TiVo General TiVo Discussion Part 2 - Page 407

zekeisaszekedoes · 27-11-2011, 14:12

From what I know both TiVo types are identical apart from hard drive size and have the same modem. This is a DOCSIS2 modem not a DOCSIS3 like Super Hub or VMNG300, so from the way VM arrange their network it should be capable of the same speeds as the old small blue/black Ambit 250/255/256 modems which is 20Mb maximum. Can't see a need for the speed to be doubled in the foreseeable future but who knows what VM have in store?

HDFootyMan · 27-11-2011, 14:25

Quote:

Originally Posted by spiderplant

but so does video compression, so you need less bandwidth not more. A few years ago it wouldn't have been possible to get decent HD on a 10meg connection.

True, you can stream 1080p content with 5.1 surround sound now on sub-10Mb connections from Xbox Live, so while 20Mb would be nice, I can't see much need for it....yet.

And on the subject of streaming, my new blog may be of interest:
http://uktvstreamingservices.blogspot.com/

27-11-2011, 14:26

I take it that at the moment like all HD content it is still compressed as Mpeg2 on all VM boxes including TiVo? With Mpeg4 compression in the potential future TiVo would need even less bandwidth!

zekeisaszekedoes · 27-11-2011, 14:43

Yup, all VM streams whether SD or HD are MPEG-2, to ensure compatibility with the half a dozen different STBs on their TV network. Can't see this changing for at least a couple more years.

nstokes · 27-11-2011, 14:56

is Mpeg 2 better than Mpeg 4

27-11-2011, 15:00

Quote:

Originally Posted by zekeisaszekedoes

Yup, all VM streams whether SD or HD are MPEG-2, to ensure compatibility with the half a dozen different STBs on their TV network. Can't see this changing for at least a couple more years.

I suppose that VM only actively support 4 box types at present, the 2 new cisco boxes including TiVo and fault replacement for both Samsung V+ and it's SD counterpart! For all other boxes once faulty are decommissioned!

In the future I wonder if VM could transmit in 2 different video compressions simultaneously, mpeg4 to newer boxes and Mpeg2 to the older ones?

muppetman11 · 27-11-2011, 15:13

Quote:

Originally Posted by nstokes

is Mpeg 2 better than Mpeg 4

No difference really , Mpeg4 is more compressed. A TIVO 1TB box recording HD can do 120 hrs as opposed to a Sky+HD 1TB box which can record 240hrs HD so there are advantages for the customer also.

Digital Fanatic · 27-11-2011, 15:17

Quote:

Originally Posted by mlayzell

I suppose that VM only actively support 4 box types at present, the 2 new cisco boxes including TiVo and fault replacement for both Samsung V+ and it's SD counterpart! For all other boxes once faulty are decommissioned!

In the future I wonder if VM could transmit in 2 different video compressions simultaneously, mpeg4 to newer boxes and Mpeg2 to the older ones?

That would take up a lot of bandwith, the plan is to move everyone over to TiVo and that is MPEG4.

zekeisaszekedoes · 27-11-2011, 15:22

Quote:

Originally Posted by nstokes

is Mpeg 2 better than Mpeg 4

No, it's an older standard. Good for the time, but deprecated now.

MPEG-4 offers superior compression for the same bitrates, and that compression has variable macroblocking (MPEG-2 is fixed at 8x8) so any aliasing will be much less obvious due to this and some other techniques such as CABLC which increase efficiency.

For quick reference, MPEG-2 is used on DVDs and MPEG-4 on Blu-ray. Basically if all Blu-ray content were encoded in MPEG-2 at roughly the same quality settings the files would be roughly four or five times the size!

muppetman11 · 27-11-2011, 15:26

Quote:

Originally Posted by zekeisaszekedoes

No, it's an older standard. Good for the time, but deprecated now.

MPEG-4 offers superior compression for the same bitrates, and tvyhat compression has variable macroblocking (MPEG-2 is fixed at 8x8) so any aliasing will be much less obvious due to this and some other techniques such as CABLC which increase efficiency.

For quick reference, MPEG-2 is used on DVDs and MPEG-4 on Blu-ray. Basically if all Blu-ray content were encoded in MPEG-2 at roughly the same quality settings the files would be roughly four or five times the size!

There are actually some Blu Rays that were encoded in Mpeg2 believe it or not.

nstokes · 27-11-2011, 15:27

Quote:

Originally Posted by zekeisaszekedoes

No, it's an older standard. Good for the time, but deprecated now.

MPEG-4 offers superior compression for the same bitrates, and that compression has variable macroblocking (MPEG-2 is fixed at 8x8) so any aliasing will be much less obvious due to this and some other techniques such as CABLC which increase efficiency.

For quick reference, MPEG-2 is used on DVDs and MPEG-4 on Blu-ray. Basically if all Blu-ray content were encoded in MPEG-2 at roughly the same quality settings the files would be roughly four or five times the size!

Ouch that is big. At least TIVo will be able to do MPEG 4 and if/when it does that will mean recording capacity will go up as well i assume, so win win all round

---------- Post added at 14:27 ---------- Previous post was at 14:26 ----------

Quote:

Originally Posted by muppetman11

No difference really , Mpeg4 is more compressed. A TIVO 1TB box recording HD can do 120 hrs as opposed to a Sky+HD 1TB box which can record 240hrs HD so there are advantages for the customer also.

true point but as my post above hopefully if/when does go to MPEG 4 TIVO will have more recording hours

zekeisaszekedoes · 27-11-2011, 15:29

Quote:

Originally Posted by muppetman11

There are actually some Blu Rays that were encoded in Mpeg2 believe it or not.

Ha! I bet the quality is noticeably inferior to newer MPEG-4 releases with high quality transfers!

27-11-2011, 15:30

Quote:

Originally Posted by Digital Fanatic

That would take up a lot of bandwith, the plan is to move everyone over to TiVo and that is MPEG4.

That could take a very long time, the only reason I had my 8 years old Pace SD box replace is I wanted HD!

zekeisaszekedoes · 27-11-2011, 15:32

Quote:

Originally Posted by nstokes

Ouch that is big. At least TIVo will be able to do MPEG 4 and if/when it does that will mean recording capacity will go up as well i assume, so win win all round

---------- Post added at 14:27 ---------- Previous post was at 14:26 ----------

true point but as my post above hopefully if/when does go to MPEG 4 TIVO will have more recording hours

If you want more recording time, at present the only way to do it would be open the TiVo box and replace the harddrive. Apparently it's been done but violates the terms/conditions of your agreement with Virgin Media so I wouldn't recommend it, but if you went from 500GB to 2TB (maximum these will support, I think) you'd quadruple your recording time and get well over 200 HD hours according to the screencap from the page I linked:

[img]Download Failed (1)[/img]

muppetman11 · 27-11-2011, 15:34

Quote:

Originally Posted by nstokes

Ouch that is big. At least TIVo will be able to do MPEG 4 and if/when it does that will mean recording capacity will go up as well i assume, so win win all round

---------- Post added at 14:27 ---------- Previous post was at 14:26 ----------

true point but as my post above hopefully if/when does go to MPEG 4 TIVO will have more recording hours

I agree , that was my point if VM switched to Mpeg4 TIVO would have a massive storage increase , don't get me wrong its a lot now.