I use version 5.2.1f and "KRUEGERT" solution solves this problem. thanks very much.

We still have this bug in Unity 5.2.1f1 but only the first time we initialise the camera. I got around it by using this code:

if(wTex.width <= 16){
while(!wTex.didUpdateThisFrame){
yield return new WaitForEndOfFrame();
}
wTex.Pause();
Color32[] colors = wTex.GetPixels32();
wTex.Stop();

yield return new WaitForEndOfFrame();

wTex.Play();
}

It used to be 16x16 for few frames without needing to call anything on the texture, in 5.2.0 that workaround stopped working. I'll try your advice and insert GetPixels32() also, but that's so much waste of memory...

We found a temporary workaround for this. In our init coroutine, as soon as "didUpdateThisFrame" was true, we would initialize anything dependent on the size of the WebCamTexture. The size now was always sixteen by this point, but as soon as some operations were called on the texture, specifically GetPixels32(), the size would go back to our originally requested size. So, we added this to our init coroutine:

if (webCameTex.didUpdateThisFrame) {
Color32[] colors = null;
while (webCamTex.width <= 16) {
colors = webCamTex.GetPixels32();
yield return new WaitForEndOfFrame();
}
// Do your init stuff
}