Don't believe the low bit-rate 'HD' lie

Don't believe the low bit-rate 'HD' lie

Summary: Update 6:00PM - Here’s what fake HD video looks like.Last week at CES, Comcast announced their "HD" video on demand download service over its future DOCSIS 3.

SHARE:
TOPICS: Hardware, Mobility
161

Update 6:00PM - Here’s what fake HD video looks like.

Last week at CES, Comcast announced their "HD" video on demand download service over its future DOCSIS 3.0 that allows 4 minute downloads of entire HD movies.  Attendees at MacWorld this week were told that disk-based HD formats like HD DVD and Blu-ray are essentially obsolete because you can simply download "HD" movies from your Apple TV 2.0 box on demand.  Microsoft started offering HD downloads for the XBOX360 starting in late 2006.  You can even watch "HD" videos from ABC right from the web.  There are even YouTube competitors that offer user uploaded "HD" content.  There's just one minor little problem, it's not HD.

As I've tried to educate my readers last year with my blog "Why HD movie downloads are a big lie", these so-called HD movies use very low bit-rates compared to even standard definition DVDs let alone something like HD DVD or Blu-ray DVD.  Raw uncompressed 1080p video at 60 frames per second is about 3000 mbps so even HD DVD's 28 mbps needs to be compressed about 107 to 1 with the H.264 or VC-1 codec.  By all reasonable standards this needs to be the minimum bit-rate for acceptable loss in quality on 1080p video.

Updated 4:30PM - Standard definition 480i DVD movies are typically 5 to 8 mbps (megabits per second) MPEG-2 whereas these so-called HD wannabes weigh in at a pathetic 1.5 to 4 mbps of 720p H.264.  Apple's new HD service is capable of 4 mbps which simply isn't enough to be considered HD.  XBOX360 downloads are 6.8 mbps 720p VC-1 so they're semi-decent borderline HD.  Marketing will push the nicer sounding "720p" aspect of the video but they don't tell you it's way too compressed to offer good video fidelity.  Blu-ray has a maximum bit-rate of 40 mbps while HD DVD offers a maximum of 28 mbps.  Over the air broadcasts can be up to 24 19.38 mbps.

Modern video compression codecs like H.264 or VC-1 can hide these compression artifact problems much better than MPEG-2 video compression but there's only so much it can do.  At best you might get away 50% more compression over older compression technology but 1.5 to 4 mbps H.264 will not be better than 8 mbps MPEG-2 under most video complexity requirements.  The only time 4 mbps 720p will look better than 8 mbps 480i is when the video on the screen is almost entirely stationary or it's a low-complexity video such as animation movies.  Under most normal circumstances, the low bit-rate 720p so-called "HD" video will be inferior though many companies are betting that consumers won't know any better. 

So the bottom line is that so-called "HD" video from Microsoft's XBOX360 HD download service and Apple's new Apple TV service or any other web download service is simply not HD by any respectable definition.  These companies cannot and should not use the "HD" name with video that is lower fidelity than standard DVD.  As for Comcast, there's not much detail on it but I highly doubt it's more than 4 to 8 mbps even on DOCSIS 3.0 because its 160 mbps total capacity is divided between 50 to 400 customers.  Only FiOS technology with its massive 620 mbps per 32-user capacity and possibly U-Verse (but slower than real time) has sufficient last-mile capacity to deliver true HD movie downloads at the quality of HD DVD and Blu-ray technology.

I'm not saying that you shouldn't buy these services from Apple, or other services that offer low bit-rate 720p video downloads, but consumers must be aware of the fact that they're slightly worse than a 1080p up-converted DVD.  Microsoft's XBOX service is border-line HD that is slightly better than DVD but nowhere near 1080i over-the-air HD broadcast quality.

Topics: Hardware, Mobility

Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.

Talkback

161 comments
Log in or register to join the discussion
  • What IS HD?

    HD is not a standard, the term high-definition only refers to the resolution of the image that is displayed, not the quality of the image. So I can't fault apple for saying their content is HD, because, it IS.. it's a high resolution picture..
    Otwoh
    • Technically true but...

      ...still deceptive. I think the vast majority of people who buy these devices and services will not realize what they are getting. They will be fooled by the HD in the name and will not realize until after they pay their money that the quality is not what they thought it would be.

      Then again, I know a number of people proud of their HD TV sets who don't seem to get it that if they don't pay the additional money to the cable company for HD service, they really are not getting HD on it.

      So perhaps the sheep will never even notice?
      cornpie
      • they do?

        even if you get HD services from cable or satellite they only offer 720p
        LDCMobile
        • Wrong, broadcast services are usually 1080i or 720p

          Wrong, broadcast services are usually 1080i or 720p. Even when it's 720p, they'll still feed you around 10 mbps for that stream and the 1080i stuff weighs in around 15 to 20 mbps. It's not this lower-than-DVD 4 mbps low-fidelity video you get from these download services.
          georgeou
        • Not so

          I have Cablevision here in the northeast and I get both 720p and 1080i (and they don't charge any extra for it). Also with the ATSC tuners in my TVs I can tune all the local digital channels in my area without using the cable box.
          frank_s
          • Huh?

