TiVo Community Forums Archives - More space available with 2.5.1?

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More space available with 2.5.1?
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Posted by: jpx

Is it true that more space for recordings is availble on 2.5.1? If so, how much more?

I'm quite the poster today!

Posted by: feldon23

More space is not magically available.

Shows recorded with VBR (Save Disk Space) feature enabled will use less space than they would under 2.0.1, especially if the channel is off a clear source (Satellite or digital cable) and if the program doesn't have a lot of action and movement.

Save Disk Space does not work with Basic. It is designed for Medium, High, and Best quality. I'd be thrilled to death if I could record 18-20 hours of Medium on my 20 hour TiVo. That would make my day http://www.avsforum.com/ubb/smile.gif

I can already see the 20 page articles here on the TiVo forum about whether the Save Disk Space affects the picture quality enough to warrant turning it off. Let the games begin http://www.avsforum.com/ubb/smile.gif

http://www.avsforum.com/ubb/biggrin.gif

[This message has been edited by feldon23 (edited 10-17-2001).]

Posted by: zaknafein

quote:
Originally posted by feldon23:
I can already see the 20 page articles here on the TiVo forum about whether the Save Disk Space affects the picture quality enough to warrant turning it off. Let the games begin http://www.avsforum.com/ubb/smile.gif

http://www.avsforum.com/ubb/biggrin.gif

Well, I would theorize that VBR shouldn't cause a degradation in picture quality. It should, if anything, help quality, since the scenes that require more information to encode will get a higher bitrate. Only time will tell I guess. Hopefully, TiVo sends me the update soon...

[This message has been edited by zaknafein (edited 10-17-2001).]

Posted by: Gigabit

quote:
Originally posted by zaknafein:
Well, I would theorize that VBR shouldn't cause a degradation in picture quality. It should, if anything, help quality, since the scenes that require more information to encode will get a higher bitrate. Only time will tell I guess. Hopefully, TiVo sends me the update soon...

I got 2.5.1 last night and can say that VBR does effect the quality somewhat, but I can't really say that it's worse, it's just different. It seem to me that it actually improves the sharpness considerably on some scenes but introduces noticeably more blockiness on other scenes. What I've done now is set the default quality to "best" with "save disk space" enabled. I like what I see so far and will be counting the number of programs in "now playing" to see how much I'm saving.

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Sony SVR-2000 with single 100GB Maxtor HD

Posted by: mikebridge

i would think that it would depend on the signal source. garbage in == garbage out. directv/dish users would probably love it the most since their signals are typically MUCH better than OTA or coax connections.

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"I'm coming for you, Pork Chop!" "Bring it on, Fat Boy!"
Captain, TiVo Special Forces (TMNBT) / TiVo Code - Alpha:
P1>UM/23/US/IL T1 Wbcfijklm C[f++ acez+ $p--] E3
T1>MP30 V2.0.1 Q- C+ $+ V+ S- P+++ W[ak+++ t++ d]

Posted by: dalesd

I noticed more space on my TiVo after getting 2.5 yesterday.

I previously had 127:35 at basic, now I have 128:10. This is according to the system information screen.

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Dan. Sony SVR-2000 ver 2.5.1, 128 hours
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Posted by: Otto

The increase in space on the system info screen is not related to VBR. It's a bug fix where the calculation was being done wrong before.

VBR shows no space changes when enabled, it simply has a bit more room. How much room is up for debate, because there's no way to know how much it will save, exactly.

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<FONT size="1">All comments made in this post are my opinion and my opinion alone. Deal with it.
Otto, Zen TiVo Master - Moderator - AVS Tivo Forums - Tivo Underground, Tivo Coffee House
"The way of the portable computer user is as a stony path strewn with plugs and sockets, all the wrong size..." -- Terry Pratchett</FONT s>

Posted by: HTH

So who's going to be the first to make a grab for the crown?

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http://www.war-of-the-worlds.org/tivo/HTHb.gif

Posted by: DavidMorales

quote:
Originally posted by mikebridge:
i would think that it would depend on the signal source. garbage in == garbage out. directv/dish users would probably love it the most since their signals are typically MUCH better than OTA or coax connections.

DSS feeds (DirecTV/Dish) are already VBR encoded and simply written to the hard disk directly with not loss in quality. Your DSS providers make use of very expensive encoders at the point of uplink to satellite and the information beamed down to your dish is typically a 3.5 - 4 Mbps VBR MPEG2 stream. DirectTiVo would hence have no “Save Disk Space” option.

Posted by: zaknafein

quote:
Originally posted by DavidMorales:
DSS feeds (DirecTV/Dish) are already VBR encoded and simply written to the hard disk directly with not loss in quality. Your DSS providers make use of very expensive encoders at the point of uplink to satellite and the information beamed down to your dish is typically a 3.5 - 4 Mbps VBR MPEG2 stream. DirectTiVo would hence have no “Save Disk Space” option.

Clearly. This is a discussion of 2.5.1 for SA boxes. Those who have a SA DirecTV/DISH receiver and a SA TiVo should see the most benefit from VBR. DirecTiVo is completely unrelated.

Posted by: feldon23

You're describing what a DirecTiVo does. Unfortunately, no setting on a standalone will directly record what DirecTV, Dish, or Digital Cable provide using their pricey VBR boxes.

It's the lack of analog picture noise and shifts that will make Dish/DirecTV/Digital Cable great sources for the Save Disk Space feature on standalone TiVos.

Posted by: MighTiVo

quote:
Originally posted by zaknafein:
Well, I would theorize that VBR shouldn't cause a degradation in picture quality. It should, if anything, help quality, since the scenes that require more information to encode will get a higher bitrate. Only time will tell I guess. Hopefully, TiVo sends me the update soon...]

VBR can work in several ways, while you could say try to maintain an average bit rate going up or down x% you could also say use a minimum bit rate going up x% or use a maximum bit rate going down x%. It seems TiVo uses the latter, a MAX bit rate equivilent to the old CBR rate and then will drop x% if it doesn't need it, thus Saving Disk Space for a given recording quality.

Anybody willing to share the technical details of how VBR was implimented on TiVo?

Posted by: Tiger

What VBR will do is not necessarily increase or decrease picture quality, but make the picture quality more consistent across scenes. As a side effect, it uses less space, because some scenes just don't require much compression to get a decent picture.

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TMNBT Special Forces
Are we not men? We are TiVo!

Posted by: teflon

quote:
Originally posted by Tiger:
What VBR will do is not necessarily increase or decrease picture quality, but make the picture quality more consistent across scenes. As a side effect, it uses less space, because some scenes just don't require much compression to get a decent picture.

Actually you mean some will use less space because some scenes can be compressed MORE not less.

Posted by: Otto

quote:
Originally posted by MighTiVo:
It seems TiVo uses the latter, a MAX bit rate equivilent to the old CBR rate and then will drop x% if it doesn't need it, thus Saving Disk Space for a given recording quality.

Anybody willing to share the technical details of how VBR was implimented on TiVo?

I'm willing to bet that this is how it was done. Worst case = CBR.

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<FONT size="1">All comments made in this post are my opinion and my opinion alone. Deal with it.
Otto, Zen TiVo Master - Moderator - AVS Tivo Forums - Tivo Underground, Tivo Coffee House
"The way of the portable computer user is as a stony path strewn with plugs and sockets, all the wrong size..." -- Terry Pratchett</FONT s>

Posted by: jmccorm

Does this mean we can elect a new TiVo King!!?!

quote:
Originally posted by Otto:
The increase in space on the system info screen is not related to VBR. It's a bug fix where the calculation was being done wrong before.