EFF Reviews HDTV PVR Solution for Mac

enrico_suave points out this "PVRBlog post about EFF's Review of Elgato's EyeTV 500, an HDTV solution for the Mac. Well, a very speedy dual-processor G5 Mac, apparently. The Electronic Frontier Foundation has been doing a lot of important work defending our online and digital rights including opposing the dreaded FCC mandated broadcast flag (cue boos and hisses) Elgato and Plextor also have a Standard Definition homebrew PVR solution with an EyeTV and ConvertX PVR bundle (Wired review)." (See also this earlier review from a Slashdot reader.)

Comments

iTele

[ed 'g3']

iTele [for os x] is free, works with generic digital tv tuner cards and supports the high definition picture for those regions where it is available, i.e. everywhere except the uk.

http://www.defyne.org/dvb/

Re:Broadcast flag

[Anonymous Coward]

such a box would constitute a "circumvention device" wich is, as far as I have understood, exactly the thing you're not allowed to have.

It's a minor technicality, but you are allowed to build and possess them. That's why the law does not violate your rights (ha ha). The law makes it illegal to traffic in circumvention devices or to use them to access copyrighted works.

It is also illegal to traffic in the technology to build one. But if you can build one using nothing but your own knowledge, you're golden!

Re:Comments

[Jozer99]

If you read the article, it clearly mentioned that although modern Mac graphics cards have hardware MPEG2 decoding, the APIs for accessing it are not documented by Apple for 3rd party manufaturers.

Re:Comments

[mkldev]

Even when the hardware is doing some of the work, it's usually not doing all of it, a few specialized MPEG-to-video output cards notwithstanding. There are several different parts of playing back MPEG video, including: decompressing, deinterlacing (optional), scaling, color space conversion, etc. The hardware only provides the last one, and sometimes the next-to-last, IIRC. The actual decompression occurs in software (doing all the inter-frame math, etc.), as does deinterlacing, generally, assuming you are using an MPEG player that supports it.

Basically, doing full MPEG decode in the GPU made sense before we had vector units in the CPU, but these days, it isn't enough of an advantage to care. And besides, you usually want to have some software control over the presentation---the ability to float windows over it, etc. That sort of thing doesn't work too well if the GPU is doing all of the decoding for you.

And, of course, HD video is a different animal---different resolution, higher data rate, etc. Even if you have custom hardware to decode SD video and send it to a TV on-the-fly, doing the same for HD is sufficiently harder that it probably isn't worth it, particularly since you have a fast CPU handy already.

Dual G5 requirement should be improved

[tji]

A dual G5 requirement for smooth HDTV playback is a big problem. You should be able to easily do this with a midrange G4 system.

The problem is that Apple has not opened the API for the MPEG2 acceleration available in most of the video chips in Macs. ( The equivalent of DxVA in Windows, or XvMC in XFree86 ). In the x86 world, this takes the CPU requirement down from ~ 2.4GHz P4 to ~ 800MHz P3.

Apple's DVD player uses the MPEG2 acceleration, but they don't allow others to use it. So, we're stuck with extremely high CPU requirements of dec oding those hi-res HDTV files.

Re:Dual G5 requirement should be improved

[arazor]

just go to http://www.avsforum.com and find the correct topic for your area. Exellent info on HDTV and other expensive AV equipment. You might also want to check out http://www.antennaweb.org for the general antenna info.

Re:Dual G5 requirement should be improved

[steve_bryan]

"In the x86 world, this takes the CPU requirement down from ~ 2.4GHz P4 to ~ 800MHz P3"

That is a marketing lie which was commonly told a few years ago. There are HD tuner cards that specifically include hardware decoding on the card (not the video card) which people have used successfully in less powerful PC's. But using DxVA from a video card doesn't buy you much if you are using a Fusion card or some other software decoding solution.

Also it is worth noting that although Apple's DVD player uses MPEG2 acceleration it still doesn't do de-interlacing decently. You can probably get better results with VLC.

Re:Dual G5 requirement should be improved

[tji]

> That is a marketing lie which was commonly told a few years ago.

Actually, No.. DxVA is what makes the CPU requirements reasonable, even with the software decode products. The 2.4GHz -> 800MHz was specifically addressing DxVA offload of HDTV MPEG2 decode.

