Digital TV Technical Discussion


#656

that is your opinion, the broadcasters have a very different view, I will take their side considering they are stream-casting the terrestrial channels in MPEG4 via multiple platforms, if they were not then Freeview would be a very different service.

the fact is that anyone with access to Freeview can view terrestrial channels via several platforms not just old fashioned antenna and TV, that’s the whole point of it, the broadcasters would have real time data of how many people are viewing the CDN servers at any given time, then there are many TV’s that have ability to use the broadcaster apps to view live stream TV, for example I know many people that do that for 9Life which is 720p HD v the terrestrial 576i, so to dismiss it is a failing argument, put it this way, its where TV is heading towards, well to say it another way, that is my viewpoint about it.

Wont make a difference at all as the encoder has ability to set aspect ratio while still keepping resolution^. the fact is that UHD is not really 4K and as such should not be marketed as 4K, they should market it as UHD which is what the TV set makers are doing.

^Which is why a lot of SD content at 720x576i is forced to 16:9AR as its ratio is 65:45AR

A good encoder will have these options built into the software.

and also anywhere up to 250Mbits … good luck trying to stream that with our lazy NBN MTM and sure you can via LTE-CA but you would need a heap of data to do so.


#657

Just to clear a few things up… someone doesn’t sit there and decide to up the bitrate on Ten HD, it’s a variable bitrate that is determined by many factors… consistent fast motion is one of them. So your fast camera pans in sport would tell the encoders to increase the rate to compensate.

Interestingly, there is a long Survivor promo on air at the moment that cuts to black then smash cuts into a frenzied type graphic… the encoder can’t handle such a rapid change and the entire transmission is garbled for about half a second.

As for the age of the equipment, as I understand it most of it was due to be replaced around last year to the end of the decade… obviously a change of owner has restructured those plans, but from what I hear there is movement at the station.


Saving Ten
#658

for the most part that is right.

That said during live news and current affairs & sport they do have ability to up the bit rate, this is done via constant quality (CQ) method and using padding to ensure bit rate does not drop below minimum levels to avoid bit rate starvation.

using a 2-pass method in real time (which explains delay of up to 30 seconds in some cases) they would have a max bit rate and a minimum bit rate and then use CQ to adjust the level of %, it’s all software based and can be timed to adjust when needed, so for sport they would up the CQ to around 85% and when programming reverts to standard programming they would drop it down to 40 to 50%, hopefully when HEVC starts up they can change the levels around so every channel gets the near same bit rate.

Shame they cant get equipment from CBS since they don’t use DVB-T as they do ATSC


#659

AFAIK Ten don’t use software passes on the headends, the delay from presentation to broadcast is 6 seconds… there is no delay from studio to presentation… (okay, maybe half a second.)

That’s not to say that the CQ isn’t there though.

Like the IGA promo says, bigger buying power reduces costs :wink:


#660

the hardware is programmed that way, every broadcast MPEG2 h.262 / MPEG4 AVC encoder would have that ability.

I suspect it is as you notice Ten Sport/News is easily getting more bit rate and as such they can’t go beyond a fixed limit so the CQ % is changed to a higher number.

it’s all done in real time well as fast as real time gets so as you say from 6 to as I say up to 30 second delay from the initial raw feed.

In any case either way TEN seem to be managing bit rate pretty well for the main channels while being right on the verge of bit rate starvation of TVSN and Spree.


#661

I know for a fact it is a fixed 6 second delay.


#662

Er, no way. 30 seconds is an absurdly long time. Try 4 to 6 seconds for most broadcasters.


#663

Fair enough,.

okay.

I did say “it could be up to”. Sometimes it is :slight_smile:


#664

I do agree with @lexington, ill do some tests tomorrow but it’s around a 6 second delay. Seven on sports are around the same too.


#665

If it didn’t reveal my source I’d show you.


#666

I’m currently in the Central West & have noticed that the LCN name for SCA Nine & 9HD is now “Nine Central West” & “9HD Central West” respectively. When I was last in the region 2 years ago, just after the affiliation change, its respective LCN names were “Nine Orange” & “9HD Orange”.

Prime7 & WIN’s channels still have “Orange” on their LCN names, ie:

Prime7 Orange
Prime7 HD Orange
7TWO Orange
7mate Orange

WIN Orange
WIN Orange HD
ONE Orange
ELEVEN Orange


#667

I know there are “South Coast” stations that are pretty much or entirely identical to the Illawarra station feeds, but for a different LCN name. I wonder if that change to ‘Central West’ is simply undoing a similar split like that between an Orange and a Bathurst feed, or if they’ve combined the market with a previously distinct Dubbo market.

