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Bit Rate of HD channels

Cband55

SatelliteGuys Pro
Original poster
May 14, 2008
202
1
Hello does anyone know of a chart for this information, I dont know if you need a FTA Box to view this information

Thanks
 
Ask DigiBlur, he can pull up the bitrate of channels on a transponder or give you an idea where they are running at, but remember that MPEG 4 channels will be much lower than Mpeg 2 HD channels as the compress alot better and retain the same information for the most part.
 
I just want to confirm that basic HD cable channels are at a whoping 5MB but on h264
 
Actually I think there running around 6MB on H264. If your on Eastern arch (61.5, 72, and 77) they are defiantly in H264. Over at Western arch 110,119,129, the newer ones are but I think there could be some old ones that are still in mpeg2 but dont hold me to that!
 
Dish runs variable bit rate encoders, so it is tough to tell, but 5-7 Mbps is common. The bit rate is also dependent on what else is going on in the transponder. If one channel doesn't need the space, another channel can borrow the space. You can get a decent estimate of the average with an EHD as it gives you recording size.

For instance, a recent 2 hour and 54 minute recording of Patton was 6,742 megabytes, yielding an average bit rate of about 5.17 Mbps. But it was letterboxed and didn't have a lot of fast motion.

A 1 hour 4 minute recording of another program (Coral Reef Adventure, which I know has a lot of movement and color, and was full screen) was 4,048 MB, for an average bit rate of 8.43 Mbps.

But again, the bitrate varies throughout the transmission.
 
The image below shows a number of average HD video bitrates from the past few weeks. All programming is HD (nothing being upscaled). 12 different channels are represented across 3 satellites: 61.5W, 72.7W, and 110W. All samples were at least 60 minutes in duration.


​

As HDRoberts mentioned, the bitrate is going to vary under different conditions. I wouldn't say that 5-6 Mbps is common anymore, but it does still happen under some conditions.

You're looking at transponders supporting about 41 Mbps typically having at least 8 HD channels for the satellites shown above. Subtract about 3 Mbps for 8x 384 Kbps audio streams, plus say 1 Mbps for the NULL stream (although it can be quite a bit higher on average on some transponders), plus another 1 Mbps for the normal data streams and you have 36 Mbps left. With that, you're averaging about 4.5 Mbps video per channel with 8 channels/transponder, about 4 Mbps with 9 channels, and 3.6 Mbps with 10 channels (or 9 channels plus a bunch of extra data streams, like transponder 32 on 61.5W).
 
goaliebob99 said:
DISH HD WISH LIST: AMCHD, TCMHD, CCSN-ChicagoHD fulltime, G4HD, MLBTVHD, OutermaxHD, ESPNUHD, SPROUT & MLB Extra Innings PLEASE!
Click to expand...

TCM HD seems to really be uplinked now . It averaged 8.3 Mbps over a 40-minute sample about an hour ago.

Of course, that's on one of the new transponders on 72.7W that only has three active channels on it right now, so that's not likely to last for long. Still, it's there, so hopefully it will be available soon.
 

I think DISH uses 24 Mhz wide transponders and with DVB-S2 and 8PSK they should be getting around a MUX Rate 51 Mbps.

Motorola DVB-S2 and 8PSK field trials: The first is using the advanced modulation techniques offered by the newer DVB-S2 8PSK satellite transmission standard that allows as much as twice the amount of bits to be sent over existing 36 MHz transponders. With this technology, programmers can deliver up to 77Mbps over the same transponder that is currently delivering 40 Mbps.
http://www.motorola.com/staticfiles/Business/Solutions/Industry%20Solutions/Service%20Providers/Broadcasters%20and%20Programmers/_Documents/Programmer_Distribution_Trends.pdf?localeId=33

77Mbps@36Mhz scales to 51Mbps@24Mhz

Smith.P measured a MUX rate ~50Mbps
http://www.satelliteguys.us/attachment.php?attachmentid=40191&d=1248797069
 
JimK2 said:
I think DISH uses 24 Mhz wide transponders and with DVB-S2 and 8PSK they should be getting around a MUX Rate 51 Mbps.

...

Smith.P measured a MUX rate ~50Mbps
http://www.satelliteguys.us/attachment.php?attachmentid=40191&d=1248797069
Click to expand...

That's interesting about 119W, I haven't tuned into any 8PSK transponders on it before. However, everything on 61.5W, 72.7W, and 110W is about 41.2 Mbps as seen in my previous post here: http://www.satelliteguys.us/dish-ne...-scheduled-september-18-a-35.html#post1997286.
 
HDRoberts said:
Dish runs variable bit rate encoders, so it is tough to tell, but 5-7 Mbps is common. The bit rate is also dependent on what else is going on in the transponder. If one channel doesn't need the space, another channel can borrow the space.
Click to expand...

Are you saying that they dynamically re-encode the video based on the currently running programming? Is that something they do in real (or near real) time? That would surprise me although I guess H264 encoding is getting faster. Or do they just prepare their encoding ahead of time based on the schedule so it all comes out just right when aired? Of course that wouldn't work for live programming.
 
JimK2 said:
I think DISH uses 24 Mhz wide transponders and with DVB-S2 and 8PSK they should be getting around a MUX Rate 51 Mbps.
Click to expand...

On HD TPs Dish usually runs 21.5 million symbols a second. This is 21.5 * 3 bits (8PSK) or 64.5 megabits per second raw throughput.

But, you need a lot of error correction. Dish typically uses 2/3 FEC - essentially 2 bits data 1 bit forward error correction.

2/3 * 64.5 = 43 megabit data rate.

Then they use another ECC algorythm. Non turbo coded used to give 188 bytes of data per 205 bytes transmitted which gave them 39.434 megabits/sec.

But Dish uses Turbo coding, so their error correction overhead is slightly less. I do not know the exact formula but it seems that they get around 41 mbit/sec using it.
 
Near real time


It is active and does this in "real time". The encoders they use have links between them that "follow" each others use of bits. So a talking head show will get a lot less than say a fast action section of a football game. I had hands on some of the encoders just after E* & D* had ordered a large number of them. In fact that was one of the selling points the engineer and sales agents used in their pitch (yes there were both there). The reaction times between a linked set of encoders for shifting the bits is nanoseconds. So the delay is "near real time". They also use what is know as predictive adaption in "pre-sampling" the video. The encoders are very sophisticated devices. And what mike said.
 
Last edited:

Exactly. The same type of system is used on OTA channels with sub-channels. I got to see it in action at the CBS/CW affiliate here. Bandwidth for each channel is dynamically allocated. Really cool stuff.

Dish just does it on a much 'larger' scale, with a better encoder
 

Can't check right now... 8PSK adapter bit the dust for some reason.
 

That's an 8PSK 5/6 FEC transponder, there are a few of those in the system but that is not the norm.
 
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