World's Digital OTA TV Standards: ATSC, DVB-T, ISDB-T, DTMB - Page 4 - Canadian TV, Computing and Home Theatre Forums

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post #46 of 66 (permalink) Old 2009-02-10, 11:54 AM
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LCD's last for what seems like forever - unless they're damaged physically (i.e. bump/hit/smash the screen with something) or the backlight goes (just need a new backlight and it's good to go)
While CRT is the "tested and true" technology, I wouldnt stake my money on it lasting longer than my LCD
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post #47 of 66 (permalink) Old 2009-02-10, 11:12 PM
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Discussion of actual TVs is best done in 57's forums and threads.

Back to the topic please...
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post #48 of 66 (permalink) Old 2009-02-16, 03:32 PM
 
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Is ATSC standard only the standard that has capablity of subchannels?
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post #49 of 66 (permalink) Old 2009-02-16, 07:07 PM
 
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Quote:
Originally Posted by tablo View Post
Is ATSC standard only the standard that has capablity of subchannels?
No. Any digital system using an MPEG transport stream can be broken into multiple channels. The number of channels depends on the type of program content (HD, SD) and the total available data capacity of the transport channel. I think all the digital TV broadcast systems around the world use some version of MPEG transport stream. The digital transmitters (DVB-T) in the UK have multiple SD programs but no HD as far as I know.
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post #50 of 66 (permalink) Old 2009-02-18, 02:29 PM
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The UK is getting terrsitral HD in a couple of years. They have it on satellite and I think cable, and I think only one or two channels at best.

Their current digital OTA network is nearly a decade old, and owned by a private company operating under contract from the various broadcasters. They have also for that time primarily been broadcasting widescreen and TVs, including SD sets, have been widescreen. AFAIK, a large propoertion of UK residents receive their TV from antenna, compared to here and the USA, whom tend to subscribe to pay TV services.
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post #51 of 66 (permalink) Old 2010-02-24, 11:07 PM
 
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Question ATSC Sub Channels Like DVB-T?

Are they multiplexed on demand (like the DVB-T system) or are fixed bit rates assigned to each sub channel?
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post #52 of 66 (permalink) Old 2010-02-25, 02:43 PM
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Depends on how each station decides to configure their equipment.
If the engineering staff decides to allocate Constant Bit Rates (CBR)
to all sub-channels, then they don't "steal" bits from less busy programs.
In San Diego, this is typically used when there are none or only one
video sub-channel.

But if they configure it for Variable Bit Rates (VBR), busy programs
can "steal" bits from less busy programs.

You can look at the TSReader Output reports for US markets here:
http://www.rabbitears.info/market.php
In San Diego, KNSD and KSWB use Variable Bit Rate (VBR),
and the "unknown" report for KPBS appears to also be VBR.
Rather than reporting a Constant Bit Rate setting, when in VBR
mode, the TSR report shows the station setting a ridiculously
high bit rate (e.g. 90 Mbps!!!)....probably a maximum assigned value.

Statistical Multiplexers have been in use for many years on both Cable and OTA.
Here are some ATSC OTA experiences:
http://broadcastengineering.com/digi...ultiplexing_5/
http://broadcastengineering.com/hdtv...hd-sd-channel/
http://broadcastengineering.com/news...s-pipe-090709/
but KAXT is now down to 12 "SD" video and 3 audio channels:
http://www.avsforum.com/avs-vb/showt...php?p=18054979
[PS: Our cable system (QAM is twice the data rate) only carries 13 SD programs.]

