05d.bmp", index);
CString strtemp = strBmpDir;
strtemp += "\\";
strtemp += FileName;
FILE* fp=_tfopen(strtemp ,_T("wb"));
fwrite(&stFileHdr,1,sizeof(BITMAPFILEHEADER),fp);
fwrite(&bih2,1,sizeof(BITMAPINFOHEADER),fp);
int ff = fwrite(Bits,1,bih2.biSizeImage,fp);
int e = GetLastError();
fclose(fp);
/////
delete Bits;
//CreateFromPackedDIBPointer(pDIB, index);
}

AVIStreamGetFrameClose(pFrame);

//close the stream after finishing the task
if (pStream!=NULL)
AVIStreamRelease(pStream);

AVIFileExit();
}

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