94 replies to this topic

[SBS Broadcast Engineering]

SBS is upgrading its HD format to 1080i from 720p on 5 June 2012.

Dear forum users,

Due to ongoing issues providing an accurate closed captions service across both SBS One HD and SBS One SD simulcasts, SBS will be moving to a full interlaced based workflow across all its production chains. All SBS One services (HD, SD and Analogue) are derived from a single HD play out system, with down conversion to SD and Analogue at the end of the play out and transmission chain. For some time, SBS has been unable to provide accurate closed captions across the required and simultaneous, progressive and interlaced formats. On 5 June 2012, SBS will progressively work across all markets to change the HD transmission format from 720p50 to 1080i50.

Due to unique spectrum limitations resulting in SBS having less available transmission bandwidth than other broadcasters, SBS has chosen a transmission raster of 1280x1080.

This raster choice comes from significant testing to determine the best overall viewer picture quality from the available bandwidth, across the various content types presented on SBS. As native 1080i50 content will no longer need to be cross-converted to 720p50, SBS viewers will see sharper high definition pictures on SBS One HD with closed captions available on required programs, making SBS One HD accessible for people who are deaf or hearing impaired.

Viewers who experience transmission issues are advised to re-scan their television or digital tuner as per the manufacturer's instruction manual.

SBS Broadcast Engineering

Edited by SBS Broadcast Engineering, 01 June 2012 - 11:43 PM.

[alanh]

SBS Broadcast Engineering
Thank you for posting on this forum.

AlanH

[TheFrog]

so you moving to a lowly 256k sound as well?...up from a ridiculous 192k?

[DrP]

ABC tried a non-standard format when it introduced ABC NEWS24 (IIRC 960 x 720p50) and had to back out due to the number of receivers that would not display it properly (it was well within their capability to do so, firmware let them down).  I wonder how many receivers are going to react poorly to 1280 x 1080i.

[:)]

a strange choice sbs engineering. is the bandwidth limitations ever something going to resolve ? ie drop off one of the multichannels ? also is the audio going to improve to ? is DD5.1 ever a possibility ? given the amount of movies broadcast on sbs. It really would be a great move for the audience to provide DD5.1 surround sound to complement the HD movies

anyways look forward to the change, will be sure to provide feedback

[cooksta]

Will wait and see with this, anything that can be done to improve the video will be welcome imo.

To be fair to sbs at least they are trying to improve the picture quality as compared to the commercial channels who seem intent on decimating their HD channels for the sake of infomercial dedicated channels. I mean who actually watches that.

[GoForMoe]

SBS have to add the new indigenous channel to their multiplex, so the bandwidth situation will only get worse. The 3 SD and 1 HD configuration is bad enough on the channels with 4Mbps more to work with, and while SBS do give HD priority over SBS One SD, I don't think that will be enough to leave an acceptable HD service after adding extra channels.

[cwt]

Interesting resolution chosen reminds me of the reduced horizontal res 1080 x1440 rather than 1920 a few channels use Step in the right direction ; its too much to expect a channel to go I suspect but  how much better to lower the bandwidth a little on sbs 2 or sbs1 and get dd5.1 on a few movies

Audio doesnt chew bandwidth like video and would show up all the channels who cant count past dd2.0

edit less bandwidth goformoe ? bummer

Edited by cwt, 02 June 2012 - 07:32 PM.

[Slattery]

Out of interest, is the available bandwidth to FTA channels going to improve anytime soon? What will they do at the end of 2013 when the rules change and HD becomes the primary channel?

[GoForMoe]

Slattery, on 03 June 2012 - 09:39 PM, said:

Out of interest, is the available bandwidth to FTA channels going to improve anytime soon? What will they do at the end of 2013 when the rules change and HD becomes the primary channel?

The HD as the primary channel thing is just speculation. On my understanding of the law it is only implied that the main channel is SD after switch-off, with the only specific requirement being MP2 audio for the main channel. However parts of the law regarding anti-siphoning, local content points and others make specific mention of the primary SDTV service. So while it might be possible legally to make the HD channel the primary one, other clauses in the legislation would still necessitate simulcasting.

And beyond the potential legislative blocks there is the fact that the hangover from when SD devices were common, and the fact SD boxes are still being sold, the networks would need to be very sure that their audience is totally HD before making a swap - so I don't see that happening in 2014.

What does happen is the HD quota expires and so do the SD and HD channel legislative limits. I believe this is more likely to result in HD services going SD than it is to result in the return of main HD channels. However, the benefit of removing the limits is that a HD simulcast would no longer mean sacrificing a potential multichannel, so the concern is more one of bandwidth allocation.

Nothing changes on digital switchover giving any network more bandwidth. In the future there will be one spare channel worth of digital TV spectrum, but there's every chance that existing broadcasters won't be able to bid for that spectrum. SBS is in a unique bandwidth position - which may change eventually, but would still only put them up to par with the other networks.

Any further bandwidth increases mean replacing receivers to utilise more modern digital TV technologies that aren't compatible with most existing viewers, or again, not enough to make broadcasters willing to make the sacrifice.

