用fileStream.write 将加密后的TS流数据写入文件，速度超级慢，跪求高手帮忙解决，标题一定要长

代码如下：
 FileStream fs;
                fs = File.Create(textBox1.Text+".cpk");
                while (true)
                {
                    ret = Get_next_TSPacket(iName, tspacket);
                    if (ret != 0)
                        break;
                    cryptpacket = tspacket;
                    if(Parse_TSPacket(tspacket,ref offset,ref size) != 0)
                    {
                        ivv_bak = aes_ivv;
                        Aes_crypto(tspacket,cryptpacket,size,ivv_bak,aes_ivv);
                        cops++;
                    }
                    fs.Write(cryptpacket,0,188);
                    progressBar1.Minimum = 1;
                    progressBar1.Maximum = cops;
                   // progressBar1.Maximum = 100;
                    progressBar1.Step = 1;
                    progressBar1.PerformStep();
                }