Directivo, TivoNET, and ExtractStream

[son_of_mogh_worf@h...]

--- In ExtractStream@y..., sharkey@a... wrote:
> Somehow I doubt that DirecTV's encodings are really that much better 
than
> the SA Tivo's best quality recording. And if they are better, the
> difference is too small to be significant. I almost never use best 
quality
> becuase I don't feel that I need better than medium for most things. 
Yes,
> I can tell the difference, but I don't really care.

Well, at least DirecTV's encodings are more bit-efficient, thus their 
bitrate is lower. I mean, at the Best encoding rate, the bitrate is 
higher than that of a DVD! Yet the picture with the cleanest of inputs 
does not look like a DVD, and I'm sure DirecTV's streams don't look 
like a DVD... thus, lies the truth of encoders -- quality for a given 
bitrate. Even using VBR, I doubt the SA TiVo encoder would generate 
pictures equivalent to the quality of a DVD (assuming perfect 
digitization, etc), given DVD bitrate. Heck, DVD's aren't all that 
perfect either... (Again, it's the cost issue. A remastered DVD might 
get the "premium" treatment and go through a costlier encoder to 
achieve the better quality, while a crappy movie goes through a 
TiVo-ish type encoder). That's the nice thing of MPEG encoding. The 
final output is dependent on the quality of the encoder. You want 
cheap output, you use a crappy encoder. You want 
excellent-digital-theatre-quality-output, you pay the $$$ for a higher 
quality encoder.


> DirecTV pays a lot more for their encoders because they can handle 
multiple
> streams. How many channels do they provide? They have to encode 
all
> of them simultaneously. That's something that just can't be done on 
a
> $200 box at any quality. (And licensing the required patents from
> the MPEG LA scales with the number of channels which can be 
provided, so
> the cost goes up there, too.) $10K+ sounds pretty cheap to me.

Maybe it's $1000/channel. Havne't priced broadcast-quality equipment 
lately. Plus, not all feeds are analog -- some of the more premium 
channels do digital encoding themselves rather than leaving it in the 
hands of a 3rd party who has to encode it...

Anyhow, a $200 box, times lets say, 200 channels, is only $40,000 or 
so. So there's a reason... (lets see, 200 channels, or 40 channels, 
you decide...). Of course, there is the added aspect that well, 
DirecTV has to fight for bandwidth - the bandwidth is limited to each 
dish, and you gotta fit all the programming into that bandwidth -- VBR 
helps, as does bit-allocation schemes and whatnot, but I'm sure the 
equivalent output has a much lower bitrate for the same quality (case 
in point... a 60 hour DirecTiVo has how much disk space? 45GB? at 
"best" quality... heck, that out-beats "basic" quality on bitrate...)