It will in the end come down to a network decision - more channels and more potential advertisers, or higher picture quality. Networks have so far overwhelmingly chosen more channels - and there's no reason to think that they will not continue to do that once HD is no longer required.

[Slattery]

And here I was thinking 9s summer of cricket might actually finally be in HD for season 2012/13. Free to air TV in this country is an absolute cluster f$$k.

[laurie]

Slattery, on 04 June 2012 - 12:02 AM, said:

And here I was thinking 9s summer of cricket might actually finally be in HD for season 2012/13. Free to air TV in this country is an absolute cluster f$$k.

It is if there is a replay on Foxtel!

cheers laurie

[alanh]

BamBBBamm
Read the original post from SBS. It has nothing to do with NITV. Its for Captions for the hard of hearing regardless of race.

AlanH

[pc9]

GoForMoe, on 03 June 2012 - 10:06 PM, said:

The HD as the primary channel thing is just speculation. On my understanding of the law it is only implied that the main channel is SD after switch-off, with the only specific requirement being MP2 audio for the main channel. However parts of the law regarding anti-siphoning, local content points and others make specific mention of the primary SDTV service. So while it might be possible legally to make the HD channel the primary one, other clauses in the legislation would still necessitate simulcasting.

And beyond the potential legislative blocks there is the fact that the hangover from when SD devices were common, and the fact SD boxes are still being sold, the networks would need to be very sure that their audience is totally HD before making a swap - so I don't see that happening in 2014.

What does happen is the HD quota expires and so do the SD and HD channel legislative limits. I believe this is more likely to result in HD services going SD than it is to result in the return of main HD channels. However, the benefit of removing the limits is that a HD simulcast would no longer mean sacrificing a potential multichannel, so the concern is more one of bandwidth allocation.

Nothing changes on digital switchover giving any network more bandwidth. In the future there will be one spare channel worth of digital TV spectrum, but there's every chance that existing broadcasters won't be able to bid for that spectrum. SBS is in a unique bandwidth position - which may change eventually, but would still only put them up to par with the other networks.

Any further bandwidth increases mean replacing receivers to utilise more modern digital TV technologies that aren't compatible with most existing viewers, or again, not enough to make broadcasters willing to make the sacrifice.

It will in the end come down to a network decision - more channels and more potential advertisers, or higher picture quality. Networks have so far overwhelmingly chosen more channels - and there's no reason to think that they will not continue to do that once HD is no longer required.

Totally agree with you. There's a young guy in our office who recenlty upgraded to a Panasonic 55" plasma and thinks he's in heaven with with FTA and his 200 odd channels on Austar.  He neither cares or understands high definition but rather is happy to lounge around channel surfing crappy compressed MPEG 2 standard defintion channels; for him and I suspect the majority of dudes its all about content. To enjoy a good quality high definition source you actually have to sit down, put your feet up, leave the remote alone and enjoy the program, a routine which is unfortunately foreign to the majority these days.

Its also a bit naive to think that MPEG 4 technology will solve the picture quality issue; look at what Foxtel is doing with its high definition services going from 5 to 6 to 7 channels per transponder and inevitably to 8, I suspect.  The pay TV providers and FTA's will simply use the technology to saturate the bandwidth with useless shopping/info channels.

[davmel]

:), on 02 June 2012 - 07:57 AM, said:

a strange choice sbs engineering.

It's not a strange choice. 1280ix1080i has been a very common choice overseas in some markets. Just be glad they didn't go with the next lower choice of 960x1080i which one UK broadcaster chose even though they knew people would complain. It's the first time we've seen 1280x1080i in the Australian market however.
The sad part is that it fools the masses that think 1080i must be better than 720p. That must be why they conveniently left out the horizontal resolution details in all the press releases!

It had better not be the start of resolution down-scaling for terrestrial FTA TV in this country. The next step could be a drop for SD channels from 720x576i to 544x576i or even 480x576i. I guess that would be inevitable if they all want to cram a million crap shopping channels and other garbage in their multiplexes.

[alanh]

All,
This is a temporary situation.
When analog TV is switched off, then the SD signal will not be required for conversion to analog at transmitter sites. There is will be no reason why simulcasting of HD and SD should continue.
Then the horizontal resolution could be returned to what it was.

Davmel
As taxpayers we have subisidised the rollout of digital TV and with so many full HD TVs around and increasing then the DBCDE should legislate for the primary channel of each network must be in 1920 x1080 x 25p or better. Afterall the HD quota law ends at the end of next year.

Alanh

[digitalj]

alanh, on 05 June 2012 - 09:00 PM, said:

All,
This is a temporary situation.
When analog TV is switched off, then the SD signal will not be required for conversion to analog at transmitter sites. There is will be no reason why simulcasting of HD and SD should continue.
Then the horizontal resolution could be returned to what it was.

Davmel
As taxpayers we have subisidised the rollout of digital TV and with so many full HD TVs around and increasing then the DBCDE should legislate for the primary channel of each network must be in 1920 x1080 x 25p or better. Afterall the HD quota law ends at the end of next year.

