如何从IP摄像机获取更高Fps的JPEG格式的图像

public partial class Form1 : Form
{
    // indicates wether to prevent caching in case of a proxy server or not
    private bool preventCaching = false;                

    public Form1()
    {
        InitializeComponent();
    }

    private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
    {
        while (true)
        {
            this.pictureBox1.Image = this.GetSingleFrame(@\"http://ipaddress/SnapshotJPEG?Resolution=320x240&Quality=Standard\");                
        }
    }

    /// <summary>
    /// Get a single JPEG frame from the camera
    /// </summary>
    /// <param name=\"source\">JPEG Stream source</param>
    /// <exception cref=\"WebException\">If the IP camera is not receable or an error is occured</exception>
    /// <exception cref=\"Exception\">If an unknown error occured</exception>
    public Bitmap GetSingleFrame(string source)
    {
        byte[] buffer = new byte[512 * 1024];   // buffer to read stream
        HttpWebRequest req = null;
        WebResponse resp = null;
        Stream stream = null;
        Random rnd = new Random((int)DateTime.Now.Ticks);

        try
        {
            int read, total = 0;

            // create request
            if (!preventCaching)
            {
                req = (HttpWebRequest)WebRequest.Create(source);
            }
            else
            {
                req = (HttpWebRequest)WebRequest.Create(source + ((source.IndexOf(\'?\') == -1) ? \'?\' : \'&\') + \"fake=\" + rnd.Next().ToString());
            }
            // set login and password                
            req.Credentials = new NetworkCredential(\"root\", \"a\");                

            req.Timeout = -1;

            resp = req.GetResponse();

            // get response stream
            stream = resp.GetResponseStream();

            // loop
            do
            {
                read = stream.Read(buffer, total, 1024);

                total += read;
            }
            while (read != 0);

            Bitmap bmp = (Bitmap)Bitmap.FromStream(new MemoryStream(buffer, 0, total));

            return bmp;
        }
        catch (WebException ex)
        {
            string s = ex.ToString();
            return null;
        }
        catch (Exception ex)
        {
            string s = ex.ToString();
            return null;
        }
        finally
        {
            // abort request
            if (req != null)
            {
                req.Abort();
                req = null;
            }
            // close response stream
            if (stream != null)
            {
                stream.Close();
                stream = null;
            }
            // close response
            if (resp != null)
            {
                resp.Close();
                resp = null;
            }
        }
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        this.backgroundWorker1.RunWorkerAsync();
    }
}