Discussion Topic: 1080p Movies Coming to your Satellite Box Soon - John E. Johnson, Jr. - November 17, 2008
The other day I received notification from DirecTV that they would soon be delivering movies in 1080p to my satellite box, and that the box could handle them, and I could watch these movies on my HDTV as I would any other programming.
Well, the question is how well this will work, and will it provide us with anything we don’t already have in terms of the final image on our TV screens.
First, programming is currently delivered in 1080i, and the end result is different when the source is, say, a live TV program shot in 1080i, vs. a 24fps movie shot on film or digital. With the live program, each field, which consists of 540 lines, representing 1/60th of a second of video action, does not allways merge with the subsequent field because it represents the subsequent 1/60th of a second in the video action. On old 1080i CRTs TVs you end up with “combing” where edges of object are not straight because they moved between one field and the next. On newer 1080p TVs this material is deinterlaced with variable quality. If done incorrectly, entire frames are interpolated from individual fields, resulting in only 1/2 the resolution. If done correctly though, only areas of the picture in motion lose resolution, and the remainder of the picture is full 1080 line quality.
Film on the other hand, has individual frames, 24 of them per second, and each frame gets divided into two fields. 1080p TVs are able to recombine the fields into frames yielding a true 1080p image.
So, whether the filmed movie is sent to us via cable or satellite in 1080i or 1080p, the end result will look the same when the TV merges the two fields to become 1080p.
What then is the point of this new venture?
Marketing? Probably. Will it increase subscriptions? Probably.
Will it work? Probably, as long as the cable or satellite box can downconvert to 1080i or 720p so that it can be connected to the majority of HDTV’s out there that were purchased before 1080p.
Dish Network has been offering 1080p24 movies as part of their VOD (Video On Demand) service now for several months. It seems to be working.
Whether the movie is sent the cable or satellite box as 1080p24 or 1080i60 is unimportant, as long as the box gives a choice of, and can output it correctly as, either 1080i60 for old HDTVs, 1080p60 for the newer ones, or 1080p24 for those lucky enough to have one of the new TVs that accept 1080p24 and interpolate in between frames to give us a 120 Hz image (120 frames per second, with each native frame in the 24 FPS movie having 4 interpolated frames in between). I don’t think that is what is going to happen, but, we will see, and it looks like it will be soon.
November 17th, 2008 at 9:41 am
While the 120Hz (e.g., MotionFlow) display modes are nice, people don’t necessarily need these to enjoy a judder-free image. There are many sets available today that have a 24p compatible mode (e.g., my Pioneer plasma displayed 24p movies at 72 Hz, while my old Sony projector displayed them at 96 Hz), so just because one’s TV doesn’t have a 120 Hz mode, a person should not be discouraged!
That being said, depending upon what the Sat provider’s production chain looks like, the switch to 24p MAY save them as much as 20% of the bandwidth vs. sending things out at 1080i. However, this is really dependent upon what type of encoders they are using to process the video before bouncing it off the satellites.
One way to test this would be to use a video processor where you can alter what bias it has for deinterlacing mode. If you set it to “film” and a 1080i video starts to break apart (lots of artifacts), or it drops back into video mode, then the Sat provider did not bother to encode the movie as film-sourced content. If you get a good cadence at 1080i, then this really is more marketing hype than real benefit to either consumers or to the satellite providers.
November 18th, 2008 at 7:59 am
The picture is hype… however a 1080p signal would not have to be up converted and would save the signal from one more conversion to a 1080p HDTV. And what of Dolby Digital TrueHD and DTS HD Master? When will they “catch up” to lossless audio?
November 18th, 2008 at 8:27 am
I currently (and for the past 2 years) receive 100% of my TV programming from an aluminum antenna in the attic, so I don’t have any recent direct experience with any of the recent technology changes that the satellite providers have been pushing through. I have however, been trying to keep up with the “literature” so to speak.
It seems to me that this is most likely marketing hype, and that we won’t see any improvement in picture quality. This is IMO especially so since there is no required or suggested change in home hardware.
Further to what Bill said, there are (aren’t there?) some HDTV models out there that display at a max of 60Hz, but do also accept 24p video, and just properly execute the 2:3 cadence process. In other words, I didn’t think that a 120Hz display was a requirement to view 24p material without errors.
