dspack怎么播放影片指定的区域？

Question

如果用TMEDIAPLAYER控件，可以用DisplayRect来实现，播放画面的坐标，现在用DSPACK怎么实现啊？我想播放指定区域的图象，例如播放坐标为“0，0，高度，宽度”，谢谢知道的提供下

Answer 1

使用SampleGrabber,拷贝图像
然后就是canvas的操作

Answer 2

知道大概了，谢谢啊
procedure TForm1.SampleGrabberBuffer(sender: TObject; SampleTime: Double;
  pBuffer: Pointer; BufferLen: Integer);
begin
  if CallBack.Checked then
  begin
    Image.Canvas.Lock; // to avoid flickering
    try
      SampleGrabber.GetBitmap(Image.Picture.Bitmap, pBuffer, BufferLen)
    finally
      Image.Canvas.Unlock;
    end;
  end;
end;
另外，还想问问canvas的操作，用哪个函数控制显示画面的区域，我只要显示指定的坐标的。怎么实现啊

Answer 3

procedure TfrmPlay.copyimage( tpb:timage; SampleTime: Double; pBuffer:
  Pointer; BufferLen: Integer);
var
  gd,kd:integer;
  gdb,kdb:integer;
  rc1:trect;
  //cd:integer;
  //strsj:string;
  x,y:real;//空白比例
begin
  //拷贝图像
  //  hxh 2006-12-12
  //由于lock  编译状态下可以,直接运行exe不可以  郁闷
  //内存中  image就行
  //tpa.Canvas.Unlock;
  //if self.isdrawing then exit;
  //self.isdrawing:=true;
  if self.issize then
  begin
    tp.Picture:=nil;
    self.issize:=false;
  end;  //tpb.Picture:=nil;
  tpa.Canvas.lock;
  tpb.Canvas.Lock;
  //tpb.Canvas.Lock;
  //tpb.Canvas.Lock;
  try
    //image.Picture:=nil;
    //tpa.Canvas.Lock;                // to avoid flickering    SampleGrabber.GetBitmap(tpa.Picture.Bitmap, pBuffer, BufferLen);
    //tpa.Canvas.Unlock;
    //tpa.Canvas.Unlock;
    //tpa.Canvas.Unlock;
    //draw my text.by s.f.
    //cd := Image.Picture.Bitmap.Canvas.TextWidth('hello');
    //if (OffsetX + textLength) > 0 then
    //tpa.Canvas.Brush.Style := bsClear;
    //tpa.Canvas.Font.Color := clRed;
    //tpa.Canvas.TextOut(100, 10, 'hello中国海军');
    //tpa.Canvas.TextOut(100, 50, datetimetostr(now));
    //tpa.Canvas.Pen.Color:=clgreen;
    //tpa.Canvas.Rectangle(20,20,50,50);
    //Dec(OffsetX, 1);
    //exit;    gd:=tpa.Height;
    kd:=tpa.Width;
    gdb:=round(gd/2);
    kdb:=round(kd/2);
    //左边，中间，有白边
    x:=0.035;
    y:=0.01;
    if bf=1  then
    begin
      //左上
      rc1:=rect(round(kdb*x),round(gdb*y),kdB,round(gdB*(1-y)));
    end
    else  if bf=2 then
    begin
      rc1:=rect(round(kdb*(1+x)),round(gdb*+y),kd,round(gdB*(1-y)));
    end
    else if bf=3  then
    begin
      //左下
      rc1:=rect(round(kdb*x),round(gdb*(1+y)),kdb,round(gdB*(2-2*y)));
    end
    else  if bf=4 then
    begin
      rc1:=rect(round(kdb*(1+x)),round(gdb*(1+y)),kd,round(gdB*(2-2*y)));
    end
    else  if bf=5 then
    begin
      rc1:=rect(0,0,kd,gd);
    end;
    //tpb.Canvas.Lock;
    //tpb.Canvas.Lock;
    //tpb.Canvas.Lock;
    //tpb.Picture:=nil;    tpb.Canvas.CopyRect(tpb.BoundsRect,tpa.Canvas,rc1);
    {
    //文字
    tpb.Canvas.font.Color:=cllime;
    tpb.Canvas.Font.Size:=12;
    cd:=tpb.Canvas.TextWidth('文件:'+self.filetitle);
    tpb.Canvas.Brush.Style:=bsclear;
    tpb.Canvas.TextOut(tpb.Width-cd-30,20,'文件:'+self.filetitle);
    if self.begintime<>0 then
    begin
      strsj:='开始时间:'+FormatDateTime('yyyy-mm-dd hh:nn:ss',self.begintime);
      cd:=tpb.Canvas.TextWidth(strsj);
      tpb.Canvas.TextOut(tpb.Width-cd-30,40,strsj);
    end;
    }
    //tp2.Canvas.font.Color:=cllime;
    //tp2.Canvas.Font.Size:=12;
    //tp2.Canvas.TextOut(10,20,'文件:'+self.filetitle);
    //tp2.Canvas.TextOut(10,10,'hello中国海军');
    //tp2.Canvas.TextOut(10,40,strsj);
    //tpb.Canvas.Unlock;
    //tpb.Canvas.Unlock;
    //tpb.Canvas.Unlock;
    //IMAGE.Canvas.CopyRect(tp.ClientRect,TP.Canvas,rc1);
  finally
    //tpa.Canvas.Unlock;
    tpb.Canvas.Unlock;
    tpa.Canvas.unlock;    //tpa.Free;
  end;
  //self.isdrawing:=false;
end;