HD Broadcasting

[xyz223]

@Nick

But what is making Seven hesitate? It surely can’t be population size, RQLD is approaching the heels of Perth and has long surpassed Adelaide.

Most plausible answer:

@WAtvVideos

if Seven struggles to get 7flix up and running without the aide of MediaHub, and they’re currently in talks with Nine to start a joint-venture centralised presentation centre, then my guess is BCM isn’t equipped to handle multiple 7HD’s for Qld

7mateHD in RQLD is likely combined feeds as opposed to one feed of the main channel for each broadcast region

[webguy]

As discussed here previously, Seven’s lack of HD is RQLD is because of their limited technical capacity at the moment. To explain, he’s a simplified rundown of the step to get TV to your TV.

Step 1: Playout
In this step, a computer combines the TV shows, ads etc. into a continuous feed. It’s basically a big playlist, similar to how iTunes or whatever your favourite media played works, except it’s got some more features and has the ability to select not only files saved on the hard drive (such as ads and pre-recordeded shows), but it can also select live feeds (eg. from sporting events, TV studios etc).
A playlist needs to exist for each channel, eg. 7 Melbourne, 7two Melbourne, 7mate Melbourne, 7 Sydney, 7two Sydney etc. (but some parts can be shared between multiple channels to avoid double entry)
At Seven, this is all done in HD (with the exception that some of their news studios are only SD).

Step 2: Encoding
This is where the format and resolution are chosen - so, MPEG2 or MPEG4, SD or HD, and whatever bitrate they choose to run the channels at. This is done individually for each channel to be broadcast, and usually requires individual, expensive, equipment for each channel.
So Melbourne requires 5 encoders:

1. 7 SD
2. 7 HD
3. 7two
4. 7mate
5. 7flix (this is actually done at MediaHub, not BCM due to the lack of capacity).

Their sixth channel, racing.com, only needs to be encoded once since no geographical differences mean all cities can share the same output.

Therefore, to add the HD channels for the 5 cities, they needed to add in 5 new encoders. To add HD to RQLD (including the Gold Coast) would require another 8 new encoders, plus the space to house these.
This is the same reason why Prime didn’t get PrimeHD until after they moved to MediaHub, and SCA9 didn’t get all their channels for a few weeks after the affiliation switch.

Step 3: Multiplexing & Transmission
The required encoded channels are “combined” into one 23mbps signal ready for transmission (known as multiplexing).
It is then sent by an IP-based network to the transmitter, where it is then broadcast from the transmitter and can be recieved by your TV.
(I believe this is the most common given it centralises most of the processing.)

Variations:
Sometimes the encoding and multiplexing happens in a different order.
For example, but the remote areas that use VAST, they have some terrestrial transmitters that broadcast using VAST as the input feed. In this case, they have number of VAST receivers at the transmitter site, then re-encode the signal on site as required (the signal was previously encoded for it be broadcast using VAST), the channels are multiplexed and transmitted. This setup works well because there’s next to no IP connectivity in many of these sites, but it does require any changes to be made individually at each site. This, along with the limited capacity of VAST are why regional WA doesn’t have the full suite of channels offered elsewhere by WIN and Prime.

So specifically for regional Queensland and why they can’t just turn on 7HD now.
These areas currently have:

1. 7SD - MPEG2, SD - localised
2. 7two - MPEG2, SD - localised
3. 7mate - MPEG2, HD - localised
4. 7flix - MPEG2, SD - statewide feed
5. racing.com - MPEG4, SD - national feed

To add 7HD, the same as what the cities and Prime areas have, they need to add a new encoder to allow them to have a 6th channel - 7HD in MPEG4 HD. (x8 to cover each area, including Gold Coast).

An alternatives discussed here has been to switch 7mate and 7SD. However, this would mean that the main channel is also broadcast in MPEG2 HD, so anyone with an old TV/set-top box that can’t receive HD would no longer receive the channel at all.

Finally, this is why Seven are moving their playout
As discussed previously, there’s a plan for Seven and Nine to combine their playout into a shared facility in Sydney. (Time will tell if this is a new facility or Nine’s existing playout facility to Frenches Forrest).
Seven are going down this route because they realise that they need to replace some of their equipment and increase their capacity. This move will almost certainly result in RQLD getting 7HD and the playout of 7flix coming back “inhouse”. Unfortunately it’s just a matter of waiting until the move is done - Seven have indicated this will be April 2019.

[Vidiot]

@webguy

An alternatives discussed here has been to switch 7mate and 7SD. However, this would mean that the main channel is also broadcast in MPEG2 HD, so anyone with an old TV/set-top box that can’t receive HD would no longer receive the channel at all.

Could you explain what you mean here? MPEG2 is the old standard so why would anyone “lose a channel”. And MPEG4 is used for 7 HD in all other markets AFAIK.

Regardless of all the localisation issues, putting 7Mate on an MPEG2 SD channel and introducing 7HD as an MPEG4 won’t mean anyone loses a channel. It’s just that some folks with older TVs won’t be able to pick up the new 7HD. As is the case everywhere else in Oz.

[NQCQTV2]

@xyz223

7mateHD in RQLD is likely combined feeds as opposed to one feed of the main channel for each broadcast region

Nope, each 7mateHD feed is entirely localised, with local ads and local location name in the watermark.

@webguy

7flix - MPEG4(??), SD - statewide feed

MPEG2

[webguy]

@Vidiot

Could you explain what you mean here? MPEG2 is the old standard so why would anyone “lose a channel”.

