The similarities between these apps go quite a bit deeper than their identical price points. Both of them include a free server app that, once launched, appears as a menu extra with an Airport-esque icon (Air Video Server's icon has a filmstrip; StreamToMe's app, called ServeToMe, features a Play button). Air Video also has a Windows version of its server app, while the Win version of ServeToMe is in development.
Both server apps leverage the open-source ffmpeg project for video transcoding, and both can handle an impressive array of video codecs and format wrappers (lists here and here, respectively), including the EyeTV MPEG container format. Air Video's Mac server requires 10.5.6 or higher and is a Universal app; ServeToMe requires 10.5 and is Intel-only.
I didn't get a chance to test Air Video on PPC, so I can't speak to performance there, but I wouldn't expect to handle high-rate video on anything but a Core 2 Duo Intel machine. Both apps also support streaming over the Internet, and will attempt to set your UPnP router to allow the correct port mapping automatically; Air Video has a handy PIN code feature, which "bookmarks" your external IP address so you don't have to remember it. My home network setup is notoriously sharing-hostile, but I'll try to test out the remote streaming features of both apps soon.
Setting up both servers is quite straightforward: run them, add the folder paths where your videos live, and then leave them be. Air Video's interface is a bit more utilitarian, with six panes of settings with a traditional preferences look, but it gives you fine control over sharing ports, conversion preferences, streaming bandwidth, and more. ServeToMe has far fewer controls, but delivers them with a slightly more sleek and modern look.
On the iPad side, the app similarity continues; the trend of more control on the Air Video side, and more thought-through design on the StreamToMe app is also apparent there. StreamToMe automatically displays any serving machines on your local network; tap on one to display the lists of folders, tap again to see the list of videos. You can select three different playback/repeat modes, sort the video list as you like, or "flatten" the subfolders displayed into one long list of videos (very handy). StreamToMe also follows the iPad UI convention of supporting all navigation and playback in both landscape and portrait modes, so if you want to play back a movie while your iPad is sitting vertically in the dock, you're all set.
Air Video is a landscape-only app, so the dock show is a no-go. It also has an extra tap or two involved in adding the server machine to your list, but it's easy enough to roll forward once you add it. As with the server app, there are several additional controls and buttons, including a Global Settings option that lets you adjust the maximum resolution of your files and available bitrates for live streams.
It's a familiar refrain, but playing back a video shows the same basic rule in force: StreamToMe is a "one big button" kind of app, with simplicity on its side. Tap the video name and it begins to play; quality may start out a bit choppy but tends to improve after 15 seconds or so as the iPad negotiates a maximum rate with the server. If you keep an eye on Activity Monitor back on your Mac, you'll see the ffmpeg process spike to 100% processor usage or more as the video is transcoded for streaming.
With Air Video (formerly known as Wi-Fi Video), as you may have guessed by now, you get feedback and choices. To begin, the playback area reports the movie's resolution, file size and duration. For source files where the iPad can't natively handle the format (anything other than .mp4 and .mov/H.264 files, by and large) you get two options for playback: Play with Live Conversion (instant streaming) and Convert. Clicking the Convert button queues up an offline transcode back on your server machine, which you can track with the Queue button above -- for slower servers, this may prevent jerky playback on high-res files, but you will need to wait for the process to complete before streaming the clip. Serving from my Core 2 Duo iMac, I got good results by using Play with Live Conversion on AVI and other files.
For natively-playable .mp4 files, Air Video gives you another tool in the utility belt. These videos add a simple "Play" button, which means that the straight H.264 stream will be sent across the network, sans transcoding. This may take a moment or two longer, but the results are great -- clear and highly watchable video, on demand.
When it comes to quality, both apps did well with a variety of MOV and AVI files at standard resolutions, including camera recordings and downloaded content. The surprise came when I tried to play back a set of TV episodes (The West Wing) that I had converted from DVD (using Handbrake) into iPhone-friendly .mp4 files. Air Video played them back smoothly and cleanly, whether using the Live Conversion mode or the straight Play approach -- they looked great.
On StreamToMe, unfortunately, the same files didn't look great; blocky playback and heavy artifacting were the norm. This was the only filetype where I saw a dramatic difference in quality, but unfortunately, it represents a large chunk of my video collection. I did check with the developer about playback quality, and he suggested that it should improve after a few moments of streaming; I didn't observe that, but your mileage may vary.
I expected my preference in this faceoff to be pretty narrow, since these apps are so close in so many ways. StreamToMe is easier to use, and the portrait-mode support is a lot more useful than one might think. Unfortunately, the quality hiccups I experienced with .mp4 files make me uneasy about it. Still, for $2.99 it's a bargain, and if you try the free Air Video Lite but decide you need portrait mode, it's a worthy choice.
What tips the balance in favor of Air Video, aside from the playback quality edge, is the availability of the free Lite version of the app. It limits your video listings within folders to just the first few files, but that's more than enough of a preview to know, immediately, whether or not the app is going to work the way you want it to, with the files you normally play. I miss the portrait playback option and some of the UI refinements, but considering that the Air Video team is operating from iPad-free Europe and has had to do most of the work on this version without access to hardware, it's quite impressive.
Here's hoping that your video streaming fun is unimpaired and rapid; thanks for reading this TUAW Faceoff, and if you have great ideas for the next two-product showdown, please do let us know.