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DirecTV's 1st MPEG4 Satellite Launch Successful
tivoKlr writes "Looks like the 1st Spaceway satellite to provide "1500 channels of HD" has made it successfully into space. MPEG4 compression and local HD channels, something that the cable company can't offer in my area." Unfortunately the new satellite obsoletes the HD Tivo, and there's no word on when there will be a new one.
I believe the High Def Tivo uses MPEG2 for its data streams, won't be capable of decoding the MPEG4 streams.
Note that comm satellites are just 'bent pipes'. This keeps them simple and independent of changing technology. So, there likely isn't any MPEG4 technology on board the satellite. Rather, the technology will be in the ground station. Therefore, DirecTV could have used an existing satellite in orbit, or even shared space with someone else on a satellite...
Digital TV has 18 different formats (resolutions), 6 of which are considered "HD". A couple of them are equivalent to NTSC resolution; 640x480 pixels. So NTSC stuff would presumably be broadcast in the standard appropriate digital format, taking up less bandwidth than one of the HD formats.
Craig Steffen
http://www.craigsteffen.net
I will confirm that a software update will not allow an HDTiVo to decode MPEG-4. TiVos are very low powered devices, and thus use hardware decoder chips, not software decoding. So they have an MPEG-2 decoder chip to complement a comparibly underpowered CPU. They can't simply push a new codec down to the TiVo to decode MPEG-4.
HD DirecTiVos will be obsolete next year.
Note that cable providers recompress the original MPEG2 streams themselves to reduce bandwidth used by HD channels.
Yes, though not at the specific data rates used for broadcast. In general MPEG4 is vastly superior to MPEG2, however. Also, an MPEG2 stream would never be recompressed as MPEG4, the broadcaster would feed the uncompressed signal into the MPEG4 compressor. All in all this is a move to increase quality at the same bandwidth.
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The "killer technology" on the Spaceway birds are their ability to form tight "spot beams" using Ka band (~20 Ghz) downlink signals.
The spot beams are formed using a 1500 element phased array. The array can form as many as 780 downlink spot beams and 112 uplink spot beams across the US. Compare this with a typical Ku-band (~12 GHz) satellite which has a single beam over the entire US.
Spaceway uses digital regenerative switching of up to 10 Gbps, as opposed to the analog transponders of most geosynchronous communications satellites (despite the fact that most of those transponders are used with digital services these days).
Spaceway was originally supposed to provide satellite point-to-point and point-to-multipoint IP connectivity, but that was dropped in favor of providing massive localized HDTV capacity using spot beams.
Unfortunately, Ka band is more sensitive to rain fade outages than Ku band.
Dish Network bought the Voom satellite, so you may be able to get those channels on Dish soon.
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Most of what they have was filmed in 4x3. The major networks are not going to suddenly limit themselves to only 16x9 and change their whole schedule. As more and more new episodes are filmed in 16x9 you'll see more.
Comcast near Atlanta just added TNT in HD. For some reason they are stretching all 4x3 into 16x9. Now that's REALLY annoying.
Dish is buying the satellite and the uplink facility. However the content and encoding equipment wasn't included in the deal (yet..stay tuned though ;) )
The launch can be seen at the Sea Launch website www.sea-launch.com This was the heaviest launch for Sea Launch to date.
DirecTV is offering a $200 rebate for voom customers looking to move to DTV.
http://www.directv.com/voom/
"Any "visualphile" will know that a decent analogue signal usually looks a lot better than it's digital equivalent (ref: I'm comparing Digital Terrestrial to Digital Satellite and Cable services available in the UK)."
No, it doesn't. A clean analog signal looks better than an overcompressed digital signal, true. But a truly "clean" analog signal doesn't exist.
Compare the quality of DVD to the much-vaunted Laserdisc. LD is about as close as you can get to a "clean" analog signal, and it still had a number of quality issues (mostly related to color-space compression).
"They don't seem to be able to transmit TV in the current resolution without severely degrading the picture."
Evidently your cable and satellite providers in the UK suck. They do here, too. DirecTV's picture is already overcompressed garbage.
That's why we're so psyched about SPACEWAY - there's plenty of bandwidth to transmit every local channel in the US, in HD, with a decent bitrate.
"My worry is that even with MPEG 4 (which will probably be recompressed MPEG 2 sources anyway for quite a while) they may not have enough bandwith to send me a 1080 line picture without artifacts..."
There is plenty of bandwidth with SPACEWAY. Bandwidth will now be in the 10-12MBit range, up from 1-2MBit for DirecTV's current SD service. They're using MPEG-4, too, so that provides an additional quality increase.
