视频聊天ICSeqCompressFrame出错，返回NULL（请指教）

//压缩视频帧
问题就是：ICSeqCompressFrame老是返回NULL
// p=(char*)ICSeqCompressFrame(m_pcv,0,pin,&k,&s);
//       p=(char*)ICSeqCompressFrame(m_pcv,0,pInBuf,&k,&s);这两句都试过，都有问题BOOL CCodecMgr::EncodeVideoData(char* pin,int len,char* pout,int* lenr,BOOL* pKey)
{

BOOL bRet=FALSE;
char*p;
long s=2000;
BOOL k;
char *pInBuf;
char temp[21];
CString str;
if(!pin||!pout||len!=(int)m_pBmpU->bmiHeader.biSizeImage||!m_hIC)
{
goto RET; }
//pInBuf=new char[len];
pInBuf=new char[200*1024];
CopyMemory(pInBuf,pin,len);
// p=(char*)ICSeqCompressFrame(m_pcv,0,pin,&k,&s);
p=(char*)ICSeqCompressFrame(m_pcv,0,pInBuf,&k,&s);
if(!p)
{
goto RET; } 
else
{
AfxMessageBox("a");
}
if(lenr)
*lenr=s;
if(pKey)
*pKey=k;
if(s>MAX_UDP_SIZE-sizeof(PACK_VIDEO))
{
goto RET;
}
else
{
// str.Format("s=%d",s);
// AfxMessageBox(str);
}
 
//CopyMemory(pout,p,s);
CopyMemory(pout,pInBuf,s);
bRet=TRUE;
RET:
delete pInBuf;
return bRet;
}