A Harmonic White Paper from 2002:
http://www.harmonicinc.com/view_collateral.cfm?ID=51
Note how the MPEG2 coding efficiency has improved over the years,
making it possible to stack more and more programs:
https://secure.connect.pbs.org/confe...tat.Muxing.pdf
The H.264 (MPEG4) coding efficiency curve has only just begun to come down
from 2:1 more efficient than MPEG2 to about 3:1 more efficient....so far....
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post #53 of 66 (permalink) Old 2010-02-25, 11:34 PM
 
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Thanks for a as usual complete reply holl_ands
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post #54 of 66 (permalink) Old 2012-06-07, 05:29 AM
 
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The current multiplex for the ABC (Australian Broadcasting Corporation) in Australia:

LCN, Channel Name, Res
2, ABC 1, SD (576i)
21, ABC 1 (same as above, links to exact same datastream in the multiplex)
22, ABC 2, SD (576i)
23, ABC 3, SD (576i)
24, ABC News 24, HD (720p)
200, ABC Dig Music, DVB-T Radio
201, ABC Jazz, DVB-T Radio

Currently we use MPEG2, and the original DVB-T standard, with 7Mhz width channels

Last edited by stampeder; 2012-06-07 at 10:40 AM. Reason: quote removed as per my reply
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post #55 of 66 (permalink) Old 2012-06-07, 10:37 AM
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We shouldn't be quoting posts from almost 4 years ago for replies. Anyways a general information post or update is always welcome for fresh discussion.
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post #56 of 66 (permalink) Old 2013-04-08, 10:51 AM
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ROM1 DVB-T (Saint-Pierre et Miquelon) reception in Newfoundland

Hi everyone, I'm new here. Just a question out of interest for you all as I live in the United Kingdom so have no real knowledge myself. Just curious :

After France completed their digital switchover in 2011; the overseas territories including St-Pierre et Miquelon all went digital too using our European DVB-T standard with 576i 50Hz video.

Having done a bit of reading, I found that some Canadian cable providers used to pick up Saint-Pierre et Miquelon 1ère (RFO) via an antenna in Newfoundland with pretty ropey quality and carry it in their offers.

As Canadian providers are allowed to do this, I've read that with the arrival of TNT including all of the public national French channels (France 2, France 3 etc.) in the islands, Viaccess encryption has been deployed to protect the broadcasts. From what I understand though, SPM 1ère remains unencrypted. I was just curious as to whether any of you in the areas of Canada nearest to Saint-Pierre et Miquelon can receive the multiplex in DVB-T? I'm guessing DVB-T equipment is rare over though (I've never seen any ATSC equipment at all myself!)

Also, on a related (but not to OTA reception) note. I've seen that SPM 1ère is still available via Canadian cable and satellite providers via a satellite link provided by SPM Telecom on the islands. What's the quality of this like? I'm guessing the picture must be a little poor owing to transcoding from 576i at 50Hz to 480i at 60Hz?

Thanks to anyone who can give any info.
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post #57 of 66 (permalink) Old 2013-12-29, 03:17 AM
 
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Hey everyone,

I moved to Sydney (Australia) so I won't be posting much relevant information over the next year. I'll be following along though to see how you're all doing.

OTA is popular here, so I might just let you know what I get when I'm able to get it.

Winegard HD 7084P pointed at Paris and a CM7777
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post #58 of 66 (permalink) Old 2013-12-29, 09:01 AM
 
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Well, when you said Sydney it is good that you also said Australia, or we would think you were merely down east rather than down under. Sounds like one of life's exciting journeys - hope it all goes well.

Please do let us know what is the OTA situation there. It will be interesting to hear along with details of your adventure. I have friends who i have never met in person in Australia from my IronHead motorcycle forum.

Thank you for the help while you were here. All the best in this new adventure,

Mick
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post #59 of 66 (permalink) Old 2013-12-29, 02:29 PM
 
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Smile

Wow, that is exciting news Micah. Good luck downunder. I've heard from other people that they really like Canadians. I would also be interested to know what channels you can get, how many, quality, Hd or Sd etc.. I will think of you every time I look at my antenna tower! It is still standing btw.

CM 4221hd, CM 7777, CM 9521A, 30 foot tower, Farthest station KWKB Iowa City, Iowa 525 miles.
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post #60 of 66 (permalink) Old 2013-12-30, 08:46 PM
 
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According to rabbitears.info australia database.

There are just 5 main national channels in each city.
ABC, NINE, SBS, SEVEN & TEN. (maybe subchannels?)
Perth does have an IND channel though.

Oh, have fun micah.

OTA: DB8 + Y5 2-6 + CM777. FTA: 30W + 72W + 87W + 97W
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