Cabal
Premium
join:2007-01-21
Boston, MA
| reply to partysource
Refresh my memory
Obviously more compression = more data in the same bandwidth, but does MPEG-4 offer lossless compression or just lossy? I'd think people would be clamoring for uncompressed, higher quality HD content.
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nanoflower
join:2002-07-14
30876
| MPEG is designed for lossy compression. It's just designed so that you won't notice the compression unless the video is highly compressed. Given the desire to keep adding more channels I don't think you will ever see uncompressed HD video on cable or satellite.
To get back to what you probably meant to say, I don't think you will see lossless HD video on cable or satellite. Maybe a channel or two for special events but the majority will be heavily compressed so they can put in more HD channels. Now with Switched Digital Video they might could go to uncompressed video, or lossless compressed video but I doubt that will happen. |
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davoice
join:2000-08-12
Saxapahaw, NC
 ·Comporium
| For most people the compression isn't visible. What is visible is how well the signal is handled before and after it gets compressed.
A first generation transcode of a 1080i uncompressed feed compressed w/ MPEG4 looks pretty much as stunning as the original (except for fast motion).
The big problem is that in most cases the cable company (and the satellite providers to some extent) is recompressing and retranscoding a signal that has already been compressed or degraded somewhere else along the way.
Here, DirecTV and DishNetwork have an advantage when it comes to national channels. They only have to get the original signal back to 1 main location. For the cable companies they need that same national signal available to each and every head-end. That enables the satellite companies to spend a little more to get a good signal back for those channels - i.e. direct fiber feeds from the originating programmers instead of pulling it off of c-band or similar.
Now for local channels it's the opposite. Satellite companies have to push all these local broadcasts back to their main hub. Pulling all those locals in costs a lot of money. To maximize capacity, most of them are highly compressed in transit. The cable companies can pull the native format signal out of the air locally with much less trouble and potentially no backhaul. Or for larger/remote cities they may have a fiber feed from the local TV station.
}Davoice |
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