Comcast Cable Communications, LLC, one of the largest cable providers in America, has decided to degrade high definition (HD) channels in order to add additional HD channels to its line up. The image quality degradation is quite apparent by the message board posting found here:

http://www.avsforum.com/avs-vb/showthread.php?t=1008271

Previously, Comcast had two HD channels per 38.8Mbps QAM (see http://en.wikipedia.org/wiki/Quadrature_amplitude_modulation ), so each channel had the full 19.4Mbps bitrate 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. - Paraphrased from the AVS Forum post

This petition is to get Comcast to only allocate two HD channels per QAM, therefore returning high quality broadcasts and to drop lesser rated channels in order to bring more HD content to its customers. We understand that the spectrum can only contain so much and are willing to sacrifice channels that aren't often watched for video quality on the "higher class" HD channels. After all we do pay extra for HD content.

If that is not an option then they should provide all of their subscribers with digital converter boxes and do away with analog channels so that HD quality broadcasts remain in all their high definition glory. This will free up the spectrum tremendously and give Comcast a competitive edge against Verizon FiOS.