Is Apple TV's (and Xbox Live and VOD's) HD truly high definition?
by Richard Lawler 
posted Jan 19th 2008 at 9:39AM
HD is coming in a lot of forms these days, but ZDNet's George Ou thinks some of them -- like Apple TV, Xbox Live Marketplace, ABC.com streaming and cable VOD -- don't count. Sure all of these sources are HD resolution, but George's argument is that due to overcompression and low bitrates, they don't compare with 1080p upconverted SD DVDs, much less Blu-ray or HD DVD. Low bitrates might mean less detail than we're used to and some issues with fast moving action, but we've checked out all of the above, and if you've got the pixels, then you're HD. Whether or not thats enough to satisfy is up to the viewer, but we're sure there's a faction out there arguing if you have to get off your couch to buy it, it's not really a high def experience either.
Filed under: Blu-ray, Media streamers, Fiber, Internet
Reader Comments (Page 1 of 1)
Kon @ Jan 30th 2008 4:26AM
Wow. So many incorrect facts in that article. This type of ignorance really annoys me. The author knows absolutely nothing about the topic and should probably stick to writing about something he is more knowledgeable on. *Total amateur hour*.
Let's go down the list:
1. To say that 28Mbit is the minimum because of a compression ratio of 107:1 just demonstrates pure and utter ignorance of how digital codecs work.
2. DVD movies are not '4-8Mbits'. The maximum standard transport bitrate is 9.8Mbit. The disc maximum bitrate is 11Mbit with a 1Mbit overhead to allow for device buffer compensation.
3. Over the air is not 19.38Mbits. ATSC is 19.393Mbits. DVB-T with QAM64 weighs in at 24Mbit (the author was almost right - just didn't know what country, transport, and modulation standard he was talking about). And then you factor in the other elementary streams in the transport. 18.2Mbits is probably the max you will get.
4. The article compares live broadcasts to VOD. Hey, let's just forget about the fact that VOD can be encoded with multi-pass. Same thing right? Jesus.
5. 50% H264 won't beat MPEG2 at 2x the bitrate? Must mean all MPEG2 encoders are built alike.
6. The math for DOCSIS user allocation to bitrate is completely wrong. Let's ignore edge device caching, multicast delivery to the edge, and statmuxing!
7. AppleTV's maximum bitrate is 5Mbits, but 99% of the time encoding at 4.85Mbits yields the optimum bitrate with the added jitter and packet overhead.
8. Microsoft's HD quality can in many cases surpass over the air (ATSC) MPEG2 1080i. Most stations are going exclusively 720p24, and running at 12-14Mbits MPEG2. Some as low as 9-10.
9. 6-8Mbits is actually a 'sweet spot' for 720p24H264 in many implementations.
And lastly HD is defined strictly by resolution, format, aspect ratio, pixel count, frame/field and associated rate. People need to stop pulling some bitrate out of their ass just to tout that as being 'HD'. It's not, and pertains to user *perceived quality*. It is irrelevant to the spec.
AppleTV *fails* because it has horrid gamma representation and low-quality image enhancement on the H264/MPEG4 decoding, which actually ends up over-sharpening edges and producing artifacts that ruin the image.
Robert Pitard @ Feb 16th 2008 9:38AM
Yawn, Yawn.....
It is obvious that any "Tangible" Media format such as Bluray & HD-DVD Disc is far superior to any current early_2008 movie downloads. No translation loss
AppleTV has the Front end "User Experience" perfected. Now, them and others must solidify the media delivery portion.
In Closing..........I Quote: "It's a shame for any & all Current/Future HD content, not to be provided to the end user to it's fullest capacity."
Robert Pitard
http://www.audioelite.net
PS: I tired of CONSUMERS, being tricked with regard to HD. Smoothing an image is NOT HD TV.
Ben @ Jan 19th 2008 9:43AM
I'll take a 4Mbps 720p h.264 OAR movie with a good Dolby Digital 5.1 sound track over an upconverted SD DVD any day of the week. Sure, it's no Blu-ray, but comparing it to SD DVD is a joke.
Matt @ Jan 19th 2008 10:13AM
yeah, I would totally agree.
JD @ Jan 19th 2008 10:20AM
Frankly I'll make better use out of my SkyHD with dual DVR's, pay per view for movies and a Blu-ray player for watching the things I really want to watch with top quality sound and picture.
hmm, I suppose I can see a handful of situations where it would be good, for example watching with friends and you want to see a new release but can't be arsed to go to the store to buy or rent or you don't want to order online... oh and assuming the release isn't playing on the HD movie channels.
