Neeed clarity for batch-size and batched-push-timeout for rtsp source

One more thing is does bitrate from rtsp camera affects the decoder performance?
Like if i set it 1024, then 6 cameras runs fine, if i set it to 4096, then glitch appears.
Also what should be the ideal iframeinterval for 20fps?

Note-
Network Bandwidth is not the bottleneck.