Re: Can MCE2005 record Cable-Originated HDTV Broadcasts?

Tech Tip: Click here to run a free scan for Windows Errors and optimize PC performance

From: Lampright (Lampright_at_discussions.microsoft.com)
Date: 03/04/05 

Date: Fri, 4 Mar 2005 08:41:10 -0800

Using the firewire outputs of the current HD set top box's is a no brainer
for HD capture with a media PC. This would be such a simple patch that
Microsoft could build, why they haven't already done it is beyond me. There
are tools in the hacker community to do it, I wish Microsoft would support
it. It's as simple as emulating a "dumb" DVHS machine...that's it...it's
that simple! My Motorola 6412 HD DVR has two firewire ports which connect
directly to a DVHS and allow recording to it. I can currently connect either
my Mac or XP machine and use software to emulate a DVHS to capture HD from
it. If I could do this with MCE, I would build an MCE machine today!

Hurry hup Microsoft...let's get this done! Until they have an HD solution
better than OTA, I'm not interested.

This is so simple...it really drives me nuts MS hasn't implemented it yet.

Brian

"Ben Ranson" wrote:

> Thanks, Steve, for clarifying the difference between OTA and cable HD
> broadcasts, and for your discussion on where is a suitable point to try and
> grab the HD signal from the cable (i.e. from the cable itself, or from some
> signal that has been processed by the cable box).
>
> I found these two links related to recording Firewire outputted HD signals
> from a cable-box to Windows. Maybe this is the best way to go currently?
>
> http://replayguide.sourceforge.net/dct6412/index.html
> http://www.avsforum.com/avs-vb/showthread.php?s=&threadid=403695
>
> It still sounds like, however, that MPEG2 [re-]encoding would be required,
> and that would mean MCE would refuse to recognise it AFAIK, as it demands the
> presence of a hardware MPEG2 encoder.
>
> Any comments on the Firewire->Windows MCE approach?
>
> - Ben Ranson
> Electronics Nexus
> http://elnexus.com
>
> "Stephen Neal" wrote:
>
> >
> > "Ben Ranson" <Ben Ranson@discussions.microsoft.com> wrote in message
> > news:1A746665-470C-4AF8-A3FF-0B0372B8667D@microsoft.com...
> > >A simple question, but, having read MANY posts on the subject of HD and
> > > MCE2005, I am more confused than ever.
> > >
> > > As a system builder of servers and workstations, I have been asked by a
> > > number of my customers about building MCE2005 HDTV recorders for them at
> > > home, so could see a good revenue stream here. Yet, I don't know what to
> > > tell
> > > them when they say they want to record their HD broadcasts from cable.
> > >
> > > I understand that the ATI HDTV WONDER will only receive OTA
> > > ("Terrestrial")
> > > HD broadcasts and not cable or satellite, because of the encryption
> > > standard
> > > or something. Is that right?
> >
> > Yep - AIUI the ATI HDTV Wonder only supports the 8VSB ATSC modulation
> > system - i.e. what is used in the US for OTA digital television via an
> > antenna (or aerial as we in the UK call them)
> >
> > US Cable HD transmissions don't use 8VSB - it has facilities specific to OTA
> > transmission conditions that are less relevant to cable transmission - so
> > instead US HD cable uses QAM modulation which is not compatible, but has
> > benefits for cable TV companies. Additionally many of these digital cable
> > transmissions are also encrypted - so that you require an authorised
> > subscription to view them.
> >
> > Now there ARE HDTV capture cards that are QAM compatible I believe - at
> > least for the unencrypted basic channels - I don't know if they support the
> > "cable card" standard that HD Cable-Ready HDTV sets with QAM tuners have a
> > slot for (this contains the decryption and authorisation gubbins)
> >
> > However AIUI MCE 2005 doesn't support these cards yet - or suitable drivers
> > aren't available. (Not sure which...)
> >
> > (In Europe we have DVB-S and DVB-C satellite and cable standards, with PC
> > cards readily available for both, some even including decryption module
> > interfaces. Annoyingly MCE doesn't support these either - just OTA digital
> > DVB-T- which is our equivalent to your 8VSB ATSC system in transmission
> > terms)
> >
> > >
> > > The implication is that MCE can certainly encode and deal with a processed
> > > HDTV signal (as I've read on this forum of people using the HD WONDER with
> > > their MCE successfully), so maybe the problem is between the cable box and
> > > a
> > > suitable tuner card.
> > >
> >
> > MCE is fed an HDTV MPEG2 signal from the ATI HDTV Wonder card - this is
> > basically the HDTV signal as compressed by the broadcaster, all the card
> > does is pass it to MCE as MPEG2 (no processing of the video signal) in a
> > form that MCE likes. Thus recording and replay are essentially lossless
> > compared to live viewing.
> >
> > However Cable boxes don't output HD in MPEG2 format (apart possibly via
> > Firewire, and MCE doesn't support this either) instead they decode the MPEG2
> > in the box, and output it as analogue HD components, DVI or HDMI
> > uncompressed digital. To feed these into MCE you'd need to MPEG2 re-encode
> > the component/DVI/HDMI feed - which is expensive to do in realtime in
> > hardware - and there aren't any consumer level cards (or cards supported by
> > MCE 2005 that I know of) that provide this function. You're effectively
> > compressing a 700Mbs-1.2Gbs video signal to about 18Mbs - that requires
> > serious processing power...
> >
> > > If that's the case, why hasn't a TV-Tuner manufacturer just come up with
> > > an
> > > HD Cable-ready TV-Tuner card?
> > >
> >
> > I believe these already exist - but aren't fully supported in MCE 2005. Not
> > sure if they include a CableCard slot currently - so would only be useful
> > for unencrypted stuff.
> >
> > > Isn't it just a case of recognising a decrypted HD signal as, say an
> > > S-Video
> > > input signal, and having the processing power to MPEG encode 1920x1080
> > > instead of 720x480?
> > >
> >
> > S-video wouldn't be suitable - it is inherently a standard definition
> > subcarrier based format (525/480 lines in NTSC and 625/576 lines in PAL) -
> > you'd have to downconvert to SD for an S-video link to work - but this is a
> > way of getting HDTV cable channels into an MCE 2005 PC now - albeit not in
> > HD resolution...
> >
> > Component analogue would be the minimum quality output you'd need to feed
> > into a PC capture card - but as mentioned above the cost of the A/D
> > converters and real-time MPEG2 hardware compression (both 4-6 times more
> > involved than their SD equivalents, and not covered by the economies of
> > scale that DVD recorders, PVRs etc. have brought to the SD MPEG2 encoding
> > hardware market as yet) make this prohibitive at the consumer level
> > currently.
> >
> > There are also the issues of copyright protection - HDMI and some flavours
> > of DVI employ HDCP - meaning rights holders (the people who own the rights
> > to the film or tv show you are watching) can employ systems to actively
> > prevent HDTV recording in quality. (This is why the US is so lucky to have
> > gone HD first and to haveFirewire MPEG2 outputs from set top boxes to DVHS
> > VTRs, TVs etc. - even if this also supports a form of copy protection. Other
> > HD countries are unlikely to get this...)
> >
> > > Any clues would be helpful...
> > >
> >
> > Sounds like a wait-and-see situation for digital cable and digital satellite
> > reception within the PC in MCE for a while at least.
> >
> > Steve
> >
> >
> >