Slashdot Mirror
Comparing the DVRs?
zonker asks: "We are
getting hooked up with Dish
Network Satellite TV this weekend and opted to go with one of
their PVR
(personal video recorder) plans. I started wondering if anyone has
done any technical reviews or comparisons of the video quality (not
just features) of the various digital video recorders out there (TiVo, DishPVR,
ReplayTV, etc.). I am curious
mostly about recorded video quality compared to the source video.
All of them make claims to have various recording 'speeds' like
VCR's. VCR's analog output is predictable (fuzzy recording with bits
of static here and there, worse when signal quality is bad).
However digital recorders have varying levels of pixelization. I was
curious which ones fared the best and if anyone has comments on
either systems?"
All it does is record the stream sent down by the sat, so what you're watching is what you would get if it was live TV. I belive UltimateTV works the same way, so I would assume most dish PVRs work this way.
Free Mac Mini
Personally, what sold me on Tivo when I got it a year and a half ago was the great community at the AVS Tivo Forum. More info than you could ever want and a very supportive bunch for all kinds of questions. The Tivo FAQ is a good place to get answers to the basic questions first, though.
Although I'm a big fan of TiVo, in your case I'd reccommend a DishPVR if all you're concerned about is picture quality, unless you can get DirectTV in which case I'd reccommend a DirecTiVo.
DishPVR, DirectTiVo and UTV all store the satellite bitstream directly, so there is no quality setting, since there is no further compression.
Buy a Tivo and don't do the subscription. It'll act like a VCR. You just manually tell it when to record...and you still get to control live TV.
1) You can select to record programs by searching by name, but it only searched within a limited horizon of programming (the week or so for which it has the guide). If not found, it can be recorded. For example, you couldn't ask it to record "Mission to Mars" whenever it comes on next.
Sure you can. Make a Title Wishlist for MISSION MARS and set it to auto-record. Done. That is the point of Wishlists, to record matching type things. Wishlists are in the 2.0 and up software, so if you just bought the Standalone unit, it'll only have 1.3 on there. It'll upgrade after it dials in a few times.
2) You can't ask it to record programs matching criteria like a particular actor, or keyword in title etc.
Again, use Wishlists. The possible wishlists are: Actor, Director, Keyword, Title (keyword but only in the title), and Genre.
3) Once a program has been selected for recording, you can't change the record quality without cancelling it, finding it again via search, channel guide or whatever, and re-selecting to record it.
Huh? Go to the ToDo List, find the show you want to change, hit select, then go to the "options" screen on that show. Change all the settings for that recording you like, including the quality.
4) It takes 2-4 hours to process and index the program guide after making a call to TiVo! (what on earth is it doing?)
Indexing the new data into it's database. However, this does tell me you have 1.3 software and not 2.0. The newer 2.0 software indexes in the background.
5) There are a few subtle bugs in the menu display software that sometimes cause display artifacts (rarely though).
Mostly fixed in 2.0 and up (2.5 is out now).
6) If you have a partial recording of something that you are also currently recording, it doesn't distinguish between the two - so you can delete the partial until the current recording it complete
Huh? I fail to understand this one, but all recordings are treated separately. If you record something and then it doesn't finish so you record it again later, those are separate and treated separately.
7) Sometimes the GUI is slow to respond (I assume the CPU is busy - just evert so slightly underpowered to do everything it needs. Although the record/playback seems to get highest priority - I've noticed no artifacts there)
Yes, it it a tad slow to respond at times. This was improved, but not fixed, in 2.0 and up.
In short, wait until you download the new software before passing judgement. The new software is tremendous compared to 1.3. It'll download 2.5 for you in under a week or two of first setting it up.
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
The three big ones for Dish based setups (DirecTivo's, UltimateTV's, and DishPVR's) all record the actual digital stream coming from the satellite. No encoding is done in the unit, so what you see on the feed is what you get on the recording. This doesn't mean there's no artifacts, it means that the artifacts will be the same as if you were watching it "live".
The other two major ones (Tivo standalone units, ReplayTV) are mostly comparable in picture quality.
Tivo has 4 picture quality settings, that range the spectrum pretty well, with "Best" being very close to live, and "Basic" being about VCR quality, but slightly sharper. Replay has 3 quality settings, I believe, and they are mostly the same as Tivo, picture wise.
Audio wise, it seems as if the Replay lowers the bitrate on the audio as well as the video in the lower quality settings, but this may be untrue or a rumor. Tivo definitely uses the same audio quality regardless of the quality setting. It sounds pretty good and I've not noticed any weirdness on Tivo audio except for some loss on the rear channel on Dolby Pro-Logic signals from time to time. Neither unit can record Dolby Digital, while the Dish/DTV-based units can and have digital outputs as well.