If you're worried about 1080i looking poor at 12MBPS, keep in mind that Microsoft's WMV-HD demos (at 1080p, no less) are in that range. Go download one and take a look for yourself.
DirecTV also won't be re-encoding MPEG-2 boradcasts - they will get a clean signal that they can encode, just like they do today with MPEG-2.
"Maybe with Fiber To The Home we might actually get enough bandwidth to watch the channels we want at the resolution we want, without thinking that it looks like your TV has gone though 4 copes of RealPlayer..."
FTTP is completely unnecessary for the cable company. The coax they have in the ground right now is already capable of delivering 120+ HD channels at full broadcast bitrate (~20mbps). That's only counting the spectrum they are currrently using for analog channels.
There's plenty of bandwidth with the current coax. There's no need for FTTP just to get decent HD services.
If I was a DirecTV customer, I would care, as do many others.
I do not live in a major metropolitan area, so I do not get a very good signal (analog or digital) from the local stations. Many people also have issues due to terrain. With satellite, line of sight is much better (either you get it or you don't), and barring severe weather, the signal is much more dependable.
I currently get my locals on Dish, just not in HDTV. And due to market rules, I do not qualify to receive the distant network HD feeds. So if they did add locals in HDTV, it would be an appreciated increase in service.
RawDigits: I would imagine an operation as large as DirecTV is probably not going to be re-encoding an MPEG2 signal, but using a more raw format for HD and compressing it from the 'master' copy just as they do when they convert to mpeg2 now ...
mecro: The FCC only gave broadcasters a small chunk of the spectrum to broadcast, which means the MPEG2 signal is compressed somewhere between 49-55:1.. That's insane, and MPEG 4 will hopefully lessen the compression ratio.
flimflam: Yes, though not at the specific data rates used for broadcast. In general MPEG4 is vastly superior to MPEG2, however. Also, an MPEG2 stream would never be recompressed as MPEG4, the broadcaster would feed the uncompressed signal into the MPEG4 compressor. All in all this is a move to increase quality at the same bandwidth.
For OTA signals, DirectTV and Dish currently have an antenna in the city that receives the analog OTA signal, which they compress for transmission. They only have a direct connection to the national signals they provide to people too far from local affiliates (I believe from NY and LA). It's unlikely they will obtain a more direct connection for digital OTA signals. So it's almost certain that the video will be doubly compressed--MPEG-2 by the channels, MPEG-4 by DirectTV.
Satellite channels (ESPN-HD, etc.) are currently pulled off of the high bitrate (MPEG-2) satellite feeds and compressed to low bitrate MPEG-2 by DirectTV and Dish. The encoder will likely be MPEG-4 for these types of sources.
jchapman16: Note that cable providers recompress the original MPEG2 streams themselves to reduce bandwidth used by HD channels.
I can't speak for every cable provider, but stream analysis done by those of us with FusionHDTV cards (capable of recording cable's QAM modulated HD streams) have shown that the video is not recompressed. It is re-wrapped, with much of the transport stream adjusted, but the data itself is not decompressed and re-compressed.
Xesdeeni
The DVD standard is MPEG2 at either 720x480 (NTSC) or 720x576 (PAL). That's 480 or 576 lines, respectively. DirecTV is (currently) MPEG2 at 480x480.
HDTV is 720 lines or more. DirecTV is converting to MPEG4 so it has the bandwidth to broadcast more channels at HD resolutions. At least initially, only HD channels will be broadcast with MPEG4.
I've gotten to see a little bit of this, since my company (TandbergTV) is supplying the encoders. The bitrates on the mpeg-4 stream are going to vary from 4mbps to 20 mbps, which in mpeg-4 is pretty good looking. There's a load-balancing system that will adjust a channel's bitrate as it needs more (for say fast-panning scenes in sports). The encoders are installed now in two locations and running, but as with all projects this will take time.
Most of the issues you raise in point 1 deal with the transition from NTSC to digital in general. The monitor is still the largest single expense, so it doesn't matter if the transmission medium is OTA, DBS, or cable. And there should be exactly one encode at the uplink/headend, and one decode at the customer's tuner. If your provider of choice is recompressing mid-stream, they've screwed something up.
These gaming and information services you speak of are already the norm. Perhaps you've heard of the Internet and XBox Live? Maybe if customers were demanding One True Set Top Box that has all these features, you'd have a point. More likely, these features are being crammed into STBs the way Microsoft would cram features into Office, just so they can brag that the "other guys" don't offer Esoteric Feature That Nobody Asked For #7.
Do you honestly think that cable will have a better track record than DBS on DRM? Name-dropping Rupert Murdoch and Circuit City DiVX won't change the fact that DBS and cable providers will all answer to the Big Media content providers.
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