HDTV PC Capture Solutions?

Akai asks: "With HDTV DVR's costing upwards of a thousand US dollars or more, I was looking for a HiDef capture card that would work with Linux and an external HD receiver. The pchdtv card looks nice but it's RF input only for HiDef content, and only supports OTA at this point. Both DirecTV and DishNetwork HD STBs can be hacked with FireWire ports, but it's not cheap, so I was trying to find a capture card with either DVI or Component inputs, or a converter to take either of those to FireWire. The old Dish Network model 5000 receivers had an option to output HDTV RF but they are no longer compatible with Dish's current HDTV broadcasts. Google has not been helpful in this regard, and all I've found is professional (>$2000US) format conversion gear. Is there a PC (hopefully Linux) based video capture solution that can capture the output of a cable of DBS STB (RGBA, DVI, or Component out) without a significant loss of image fidelity?"

Comments

One word

[ObjetDart]

BitTorrent. The world is my TiVo.

Cable

[clinko]

"With HDTV DVR's costing upwards of a thousand US dollars or more"

It's $3 more a month than the normal DVR Time Warner offers.

I know this might not be an option for you, but others might want to know that HD DVRs might just be $36/yr. away from them.

Bandwidth.

[Joseph Vigneau]

One of the reasons this is so expensive is that the amount of data coming in from an uncompressed source (like component cables or DVI) is immense. This is why the pcHDTV card only accepts compressed broadcast streams: it captures the already encoded video stream. A device that can capture raw video would have to compress it before it can be feed to the computer.

Samsung SIR-T165

[Reeses]

The samsung SIR-T165 can capture OTA HD broadcasts. It has firewire out ports.

I've hooked it up to my Mac, with a piece of sofware called VirtualDVHS and captured HD streams off of the device.

HD Streams gobble disk space like you wouldn't believe.

I think they may even have made a model that does satellite feeds also, with firewire ports, but you'd have to check around, and maybe hit ebay.

Not anytime soon

[crow]

The problem with recording HDTV is that you have to generate a MPEG2 stream from the component or DVI signal. Real-time encoding of HDTV signals takes vastly more work than encoding NTSC signals, so you can't buy a consumer-priced card that does it.

Fortunately, HDTV is broadcast as a MPEG2 stream to begin with (with additional error correction). So you can get a tuner card that simply saves the raw data that is broadcast. This works great for over-the-air signals. For satellite and cable, you need to get to the signal after it's been unencrypted, but before it's been decoded. Your two options are to use a decoder with firewire output, or to put your recorder into the decoder box (like TiVo does).

Re:Not anytime soon

[crow]

Yeah, the whole thing is rather confusing until you understand exactly what all is going on.

Regular analog TV, whether broadcast NTSC/PAL/SECAM, older analog cable (for me, channels under 100), or regular VHS tapes, is a signal that is essentially fed directly to the electron beam in your traditional TV. There is some funky electronics magic going on, but essentially, each dot in each frame corresponds to a specific fraction of a millisecond of the signal. (Some analog cable channels are scrambled, and decoder boxes will correct the mangled signal. There was a project, fscktv, to do this with a video card, but I never saw it actually work.)

To record an analog signal, you have two important steps. First, you need a TV tuner card that digitizes the signal. Second, you need to compress the video into something managable, such as MPEG-2. The PVR-250 cards are popular because they do both steps.

Digital broadcast TV is simpler. You just need to extract the digital information from the broadcast, much like a modem gets the digital information encoded on a voice phone line. With digital broadcasts, the process of compressing the data is done by the broadcaster, so you don't need any extra work to get a MPEG-2 stream.

Satellite and digital cable, whether HDTV or regular resolution, are sent as MPEG-2 streams, but the problem is that they are selling access to the channels, so they usually encrypt the streams. They assume you'll use their decoder boxes that do two things. First, they unencrypt the stream. Then they decode the stream. By "decode," I mean play the MPEG stream. That means you're back to an analog signal, whether you're using composite, s-video, or component outputs. Even if you use DVI or HDMI, which are digital, it's a decoded signal, not the MPEG stream.

