What does "Up to 45 hours" really mean?

[Padwen]

When I bought my 40 hour Series 2 I was disappointed to find that it actually only recorded about 11 hours of programming at an acceptable viewing quality. Now that I have an HDTV I'm looking to upgrade to an HD Tivo and I'm curious to know what the Premiere's "Up to 45 hours" really means. Does that mean 45 hours of uncompressed 1080p programming, or does it mean 45 hours of horribly compressed 480i programming?

[dbenrosen]

It means 45 hours of HD programming. Currently there are no broadcasts at 1080p.

Each provider/station is different in terms of resolution and compression. The TiVo records the digital HD signal as is, making no modifications. The more compression from the provider, the less space the program takes up (and the slightly lower quality). The 45 hours is an estimate of the average size of an HD broadcast. YMMV, but it should be fairly close to 45 hours of HD.

[SeanC]

Does that mean 45 hours of uncompressed 1080p programming, or does it mean 45 hours of horribly compressed 480i programming?

No, because HD Tivos don't do anything to digital streams that they receive. What your service provider sends over the line is what your Tivo saves.

[flaminiom]

All digital programming comes in at different bitrates. The bitrate of programming will determine how many hours of programming you can store. Some cable channels are highly compressed, others are less. Antenna/OTA is the least.

I'd be curious to know what bitrate 40 hours is based on.

[aaronwt]

When I bought my 40 hour Series 2 I was disappointed to find that it actually only recorded about 11 hours of programming at an acceptable viewing quality. Now that I have an HDTV I'm looking to upgrade to an HD Tivo and I'm curious to know what the Premiere's "Up to 45 hours" really means. Does that mean 45 hours of uncompressed 1080p programming, or does it mean 45 hours of horribly compressed 480i programming?

If it was uncompressed you couldn't even hold one hour of HD.

[ewilts]

Also remember that many digital shows are in SD, not HD. Those take a LOT less space. If you're recording stuff for which PQ is not that important (like cartoons, news, or talking heads), then you can choose to record those on an SD station and save the space for more important stuff like football or basketball for which HD adds a HUGE improvement on the quality of the experience.

[b_scott]

If it was uncompressed you couldn't even hold one hour of HD.

uncompressed DV (non-HD) is 16GB an hour :eek:

[gweempose]

Yep. Even Blu-ray is highly compressed compared to the original digital masters.

[wmcbrine]

In this case it means "320GB".

The highest bit rate you'll find on broadcast, and probably on cable, is 19.2 Mb/s, which would translate to about 38 hours. Most HD will be a little less than that, so you get a little more capacity. But in the end, "45 hours" can only ever be an estimate.

[fatlard]

Right

For the Tivo Premiere 45 is up to 45 hours of high definition with is built in 320GB HD


For comparison sake

Moxi has up to 75 hours of HD with it's 500GB HD.

[jdgarrido]

And the Premiere XL is 150hrs of HD compare to Moxi 75hrs

[fatlard]

And the Premiere XL is 150hrs of HD compare to Moxi 75hrs

Yes they are the same price initial purchase price as well.

Just for the tivo you have to pay month fees or buy a life time sub at $399 extra.
:up:

[brianric]

Just for the tivo you have to pay a life time sub at $399 extra.
:up:
$199 in my case.

[jmX]

Yes they are the same price initial purchase price as well.

Just for the tivo you have to pay month fees or buy a life time sub at $399 extra.
:up:

It sucks that Moxi doesnt have any tuners in it. For the few cheap people out there watching over the air HD, that rules it out. For those wondering who'd have a TIVO without cable/sat, keep in mind that with much less channels on TV, you *really* need a DVR to harvest what little there is..channel surfing broadcast sucks.

[Padwen]

Thanks everyone! Now I understand a little better what I'm about to buy.