Otherwise it's a small step over DVD for anything other than watching paint dry. (i.e. motion artifacts due to bandwidth starvation)
north @ Jan 19th 2008 10:29AM
While your enjoying your crappy sound and video I'll be watching blu-ray.
Pictor @ Jan 19th 2008 1:39PM
George Ou needs stop the rhetoric. There are tradeoffs than people will be willing to make like the MP3 format. And if bitrate was the only thing that mattered then why deal with audio formats such as TrueHD or DTS-MA? Shouldn't we all stick with Blu-Ray and LPCM audio tracks? Bottom line compressed 720p can be poorly done but bitrate isn't the whole story. And unconverted SD not going to provide any more detail than is already on the 480i disk.
Mr Stevo @ Jan 19th 2008 10:15AM
Well, this seems like the same argument with cameras pushing all those megapixels, but the pictures not making any improvements at all. They may have the megapixel claims, but how they're affected by the lenses used, converters and other factors affects the final product. With downloaded HD, it seems like they may have the pixels, but the encoding affects them the most because of how effectively the compression is being used, and to what degree.
julian @ Jan 19th 2008 10:25AM
ben did u know that the maximum bit rate for dvd is just under 10mbit/s encoded at mpeg is better then a avc endoed at 4 mbits/can be especialy with upconverter(but its nto as good as a 6 mbits avc video/ avc has just over twice as efficent compared to mpeg 2) and this is alll like the halo only runs at 640p nativly but is upconverted to 720p every one has to take a stand demand better quality becuase very few donwloaded movie have good pq quality-bit rate ration ( a 4 mbit avc 720p can look amazzing!!! but a 7 mbit one look that much better and u mite actrualy get hd audio)
superklye @ Jan 19th 2008 11:20AM
Punctuation. PLEASE.
Ben @ Jan 19th 2008 11:41AM
Julian,
Good point, but honestly it is very hard to understand what you are saying when you don't use punctuation or capital letters.
But I still think that a 720p movie at ~4Mbps would look better than a upconverted DVD. Sure, it'll have more compression artifacts during some shots, but overall the PQ will be better. As for the audio, it should be the same since they are both DD 5.1.
Siva @ Jan 19th 2008 12:08PM
Since we have not seen a single HD AppleTV rental yet - let us wait 2 more weeks (hopefully less) and see it first hand before arguing it to death. May be some objective renters can then compare the picture and sound to SD-DVD as well as Bluray/HD-DVD. I have a PS3 and Bluray. I have several Bluray movies. May be I will pitch in the $4.99 or $3.99 to do the comparision. I have a 61" 1080p JVC RPTV (1080i through HDMI though), HK AVR 745 receiver and Klipsch Reference speakers. I also have an AppleTV (that will need the software upgrade once released).
Ben @ Jan 19th 2008 12:15PM
We've seen the HD trailers on an ATV, what makes you think they'll look any better.
But in the end you are right, we'll do a full comparison between ATV HD and Blu-ray/HD DVD when it hits.
Invader J @ Jan 21st 2008 11:45AM
Actually there's a twist to this. Where I am, Optimum/Cablevision offer an HD VOD service. But *unlike* the normal cable HD channels (HBO, NGC, etc) the bitrate is much higher, compression much lower with the HD VOD content. Transformers looked *incredible.*
rhodiad @ Jan 19th 2008 12:26PM
Just a note of clairification: no need to get off the couch for the updated appleTV. You can purchase and rent movies and music and access other free content directly now without having to "send" the content from iTunesOn the other hand, there are several things to dislike.
First, cost is still too high for movie rentals and purchases, IMO, (especially now that netflix offers unlimited downloads for a fixed subscription price, not to mention that in reality, ALL media distribution has to compete with "free" now whether the studios want to admit it or not.)
Second, HD content can't leave the appleTV for other devices (SD can).
Ah forget the numbers. AppleTV rentals are also a month later than disc releases. The catalog is pretty limited at the moment. You have to watch a rental within 30days of purchase and finish watching within 24 hours of when you start. That's lame especially compared to netflix.
Sigh... Take 3 maybe?
