NNSquad - Network Neutrality Squad
[ NNSquad ] Comcast increasing compression of some HD sources
[ This is not an Internet Network Neutrality issue per se, but
since it involves an ISP taking source digital signals and
reducing their quality before passing them along to customers
(presumaby without any warning to subscribers or reductions in
the fees that subscribers pay for those channels) it still seems
interesting. As the article notes, this has been a common
practice by satellite video providers, and if cable generally
goes the same route they may be eliminating a key advantage that
cable has had against satellite in terms of image quality. Of
course, cable is also attempting to find ways to match the HD
channel *quantity* advantage of satellite, and content sources
are not necessarily in a "political" position to complain about
such practices if they want continued carriage. I believe there
are some useful parallels with the Internet cases that we
usually deal with.
-- Lauren Weinstein
NNSquad Moderator ]
------- Forwarded Message
From: David Farber <dave@farber.net>
To: "ip" <ip@v2.listbox.com>
Subject: [IP] Comcast HD Quality Reduction: Details, Screenshots - AVS Forum
Date: Wed, 2 Apr 2008 08:40:28 -0400
http://www.avsforum.com/avs-vb/showthread.php?t=1008271
Comcast HD Quality Reduction: Details, Screenshots
Last updated: March 24, 2008
Until recently, most Comcast systems passed all HD as is from the
content provider, without any added compression or quality reduction.
In response to competitive pressures from DirecTV and Verizon FiOS,
Comcast recently decided to sacrifice some quality to improve
quantity. By early April, most Comcast systems will recompress and
degrade their HD, much like DirecTV and Dish Network do on their
MPEG-2 channels. This creates room for new HD channels without the
need to eliminate a significant number of analog channels.
Previously, Comcast allocated a maximum of two HD channels per
38.8Mbps QAM, so each channel had the full 19.4Mbps available if
needed. Now, with the addition of new channels, Comcast is squeezing
three HD channels into each 38.8Mbps QAM. Furthermore, some existing
QAMs with two HD channels are being recompressed in preparation for
new channel additions.
But what does that mean? How much difference is there, really?
To find out, I decided to compare the quality of the same programs on
Comcast and Verizon FiOS. I recorded the same program from the same
channel, at the same time, on both Comcast and Verizon FiOS in N. VA.
I compared the size and bitrate of each MPEG-2 recording, as well as
the subjective quality with video.
Note when I tested channels late last year, there were no differences
between the two providers on HD. Any differences are new.
picts etc follows djf
- -------------------------------------------
Archives: http://www.listbox.com/member/archive/247/=now
RSS Feed: http://www.listbox.com/member/archive/rss/247/
Powered by Listbox: http://www.listbox.com