Originally Posted by BrightonJohn
Good question - I would have to guess that we get the feed on TiVo from different SKY dishes locally - so down here they are based at Shoreham Harbour (I believe) and then distributed across our local cable network. BUT I could be totally wrong about all or any of this. Are there any reliable websites or journals that discuss how all of this stuff works?
cableforum.co.uk is as reliable as it gets
VM acquire almost all channels centrally in Langley, so they start out the same. The sync should stay the same as the signal progresses throughout the VM network, as it is encoded into the digital signal. But once it's into the decoder in the STB, and through the equipment in your home, there is the potential for a little delay to the audio and/or video at each stage. If the audio and video get delayed by similar amounts, they cancel each other out and end up in sync. On the other hand, if either the audio or video gets consistently delayed more at each stage, they can end up a long way out. The delays might vary depending on things as subtle as which video resolution you use.
Also some people are more sensitive to sync issues than others.