Jeremy Charette @ Jan 19th 2008 12:27PM
http://www.xyhd.tv/2006/12/reviews/why-xbox-live-video-marketplace-competes-well-visually-with-hd-dvd/
Over at XY HD.TV, they looked at this very issue over a year ago. The Xbox Live Video Marketplace downloads were nearly identical to the HD DVD versions of the same movies. The only significant difference is that they seem to be encoded in different color space, so the black levels are slightly different.
Direct quote from the article:
"So what does this all mean to you the end user?
HD-DVD is spectacular I was unable to find a single artifact in the copy of 'V' the same was true for Tokyo Drift which is rather hard content to encode. Marketplace videos on most TV's in most home theatres, also spectacular. You being the Video enthusiast and cocky SOB that you probably think you have a home theatre that the quality difference will matter, well you are probably wrong.
Unless you have:
A 1080p Display, that really runs at 19201080 as its native resolution.
Have paid someone to calibrate the TV to reference, not the Dynamic, or Vibrant mode that many TV's are set to.
Have disabled noise reduction on your TV.
Are Viewing in a theatre lit room."
George Ou @ Jan 19th 2008 10:41PM
If all you're looking for is artifacts, then you can compare standard DVD and Blu-ray and declare both the same. That would be kind of silly.
In his tests, he clearly stated that you're missing the film grain from the Xbox Market place version which automatically indicates lower optical resolution (lines per inch). One might say what do I need to see film grain for? Well for old movies you'll see grain but for new movies you'll see finer detail like the individual strands of hair and the individual eye lashes of a beautiful woman. The inability to see grain equates to the inability to see detail.
Jeremy Charette @ Jan 20th 2008 12:41AM
George:
Yes, the optical resolution is lower. XBLVM HD downloads are 720p, not 1080p. But as pointed out in the article linked above, the bit rate pixel for pixel is practically identical. The signal to noise ratio is nearly identical, which means the compression ratio is the same. Maybe you do lose some film grain, but keep some caveats in mind. The vast majority of HDTVs in homes and stores today are 720p. To tell the difference between 1080p and 720p in a living room setting, it has to be 50" or larger. Any smaller and the human eye can't tell the difference. And as already pointed out, unless you have a professionally calibrated 1080p set in theatre lighting with 1:1 pixel mapping, you will NEVER see the difference.
For 99.999% of the HDTV owners out there, the XBLVM videos are just as good as HD discs. I would defy the other .001% to tell me which is which in a side by side comparison.
George Ou @ Jan 20th 2008 2:18AM
I don't know why you INSIST on saying that you don't need anything more than 720 unless you have a "professionally calibrated 1080p set in theatre lighting with 1:1 pixel mapping". Where do you even get this crap?
Any 1920x1080 interlaced/noninterlaced set will definitely look better with 1080i or 1080p content than 720p. It's bloody obvious under any lighting with or without calibration. Lighting makes the image have less glare and calibration makes the colors more accurate, but bad lighting and bad calibration won't prevent you from seeing the extra resolution. Even on a $200 1680x1050 20 LCD computer display you will see the extra optical resolution and detail though it obviously wont be as compelling.
Now I will concede your point that on a typical 1366x768, 1280x720, 1024x768, or 800x600 HDTV, you will not see the benefit of added resolution. But don't go making this other crap up about calibration and lighting playing a factor in resolution.
You can now get DLP TVs that are under $800 with 1080p resolution and this year the 42" 1080p LCDs and Plasmas will be around $1000. Even the MSRP of a 42" 1080p LCD from Philips is only $1400. Now don't give me more of this crap that you can't see it below 50" because it depends on how closely you sit to the TV and how good your eyes are. Anyone with a smaller living room (lots of us in the Silicon Valley given real-estate prices here) will be fine with 40" displays and you WILL see the extra resolution. If youre buying a TV these days, youd be nuts to buy anything less than full 1920x1080 resolution because the prices are so low starting this year and they will only get cheaper.
Jeremy Charette @ Jan 20th 2008 10:50AM
George:
From Geoffrey Morrison at Home Theater Magazine:
http://www.hometheatermag.com/gearworks/0105viewvrez/
"The average 42-inch-diagonal, 1,280-by-720 plasma or LCD display has pixels that are roughly 0.029 inches wide. (Of course, each model has different inter-pixel spacing, but, for now, we'll assume they don't.) If the same size display had a resolution of 1,920 by 1,080, the pixels would be 0.019 inches wide. As you can see, in a 42-inch display at a distance of 10 feet, your eye can't discern the resolution available even with 720p. Even more resolution is "wasted" at 1,920 by 1,080.