When we first got digital TV, HD wasn’t really a thing, and a lot of the original equipment wasn’t HD compatible. This gear is only capable of receiving an SD MPEG2 signal. While this is limited to the oldest of gear that’s now 10-15 years old, it would be poor form to essentially cut off a free channel without significant warning.

@Vidiot

And MPEG4 is used for 7 HD in all other markets AFAIK.

Correct. But in this scenario, they’d be using the encoders they already have - these are likely still the original HD encoders from when they began digital transmissions, so they wouldn’t be MPEG4 compatible.

@Vidiot

Regardless of all the localisation issues, putting 7Mate on an MPEG2 SD channel and introducing 7HD as an MPEG4 won’t mean anyone loses a channel. It’s just that some folks with older TVs won’t be able to pick up the new 7HD. As is the case everywhere else in Oz.

That will be the long game. However, as I explained, this requires more equipment and so isn’t an available option in the short term.
2 steps are required:

1. 7HD - requires new equipment a) to broadcast in MPEG4, b) because it’s adding a new channel that doesn’t exist yet.
2. 7mate - change from HD to SD to free up capacity for extra channel. They can most likely use the existing encoder as it should be MPEG2 HD and SD compatible.

@NQCQTV2

MPEG2

Thanks, I knew the metros get it in MPEG2, but wasn’t sure about Queensland.

[Sully]

@webguy well done

[SydneyCityTV]

@webguy

SBS also have 6 channels including 2 HD channels (SBS, SBS HD, Viceland, Viceland HD, Food and NITV).
Before they got Viceland HD, SBS HD was in MPEG2. They were able to find the capacity for Viceland HD by making both SBS HD and Viceland HD MPEG4.

To be technical, SBS actually has 10 channels if you include the four radio services (SBS Radio 1, 2, 3 and SBS Arabic24) but of course those streams are only 128kbps each IIRC.

@laurie

Hang on! I thought Racing.com,7flix,7Two,7mate were MPEG2 if they change them to MPEG4 it will allow an extra HD channel y/n?

RACING.COM is a MPEG4 SD channel.

7Flix was in MPEG4 SD channel at launch, but changed to MPEG2 (complete with a “Now Available on More TVs” promotional campaign) shortly after the demise of 4ME in mid-2016.

Obviously Seven (SD), 7TWO and 7mate are in MPEG2 SD.

[Vidiot]

@webguy

2 steps are required:

7HD - requires new equipment a) to broadcast in MPEG4, b) because it’s adding a new channel that doesn’t exist yet.
7mate - change from HD to SD to free up capacity for extra channel. They can most likely use the existing encoder as it should be MPEG2 HD and SD compatible.

NQCQTV2:

Yeah, we know all of that. Not sure why you’re explaining it.

Also are you only guessing about what encoders 7 QLD has? Or do you have inside info?

[webguy]

@Vidiot

Also are you only guessing about what encoders 7 QLD has? Or do you have inside info?

Educated guess.

[Vidiot]

I find it hard to believe they’re still using the encoders that they installed 15 years ago.

[Sully]

@Vidiot

I find it hard to believe they’re still using the encoders that they installed 15 years ago.

…What happens when a network dominates a market.

They become complacent, don’t give a stuff and run a half arsed operation (no offense to 7QLD who have to credited with their success).

Much like Seven metro, complacent, lacklustre and they’re declining!

[Vidiot]

@webguy

Educated guess.

As a better guess… if 7 QLD is running racing.com as an MPEG4 channel, then the encoders won’t be that old. And can indeed output other channels in MPEG4.

[webguy]

@Vidiot

As a better guess… if 7 QLD is running racing.com as an MPEG4 channel, then the encoders won’t be that old. And can indeed output other channels in MPEG4.

Each channel requires it’s own encoder. Adding racing.com would have required them to purchase a new encoder which will work for just that channel - it requires no change to the setup for the other channels.

Also remember, the move to the shared playout facility isn’t just for fun - it’s largely because the equipment at BCM has reached end of life and needs to be replaced.

[TV_Addict]

So how come was it Win HD? appeared so fast after the changeover in regional Qld. Regional viewers were given the channel a milllion times quicker than Seven is with Seven HD.

[Sully]

@webguy

BCM

It opened in early 2000s didn’t it, after Sydney Olympics?

It was state of the art, central play out, et al. back then. A few years ago they replaced all the old ‘box’ monitors with flatscreens in the Master Control Room (formerly backdrop of Seven News national bulletins).

But yes, all the servers, computers, visual, audio, transmission, comms, etc. equipment must be very old now.

Sad to see it go, mass staff lost, but I guess more economic and easier. They may still run certain aspects of presentation out of Docklands and a number of senior broadcast staff/engineers will relocate to Sydney.

[pelican]

@TV_Addict

So how come was it Win HD? appeared so fast after the changeover in regional Qld. Regional viewers were given the channel a milllion times quicker than Seven is with Seven HD

WIN HD was “rebuilding” for many years in the mid to late 2000s.

[JasonF]

So why can’t foxtel recieve 7flix via fta

[WAtvVideos]

Brilliant post!

[Vidiot]

@webguy

This gear is only capable of receiving an SD MPEG2 signal. While this is limited to the oldest of gear that’s now 10-15 years old, it would be poor form to essentially cut off a free channel without significant warning.

I still don’t get why changing 7 mate to an SD channel in MPEG2 would mean you’re cutting off a channel?? What free channel are you talking about getting “essentially cut off” if it’s all still MPEG2?

[Sully]

Call out to mods/admin:

Can WebGuy’s absolutely fantastic post (which has already been praised) please be pinned somewhere better, for regular reference?

As it’ll no doubt answer future queries