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
32 Khz audio is all you need to accurately reproduce NTSC sound because the NTSC spec says that the maximum frequency is 16 Khz. Thus says Shannon's Law/Nyquist's theorem.
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
Oops. Just noticed we were talking about DBS, not NTSC broadcast. ;P
Anyone know what resolutions the various DBS broadcasters use?
32khz is the *absolute minimum* for capturing 16khz according to Shannon/Nyquist. In reality you want a bit extra for breathing room, because analogue audio isn't algorithm-on-paper perfect.
Well, try capture at 32khz and 44.1khz. You *will* notice a difference.
Huh? What version of the software do you have?
:)
1) You can select to record programs by searching by name, but it only searched within a limited horizon of programming (the week or so for which it has the guide). If not found, it can be recorded. For example, you couldn't ask it to record "Mission to Mars" whenever it comes on next.
Sure you can. "Pick programs to record", "Search using wishlists", "Create a new wishlist", "Title Wishlist". You can even use wildcards. Record all movies that match "*mars*" and it will do it.
2) You can't ask it to record programs matching criteria like a particular actor, or keyword in title etc.
From the main menu, pick "Pick programs to Record" then "Search using Wishlists". You can choose programs by Actor, Director, Category, Keyword or Title.
3) Once a program has been selected for recording, you can't change the record quality without cancelling it, finding it again via search, channel guide or whatever, and re-selecting to record it.
"Pick Programs to Record", "To do list". Choose your program, then "Cancel/Edit the Season Pass", "Change recording options". In there you get the settings "Record Quality", "Keep at most", "Show Type", "Keep until", etc...
4) It takes 2-4 hours to process and index the program guide after making a call to TiVo! (what on earth is it doing?)
You fail to mention that it only does this ONCE, when you first buy it. It's not like you'll ever see it again. (and it's generating indexes for all those ways you can search for programs - much much better than downloading extra data over analog modem lines)
6) If you have a partial recording of something that you are also currently recording, it doesn't distinguish between the two - so you can delete the partial until the current recording it complete
I couldn't parse this sentence at all... Could you rephrase?
If you have a Comcast General Instrument cable box, the supplied infrared blasters for channel changing are not strong enough and you'll have to but better ones (for ~$30).
Hrm, I couldn't find any mention of this on the tivo forums... I've got the GI DCT box myself, and haven't had a problem.
You sure you don't work for ReplayTV or something?
I suppose I should mention there are rebates on Sony TiVo units. I prefer Sony equipment and the $100 rebate on the SVR-2000 standalone Tivo made the deal for me.
.pdf format
0 20 131.pdf
You can download the rebate form here in
http://www.jandr.com/images/pdf/rebates/SON9_20
They almost did. A while back, any Gateway system came with some DishNetworks coupons. Why? Well at the time, they were working togther to bring Dish service to the Destination systems. The deal fell through, a few cards were made by Adaptec, and not much came of it.
That card on Happauge looks interesting. My biggest hurdle was the Nagravision Dish uses, but aparently that card supports it now. If only the links wern't broken on that page...
Which is to say that 32khz sounded better, all said. Nyquist be damned.
:)
Hey, leave me outta this!
Seriously, if you are getting artifacts at 44.1khz that you aren't getting at 32khz, there's something wrong with your codec setup (ie, its Xing/Audiograbber/etc.)
Previous poster's comment at 32khz being the absolute lowest for 16khz is correct, in fact 32khz won't even do 16khz properly b/c you need a lowpass filter to prevent anti-aliasing. So, all of this is to say that 32khz on a PVR is IMHO sub-par.
-- "Ignorance more frequently begets confidence than does knowledge." (Charles Darwin)
Ok, there are two basic classes of PVR's out now...
Ones for Digital Satellite Systems (They record the bit stream directly from the satellite without an analog to digital encoding process), and those for other systems (They convert analog TV into a digital MPEG stream and store it on disk).
To understand satellite systems. Incoming signals are buffered off the hard drive. (Long discussion about MPEG multicasting not gone into here, but the hard drive allows a longer error buffer to catch out of sequence key frames). You can then watch that stream or another stream off the hard drive. This allows you to watch a recorded show and record at the same time. But you cannot watch live and record something else.
DISH SYSTEM
Two Basic Systems
Dishplayer/WebTV (7100 and 7200)
The software for these were created by a division of microsoft. (Based on a unix core!).
They basically record the bitstream to disk. They have a very nice UI compared to other dish recievers. They have a 7 day guide, and support searching. (The searching is not as deep or complete as TIVO's searching).
