Humax HD DTT PVR

with 10 gigabit ethernet and half a terrabyte of disk per hour of
programming it might just work....

when I referred to NAS etc had in mind backing up from the Humax HD and
then restoring it to the Humax to play rather than real time transfers.
If the hard disk fils up before I have watched it then I don't see it
that as a hardship. Of course if Humax went for Gigabit LAN then things
would be different.

What rates are the UK test HD broadcasts using?

I have read the BBC were aiming at 16 to 20 20Mbps; the few snips of
transport streams I've taken are consistent with that and so are the
results others have (more reliably) reported. They have also indicated
the ITV etc trials are if anything at lower bit rates. That is indeed
h.264. And I assumed that is what the Humax would save (and be
transferred across the network). So I'd not expected to be able to do a
lot in real time (especially if the Humax is already recording 2
streams).


--
Robin

Robin wrote:
with 10 gigabit ethernet and half a terrabyte of disk per hour of
programming it might just work....

when I referred to NAS etc had in mind backing up from the Humax HD
and then restoring it to the Humax to play rather than real time
transfers. If the hard disk fils up before I have watched it then I
don't see it that as a hardship. Of course if Humax went for Gigabit
LAN then things would be different.

What rates are the UK test HD broadcasts using?

I have read the BBC were aiming at 16 to 20 20Mbps

& with a horizontal resolution of 1400 & something, from what I've just
read, not 1920.

Good grief - what are they doing the encodes with? An abacus?

the few snips of transport streams I've taken are consistent with
that and so are the results others have (more reliably) reported.
They have also indicated the ITV etc trials are if anything at lower
bit rates. That is indeed h.264.

Saner bit rates, assuming the encoder isn't a pos.

And I assumed that is what the Humax would save (and be transferred
across the network). So I'd not expected to be able to do a lot in
real time (especially if the Humax is already recording 2 streams).

20Mbps isn't a lot to ask of 100BaseT Ethernet, let alone gigabit, but
aiui (not much iow) the bottleneck with PVRs is managing multiple near
simultaneous reads/writes to the hard disk whilst avoiding unacceptable
delays & subsequent data loss.

20Mbps per stream has got to be pushing it in that context. All
guesswork on my part mind - I know nowt about the actual hardware
implementations.

--
Michael
m r o z a t u k g a t e w a y d o t n e t

Michael Rozdoba wrote:
20Mbps isn't a lot to ask of 100BaseT Ethernet, let alone gigabit, but
aiui (not much iow) the bottleneck with PVRs is managing multiple near
simultaneous reads/writes to the hard disk whilst avoiding
unacceptable delays & subsequent data loss.

20Mbps per stream has got to be pushing it in that context. All
guesswork on my part mind - I know nowt about the actual hardware
implementations.

I don't think it should be much of a problem. IIRC, the STi5514 chip used in
several current models of Freeview PVRs is capable of handling three 20 Mbps
transport streams simultaneously. And that was released in 2002...

Pyriform wrote:
Michael Rozdoba wrote:
20Mbps isn't a lot to ask of 100BaseT Ethernet, let alone gigabit, but
aiui (not much iow) the bottleneck with PVRs is managing multiple near
simultaneous reads/writes to the hard disk whilst avoiding
unacceptable delays & subsequent data loss.

20Mbps per stream has got to be pushing it in that context. All
guesswork on my part mind - I know nowt about the actual hardware
implementations.

I don't think it should be much of a problem. IIRC, the STi5514 chip used in
several current models of Freeview PVRs is capable of handling three 20 Mbps
transport streams simultaneously. And that was released in 2002...

http://www.st.com/stonline/press/new...2001/p934p.htm agrees with
you, I think. And as you say, this was four years ago.

--
Michael
m r o z a t u k g a t e w a y d o t n e t

David Taylor wrote:

Well, uncompressed 1080i HD apparantly[1] requires around 1200Mbit/s, so
with 10 gigabit ethernet and half a terrabyte of disk per hour of
programming it might just work....

1.485 Gb/s for industry standard HD-SDI (270 Mb/s for uncompressed 576i SD)

--
Mark
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