Long time streaming industry encoding guru Jan Ozer compiles statistics each year on his blog (http://streaminglearningcenter.com/articles/average-us-broadcasters-streaming-at-837-kbps-total-data-rate.html) that you can use as a rough guide for determining what video data rates, sizes, codecs, and other specs are being used by the big players, and consequently what you might want to use in encoding your videos to reach off-campus audiences.
Looking at organizations such as the NY Times, WSJ, CNN, ESPN, and others, Jan concluded in December that “the average video configuration was very close to 640×360, with a combined audio/video data rate of 837 kbps (758 kbps video, 79 kbps audio).”
To do this study he downloaded videos from these sites, and used industry tools such as Media Info (available for free for Mac and PC here http://mediainfo.sourceforge.net/en/Download) to analyze the videos for detailed technical information about how they were encoded. All the specific results are tallied up in this spreadsheet in case you’re interested in looking at what any particular site is delivering https://docs.google.com/spreadsheet/ccc?key=0AiziwopFYajsdFg5T2ptcllrWHo4ZE4wVkhtaDY4cGc#gid=0
One additional point he makes in his post is that the data rates many of these companies are using don’t seemed to be constrained primarily by available bandwidth, but instead by bandwidth costs, since the the average broadband download speed seems to be currently around 3.0 Mbps.
A lot of us who work with encoding on campus have historically used data rates between 300 and 800Kbps for off-campus delivery, and certainly any project should take into consideration constraints of its users as specifically as possible. But in general, given all of the above, maybe it’s time for us to be a little bit more generous with our encoding specs.