            [i]"I have Cablevision here in the northeast and I get both 720p and 1080i (and they
            don't charge any extra for it)"[/i]

            Did you not sign up for the HD service? Did you get the HD receiver and pay the
            monthly HD programers fee? or did you get the everythings included with the kitchen
            sink plan. I dont know how that one worked for you as everyone else has to pay.
            Bigshott
      • Most people don't see it.

        Nevermind not getting it. A lot of people just plain don't see it. Even those of us that are anal and perceptive find a hard time objecting to content compressed at the levels that Ou is complaining about. h264 isn't just a "slightly better" codec. It' a dramatically better codec. Depending on the content (mainly TV) you can crank up the compression rate even with divx and most of the viewing audience won't notice. Even the grumps in the audience may find it hard to tell.

        A lot of the sheep won't notice even if they are on the lookout for it. Even someone of the enthusiasts may not necessarily notice.
        hulse_kevin
        • Most viewers are still watching ...

          ...video on analog TV's. Even those sub $800 (usually meaning sub 32") LCD HDTVs are not capable of delivering full fidelity. Nevertheless, it doesn't excuse misleading claims. It's a truth in advertising issue.

          In the days of LPs, the cassette tape was the low-quality, low-cost alternative (and 1/4" tape was the Cadillac of high-fidelity) More people didn't notice -- or they didn't care about the loss of fidelity, because of the price and convenience of the format. The CD replaced the LP (and 1/4" tape) and the MP3 replaced the cassette as the low-quality alternative.

          No matter, folks are listening to their MP3s on $30 earphones -- and only rarely on a pair of $200 Bose headphones. No one is listening to MP3 files on a 200-watt sound system with a pair of Altec Lansing A-7s these days.

          In the video world, the DVD displaced the Video Cassette and downloaded video is the "MP3" of the video world.

          As long as downloaded video is relegated to mobile devices with 3.5" screens (like the iPhone/iTouch), or even a 17" computer monitor, George's point is moot. Nevertheless, as consumers, we need to be warned that not all "HD" content is created equal. When watching content on our $2,000 HDTV's, we need to stick with DVD/HD-DVD/BluRAY and leave our downloaded content on our 3.5" screens.
          M Wagner
          • You're wrong about that 17" computer monitor

            You're wrong about that 17" computer monitor because you're sitting 2 feet from a high-resolution screen that's much better quality than your typical low-end HDTV. Even the CHEAPEST $140 19" widescreen displays are 1440x900 resolution. Trust me even on XGA 1024x768 you will notice the problems with sub-DVD quality so-called HD downloads video.

            On a 3.5" display, you typically don't need more than 320x240 content.
            georgeou
          • Where I disagree with this article

            Is the assertion that newer video codecs only achieve a 50% compression advantage over MPEG2. Do you have any data to back this up?

            The general consenus for years has been that MPEG4-generation codecs typically achieve at 10x compression improvement over MPEG2 for the same quality output.

            Clearly, that must be a factor considered carefully in this report.

            I challenge anyone but the most obsessive videophile to distinguish between a downloaded Xbox Live 720p video and the 720p playback of an HD-DVD.

            In fact, if your numbers are correct - isn't the Xbox 720p file actually a higher bitrate to resolution ratio than the HD-DVD and BluRay discs? (which store their data at a higher bit-rate, but at 1080p).

            In that case, the disc-based files may have the advantage on larger 1080p sets, but will actually be worse off on a 720p set (or a smaller display at a viewing distance where the added resolution doesn't help as much as the higher bitrate).
            threedaysdwn
          • The industry would like you to believe there is a 2 to 1 advantage

            The newer codecs are great but they're being abused. The industry would like you to believe there is a 2 to 1 advantage and they'll point to tests on how they achieve similarly low noise levels. But what they won't point out is that they're cutting down on actual detail levels and optical resolution because they can do a better job of faking the detail.

            There's no question that the newer codecs are better at the same bit-rate or even slightly lower bit-rates, but to say that you can get away with better than 50% more compression and still faithfully recreate the same level of detail is nonsense.

            They fact that you are willing to say that 720p off Xbox Live is the same (at least perceptively) as HD-DVD tells me you're willing to bend the truth. Maybe if all you had was a 720p display you might be able to say that but that's a ridiculous argument to make. You can say that if all you have now or all you will ever own is a 720p TV, then it makes no sense to buy 1080p content. But you don't try to claim 720p content is no better than 1080p content.

