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General => Users => Topic started by: dthrock on January 06, 2008, 07:43:07 pm

Title: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: dthrock on January 06, 2008, 07:43:07 pm
Westinghouse Unveils Wireless HDTV

Las Vegas (NV) - Users will soon be able to send high definition signals to their HDTV sets without any physical cable connection, thanks to a new partnership between Westinghouse Digital and semiconductor company Pulse Link.

"HDMI digital transport provides the full HD resolution our customers expect," said Westinghouse VP John Araki in a statement. Through the wireless HDTV technology, users will be able to set up their television anywhere in a room, and have HDMI connections sent from sources like HD DVD players or the Playstation 3 wirelessly.

The technology uses Pulse Link’s CWave UWB chipset, which has a 1.35 Gbps over-the-air signaling rate and can deliver 890 Mbps. According to Westinghouse, the signal was still as strong as 115 Mbps when the devices were 40 feet apart.

It "is an experience beyond comparison with anything that has come prior to now," said Pulse Link president Bruce Watkins. He claims, "This really changes everything."

The new TV will be on display and will make its official unveiling at next week’s Consumer Electronics Show.
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: Matthew on January 06, 2008, 08:10:07 pm
The HDMI support is supposed to be transparent, therefore LMCE wouldn't need any special support beyond plain HDMI.

Also, there are other wireless HDMI products announced, including a chipset that replaces just the cable with components that can connect between existing equipment (this TV embeds the receiver). Since UWB can carry something approximating HDTV and UWB chipsets are in commercial production, there will be lots of these kinds of products.

But 1audio posted this past week (http://forum.linuxmce.org/index.php?topic=3682.msg20253#msg20253) that it's not really HDMI:
I have had hands on experience with virtually every wireless HDMI solution being proposed. First for the UWB solutions 30' (10M) MAX and worse in many environments. Second, they all truncate content somehow- either recompressing or artfully dumping some image component not deemed necessary. Third and most important they will be between $450 and $800 retail.
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: teedge77 on January 06, 2008, 08:20:23 pm
for videophiles that may mean something. its basically doing the same thing as an mp3 does but for video instead...even similar to divx. anyone ever use divx or mp3s???
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: golgoj4 on January 06, 2008, 09:12:14 pm
“There is no such thing,” Chard says, noting that the moniker is “misleading” because it suggests the technology is standardized through the HDMI camp. “Basically it means that there’s HDMI on one end and a wireless link on the other. … We asked them to start calling it wireless for HDMI.”

taken from slashdot earlier this morning - http://www.cepro.com/article/hdmi_execs_discuss_13_displayport_cec_wireless_hdmi_more/
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: colinjones on January 06, 2008, 09:36:52 pm
I agree, nonsense! HDMI 1.3 is over 10Gbps. Even a basic 1080i signal at 30Hz frame rate with only 24bpp colour depth would require approx 1.5Gbps just for the video signal! Taking a video signal that was already compressed (HD DVD for instance) professionally and not in real time and then decompressed with your player, and then attempting to recompress it real time just to send it wirelessly, and then re-decompress it again is asking for trouble. They would have to get a compression ratio of at least 3:1 reliably and time-averaged to support this working over the distances they are talking about - and that spells doom to the picture quality.

I don't think this is a consideration for videophiles alone - if you've gone to the expense and effort of getting HDMI, HDTV and an HD source like HD DVD or worse BluRay, then I don't see why you would compromise all that with this "weak link"....
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: teedge77 on January 06, 2008, 09:42:31 pm
what i was saying was videophiles would give a crap about losing stuff most people wont notice. like the so called audiophiles who hate mp3s. the average person will have an hd signal they think is better than the old 480.
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: Matthew on January 06, 2008, 09:49:34 pm
what i was saying was videophiles would give a crap about losing stuff most people wont notice. like the so called audiophiles who hate mp3s. the average person will have an hd signal they think is better than the old 480.

Probably only because they paid for something called "HD", not because it has any better quality. Better than 1080i or 720p, anyway.

What I wonder is whether H.264, which usually gives 50:1 compression, will shrink the uncompressed HDMI from 10.2Gbps to 204Mbps. Which would sail across Gb-e wires, and even fit in a couple-few WiFi 802.11g channels. If so, cheap multichannel 802.11g transceivers could be right around the corner, like at the 2009 CES ;).
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: colinjones on January 06, 2008, 09:50:41 pm
teedge77 - no, I realise that's what you meant. What I was trying to say was, this is a very different situation because of 1) the sheer data quantity involved in the compression, and 2) the fact that it has to do it real time.