Alanh

no alanh, 25p or 24p are unsuitable for general entertainment channels containing sport or sport channels, or any other channel that may have content with lots of fast movement. 50i has the ability to provide 50Hz motion while taking up no more space than 25p and can be weave de-interlaced back to the original 25p without any losses when the content provided is 25p/24p native, e.g. movies, TV series.

[Smacca]

alanh, on 05 June 2012 - 09:00 PM, said:

When analog TV is switched off, then the SD signal will not be required for conversion to analog at transmitter sites.

alanh, on 05 June 2012 - 09:00 PM, said:

There is will be no reason why simulcasting of HD and SD should continue.

alanh, on 05 June 2012 - 09:00 PM, said:

[...] the DBCDE should legislate for the primary channel of each network must be in 1920 x1080 x 25p or better.

This is AlanH's opinion everybody. Not fact.

My job is done!

[alanh]

digitalj and Smacca
SBS proposal is to go to 1280 x 1080 x25i This means 25 frame/s using interlaced scanning. This is the frame and field rates as used for all commercial stations in Australia.

SBS uses their SD signal to PAL encoding which is why I did not suggest an immediate switchoff of the HD simulcast.

So who is proposing the use of 25 frame/s progressive?

By the way how many purchasers of Blu-ray discs or cinema goers complain of 24p signals?

AlanH

[DrP]

Anyone that thinks SBS is going to drop one of its two standard definintion services once analogue is 'switched off' clearly doesn't have a very good grasp of reality.

Should SBS cleave its SD/HD simulcast it is far more likely that one of the two will become NITV or perhaps the one day coming 'SBS 3'.


Of course, it should be noted that people that think SBS will cease one of its SD services [to free up bandwidth and thereby allow SBS HD to be broadcast as 1440 or 1920] also thought that SBS was going to change its modulation to QAM64 (which as we all know, it already is and has been since SBS digital commenced) therefore not much weight should be given to such suggestions.

Edited by DrP, 06 June 2012 - 07:15 AM.

[Malich]

alanh, on 06 June 2012 - 01:34 AM, said:

So who is proposing the use of 25 frame/s progressive?

I think that was you ...

alanh, on 05 June 2012 - 09:00 PM, said:

... then the DBCDE should legislate for the primary channel of each network must be in 1920 x1080 x 25p or better.

By the way, as I mentioned here I'm still genuinely interested to find out about Nokia phones that include DAB+. Since you mentioned "it was released last year in Europe", can you give me a link or model number?

[GoForMoe]

alanh, on 05 June 2012 - 09:00 PM, said:

Davmel
As taxpayers we have subisidised the rollout of digital TV and with so many full HD TVs around and increasing then the DBCDE should legislate for the primary channel of each network must be in 1920 x1080 x 25p or better. Afterall the HD quota law ends at the end of next year.

Alanh

The sell off of the digital dividend spectrum is what subsidises the rollout of digital TV. Switching will be a net gain to taxpayers once that is completed.

Quote

It had better not be the start of resolution down-scaling for terrestrial FTA TV in this country. The next step could be a drop for SD channels from 720x576i to 544x576i or even 480x576i. I guess that would be inevitable if they all want to cram a million crap shopping channels and other garbage in their multiplexes.

Go went from 720 to 704x576i when Extra started - so while not to the degree of 544 or 480 (something the old VPGs mostly used), the loss of horizontal resolution is starting.

Once the limits on multichannels end and the HD quota is gone, all quality bets are off.

[DrP]

WIN Gold is 480 x 576i.

720 being reduced to 704 is not actually a loss of definition.  704 does not expand to become 720 upon decode, the 704 samples are placed in the centre of a 720 plane (ie, 8 black dots either side).

Edited by DrP, 06 June 2012 - 02:23 PM.

[davmel]

GoForMoe, on 06 June 2012 - 01:07 PM, said:

Go went from 720 to 704x576i when Extra started - so while not to the degree of 544 or 480 (something the old VPGs mostly used), the loss of horizontal resolution is starting.

Hate to be the one to point out that GO has always been in cropped D1 (704x576i) resolution ever since it started. I presume that was because they originally used the crappy old VPG encoder when it started which didn't seem to be capable of full D1 resolution. It's never changed since it started (at least in Melbourne). I know because I regularly check it and all my recordings from GO are in 704x576i.
The cropped D1 resolution was designed to chop out the black overscan on legacy analogue platforms when converting to digital. Many of the early generation MPEG encoders were only capable of cropped D1 resolution encoding. It's never chosen to minimise bitrates as there is bugger all difference between cropped and full D1 resolution. 3/4 D1 and 2/3 D1 resolution is used for that reason.

[GoForMoe]

davmel, on 06 June 2012 - 02:32 PM, said:

Hate to be the one to point out that GO has always been in cropped D1 (704x576i) resolution ever since it started. I presume that was because they originally used the crappy old VPG encoder when it started which didn't seem to be capable of full D1 resolution. It's never changed since it started (at least in Melbourne). I know because I regularly check it and all my recordings from GO are in 704x576i.

Hmm, could have sworn it was 720 for a while there. Seems odd regardless that Nine has the 720 and the other SD channels don't - if it's not a resolution loss/bit rate saving measure, the move to the new Sydney playout centre should have undone that.