You can absolutely run composite video over RG-59 or RG-6 without any trouble up to a few hundred feet in my experience. (Analog style security cameras utilize composite connections and run hundreds of feet.) You could even use a video amp to extend further.
Also consider that when you encode/compress the stream for broadcasting, you are essentially throwing away a lot of the original quality. There are two ways to look at this, 1… Start with the highest quality image possible because you are going to loose a lot of quality in the codec. Also, the less noise in the input signal, the better the codec will perform. 2… The input image quality doesn't matter because the output is still going to look poor by comparison. You may be in the 1st group or the 2nd group.
Another thing to consider is the camera itself. It will affect the image quality far far more than composite vs. s-video vs. component vs. 1394 vs. HDMI. A prosumer 3CCD camera connected via composite over coax will give you a far better image than a consumer 1 CCD camera connected via 1394.
Other things to consider...
- SD or HD?
- How many cameras do you want to use?
- Will you use a video mixer? Digital or Analog?
- How are you feeding the audio into the encoder?
- What are you using for encoding?
- What are you using as a streaming host?
- Size of online audience? If two people are watching
online, that suggests a small investment. If one hundred people are
watching online, that suggests something else.
- How many people are available to run the system if there are multiple cameras?
- Are you recording to DVD or some other media?
- Are you feeding into a CCTV system for nurseries or overflow areas?
That's not an exhaustive list, just what came off the top of my head.
I would advise against using a WiFi camera for this type of application.
If you have other questions let me know.