Openreach engineers 4th visit...

[MissRiaElaine]

Best of luck doing that with us, not enough savings to worry about, apart from anything else :-(

[tahrey]

replying to Martin Brown, tahrey wrote: I dunno, depends on the compression level and codec efficiency. It's more than

4x what DVD could deliver, with a relatively inefficient MPEG2 codec, so it would be way more than enough for regular 1080p with MPEG4 at mid-level settings (for comparison, Blu-Rays and consumer HD camcorders, plus phone HD recording, tends to sit somewhere in the mid 20s megabits). If you could improve the encoding efficiency twofold - turning the MPEG4 settings all the way up for example - then 8K would be entirely possible. And that's assuming you want/need the same compression level at the pixel-by-pixel level, which isn't necessarily so. As resolution increases, the amount of compression you can get away with also increases by a lesser degree. After all, there are more macroblocks in an 8K image than there are individual pixels in a DVD frame, so the picture can "break up" quite badly due to insufficient bandwidth and it still wouldn't end up looking any worse than an upscaled DVD - the flipside being that much greater areas of a typical image can be compressed very hard, even down to the level of macroblocks having a single solid colour (something that on a DVD, and particularly a VCD, would look horrific outside of some very specific situations), and it won't visibly corrupt the output because that's essentially what the output looked like in the first place, other than for a little random noise.

And framerate plays a big part in such cases. If it's cinematic material, you can easily halve the demands vs televisual; all the BBC iPlayer HD streams run at a flat 25fps regardless of source (meaning judder can get quite noticeable, especially vs the broadcast originals), and they're delivered at a constant rate of 12Mbit... without any further compression that implies no more than

48Mbit for 4K, and that using the extremely primitive CBR mode of compression (and a very low level MPEG4 model) which even pirates making home-use VCDs of DivX downloads back in the day thought was old hat and inefficient.

[Jim K..]

No but he's lurking...