And a question for Bill: Where and/or how does the 20% bandwidth savings come in for a video provider if they switch to transmitting 1080/24p material via 1080i to transmitting it natively? I thought the two were virtually the same bandwidth. I can see their processing overhead going down, but don’t see the bandwidth savings.
If any of the staff here at Secrets will be able to run an experiment such as Bill suggests, I will be interested to see the results.
For anyone wanting more, this is a good time to review Brian and Colin’s excellent 1080p article!
http://www.hometheaterhifi.com/features/technical-topics/high-definition-1080p-tv-why-you-should-be-concerned.html
November 18th, 2008 at 10:11 am
DISH Networks introduced TurboHD for a few months ago featuring 1080p as well as more HD channels. I remember hearing an ad on the radio and figured I would have to investigate what was required to get TurboHD, but when I turned on our system to watch TV there was a notice on the screen that indicated that my several year old ViP 622 receiver was automatically “upgraded” to TurboHD. Cool, I thought, but I was a bit suspicious when I checked the HDTV setup menu and the choices were 480i, 720p and 1080i, no 1080p. When I checked the DISH Guide or the Video on Demand (VOD) selections, however, I could see a movie listed in both HD and 1080p formats.
The 1080p movies automatically show up in the VOD area of the guide if you turn your receiver off at night. If you don’t turn your receiver off at night, or have something scheduled to record in the early morning hours, a given VOD movie might not be downloaded. A few nights ago, I didn’t see any 1080p movies in the guide, but a turned my receiver off that night for sure, and the next morning I had “Iron Man” in 1080p waiting for my viewing pleasure.
Since the HDTV setup still did not list a 1080p option, I again wondered how the DISH receiver would know that my display could handle 1080p, but when I selected “Iron Man” in 1080p, I got a screen saying that my display may go blank for a few seconds followed by a, “Do you want to rent this movie in this format” dialog box, obviously testing whether the display was capable of displaying 1080p24. When I clicked, “Yes”, the movie started right away, so it had obviously already been downloaded. The projector’s info menu confirmed that it was being displayed in 1080p24 Hz. In this format Iron Man looked very good with credits scrolling smoothly, etc.
Having VOD content pre-downloaded to a reserved section of the receivers disk is obviously handy in one wants to watch VOD, but having a number of movies I’ll never watch stored on MY disk and having a given movie stored in two very similar formats 1080i and 1080p24, does not seem like the best use of disk space. I should also add however that about a year ago, I added an external 750Gb disk to the DISH ViP622 for archival storage of HD movies, etc. and that has worked very well.
November 18th, 2008 at 11:51 am
It seems with all of the efforts in marketing 1080p displays, it would make sense the content distributors would want to leverage the message that’s already been delivered to the consumer. It’s an easier sell than trying to convey the benefits of higher bit-rate programming, which would really deliver a visible difference in video quality. My comparison points being HD cable/satellite, HD OTA and Blu-ray which successively have higher typical bit-rates, and visibly better video. While there is most certainly a threshold above which compression artifacts are no longer visible, cable/satellite and even OTA depending upon the broadcasting station are well below that threshold.
I read recently that some HD broadcasts in France were beginning to use DD+ which would be a step up from the standard DD we receive (sometimes) from our broadcasts here. I would be skeptical of claims of a huge demand for higher quality audio from broadcast programming though, given the average consumer is living happily with compressed stereo. The bandwidth requirements for the lossless formats are also likely too high, although I haven’t run the numbers myself to confirm the suspicion.
November 18th, 2008 at 1:07 pm
A few weeks ago, DirecTV pushed a firmware update onto my HDDVR. Among several new enhancements, I now have the option of outputting a 1080p signal to my monitors. There is no indication as to what the frame rate is, but I’m assuming that it’s 30 fps. I can’t do anything with this toggle yet because two of my monitors are 720p and the third can display 1080i only. I was surprised that this update would work with my DVR as it is the older HR 20 model, but the toggle did show up and the device recognized that my monitor could not support this new output resolution.
