DirecTV's 1st MPEG4 Satellite Launch Successful 291
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.
Re:For someone not hip on the lingo (Score:5, Informative)
I believe the High Def Tivo uses MPEG2 for its data streams, won't be capable of decoding the MPEG4 streams.
Satellites are linear not digital (Score:3, Informative)
Re:In this kind of setup... (Score:5, Informative)
Re:For someone not hip on the lingo (Score:2, Informative)
HD DirecTiVos will be obsolete next year.
Re:Quality of MPEG4 signals? (Score:2, Informative)
Re:Satellites are linear not digital (Score:5, Informative)
The only reason they are able to do this is because they are going to be transmitting using a different band - KA. The current DirecTV sattelites transmit in the KU band. So they'll be using their existing orbital slots 101, 110, & 119 to broadcast on a different wavelenght.
Unfortunately this is going to be mean a larger dish will be required. Google dish network superdish for an idea of how big it is. Dish Network already does broadcast some local channels in KA band.
Re:Quality of MPEG4 signals? (Score:5, Informative)
Ka spot beams (Score:5, Informative)
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.
Re:Full HDTV Finally (Score:2, Informative)
Re:For someone not hip on the lingo (Score:3, Informative)
Re:Satellites are linear not digital (Score:3, Informative)
The funny thing is that MPEG-4 streams are carried within the same 188-byte packet MPEG-2 transport stream that normal MPEG-2 live video streams use.
Re:Satellites are linear not digital (Score:4, Informative)
Re:the more HD, the merrier (Score:2, Informative)
Comcast near Atlanta just added TNT in HD. For some reason they are stretching all 4x3 into 16x9. Now that's REALLY annoying.
Re:Full HDTV Finally (Score:3, Informative)
Re:Ka spot beams (Score:5, Informative)
Watch the launch (Score:2, Informative)
Re:Full HDTV Finally (Score:3, Informative)
http://www.directv.com/voom/
Re:Who asked for higher resolution? (Score:3, Informative)
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.
Re:IT's ALL LOCAL TV !!! -- WHO CARES! (Score:3, Informative)
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.
Re:Quality of MPEG4 signals? (Score:4, Informative)
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
Re:Satellites are linear not digital (Score:2, Informative)
Ironically, the smaller dishes are easier to aim, since their gain is so much lower. Remember, a satellite dish is simply a telescope that operates on microwave frequencies rather than visible light, so a more powerful antenna "sees" a much smaller portion of sky, and consequently gets a much better signal. Having aligned 1.6-meter dishes and 12-meter dishes, I can attest that the 12-meter gets a great signal, but is harder to aim.
clueless (Score:1, Informative)
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.
Re:Quality of MPEG4 signals? (Score:3, Informative)
Re:Let's see... (Score:3, Informative)
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.