They also have games (DOOM, You don't know jack, and solitare).
They also can be used as webtv terminals (though the software for webtv is a generation behind standalone webtv boxes).
The devices are somewhat hackable. You can put much larger drives in than came stock.
The software is buggy. Much more buggy than UltimateTV which uses alot of the same code as Dishplayer.
Dish Network and Microsoft have never been able to get the software update process smooth between them.
DISH PVR 501.
This is a Dish Product that is based on OpenTV and the software is written in house.
It has no search function, and has been recently upgraded to support a 9 day guide.
There are NO additional monthly subscription fees with the box.
DISH PVR 721 Next generation box due out early next year. Number one feature is to record more than one channel at a time. And to watch something live, and record at the same time.
NO monthly subscription fees.
DIRECT TV
Two basic choices.
Ultimate TV By Microsoft. Similar to Dishplayer, but able to record two streams simultaneously. A LOT less buggy than Dishplayer.
10 a month fee to use PVR.
DirectTivo
Same UI as regular Tivo, but records bitstream directly, and recently upgraded to record two streams simultaneously.
10 a month fee to use PVR
NON Satellite
TIVO
Replay
Have you run MultiMedia Center on the 2k/XP line of OSes? I'll admit MMC can be flaky on Win9x, but I've never had an issue with MMC 7 or higher on 2k/XP. Currently I'm running the recently released 7.2 on WinXP and it's rock-solid, no cashes during use no matter what I'm doing to it. The card I'm using at the moment is the All-in-Wonder 128, though I plan to buy one of the newer cards for the DV project and continue using my PCI A-i-W 128 on my regular PC for my video capture and encoding needs there as a secondary display card.
Also, I've heard that their add-on boards and external TV Wonder products can be flaky, which makes sense since they're not integrated with the display and in some cases use the USB bus to transfer video data which is obviously not optimal. But running on 2k/XP with MultiMedia Center 7.2 and a real, full All-in-Wonder, I foresee no stability problems at all, since I'm doing just that right now on my regular PC with no issues.
As an aside--go to ati.com and look at their new All-in-Wonder Radeon 8500 DV, and at the preview on Tom's Hardware. My god, that card's a monster, the remote looks perfect, and if it runs under XP as stably as my All-in-Wonder 128 does then it's perfect for a DVR project.
Chasing Amy
(We all chase Amy...)
"The more corrupt the state, the more numerous the laws"-Tacitus
Here's a CNET review that explains it pretty well.
"The guide is definitive, reality is frequently inaccurate."
We (the wife and I) bought a TiVo last year when we were trapped in an apartment with AT&T Broadband's digital cable (ick). We both fell in love with the thing, even more so after we received the software update last spring.
When we moved out of the apartment and into a house, we had a DishNetwork dish installed (I'd been a satisfied customer of theirs in the past, which is why I went with them over DirecTV), and went for the deal with one of their PVR boxes. So, we have one of each now, and I think I can provide an objective analysis from the perspective of an existing TiVo owner.
On the whole, we're disappointed with DishNetwork PVR. Yes, it records at full quality, and the PVR unit (unlike the cheaper decoder we hooked the TiVo up to) has an optical digital audio output (note, though, that DishNetwork currently only sends AC3 on pay-per-view programs, AFAIK). So, those are some obvious perks to the cheap box/TiVo combination. However, that's pretty much where the line is drawn.
My biggest gripe about the PVR is that mine is unstable (DishNetwork offered to swap it for another, but I've been waiting until after the holidays to ship it back). The software is also amateurish compared to TiVo. It has no concept of anything like TiVo's "season pass" or "suggestions," no program data beyond roughly two days, the playing interface is horrid (it's impossible to tell where you are in a recorded program). The unit is also considerably noisier, though it does spin the hard drive down when inactive (which my TiVo doesn't do, since it's *never* inactive).
Just so I can say that I haven't knocked the PVR completely, it does have a couple of goodies over TiVo. Namely, it has a 30-second skip button, and it has slightly more storage than my 30-hour Sony-branded TiVo (about 35 hours, to be exact). Also, the PVR is cheaper, overall. I pay $10/month for it, and I didn't have to buy the box. After I got finished paying for my TiVo and the lifetime programming subscription, I'd forked over $400 (it's more now).
In other words, the PVR is really just a glorified digital VCR, and probably should be considered a first generation unit (which I guess promotes TiVo to second generation?!?).
On a somewhat-related note, the new DishNetwork boxes have no serial remote control port. I was rather disappointed when I discovered I'd still have to use the IR blaster on my TiVo. However, with my custom-made "fort," I rarely encounter problems with TiVo changing the channel properly.
-Scott
-Scott Hutton