            As for your argument on more bit-rate per pixel for 720p, that is one advantage if you have extreme amounts of movement but in general I'll always take the 1080p signal which has more absolute bit-rate as well as more absolute resolution. You cannot compare this to the situation where I say DVD is better because it has 720x480 resolution with HIGHER bit-rate than video with 1280x720 resolution but lower bit-rate. But I'll simplify it for you.

            1. Higher bit-rate and higher resolution is better than lower bit-rate and lower resolution EVEN if the latter has a higher bit-rate to resolution ratio.

            2. Lower resolution (especially after you up-scale it) with twice the bit-rate is better than something with better resolution but half the bit-rate.


            Lastly, 42" true 1080p LCDs and Plasmas are going to be less than $1400 list price this year and $1000 on sale so more and more people will have access to good HDTVs. Your 720P argument is out the window.
            georgeou
        • I don't care what codec you use, you can't get around the low bit-rate limi

          I don't care what codec you use, you can't get around the low bit-rate limitations. At best a 4 mbps H.264 stream is equivalent to a 6 mbps MPEG-2 stream but it's still going to be lower fidelity than an 8 or 9 mbps MPEG-2 stream.
          georgeou
          • +1

            I've seen too many people proclaim these newer codecs like divx/mpeg4/h264 to be an improvement over mpeg2 that they are not. While they are certainly better, they are not magic.
            toadlife
          • George is 100% right

            No matter how "big" is the size of the image if the bit-rate is low.

            What is the point of having a huge image if the quality of the visuals is crappy and dirty (full of imperfections). Any bit-rate lower than the bit-rate of a normal DVD can't be called true HD no matter what.

            My HD-A2 can upconvert a standard DVD with an amazing quality. In that case, why pay for a movie with downgraded quality and a fake HD label, when the standard DVD (rent or purchase) will give me a lot better quality of image??
            wackoae
          • Your nuts

            How about an actual comparison? Like rent some DVD and then watch the same stuff on xbox and see what its like?

            Your stats are also all hokey and non-real-world.
            IUseComputers
          • It's well known that the PSNR is at best 1.5x better for H.264

            It's well known in the science of video compression that the PSNR is at best 1.5x better for H.264 or VC-1 over optimized MPEG-2. So yes you can lower your bit-rate and still have the same quality, but you just can't lower it more than 1.5x and claim it is as good or better.

            I maintain that 8 mbps MPEG-2 on a production quality standard DVD is superior to a 4 mbps H.264 stream simply because you need 6 mbps H.264 to match an optimized 8 mbps MPEG-2 stream.

            Now Xbox360 Live videos are 6.9 mbps so that may be slightly better than a DVD but it's no where near the quality of broadcast 18 mbps MPEG-2 HD content.
            georgeou
          • 4 mbps H.264 may be better

            We need to clarify whether we are talking about here -
            1. peak bit rate or average bit rate.
            A high quality SuperBit DVD is rated at 6.8 mbps average - most DVDs are below this average. (or they won't have enough room for all those extra supplements - deleted scenes, making of, behind the scenes....)
            Excluding the audio 8-9 mbps MPEG-2 is the peak video data rate a DVD can achieve - not the average it can sustain.

            Assume an average of 5mbps - and using older MPEG2 compression - DVD don't have much advantage of a 4mbps (if bit rate was average) download. SuperBit DVD will be slightly better but see below

            2. video format
            DVD is encode at 480i - there are 60 fields at 720 x 240 resolution to compress.

            720p HD from company like Apple are encoded at 24 fps

            compressing 60 pictures at 720 x 240 using MPEG2 is a lot more inefficient than compressing 24 pictures at 1280 x 720 using newer H.264

            Base on my judgement at Appleword Expo, the Apple TV HD download do look better than average DVD but not as good as Blu-ray Disc (encoded at 1080p 24 fps)
            wingc@...
      • Lack of Understanding or Understanding Lack ?

        George Ou is pointing the Image quality and sound quality of Real HD technology on Web that will be use on iTV and iPod, iPhone and now the Mac Book Air and most of similar competitor devices.

        Screen resolution is something else if you understand right in PC?s and TV?s. Quality is something else even on a 2.5 LCD screen.

        What George is doing is lowering the number of so call "Sheep" that are just missing that type of information to stop the "Abusive" and "Dishonest" "Mercantile" Habits that are unfortunately growing in expansion in our actual time.

        Print this article and send it to your relative or Email it to your entire friend that you care.

        In my concern this is more than technically true.

        Best Regard George
        pobstar1@...
        • Thanks, well said

          I'm trying to educate computers so they have a choice. Now that true 1920x1080 1080p LCD 42" TVs are coming down to the $1300 price range, it's going to be really important that people understand the difference.
          georgeou
          • Fallowing You on that for sure.

            Keep the strain on so the strainer keep running on.

            :D
            pobstar1@...