That would mean that either the hardware needed to do this compression would be wildly expensive (which I'm assuming it isn't), or the compression quality would have to be so poor to achieve the 3:1 (or more) that anyone, not just videophiles, would notice it.

By analogy, if you have a decent jpg program, not only does it allow you to trade off between quality and size, but you can also get it to do more detailed passes to achieve better quality even at lower file sizes ... but as they say, you never get something for nothing. The trade off then is that the algorithm takes much longer to do the work. So to get that level of compression real time, either the hardware is going to be impressive, or the compression artifacts will :)
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: colinjones on January 06, 2008, 09:55:21 pm
what i was saying was videophiles would give a crap about losing stuff most people wont notice. like the so called audiophiles who hate mp3s. the average person will have an hd signal they think is better than the old 480.

Probably only because they paid for something called "HD", not because it has any better quality. Better than 1080i or 720p, anyway.

What I wonder is whether H.264, which usually gives 50:1 compression, will shrink the uncompressed HDMI from 10.2Gbps to 204Mbps. Which would sail across Gb-e wires, and even fit in a couple-few WiFi 802.11g channels. If so, cheap multichannel 802.11g transceivers could be right around the corner, like at the 2009 CES ;).

Matthew - realise that the comment was tongue in cheek... but same principle, I'm sure H.264 can get as high as 50:1, but certainly not in realtime without some real kick arse hardware :)

(btw, it often only achieves this because it can handle a dynamic number of frames in buffer of upto 16 prior frames to do the motion deltas from, wherease most of the previous MPEGs only held 1 or 2 prior frames. Having to wait an indeterminate amount of time with frames in buffer would also cause more "realtime" issues in a realtime stream, lipsyncing is bad enough now!! I'm guessing that the algorithm would have to disable such a deep frame buffer for realtime streams, and that would dramatically impact the ratio, too)
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: teedge77 on January 06, 2008, 10:07:14 pm
what about the coax adapter? any better?
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: colinjones on January 06, 2008, 10:23:08 pm
Don't see why not, shouldn't need any compression then ... but its still a wire... you don't like the HDMI cables, or is the the length limitations you don't like?
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: ddamron on January 06, 2008, 10:24:42 pm
Possibly the termination... Coax you can terminate easily.  HDMI, you can't.
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: teedge77 on January 06, 2008, 10:37:35 pm
yeah its really just the lengths. i need just over over 50 feet to get it to all the places id like. the living room would be the only one that might be less. ive seen rapidrun cables and the reviews were good. i am considering those right now i guess.
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: colinjones on January 06, 2008, 10:41:31 pm
hmm.. that's always the prob isn't it? I guess as the standard develops in new versions they will extend the standard cable run lengths. Think you are just going to need to set up HDMI MDs everywhere! Certainly doesn't sound like the Wireless would get you the 50' you are looking for, they say themselves it reduces to just over 100Mb/s at 40'...
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: teedge77 on January 06, 2008, 10:52:17 pm
well...its only about 20 feet as the crow flies and then running the cable up and over in the attic and down to the tv would be about 50 for the living room and more like 75 for the other rooms. so the wireless might have covered the living room....probably wouldnt look so great. ive got coax to every room already. so i suppose that would be an option depending on price. i wanted to use the direct hdmi output on the blu ray and hd dvd players to the tvs. if lmce gets it working so i can watch blu ray and hd dvd stuff from there then id just do that with MDs.
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: Matthew on January 06, 2008, 11:35:07 pm
what i was saying was videophiles would give a crap about losing stuff most people wont notice. like the so called audiophiles who hate mp3s. the average person will have an hd signal they think is better than the old 480.

Probably only because they paid for something called "HD", not because it has any better quality. Better than 1080i or 720p, anyway.

What I wonder is whether H.264, which usually gives 50:1 compression, will shrink the uncompressed HDMI from 10.2Gbps to 204Mbps. Which would sail across Gb-e wires, and even fit in a couple-few WiFi 802.11g channels. If so, cheap multichannel 802.11g transceivers could be right around the corner, like at the 2009 CES ;).

