Mobile Blog: Video, Media, Augmented Reality, Rich Media, IVVR

First of all, Windows Mobile is so close to Windows for desktop PCs that you might expect to install some of the applications you know from your desktop on your mobile. Media Player, Outlook and Office Mobile, including Word, Excel, PowerPoint and so on -it’s all included in WM6.5 Pro. What’s left? A good mobile media player! WM6.5 Media Player doesn’t like my DivX movies and some MP4 files. For DivX there is a solution: DivX Mobile Player for Windows Mobile. Note: Although DivX Mobile supports the latest DivX codec features, your mobile processor is limiting your mobile video experience. I’ve downloaded a DivX movie from the Internet and tried it on my phone: The sound was fine, but the video was choppy. After some experiments I saw, that a video bit rate above about 300 kbit/s is causing problems. For the technical folks: It is not really the bit rate, but the complexity of the encoding that makes the mobile processor go nuts. The higher the bit rate and the higher the complexity, the more likely the video, or even the sound will be choppy.

DivX Mobile Player is for free, but it doesn’t support native MP4 containers with h.264. Therefore I bought CorePlayer Mobile for $30. It’s nice, but not really worth 30 USD. It doesn’t offer as many codecs as VLC or mplayer, and it’s user interface is too desktop-alike. CorePlayer Mobile has a lot of submenus; you need about 4 clicks to activate the fullscreen mode! Unfortunately, VLC for Windows Mobile isn’t available yet: VLC forum.

photo credit: Iain Farrell

Even with a great deal of marketing, early attempts to convert users to the video telephony technology flopped (Jones and Marsden). In contrast, desktop video conferencing is incredibly popular for private person-to-person conversations and widely used for video conferencing in business environments such as telepresence for computer-supported cooperative work (CSCW).

In desktop video conferencing scenarios, typically a stationary computer is used. Camera and microphone are fixed and usually maintain the same distance from the person participating during the conversation. Moreover, lighting conditions are generally better than “on-the-go”, as a desktop is easier to illuminate correctly than a scene in the mobile environment. When performing mobile video telephony, lighting conditions change over time when the caller moves or the environment changes; moreover, the camera is usually not fixed. During mobile video telephony, the caller is likely to hold the handset in front of his face by extending his arm, making the video wiggly. In combination with the meagre bandwidth and low-resolution video, this can considerably degrade the video quality shown on the callee’s side. These considerations about the video quality problems in the mobile environment also play a major role in IVVR (Interactive Voice & Video Response) applications that take advantage of the instant video streaming capabilities that 3G-324M video telephony offers. Bad video quality negatively influences camera-based games, gesture recognition, or P2P (Peer-to-peer) services that intentionally change the video for dynamic video overlays such as for the P2P Avatar, because motion analysis algorithms perform better with a sharp and clear video signal.