32 replies to this topic

[lizclinton]

qwawtuhs, on Jan 28 2011, 11:47 PM, said:

So I cancelled my Austar recently due to various technical problems and then purchased an Apple TV and now I've started watching FTA again... So is it just me or is the picture quality on almost all channels now worse than it ever was?

No FTA in Australia has really bad PQ now thanks to all those extra channels with repeats of old 70's shows. Get yourself back onto Austar with a Mystar HD and see what television should look like. If you care about PQ pay tv and downloading from the net are the only way to go in this country.

[lizclinton]

qwawtuhs, on Jan 29 2011, 11:34 AM, said:

MyStar HD was the problem. Chewed through 3 boxes in 12 months! Tech support was no help and always pretended they hadn't hear of the problem before.

Sorry to hear your having problems with Mystar HD I remember that most of the Austar boxes are full of bugs. I have a Foxtel IQ2 here and its worked without a problem for well over a year now. I find the HD channels on Foxtel are very good and the PQ is almost as good as a blu-ray disc. What was the problem with your Mystar?

[M'bozo]

qwawtuhs, on Feb 2 2011, 09:19 PM, said:

I still believe that our picture quality suffers greatly in Tasmania compared to most other states and territories.

I'm travelling around the mainland at the moment, and I can't see any difference  

[M'bozo]

qwawtuhs, on Feb 2 2011, 09:46 PM, said:

How odd. It's been about 12 months since I was last on the mainland so maybe they've all gone down hill  

That's normal free to air.

Not overly impressed with some of the refreshment venues I've visited. Digital distributed via RF, aspect ratio errors, yada yada.

The average punter probably doesn't notice, and with the number of programme breaks that occur while trying to watch something, I don't blame them.

[lizclinton]

Certainly the difference between WIN and 9 is very noticeable. God knows what the tech’s at WIN do but even back years ago when their SD service used to run at 8 Mbps they still had the worst PQ. As far as the others are concerned they look bad no matter where you are.

[lizclinton]

I can tell you that 7 and 10 don’t look much better here in Sydney. To think we have gone through this transition to digital to be left with TV that looks nearly as bad as analogue is very disappointing.

[lizclinton]

qwawtuhs, on Feb 6 2011, 11:45 AM, said:

Makes you wonder about all those ads

"Crystal Clear High Definition"

"DVD Quality"

They couldn't very well get away with saying that now could they?

Sadly a lot of people I talk to think that everything on the HD channels is actually in HD. While many have no access to real HD quality pictures to compare the FTA stations can keep getting away with all their BS. I think it will take some time for the average punter to realise they are being taken for a ride by Freeview and start demanding the FTA stations deliver on their promises.

[lizclinton]

qwawtuhs, on Feb 6 2011, 03:01 PM, said:

I don't suppose you have any email addresses for any tas stations?

No sorry. I guess the regionals cant do much about the rubbish they are getting from 7,9 & 10 anyway. It may be worth a snail mail to senator Conroy about our pathetic picture quality in this country but I wouldn't expect anything to improve here for a long time now.

[lizclinton]

qwawtuhs, on Feb 7 2011, 07:27 PM, said:

I wouldn't have thought the networks would have been the problem but instead the amount of bandwidth to/from the playout centre *confused*

No FTA looks bad no matter where you are in Australia not just in Tassie. Our TV stations have made the choice to sacrifice picture and sound quality to put up lots of low quality multichannel's. The average punter out there is applauding them for increasing so called choice and seem blind to just how bad the service looks at the moment. We can only hope at some point in the distant future the average viewer wakes up to the fact that the crap quality is not worth it for all those channels with reruns of old 70,s shows and begin to demand quality over quantity. Then we may see some space found for a few freeview HD channels maybe using AVC but while most people are happy with things as they are and the advertising pie continues to grow those of us who value quality will find nothing pleasing on freeview.

[_Roger_]

Although I cannot confirm it, I suspect that the playout centres would receive the programs with a fairly high data rate - ie well and truly above the average HD 12Mbit/sec or SD 5Mbit/sec.  These would then get rescaled, upconverted, downconverted, ads inserted, re-encoded and multiplexed together with the other streams and metadata  and then sent for transmission.  In Tassie the bandwidth allocated for this differs slightly from the majority of the rest of the country allegedly due to the costs of sending/receiving traffic across Bass Strait and apparently between Hobart and Launceston.  Essentially we appear to have the same bandwith as everyone else for Win/9, the ABC and SBS.  Southern Cross in the north get the same bandwidth as mainland Channel 7 but Hobart is 4Mbit/s less at 19Mbit/sec even though they are transmitting 23Mbit/sec (4Mbit/sec in null packets are inserted).  TDT is limited to 19Mbit/sec compared with 23Mbit/sec for Channel Ten in the mainland capitals but this is also their transmission symbol rate.