Now, assuming that you're not going to move your couch but you want a bigger TV, how does this work with a 50-inch set? The pixels in a 1,280-by-720 display are 0.034 inches wide, which is almost exactly what your eye can discern at 10 feet. A 1,920-by-1,080 display has 0.023-inch-wide pixels, smaller than your eye can resolve. A 1,920-by-1,080 display would have to measure more than 70 inches diagonally before you start testing your eyes' limits on the display's resolution (at least at 10 feet)."
From David Carnoy at CNET:
http://reviews.cnet.com/4520-6449_7-6810011-1.html
"On a regular basis in our HDTV reviews, we put 720p (or 768p) sets next to 1080p sets, then feed them both the same source material, whether it's 1080i or 1080p, from the highest-quality Blu-ray and HD DVD players. We typically watch both sets for a while, with eyes darting back and forth between the two, looking for differences in the most-detailed sections, such as hair, textures of fabric, and grassy plains. Bottom line: It's almost always very difficult to see any difference--especially from farther than 8 feet away on a 50-inch TV."
"...our current highest-scoring HDTV, the Pioneer Kuro PDP-5080HD, is a 720p, er--768p, model."
Numerous other experts have cited the fact that resolution is one of the least important factors when looking at a new HDTV. Black level, contrast, and color accuracy should come first. Fact is, in most setups, the signal is scaled either before or at the HDTV anyway, so some optical resolution is always going to be lost. I'm not saying that people shouldn't buy a 1080p TV; if they have the option, they should. But to argue that XBLVM downloads are vastly inferior to Blu-Ray or HD DVD discs because of slightly lower resolution is pointless.
Nevermind the fact that most people don't even know what the various resolutions are or how to set them up. I went to a vacation house for the holidays and they had 2 HDTVs in the place, a 42" LCD and a 70" DLP. Both were connected to HD cable boxes with...coax.
DrXym @ Jan 19th 2008 1:07PM
They're talking of HD downloads being 4Gb in size. Now that's H264 as opposed to MPEG2 on DVD. Even so, I doubt the quality is anything to write home about - better than SD but horrible compared to HD DVD or Blu Ray.
Personally I think it would be adequate for rentals but I have to question the sanity of anyone who BUYS a movie through a download service.
Big John @ Jan 19th 2008 1:07PM
Dur, really? 720p sources != 1080p sources?
I had no idea.
This is a really, really stupid argument by an elitest.
Franssu @ Jan 19th 2008 1:32PM
To all people bitching about how DD 5.1 or DTS is shitty compared to HD audio : Most people don't have the ears, room and gear (especially speakers) to be able to tell the difference.
It's as stupid as bitching against everything that is not 1080p. Good and well-encoded 720p HD is far superior to a badly encoded 1080p transfer (I remember seeing one of the first MPEG-2 BR25s, the artifacts were... ewwww...). Plus, at normal viewing distances, and on most material, most people can't tell the difference between 720p and 1080p, since in both cases the pixel structure will be invisible.
Forget the specs and figures people, and for once trust your eyes and ears.
TigerShark @ Jan 19th 2008 1:43PM
1080p and HD audio all the way.
aaron @ Jan 19th 2008 2:06PM
From my tests with hd-dvd/bluray and xbox live downloads show there to be very little difference between both quality wise (much less than there should be). I have downloaded one tv show episode off of the marketplace to compare against broadcast tv and it was amazing how much better the xbox live version looked (CSI:NY).
By my comparisons it would be DVD.....HD broadcast.....xbox live..hd-dvd/bluray.
As soon as one of these services brings me a netflix subscription and full studio support i am selling both my hd-dvd addon and bluray player and moving to dd exclusively.
James @ Jan 19th 2008 3:03PM
Looks great to me, and that's all that matters. :)
csreborn @ Jan 19th 2008 5:36PM
The term HD is being used to losely lately imo. I consider HD to be 1080P/24 BD or HDDVD with 5.1/7.1 lossless audio. Otherwise why not just save your $ and watch a DVD with some 5.1?
Bob Mc @ Jan 20th 2008 12:39PM
It might be compressed (like all HD), but it is 1280 X 720. Can the quality compare to blu-ray? Not yet.
Ben @ Jan 21st 2008 1:33AM
Sure, ATV is HD - in the sense that it isn't SD, anyway.
But *FULL* HD is 1080p/60 @ 44 MB/s or better. Anything less - is (obviously) less. ATV is a *LOT* less.