I dont know how my question about 3s latency ended up in control query section, I guess I accidentally clicked category button. I am using Ezwifibroadcast 1.5 for wireless transmition of video, I get 3000ms latency and I dont know why is that cause you say that latency from HD1 is less than a single frame. When I connect rospbery pi camera to pi then I get much less latency so I am confused where does latency come from.
When we discuss latency, we are talking about the time from the video signal being received by the PiCapture board to the signal being delivered to the Raspberry Pi GPU. The latency introduced for the PiCapture is roughly one frame when compared to the Raspberry Pi Camera (a bit more than one frame for the SD1 for deinterlacing, a bit less for the HD1)
There can be many other sources of latency unrelated to PiCapture. In particular, any image processing performed by the RPi or and network delays when streaming video (which can vary greatly depending on the connection and the resolution of the streamed video).
In general, for the same resolutions, the latency for the PCapture will be very close to the latency for the RPi camera module.
Without knowing the configuration of hardware and software you are using, it is very difficult to know what is causing the latency you are seeing. Because the PiCapture board is not buffering the video at all, it is the result of delays introduced in the Raspberry Pi processing/transmission.