November 18th, 2008 at 6:11 pm
My parents are Dish Network subscribers so I will be interested to see if there is a difference from the standard HD. I just looked at the website (www.turbo-hd.com), and they are offering all new “turbo boxes”. I think the first thing that should happen when these boxes come out is to tear one open and see what’s inside, I have a hunch that these boxes will simply have a slightly improved 1080p deinterlacing solution. As John stated above, it doesn’t really matter if the feed is 1080i or 1080p60 or 24, if your display has a better 1080p deinterlacing solution than these new boxes (and if they will put out an interlaced signal to avoid double dipping the deinterlacer), you will have little, if anything, to gain from 1080p or Turbo HD from any provider. The video stream will probably be a lower bitrate than Verizon FiOS, and if it is as fast, it will just be a catch up move. Another possibility is that the engineers have tweaked the compression software to more effectively send high quality HD streams, if this is the case, they will just end up using the extra bandwidth for piling on extra channels of underwater basket-weaving which will drag the quality of the better programming down.
Any way you look at it, I think there is a very slim chance that any of these “new technologies” are anything but glorified smoke and mirrors.
November 19th, 2008 at 9:25 am
…anyone try Vudu’s HDX HD downloads? Picture is said to rival BD and the audio in “a higher bitrate” (whatever that means).
November 19th, 2008 at 11:05 am
Vudu’s HDX looks nice on paper…as long as your ISP does not limit your bandwidth!
November 19th, 2008 at 11:21 am
“Further to what Bill said, there are (aren’t there?) some HDTV models out there that display at a max of 60Hz, but do also accept 24p video, and just properly execute the 2:3 cadence process. In other words, I didn’t think that a 120Hz display was a requirement to view 24p material without errors.”
The “big deal” about having an integer-multiple of 24Hz is to eliminate “judder” in the picture. Judder is a timing disconnect between the source and display framerates, and it shows up as “jerky” motion. Televisions touting 120Hz modes do so because it is the lowest framerate that is both an integer multiple of 24 and 60Hz (we will ignore fractions here, like 59.94…).
“And a question for Bill: Where and/or how does the 20% bandwidth savings come in for a video provider if they switch to transmitting 1080/24p material via 1080i to transmitting it natively? I thought the two were virtually the same bandwidth. I can see their processing overhead going down, but don’t see the bandwidth savings.”
The difference in bandwidth would come from eliminating the redundant information in the encoded video stream. The reason this might happen is due to potential differences in how a broadcaster would encode (really: transcode) its content. Many broadcast encoders in the past have been single-pass, constant bit-rate (CBR) designs emphasizing reliability and speed over absolute image quality and efficiency. Conversely, packaged media have used multi-pass variable bit rate (VBR) encoders for years. The difference between these is that a VBR approach, which requires more than one pass through the data, is a LOT more efficient (better quality output) at a given bitrate than a comparable single-pass encoder. Even where you have a relatively efficient encoder, broadcasters often have to pad data with nulls in order to make a data stream conform to meet specifications expected by some piece of gear in the chain (e.g., if you strip the nulls out of an ATSC stream, you can often save half of the resulting file size — at least with some of my local broadcasters!).
So, where did the fairly specific 20% number come from? It came from what ought to be a “best case” scenario for bandwidth savings from DirecTV or Dish. Simplistically, a 24p data stream is 20% smaller than a 30i data stream. However, whether any of this is fully realized has to do with how the data is handled (or mangled) during transmission, storage and playback. Hence my proposed experiment. If a 1080i VOD movie underwent a clean telecine process that is preserved through to the display, then one ought to be able to tell by forcing a “film” deinterlacing mode. If the movie has deinterlacing issues (e.g., loses sync, breaks up, etc.), then there is a pretty good chance that the provider’s “standard” delivery process for VOD has to force a conversion to “video” somewhere along the way, and in that case, a 24p delivery format more than likely saves them bandwidth.
November 19th, 2008 at 7:53 pm
Though only somewhat related, one thing I would like to see is that since these boxes can output a 1080p signal, I would like standard 1080i and 720p signals to be sent as 1080p. The scaler from 720p won’t be much worse, or possibly better, than my HDTV’s scaler, and it should be very simple for it to do 2:2 pulldown to get 1080p60 from 1080i. However, the main thing it would do is stop my TV from having to re-handshake with the box when I switch from a 720p channel to a 1080i one. I like to feed the signals in native format but as everything will eventually be converted to 1080p, I’d be fine if the cable box sent that.
November 20th, 2008 at 11:49 am
Two thoughts.
