Freeview PC card - dvb-s and dvb-t

Forums › Home Theatre (including HTPC and EPG Collector) › Freeview PC card - dvb-s and dvb-t

mule

209 posts

Master Geek

#18256 3-Jan-2008 20:09

Ok, so I know there has been a lot of theads that have talked about what cards people use, but i want to get a clear answer.

I currently have a HTPC with media centre 05, but I am planning to tryout media portal.

We are about to get rid of sky and go with freeview. Getting the dvb-s stream seems pretty straight forward, but I want the ability to use dvb-t when it comes available. So my question is:

- are there currently any pc cards available for the freeview dvd-t which do the conversion on the card, or it is still software based?

I was considering getting a Hauppauge HVR 3000 or 4000 card, but I am not sure. (and realise the conversion is software based)

Any advice appreciated.

Cheers

walt12

324 posts

Ultimate Geek

#102777 3-Jan-2008 20:19

Digital content does not require MPEG2 encoding like the analog streams.

Further DVB-S is SD MPEG2 so it won't tax your video card to output either.

DVB-T is another story ... H.264 + AAC encoding of video/audio respectively requires either hardware (video card) decoding, or a very recent dual core CPU.

So to answer your question, get the HVR-3000, although note it is not twin tuner so you won't be able to watch a DVB-T stream and record a DVB-S stream. HVR-4000 adds DVB-S2, which is a long way off here.

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mule

209 posts

Master Geek

#102783 3-Jan-2008 20:41

So what you are saying is that there are no dvb-t cards that do the conversion at the moement - it is done by the video card

sbiddle

30853 posts

Uber Geek

Retired Mod

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Biddle Corp

Lifetime subscriber

#102784 3-Jan-2008 20:51

mule: So what you are saying is that there are no dvb-t cards that do the conversion at the moement - it is done by the video card

I'm not sure what conversion you mean. Analogue broadcasts are typically hardware encoded by cards like the MCE150 in MPEG2 format. Because the digital broadcasts are either in MPEG2 (DVB-S) or H.264/MPEG4 (DVB-T) there is no encoding or conversion required, just the appropiate decoder on your PC.

Nety

2584 posts

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Retired Mod

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Lifetime subscriber

#102853 4-Jan-2008 10:35

mule: So what you are saying is that there are no dvb-t cards that do the conversion at the moement - it is done by the video card

Mule this had me confused to.. basicaly no card does the conversion/decoding (what ever you want to call it) on board. The only option you have if your CPU is not up to it is a video card that can do the work. But even that has limits. There are serveral threads discussing that.

Media centre PC - Case Silverstone LC16M with 2 X 80mm AcoustiFan DustPROOF, MOBO Gigabyte MA785GT-UD3H, CPU AMD X2 240 under volted, RAM 4 Gig DDR3 1033, HDD 120Gig System/512Gig data, Tuners 2 X Hauppauge HVR-3000, 1 X HVR-2200, Video Palit GT 220, Sound Realtek 886A HD (onboard), Optical LiteOn DH-401S Blue-ray using TotalMedia Theatre Power Corsair VX Series, 450W ATX PSU OS Windows 7 x64

walt12

324 posts

Ultimate Geek

#102858 4-Jan-2008 10:53

Let's just be clear about this.

Encoding is the conversion of the analog stream to MPEG2 compressed file. This is what the PVR150-type cards do. Because DVB-S broadcasts are already compressed using an MPEG2 codec, no encoding is necessary - just decoding for output which is light work for a reasonable CPU and/or video card.

DVB-T broadcasts in NZ will be compressed using a MPEG4 codec (H.264). Therefore they do not require encoding (already done at source broadcast) to store them in raw format on your HTPC, but do require decoding for output. The threads referred to are discussing the hardware and software requirements to decode MPEG4 broadcasts.

The consensus was that a recent dual core CPU, or a video card supporting the AVIVO (ATi) or PureVideoHD (NVidia) hardware decoding was required. Together with Cyberlink PowerDVD Ultra (which bundled codec is the only known to decode the H.264 broadcasts successfully). A side issue presently is the use of AAC for audio compression - which is causing some issues presently. By the time DVB-T goes live the choices on the software side should have improved.