So to record digital cable or satellite broadcasts, you have to either re-encode the signal, which simply isn't feasible right now for HDTV, or you have to somehow get the signal before it's decoded. If your PVR is integrated with your cable or satellite box, it can get the original MPEG stream (which is how DirectTiVo works). The only other option is that some digital cable and satellite boxes have a firewire port that you can connect to your computer, where they send the MPEG stream. MythTV doesn't support that yet, but someone was working on it a while ago.

In theory, you can get a smart card from your cable company that plugs into devices with digital tuners, which allows them to unencrypt channels that you are subscribed to. Some of the more expensive HDTVs accept them so you can use them without a cable box. There's nothing really stopping someone from building a card for your computer that uses the same card.

My research

[isa-kuruption]

Several months ago i spent time researching an HTPC (Home Theater PC) with the intent to have it do everything from HDTV, XM Radio, DVD Player, Music box w/ iTunes, etc.

From my research, specifically, into HDTV, I discovered that all the cards only will decipher over the air (yes, with an antenna) HDTV signals and not HDTV from a cable or satelite provider. Highly disappointing. While I do live in the NYC area, I could have gotten an antenna and received NBC, CBS, ABC and Fox all in HDTV over the air, I could not receive HBO, Discovery HD, etc. Because of this current limitation, I temporarily gave up on the HTPC and am waiting for more reasonable resources.

Oh, and something else I found, the FCC has declared that all cable providers MUST have firewire interfaces on their decoder devices as of May 2004. This would mean you could connect a PC to your cable HD converter in order to record programs, but it does not mean that once the programs are on your PC, you will be able to access them from anything other than your cable box.

Uh, no. Sorry.

[fellini8.5]

This comes up on AVSForum all the time. In a nutshell: the HDTV you get over-the-air, that gets beamed to your satellite box, or zapped to your cable box is a compressed transport stream that fits in the same bandwidth as an old-fashioned analog signal.

The satellite/cable box then decodes that stream to produce the full HDTV-resolution signal, that gets delivered to your monitor (either via analog component or digital DVI/HDMI).

That full-resolution bandwidth required to re-digitize/re-encode the full bandwidth signal to a recordable transport stream is currently beyond the capabilities of any pc-based solution under that $2000 price-point.

There are only two close-to-usable solutions so far: IEEE-1394 keeps it's delivery from device to device as the compressed transport stream. The problem being that most transport streams from these devices are encrypted. Some aren't. You might get lucky. The other is to find a tuner tuner card that can decode the QAM signals that cable companies use. The problem being again, that most cable companies encrypt those signals (at least those you can't get over-the-air anyhow).

Check back in about five years. :)

acronymonious much?

[Anonymous Coward]

The DDA in USA has a UDFF AGBG standard that might UTFF when the FCC allows XYZ in 2005, _IF_, that is, the USDHS doesnt outlaw it due to new NCIC regs that will effect the UDFF and UFDDA of IOPPUOIN, otherwise they will have to create a new agency to monitor such HDDTV bandwidth (similar to the way they currently handle UHF and VHF)

but then again , everybody knows that

Re:Sorry...

[swordboy]

I agree.

But I would also like to point out that there is a *huge* market for a "wife proof" AV solution.

Of course, when I say "wife proof", I mean "non techie" proof. The former certainly isn't politically correct. I realize that. However, in my case, it is what I'm seeking.

Basically, the whole concept of multiple sources and multiple remotes has failed miserably. It is too wonderfully complicated. We shouldn't require a flow chart to operate the AV equipment. Here's what we need:

1) A communication method for devices that does not rely on line of sight. My programmable Sony IR remote works great except for those cases when the sun is setting and interrupts a portion of a macro, etc. Then the whole system needs a technician.