The bandwidth savings is pretty simple: in a completely uncompressed stream:
720P = 1280*720*60 frames a second ~ 55.3 mbits/sec
1080i = 1920*540*60 (or 1920*1080 * 30) ~ 62.2 mbits/sec
1080p/24 = 1920*1080*24 ~49.8 m/bits or 20% less than 62.2m/bits for 1080i if you assume the compressed stream keeps a similar relationship to the raw.
*To simplify the explanation I didn’t include bits for color depth, if you want real “raw” bits rates multiple the above by 8.
Second thought is this is another example of how downloading or near timing content is surplanting the need for physical media like bluray. Yes Bluray can have a better picture due to it’s higher bit rate capability but: 95%+ of folks don’t care and convienience * cost = King. (Although if you are reading this you uare probably of the 5% that do care…). If I can get a great looking movie for $6 and it’s there when I want it…. Is it worth the trip to the store? Is it worth ordering and waiting?
November 21st, 2008 at 8:14 am
Two counter thoughts.
First, the only place you’ll find a completely uncompressed HD stream is in production. You’ll never find it hitting a consumer source or display.
Second, further to the first point, compression has tremendous impact on final quality which is why “HD” downloads or “HD” cable is notably inferior to HD physical media. Compressed bitrates of DLC is typically less than half (7-10 Mb/s) what you would find on an average Blu-ray (18-24 Mb/s). Even considering the additional bandwidth of high-res audio, the bitrate differences for video are consequential.
Lastly (unaccounted for thought), there are definitely instances where convenience overrides quality but the reverse can also be true. Wedding Crashers in high bitrate 1080p has less allure than Baraka for instance.
November 25th, 2008 at 7:48 am
This is yet another choice we have for receiving content. Technical deficiencies aside, at least we have more than one way to get HD programming and movies. I hope the preservation of choice continues. I don’t think there will ever be just one way to watch TV. Blu-ray is for the enthusiast who accepts only premium quality. DVD will no doubt linger on as the other choice for physical media. It remains to be seen how cable, satellite and internet delivery systems will fare under ever-increasing bandwidth demands. We’d all love to receive a 1080p movie with lossless multi-channel sound over an on-demand service. I hope we get there. For now, Blu-ray will rule my bookcase.
December 11th, 2008 at 7:30 am
There are two issues at play here: The first is 1080p vs 1080i and the second is whether the source is 24 or 60. If it’s 1080i, then obviously it’s 60. But if it’s 1080p, it could be 30 or 24.
In order of preference:
1. If the content you wish to download is film-based, I’d take the sat or cable provider’s 1080p24 feed miles ahead of a 1080i60 broadcast. In that case it’s not *just* marketing. Since their source D5 or HDCAM tape is most assuredly a 1080p23.98 tape, I’d like fewer conversions along the way to my display if possible. It’ll likely already be compressed to within an inch of its life, I’d like to not deal with 2:3 pulldown along the way if possible.
2. If the content was shot at 1080p30 (probably unlikely) and is available for 1080p download, then 1080p is the preferred format. However, interlacing 1080p30 to 1080i60 for broadcast and then our devices deinterlacing it *back* to 1080p30 should be seamless by most processors, but conversions are fallible. Having said that, in this scenario I’m less-inclined to purchase or download one format over the other. While I trust a broadcaster’s deinterlacer more than I do mine (Pixelworks & HQV), if I’m considering VOD content in the first place, then PQ isn’t my #1 priority - convenience is.
3. If the content was shot at 1080i60 and is available for 1080p download, I’m less-inclined to purchase or download one over the other. Given the choice of getting my content deinterlaced by a professional piece of hardware versus trusting consumer-grade hardware to do it just as well, I’ll take the pro everytime in a technical discussion, but for the reasons stated in the last paragraph - it’s about convenience.
My 2 cents is that it’s not *just* marketing. There are techincal reasons why 1080p is preferrable to 1080i in two out of three of the cases I mentioned, but as many of us have also mentioned, for over-compressed, VOD services, they may be made irrelevant.
April 10th, 2009 at 6:19 pm
My TV bill is out of control. In my house we have 3 TVs, each with cable tv service. We get about 65 channels, but no HD programming. My husband really wants HD for his sports. Baseball season is coming and he is anxious to get it. For what I consider limited service I pay $200 a month . Does that seem way too high? What is a better idea if I wanted HD??
April 13th, 2009 at 10:38 am
For $200/month you should have all HD channels. Contact DirecTV. We pay $110/month and get all the HD channels.