It's called AirVideo and it is absolutely one of the most amazing apps I have ever loaded onto my Iphone.
This is how good the picture can look
At home I have about 3GB of shows on my HTPC, ranging from regular XVids/AVI's to MPEG2, and H.264 HD movies of 11-15gb file size and this app streams all of them to my Iphone and plays them properly in HD picture quality when I am within my own Wifi range. When I am out of wifi range I can connect to the net via another wifi connection or use 3G-Unrestrictor and stream the movie to my phone. Of course cost for such high data use over 3G may not make that worthwhile but if you’re in a Hotel with Wifi or at work, etc. you can stream movies from home right to your iphone.
If you have the needed hardware (Iphone/PC/wifi router) then give it a try, it's great and they do have a FREE version that you can try before buying.
A few tips.
1) Make sure when setting it up that you use the server PIN. This makes it possible for Airvideo to find your PC no matter what IP it is on.
2) At home you can stream the videos directly without much problem, at remote locations you should lower the resolution and if that does not work, use the Convert feature and let it convert the video for you to MP4. That will be streamed much faster than on the fly conversion. BTW you might think the absolute lowest video settings would suck, but in fact they are still very good.
3) The added bonuses with AirVideo Conversion is that the MP4 file is left on your PC in the same folder with the original so the file can be added to Itunes manually and uploaded directly to your Iphone or deleted if you want. So in reality AirVideo gives you a free Video converter that converts just about any video format to MP4 and it does it super fast while not tying up your iphone.
Edited by dreadlk, 30 November 2009 - 02:57 PM.