Streamed Video Playback On The Xbox 360: Queuing Exploited

As I’ve previously discussed on several occasions, the Xbox 360’s early-May firmware update enabled the ability to stream DRM’d video (from Amazon Unbox, CinemaNow, Movielink, etc) to the console from generic Windows XP Home- and Professional-based PC clients, albeit in an imperfect-navigation fashion. I’ve replaced the Toshiba HD-A1 HD DVD player with an Xbox 360-plus-HD DVD drive combo (which is now tethered to the Samsung plasma display via good old analog VGA cabling), and last night I decided to use up some accrued CinemaNow account credit by watching 28 Weeks Later, which had just that day become available for rent from the service.

Since the file’s fully downloaded now, I can tell you that its total size is 1,204,235,373 bytes. CinemaNow reports it as being a ‘Premium 1,500 kbps’ presentation, and if you divide the file size by the movie’s 1:40:06 runtime, you’ll end up with just over a 1.6 Mbps average bitrate. My DSL bandwidth enabled me to sustain a 170 Kbyte/sec (i.e. 1.36 Mbps) download speed from CinemaNow’s servers to my laptop…but that still translated to a two-hour delay until file download was complete.

Fortunately, the video player built into CinemaNow’s client application supports progressive download; when the player estimates that enough of the file has downloaded such that the download will finish before your playback of it ‘catches up’ (assuming, of course, that you don’t fast-forward), it enables you to begin watching from the beginning. In my case, considering the bitrate discrepancy between playback (1.6 Mbps) and download (1.36 Mbps), the CinemaNow player reported that the movie was ready to watch after download was ~20% done.

I wanted to watch the movie on the plasma display via the Xbox 360, though, not directly on the laptop. On a hunch, I decided to see if progressive download capability extended to subsequent streaming to the console acting as a Windows Media Extender. I’m happy to report that it actually worked, albeit with a few more hiccups. The laptop was connected to my router via 802.11g; the console was connected to that same router via HomePlug AV. The Wi-Fi aspect of the setup’s performance was particularly impressive; through a single ‘54 Mbps‘ link the laptop was simultaneously downloading a video file from CinemaNow’s server and uploading a different portion of that same file to the Xbox 360.

What about those ‘few more hiccups’, though? Well, as I’ve previously mentioned, you’re unable to rewind and fast-forward through the video. I later discovered that you are able to use the previous- and next-track buttons on the Xbox 360 Universal Remote to navigate forwards and backwards in 10-minute chunks of time…but only, I discovered last night, after the file has finished downloading. Last night, partway through the movie, I hit the previous-track button to replay a particularly gross scene…and playback froze. After I exited to the console GUI, the only option available to me was to replay the film from the very beginning. Today, in contrast, with the entire movie sitting on my laptop HDD, I can navigate through it via the previous- and next-track buttons just fine. I can now also completely stop playback and later resume where I left off.

p.s…regarding my earlier ‘gross’ comment, I highly recommend you not watch 28 Weeks Later while eating dinner…especially if red pasta sauce is on the menu. Ahem