Matthew - realise that the comment was tongue in cheek... but same principle, I'm sure H.264 can get as high as 50:1, but certainly not in realtime without some real kick arse hardware :)

(btw, it often only achieves this because it can handle a dynamic number of frames in buffer of upto 16 prior frames to do the motion deltas from, wherease most of the previous MPEGs only held 1 or 2 prior frames. Having to wait an indeterminate amount of time with frames in buffer would also cause more "realtime" issues in a realtime stream, lipsyncing is bad enough now!! I'm guessing that the algorithm would have to disable such a deep frame buffer for realtime streams, and that would dramatically impact the ratio, too)

Well, I was "kidding on the square". Whether or not it actually works, I won't be surprised to see announcements of "working" products at the 2009 CES, especially if "wireless HDMI" continues to get the same uncritical coverage it already this year. But most video isn't really "realtime" in latency. Here in NYC, I routinely talk on the phone with people while watching the same TV channel on the same cableco, and can often hear a difference of up to 10s. Which is by no means evidence of the maximum. And who cares? Even if the lag is over a minute, the only real effect is that realtime clocks on TV (like on the half-hour TV news shows) will be out of sync by a digit, which seems inconsequential in a media environment like LMCE which can display truly realtime NTP. And even the basic FF/RV "cable movie on demand" controls I have now are "soft" by at least a few seconds or more. For LAN media playback, the same MD buffers improving compression ratios can also be used for local FF/RV while the latent network recovers more key frames outside the buffer (dropping the intermediary frames during FF/RV should improve the "compression" even more drastically) to minimize control/response feedback latency.

So while I don't know about H.264 delivering 50:1, especially on 1080p, even 11:1 or better (which is what MP3 gets for audio) would fit in Gb-e. And though H.264 consumes about 10-100x MPEG-2 processing, MPEG-2 decoders are really cheap, and there's a 16-stream H.264 DVR (http://www.tigerdirect.com/applications/searchtools/item-details.asp?EdpNo=3163580&Sku=Q300-2318) for $1200, which also compresses, so I don't think <$100 H.264-out PCI-e cards are too far away.
Title: Re: Wireless HDMI HDTV coming, need to get this in LMCE!!!
Post by: colinjones on January 06, 2008, 11:54:40 pm
Understood - but let me clarify what I meant by realtime. I don't mean "live", I agree that's not relevant.

Introducing a delay of even up to 1 min as you suggest doesn't compensate and allow for less powerful/cheaper hardware to be used. By realtime, I mean the hardware needs to be able to process the video stream at the same rate it is coming in - in other words, not take an existing file and convert it, then play it. Because TV is "realtime" in this sense, if the hardware is not powerful enough, even a delay(buffer, really) of 1 min will eventually run out, because the hardware will progressively get further and further behind .... then black screen! So it is the nature of TV not having a set "end point" like a file does that prevents you from using the lower powered hardware.

If you used that lower powered hardware against a file, that would be fine, you would just have to wait loner before you could begin watching the content. But that doesn't logically have an analogy in a realtime stream. No matter how long you waited before beginning the content, eventually the content would catch up with the hardware and the stream would stop. So the hardware needs to be able to encode at at least 1.5Gb/s.

Moreover - even if introducing a delay (buffer period) of 1 min did fix this issue of lower powered hardware, this would happen every time you changed channel - not many people would be prepared to wait 1 min per "flip" in channel surfing!

I don't disagree that there are encoders (decoders are always cheap because they have far less to do) that can do realtime streams, possibly cost effectively. I guess this goes back to my original point - these algorithms are necessarily adaptive. The higher quality you want out, the more time they take to do it (at the same price point, roughly!) - once you configure it for a level of compression quality that gets to less than 25/30/50/60 frames per second, it can no longer be used for this job, effectively setting an upper limit on the quality of the compression for a given piece of hardware (and therefore price).

Remember the first DVD recorders? Their video quality was appaling, even though some of them used MPEG2 - those encoders for CE equipment were VERY expensive initially, and so this set an effective upper limit on quality compared with what consumers were prepared to pay. As volumes and technologies progressed, they were able to achieve much higher encoded bitrates at lower costs, so quality went up. Same principle - if there is the demand for this then I agree that 2009 will be interesting, but I think that demand will only come from HDDVD and BluRay recorders, not from wireless HDMI cable replacements... much higher volume...