2) Discrete on and off codes for this system. See problem #1.

3) No more AV component switching. Just daisy chain all the damn stuff and give each device a priority. If I want to watch a DVD, then I turn on the DVD player which has priority over television content. All devices recognize this priority and do their own switching accordingly. Additionally, a single box that does everything (TV, PVR, DVD and Media) would simplify greatly. I'm open for realistic alternatives.

4) A friggin' industry standard. If everyone wasn't trying to make a buck for themselves, we'd be light years ahead.

What am I missing here?

Comcast DVR

[Domino]

The new Comcast DVR (Motorola 6208) allows capturing
of the HDTV stream through FireWire. It's a little tricky to get it working. I needed to patch libavc1394 to recognize the device correctly. Once that works you just need to send it a signal to start sending the stream (dvcont record) and then you can capture it with ddr1394. The Comcast DVR is $9.99 a month here, so that's a cheap way of capturing HDTV.

Re:Comcast DVR

[mozumder]

Recording from Motorola 6208 through firewire works great on MacOSX as well. I would say its the easiest way to record high-def so far, and you get the ability to record premium channels - Matrix trilogy was on in High Def this past weekend on Cinemax. You can use iCal to automatically schedule recordings, and set the firewire interface to capture.

Now, if only I had a MPEG transport stream player that doesn't disrupt audio that VLC player does on my PowerMac..

FusionHDTV?

[richardtallent]

Probably not exactly what you are looking for, but I have a FusionHDTV3 HD tuner card and I'm pretty happy with it.

Pros:
- Supports OTA ATSC, as well as some support for QAM64 and QAM256 (unencrypted only).
- No broadcast flag hoops to jump through.
- Recorded DTV programming is saved directly to disk as non-DRM'd MPEG-2 TP files (with full AC3 audio) that are easily converted to MPEG-2 PS format.
- Recorded NTSC (analog) programming is saved in MPEG-2 PS that could be transcoded easily for DVD.
- Image captures are saved as TIFF at full
resolution.
- Cheap: ~$150

Caveats:
- Output is only via your video card (overlay). Works with DVI, but tweaking video card resolutions to those that "HDTV-ready" televisions like might be a pain.
- Only RF inputs, no component/DVI
- No Linux support that I'm aware of
- Works best with ATi RADEON-based video cards (can offload more CPU work)
- The recording scheduler is buggy--like first year compsci student buggy.
- Slow tech support response
- Haven't tried using it with any of the popular HTPC apps yet
- Needs a decently-strong HD signal (18db+), a Radio Shack amplifier

RE: In the same boat

[Fireye]

DVI is not encrypted. There IS an extension to dvi, known as HDCP, which stands for High Deffinition Copy Protocol. I don't think there are any ways to decrypt HDCP, at least, that I know of.

Just FYI, you can find a listing of HDTV broadcast stations in your area with: CheckHD

Bah

[poptones]

I had to go to the library to do some research last night. It bugged me that I wanted to watch "West Wing" and couldn't. So while I was there I hit up usenet to grab LAST week's show which I also missed.

I was surprised to discover that, as of 7PM CST, last night's show (which would not be seen here for another hour) had been posted 11 hours earlier, most likely from an HD capture in euroupe. So, I got both shows. While I was at it I also grabbed the last couple Enterprise eps (620x320-ish avi), but I'm sure everyone here already knows about those.

If I had been on a "real" computer instead of my underpowered laptop, I could have watched last night's west wing (hi-def cap, but 480x480 svcd) an hour before it even aired in the US. I thought about getting a tuner, too - but why bother to do it myself when I can get it from someone else even quicker?

Cable HDTV - QAM Encoded

[ludey]

Try this card from DVICO. As long as your provider doesn't encrypt the QAM signal (probably does for HBO, Showtime, & the like) you can capture HDTV in full quality.