I have two MyHD cards and two FusionHDTV cards. The MyHD cards have an onboard MPEG2 decoder and they display the HDTV output directly from the receiver card - not through your video card. It does the complete MPEG2 decode in hardware, so the CPU requirements on the host are VERY low. You could do it with a Pentium II.

The Fusion cards only do the reception of the ATSC Transport Stream - they pass that 20Mbps data stream to the host for processing. All MPEG decoding and display is done in software (which is the same as with the Sasem USB HDTV device, ATI HDTV Wonder, pchdtv.com HD-3000 for Linux, and the EyeTV 500). In this model, the decoding is done on the CPU in software, and some of the more compute intensive portions are offloaded to the video card via the DxVA API. Specifically, the iDCT (inverse discrete cosine transform) and motion compensation are hardware accelerated. So, it still takes a decent CPU, to do the MPEG decoding, but much less than for full software decode. On my Athlon64 3400+, the CPU utilization goes from ~ 70% to ~ 35% when I turn DxVA on.

I prefer the MyHD cards for a number of reasons. But, their main drawback is flexibility. They just do the HD video output. If you want to integrate with a PVR solution, like XP Media Center, you need the video to be displayable on the PC video output. So, the hardware decode cards are becoming less popular.

> Also it is worth noting that although Apple's DVD player uses MPEG2 acceleration it still doesn't do de-interlacing decently. You can probably get better results with VLC.

That's just a limitation of Apple's software.. DVD Player is not exactly renowned for its video quality.
The video hardware and MPEG2 accel are fully capable of good de-interlaced display. The FusionHDTV software does a good job of de-interlacing 1080i output when using DxVA. It looks almost as good as the output from the MyHD.

Re:Dual G5 requirement should be improved

[steve_bryan]

"Actually, No.. DxVA is what makes the CPU requirements reasonable, even with the software decode products. The 2.4GHz -> 800MHz was specifically addressing DxVA offload of HDTV MPEG2 decode."

I know they claim that. What I was reporting is that it is a lie. I had a 700 MHz Athlon which was originally claimed to be sufficient for the Fusion I card (using DxVA) and it was not. I upgraded to a 1500 Athlon and finally the 2400+ which is sufficient for software decoding with DvXA assist. Without DxVA you get a more stable picture but it has to throw out every other scan line. I actually prefer that picture generally because it doesn't have the artifacts that you get with DxVA.

If someone has an older box with a sub 1 GHz processor he will need to get a MyHD card to get good results. I wouldn't recommend Fusion cards to anyone with less than a 2 GHz processor. I am using the computer monitor. Maybe the picture from the DVI port gives better results with less CPU.

It has been reported elsewhere in the comments that dual 1 GHz G4 Mac will produce good results with EyeTV 500. If that is the case then the results are not so starkly different. I'm sure the software is less finicky because I have and use EyeTV (I just use it with the EyeTV USB but it is the same software). It doesn't restart the Mac just because I commit the mistake of running VLC or some other video program. In fact on the Mac I have the option of having multiple programs running at the same time without causing a crash.

Re:The G% is a slow processor

[displaced80]

I'm not excusing Apple's behaviour -- there's a whole heap of things that they've kept undocumented/private which annoy me in current versions of OS X.

However, my impression is that much of the video rendering systems within the OS have been in flux over the course of OS X's development. Remember, QuickDraw's still in active use. QD's really in need of replacement, and will be deprecated in Tiger.

From what I've seen, The Core[whatever] frameworks in Tiger will finally put this issue to bed, and provide all the APIs a developer could want... Quartz 2D Extreme looks like it'll round things out, with some nice things like full resolution-independence for each application individually.

For those who understand these things better than I, there's the WWDC's graphics 'State of the Union' presentation available here.

It's generally a nice look at how OS X's video architecture's finally coming together.

No G5 needed now...

[AaronD12]

Elgato Systems updated their software and it only requires a reasonably fast G4 system. My EyeTV 500 works perfectly on my Powerbook G4 1.25GHz laptop at full screen.

-Aaron-

MythTV on OSX - Soon

[GameGod0]

I'd just like to throw in that over the past few months there have been TONS of patches added to MythTV that add OSX compatibility.
I'm not sure how close Myth is to working completely on OSX, but I don't doubt that once it's working on OSX, it will be a formidable entry into the world of PVR software for this operating system.