So, Hobart gets 7Mate and OneHD at 720p with sometimes freaky edge enhancement (halos) rather than 1080i.  We get Channel Ten with their shonky standards conversion causing visible motion blur/judder/combing the same as everyone else.  We get the ABC who used to do quite reasonable HD when they used HD material sending us their upscaled  news the same as everyone else.  And we get the mostly upconverted SBS the same as everyone else.  Southern Cross could in theory increase its bandwidth to Hobart and we'd have 7Mate at 1080i - the picture may or may not be any better.  The same thing might in theory be done with TDT/OneHD but there might also be technical reasons why they have increased error correction at the cost of symbol rate (eg interference).

At the moment we are stuck within the transmission limits of DVB-T and the encoding limits of MPEG-2.  Ideally when the analog transmitters get switched off the government would use the bandwidth for the next phase of DTV (eg DVB-T2/H264) rather than selling it to the mobile phone carriers.  The standards will get updated eventually but the question remains as to whether this will create a handful of high quality channels or 50 channels of macroblocked slush.

Roger.
PS I forgot to mention we also get WIN (which some hilarious pranksters might suggest is quite forgettable) with the picture quality apparently now comparable to Channel 9.  They're just having a few other problems lately with the EIT now/next being a little dodgey, no crid info in the EIT, the lack of clock/time/date packets on PID 0x14 and the inability to send closed captions for anything on GEM which isn't also simulcast on their main channel.

Edited by _Roger_, 08 February 2011 - 07:42 AM.

[fp933]

[quote name='qwawtuhs' date='Feb 7 2011, 10:14 PM' post='1670587']


But if it is bandwidth then...

Is the amount of bandwidth available to networks due to laws, money or technical issues, or a mixture?

If it is law, then it's out of the networks hands, but their own choice to multichannel making picture quality crap

If it's money then it is truly their fault along with technical issues unless of course technical has to do with the other networks as well.



/quote]

Each operator is licensed to operate a 7MHz channel in a particular area. With digital TV the maximum rate of data that can be technically transmitted in such a channel is 27.7 Mbits/s, however the maximum used in Australia is 23 Mbits/s. To give the equivalent digital coverage compared to analog, the signal has to be robust and be matched with the appropriate power. In TDT's case, they appear to have a power restriction attached to their licence to prevent interference to other services operating on channel 11 (notably Launceston) , as a result of the lower power they use a more robust set of parameters but the result is less bandwidth available for  programming, eg 19.35 Mbits/s. When analog TV is shut down, then they will be able to operate at full power and make use of the 23Mbits/s bandwidth if they so wish.

Edited by fp933, 08 February 2011 - 01:04 PM.

[_Roger_]

fp933, on Feb 8 2011, 02:03 PM, said:

When analog TV is shut down, then they will be able to operate at full power and make use of the 23Mbits/s bandwidth if they so wish.

In order to potentially use 23Mbit/s bandwidth they would need to change both the guard interval and FEC.  This is not too much of a problem by itself (it would require a rescan for some devices) however they would also need to increase the network bandwidth into Hobart.  Without more network bandwidth to send the data to the transmitter, higher transmission symbol rates are a moot point - all we'd get is more null packets such as is currently the case with Southern Cross.

[M'bozo]

_Roger_, on Feb 8 2011, 08:05 PM, said:

need to change both the guard interval and FEC.  This is not too much of a problem by itself

If this detracts from the robustness of the signal, issues can arise in poor reception areas, eg from multiple reflections, adjacent channel concerns, etc.

Edited by M'bozo, 08 February 2011 - 07:53 PM.

[_Roger_]

M'bozo, on Feb 8 2011, 08:53 PM, said:

If this detracts from the robustness of the signal, issues can arise in poor reception areas, eg from multiple reflections, adjacent channel concerns, etc.

I have already mentioned interference in a previous post although running the TDT transmission at FEC 3/4, GI 1/16 in Hobart is unlikely to cause any problems.

[beeblebrox]

M'bozo, on Feb 2 2011, 10:17 PM, said:

That's normal free to air.

Not overly impressed with some of the refreshment venues I've visited. Digital distributed via RF, aspect ratio errors, yada yada.

The average punter probably doesn't notice, and with the number of programme breaks that occur while trying to watch something, I don't blame them.

You on a pub crawl???

yes coz as long as skychannel / racing is okay and they can get one/seven  for the footy then the rest doesn't really matter...

I can't stand the picutres in most pubs or hotels that I stay in but most don't want to spend the money to fix things...