Why BET HD was causing problems

[hendrix04]

Hey guys, I just read an article at afterdawn.com about BET HD. Apparently it is the first HD channel to be going to cable/sat/telco providers in an mpeg 4 stream instead of mpeg 2. This could be why they were having so many issues with it...

BET programming goes HD

 

[digiblur]

Hey guys, I just read an article at afterdawn.com about BET HD. Apparently it is the first HD channel to be going to cable/sat/telco providers in an mpeg 4 stream instead of mpeg 2. This could be why they were having so many issues with it...

BET programming goes HD

They aren't the first. Several HD channels have been in HD MPEG-4 on their master feed via CBand for quite a while.

 

[TheKrell]

Several HD channels have been in HD MPEG-4 on their master feed via CBand for quite a while.

I like it. So, does Dish carry those mpeg-4 stream unmodified, or do they muck it up during multiplexing, change resolutions, or perform some other nepharious deed?

 

[Pepper]

What do you think.

 

[allargon]

I like it. So, does Dish carry those mpeg-4 stream unmodified, or do they muck it up during multiplexing, change resolutions, or perform some other nepharious deed?

What do you think.

 

[hendrix04]

They aren't the first. Several HD channels have been in HD MPEG-4 on their master feed via CBand for quite a while.

Ok, first for viacom then

 

[digiblur]

I like it. So, does Dish carry those mpeg-4 stream unmodified, or do they muck it up during multiplexing, change resolutions, or perform some other nepharious deed?

Of course... They don't have the bandwidth to carry those master feed muxes of DVB-S2 8PSK 30000 8/9 FEC.

 

[TheKrell]

They don't have the bandwidth to carry those master feed muxes of DVB-S2 8PSK 30000 8/9 FEC.

So for the techs among us, what is that bandwidth exactly? And who can actually use it?

 

[digiblur]

So for the techs among us, what is that bandwidth exactly? And who can actually use it?

If I figured right it would be some where in the ball park of 70+ megabit. Dish gets around 40 megabit out of their 8PSK 21500 2/3 FEC used on national HD.

And who can use it... all the satellite and cable co's that have dishes big enough to sustain that type of signal with authorized receivers. Not at a lot of room for error on 8/9 FEC DVB-S2 8PSK.

 

[TheKrell]

And who can use it... all the satellite and cable co's that have dishes big enough to sustain that type of signal with authorized receivers.

Sorry for the ambiguity; that's not what I meant. I meant to ask, "Who could use that much bandwidth in delivering signal to their customers?" Since 70Mbps exceeds even the Blu-ray specs, I don't see why they're wasting that big fat pipe on only one channel. (I'm guessing that fat pipe carries several channels at once. See where I'm going here?)

 

[digiblur]

Sorry for the ambiguity; that's not what I meant. I meant to ask, "Who could use that much bandwidth in delivering signal to their customers?" Since 70Mbps exceeds even the Blu-ray specs, I don't see why they're wasting that big fat pipe on only one channel. (I'm guessing that fat pipe carries several channels at once. See where I'm going here?)

I think I saw one mux with only 2 channels listed on Lyngsat with specs like that.

Nope. I don't see where you are going. But with your other posts it seems like you need to either live in an uplink center with master feeds available or take a step down to FIOS.

 

[TheKrell]

Nope. I don't see where you are going.

70Mbps is a jaw-dropping bandwidth for only a single channel. The Blu-ray movie spec is only 54Mbps, of which only 48Mbps is available for the audio and video streams. So, as a consumer of this jaw-dropping bandwidth, what could you possibly do with it? You could master a Blu-ray disk in real time... A completely silly proposition IMHO, and still you're wasting part of that 70Mbps. If you're the head end for Fios, you don't send 70Mbps down the pipe for each channel! It's much much less. (I don't know what Fios uses.)

So, what I'm saying is that buying 70Mbps in satellite time 24/7 has got to cost big bucks, and cannot be justified for only a single (or even 2) channels. There has got to be more than 1 or 2 channels on that big fat pipe, or network providers' stupidity is entirely beyond belief! Now if Viacom's entire national feed of all their channels were simultaneously carried on that one 70Mbps stream, then that I could believe. How many channels might that be?

If we're comparing transponders used by Dish in broadcasting to us with transponders used by Viacom to transmit to Dish, then we must divide by the number of channels on each transponder in order to get at the channel encoding efficiency.

 

[digiblur]

70Mbps is a jaw-dropping bandwidth for only a single channel. The Blu-ray movie spec is only 54Mbps, of which only 48Mbps is available for the audio and video streams. So, as a consumer of this jaw-dropping bandwidth, what could you possibly do with it? You could master a Blu-ray disk in real time... A completely silly proposition IMHO, and still you're wasting part of that 70Mbps. If you're the head end for Fios, you don't send 70Mbps down the pipe for each channel! It's much much less. (I don't know what Fios uses.)

So, what I'm saying is that buying 70Mbps in satellite time 24/7 has got to cost big bucks, and cannot be justified for only a single (or even 2) channels. There has got to be more than 1 or 2 channels on that big fat pipe, or network providers' stupidity is entirely beyond belief! Now if Viacom's entire national feed of all their channels were simultaneously carried on that one 70Mbps stream, then that I could believe. How many channels might that be?

If we're comparing transponders used by Dish in broadcasting to us with transponders used by Viacom to transmit to Dish, then we must divide by the number of channels on each transponder in order to get at the channel encoding efficiency.

That's one whole TP though on CBand. Same rent if they ran one analog SD channel on it as the fat digital stream through it. If I was a provider running master feeds I'd load up my TP with a high efficiency modulation scheme from the get go instead of changing it later. It forces the guys on the downlinks to use larger dishes due to the higher signal strength needed for this scheme from the start. Instead if you ran it around 40 megabit then changed things to 70 megabit you'd have folks complaining they can't get the signal very reliably. The most you are probably going to see on the master feeds is around 20 megabit of MPEG2 since that will allow the cable co's to fit 2 of the feeds on one QAM256 carrier. I'm not sure what they do on the MPEG4 feeds these days. But that doesn't even make a difference anymore. The cable co's are now doing 2 1080i's and 1 720p of MPEG2 on one QAM256 carrier. And sometimes an SD or two mixed in there.

And it's just not about bitrate and whether MPEG2 or MPEG4. As no two encoders are the same then throw all the settings of the encoders into the mix and you really can't compare. Remember the old school MPEG4 encoders first used for HD Locals?

 

[TheKrell]

I guess what you're telling me is that a Cband channel is so cheap, providers don't care if they waste most of it.

 

[digiblur]

I guess what you're telling me is that a Cband channel is so cheap, providers don't care if they waste most of it.

No.