[General Topics] Menneisyys:
As many users spend a lot of time watching YouTube (and other) Web videos, it’s definitely worth elaborating on the alternative technologies of playing them back.

First, let’s elaborate a bit on the two major formats YouTube content is delivered: the high-quality H.264 & FLV (with accordingly high data usage) returned by the firewall-friendly HTTP protocol, and the low-quality, low-(QQCIF) resolution 3GP (returned via the firewall-unfriendly RTSP protocol). We, of course, will mostly be interested in the high-quality version – unless we really need to decrease data usage and/or use a low-resolution mobile device like a MS Smartphone with a 176*220 screen.

The desktop YouTube Web interface isn’t the best for mobile usage (slow, huge – over 300 kbytes – pages; only Symbian + Flash Lite 3 is able to play back inline videos). There is a mobile version created and supported by YouTube, which

* Already supports all the functionalities of the desktop (account, upload etc)

* Is compatible with most mobile platforms having an RTSP / 3GP player like RealOne – no additional player needs to be installed

* Already has all the videos, unlike a year ago when it became public

However, it’s lower-quality 3GP only (no FLV / H.264) and requires RTSP. That is, it can be vastly inferior in most cases and, therefore, should be avoided.

The screenshot shows the results of a search using the native mobile YouTube interface (which, again, should be avoided, unless you absolutely don’t need the vastly enhanced video and audio quality of the FLV / H.264 videos).

Let’s continue with alternate YouTube technologies – ones that don’t depend on the Flash plug-in (because of the slow and flaky Flash plug-in on Windows Mobile) or are usable on other platforms like the BlackBerry. Fortunately, there are several of them; one of the most important is vTap.

vTap has native clients for all mobile platforms. From the Windows Mobile one (see the upper right screenshot), you can even initiate video playback (this client is highly recommended and useful because it’s capable of searching on not only YouTube but also other video sites), while you can’t do the same from the BlackBerry one.

This also means you’ll need to turn to other solutions to stream YouTube videos to your BlackBerry handheld; an example of these solutions is vTap’s Web interface (not the standalone client) depicted in the three screenshots at the bottom, showing searching for clips, opening them as a stream and, finally, the media player rendering it. (Note that the rendered contents is invisible in the screenshot on the bottom right. This isn’t a bug.)

Finally, one of the several alternative YouTube playback solutions is YTPocket, which depends on the external TCPMP FLV playback support (under Windows Mobile). The two screenshots show the results of a search and, then, initiating a download (and the consequent invocation of TCPMP for viewing).

Let’s move on to another, completely different, but, for users of non-unlimited data plans, very important question: reducing data usage. This, incidentally, can prove very helpful for users over unlimited, but very slow (for example, GPRS, like Vodafone’s non-3G dial-up) connections.

There are several ways of optimizations and major data usage saving; this slide discusses the way you can drastically lower the data usage by employing server-side (gzip) encoding, which is supported by all mobile browsers (for example, on WM, starting with the PPC2k PIE; that is, it has had support for eigth years).

As a rule of thumb, if you can, you should check the Accept-Encoding header (telling you whether the client is able to process gzip-compressed responses) along with the User-Agent HTTP header to find out whether it’s a mobile client (should you only want to return GZIP’ed contents for mobile users if you find GZIP compression is using too much CPU on your Web server). If you go this way, keep in mind that several mobile users “spoof” their User-Agent headers so that servers never return mobile-specific contents to them. With some of these clients (most importantly, IEM), you’ll want to look for specific extended (X-) HTTP headers to be able to make a distinction between desktop and mobile clients - that is, correctly identify mobile ones.

Note that several content manager and forum engines (e.g., vBulletin) support GZIP’ing “out of the box” if it identifies the client as a mobile device.