I’d be interested how many cases there are of regional splits that only exist as LCN name variations, without there being separate local news or even localised advertising.

My favourite bit of history there was how WIN never bothered to name their channel in their LCN names - I remember receiving “Latrobe Valley” and “Western Victoria”. I think it took until 2007 or so until ‘WIN’ was actually added to those names.


#668

Their weird naming conventions live on with the ‘HD’ part after the location name. Why do they do this? There would have to be heaps of set-top boxes and TV’s out there that only allow a small space for the LCN name.


#669

The ads on the “South Coast” stations are different to that of the Wollongong/Illawarra stations, in which they air local ads from around Batemans Bay & Bega instead of from around Wollongong & Nowra.

As far as I can tell, Orange & Dubbo have always shared the same feed, even going back to pre-aggregation, as CWN6 was a straight relay of CBN8, which presumably meant the same local ads.

Interestingly, WIN in Northern NSW/Gold Coast put the ‘HD’ between ‘WIN’ & the location name, eg “WIN HD Newcastle”.


#670

I think the Taree, Coffs Harbour and Lismore stations of Prime7 might be another case of the only major content difference being local ads? Similar deal with the Taree & Coffs Harbour versions of NRN when they were under SCA ownership, not sure if that’s still the case under WIN though.


#671

ABCKids/Comedy is probably the worst channel for that - I’ve not seen a TV that doesn’t truncate it. I think it’d be worth the ABC splitting the LCNs like the BBC do. Even if they were both pointing to the same video stream, just having a distinct ‘ABC Coemdy’ LCN would make it far easier to read - especially now it’s not ‘ABC2’ so doesn’t need to be on 22.

If that’s the case, then it’s strange - if there’s enough demand to have a local ad feed on the South Coast, I’d assume Dubbo would be large enough to justify an advertising only split.

And assuming they weren’t split - Orange and Dubbo are about the same size - surely ‘Central West’ is a better name for a signal covering all that area.

Their websites aren’t helpful - Prime’s lists only Orange, while WIN’s lists Orange and Dubbo separately, while grouping ‘Illawarra & South Coast’; so not sure if either would be reliable for how they actually split their feeds.


#672

I was up in Coffs Harbour and Lismore last month, and WIN had kept the same town based naming conventions as it was under SC, and as what Prime7 do e.g. WIN HD Lismore and WIN HD Coffs Harbour.

9/NBN still had the regional based naming conventions e.g. 9HD Far North Coast. Also they only have 2 different LCN names on the North Coast vs 3 for WIN and Prime7, as “9 Mid North Coast” matches their rival’s Taree and Coffs Harbour feeds.


#673

These following documents from FreeTV Australia might be helpful.

http://www.freetv.com.au/media/Engineering/Free_TV_Australia_DTTB%20_Service_Information_Register_Ver_10_Introduction_July_2018.pdf

http://www.freetv.com.au/media/Engineering/Free_TV_Australia_DTTB_Service_Information_Register_Ver_10_NSW_ACT_July_2018.pdf

http://www.freetv.com.au/media/Engineering/Free_TV_Australia_DTTB_Service_Information_Register_Ver_10_NT_WA_Tas_July_2018.pdf

http://www.freetv.com.au/media/Engineering/Free_TV_Australia_DTTB_Service_Information_Register_Ver_10_QLD_July_2018.pdf

http://www.freetv.com.au/media/Engineering/Free_TV_Australia_DTTB_Service_Information_Register_Ver_10_Vic_SA_July_2018.pdf


#674

I totally agree. How they have not done this yet is bizarre. It gives the illusion of more services and makes the channel list look a lot cleaner.

20 ABC HD
21 ABC COMEDY
22 ABC KIDS
23 ABC ME
24 ABC NEWS

Perfect.


#675

Interesting documents - I’m almost tempted to go to Griffith just to see if WIN are broadcasting a channel called ‘7Flicks’ into the region.

Some weirdly wrong stuff in there as well, like still referencing the old TVS and 31 Digital LCNs, and having a bunch of references to ‘SNOW’ on WIN, instead of the ‘WIN NETWORK’ channel.

That listing also reminds me of the other thing I hate - that Ten still call their main channel ‘Ten Digital’ after all these years of digital only broadcasting. If they don’t want ‘Ten Location’ then just ‘Channel Ten’ or ‘Ten’?