How to control resolution and bitrate of an ONVIF IP camera?

Question

My CCTV View in C# allows visualizing screens from 1 to 36. However, if all 36 cameras are connected it becomes slow. Therefore I want to create a function to adjust the resolution and bitrate for each screen.

1. Is adjusting resolution and bitrate based on screen division the right choice?
2. When setting width and height freely, do I need to manually adjust aspect ratio?
3. Are there any issues with the function below that adjusts bitrate? Is a better bitrate control logic available?

private void timer1_Tick(object sender, EventArgs e)
{
    int iBitrateValue;

    for (int i = 0; i < iViewCount; i++)
    {
        iBitrateValue = (int)((float)StructCameraList[i].width);
        if (iBitrateValue > 4096)
            iBitrateValue = 4096;
        if (iBitrateValue < 256)    //768
            iBitrateValue = 256;

        if (StructCameraList[i].deviceClient != null)
        {
            if (StructCameraList[i].mediaClient != null && StructCameraList[i].profile != null &&StructCameraList[i].VideoConfiguration != null)
            {
                if (Main.util.PingTest(StructCameraList[i].strIP))
                {
                    StructCameraList[i].VideoConfiguration = Main.controller.SetBitrate(StructCameraList[i].mediaClient, StructCameraList[i].profile, StructCameraList[i].VideoConfiguration, iBitrateValue);
                }
            }
        }
    }
    timer1.Stop();
}

public OnvifMediaServiceReference.VideoEncoderConfiguration SetBitrate(MediaClient mediaclient, Profile profile, OnvifMediaServiceReference.VideoEncoderConfiguration SetConfiguration, int bitrate)
{
    if (SetConfiguration != null)
    {
        if (SetConfiguration.RateControl.BitrateLimit != bitrate)
        {
            SetConfiguration.RateControl.BitrateLimit = bitrate;
            mediaclient.SetVideoEncoderConfiguration(SetConfiguration, true);
        }
    }
    else
    {
        SetConfiguration = GetVideoConfiguration(mediaclient, profile);
    }
    return SetConfiguration;
}