Joost's Live Test: Hiccups and Workarounds
Continued from ‘Joost’s Live Test: No Antenna? No Coax? No Fiber? No Problem‘….
One of the icons placed in the Windows XP Start menu during installation is labeled ‘Attempt to repair Joost’. That was my next step. When Joost re-launched, I got a prompt to re-enter my login details, the program window came up in 800×600 resolution mode, and all was well. I attempted to enter full-screen mode…and the video locked up again. A-ha!
After some more trial-and-error testing, I think I have a handle on what’s going on. Joost runs fine full-screen on my laptop’s built-in LCD, at the display’s native 1280×800 pixel resolution. It also runs fine on the VGA-tethered Hanns.G LCD, at window sizes of up to 1280×1024 pixels in resolution. But if I attempt to stretch the Joost window beyond those dimensions, or to run Joost full-screen on the 1920×1200 pixel LCD, I get video lockups.
Every 10 minutes or so, Joost would crash, and I’d be prompted to relaunch the program:
I eventually figured out that if I switched from the ‘high quality’ to ’standard’ stream, the crashes completely went away. Frankly, I didn’t discern much of a quality difference between the two streams, anyway, the ‘high quality’ version might have had slightly smoother playback and/or more per-frame detail, but to call either high-def would be a stretch. I’m not sure what the differences between them are from an implementation standpoint; if any of you know which stream(s) employ CoreCodec’s H.264 algorithms, for example, I’d welcome your insights.
I’d also occasionally encounter ’signal loss’ (gotta love the traditional broadcast-reminiscent terminology!), especially with the ‘high quality’ stream:
Given that Joost came from the founders of Skype, it likely won’t be a surprise to you to learn that Joost also employs peer-to-peer content distribution techniques. As I’ve written before, Joost makes pretty hefty bandwidth demands, and the error messages could have referenced temporarily starved client-side buffers caused by hiccups in the Wi-Fi (LAN) or DSL (WAN) connections, or both. Presumably, the ‘high quality’ stream also was the lower-popularity of the two, translating to fewer Joost ’supernodes’. With that all said, I never had to re-launch the Joost client or otherwise intervene; after a few seconds’ delay, the game would automatically re-appear on screen.
But these are all minor ‘nits’, which will inevitably get resolved over time. Any of you who are familiar with multicast topologies will likely agree with Joost’s disclaimer:
It’s a pretty complex technology
especially given that in this case we’re talking about a distributed-server-rebroadcast P2P architecture. All things considered, I’d call Joost’s live TV experiment a tremendous success.