High-definition television provides a crystal clear viewing experience, free from artifacts and with noticeably better quality than standard-definition television... right? Not so fast. Turns out Comcast and other providers of so-called high-def TV are intentionally compressing the video stream on many of their channels, sometimes by as much as 38 %, degrading image quality along the way. Why? Supposedly, it frees up bandwidth so the operators can pack in even more channels.
The news is the result of independent research from a user at AVS Forums, probably the best-known meeting ground for audio and video enthusiasts. Here, that user provides a wealth of examples and empirical data outlining the issue, complete with screenshots of what channels look like with standard compression and with Comcasts extra squeeze. Some of the channels dot look much different, but a few examples are particularly egregious, such as the 34.2 percent added compression applied to MHD, seen above in a "before and after" shot.
Note that this level of pixelization will be less apparent in a moving image than a still frame, bit some of the examples are so horrible they'd be obvious to even a casual passerby. Some commenters have noted that the compression is so bad they thought something was wrong with their equipment.
Comcast has yet to issue a response regarding this issue.
LINK: AVS Forum