FTA bitrate vs Dish or DTV?

[SpiffWilkie]

I have a friend asking a question regarding the bitrate on a HD FTA feed vs a feed you would get on Dish or Direct.
I was talking to my friend about how a signal from a backhaul of a football game would be better quality than watching the network feed of the same game. Now I don't have an HD t.v. or Dish or Direct, but I can see a definite difference between OTA HD signals and feeds, having switched back and forth between the both during an event.
Can someone give me some hard numbers for the bitrates of a wild feed vs the broadcast?
A related question is, does it make a difference for most people watching t.v. on an HD screen of ~50"? Would a normal person be able to pick a backhaul from a Dish signal? 1080i is 1080i right (I say with tongue firmly planted in cheek).

My friend is considering purchasing a system, but I don't have any hard facts regarding quality of feeds vs the final broadcast version of the same signal. Any help with numbers and opinions on differences visually would be appreciated.


O.k., one more question, actually Recently, I happened upon a signal that was 720p. I then found the same signal being broadcast by my local affiliate in 1080i. Does upconverting make a difference, really? Is it a marketing ploy? 1080i > 720p so it must be superior!?

No more questions. For now. I promise. Probably.

 

[Anole]

it's all relative:

I'm sure you can get info on Dish 'n Direct in the relevant forums.
There are massively outraged subscribers in both forums, bitching about HD quality.
However, both companies get away with it, because the huddled masses wouldn't know a good picture if it crawled up 'n bit them! -

I can't give you answers on HD, but DishNetwork plays fast 'n loose with both resolution (xBits by yBits) and with bit rate.
Those guys have a firm stranglehold on the feed pipe.
Shooting from the hip (using my memory), Dish's SD is 544x480, and somewhere in the 3mb/second range (and less ).
That would be 'good' quality.
I recall it being about 1gbyte of data per hour, or a bit more (probably not over 1.5gbytes), for a lot of programming.

Dish also squeezes down the data rate for some Local Stations, relative to their nation-wide programming.
In the old days (5 years back), locals were better and clearer on Dish than OTA, probably due to the clean digital delivery.
Now, they're kinda soft, but I'm sure it varies by-channel, network getting better picture than local-market stations.

As for OTA, I've got a buddy who retired from one of the major non-network stations in the area.
He used to jump up 'n down when he couldn't run the full 19mb (or whatever) data rate on his HD transmitter.
Squeezing it down for a sub-carrier really %$#@'d him off!

For such discussions , you might want to visit our HD OTA Forum department.

Anyway, my point about it all being relative is, if you
- get a clean signal, it may look better than analog OTA delivery
- get a decent bit rate, the picture can be sharp!
- have a proper TV, you might see a difference (analog vs 720 HD or 1080 HD set)
- sit close enough to tell one from the other
- have sufficient eye sight to see the difference.

Some years ago, I was in Fry's and looked at a glorious 72" TV.
The demo ran 1080-P, from a dedicated hard drive!
(OTA is just 1080i, and there are no plans to broadcast P!)
When you stood right up within three feet, you'd have thought you were looking out a picture window!
The quality brought a tear to my eye.
But, the price and lack of available source material made it pointless.

From a distance, it was just another TV!

 

[Mr Tony]

I dont have hard numbers but I can only go by what I can see on my 42" HDTV

A related question is, does it make a difference for most people watching t.v. on an HD screen of ~50"? Would a normal person be able to pick a backhaul from a Dish signal? 1080i is 1080i right (I say with tongue firmly planted in cheek).

eh most people probably wont but if you watch enough crappy HDTV when you see a legit HD feed you'll be amazed.

Think about this. Lets use a Big10 feed as example
-Feed comes from the source (Big10). They use a whole transponder for HD (this is a fact). Dish and Direct grab that feed, reconvert it and cram it (compress) on a transponder that has 3-4 HD channels.
-We as FTA'ers grab the feed the same way as Dish & Direct does but all we do is send it to the TV.

Which one do you think looks better?

I can see the difference. I have access to both the feeds for Big10 HD and its not Dish or Direct but Starchoice has Big 10 HD. That channel is on a shared TP with 3 PPV channels. I can see a difference. It doesnt look like much but the big parts I can see the difference is the scoreboard topper and also the Starchoice feed is a little washed out. The grass is greener on the feed

O.k., one more question, actually Recently, I happened upon a signal that was 720p. I then found the same signal being broadcast by my local affiliate in 1080i. Does upconverting make a difference, really? Is it a marketing ploy? 1080i > 720p so it must be superior!?

most stations broadcast in 720p only. I know locally here in Minneapolis ABC, FOX, CW & My are all in 720p. CBS, NBC & PBS are in 1080.
FSN & Big10 feeds are in 720p

OTA feeds I cant see much of a difference. ABC HD looks the same to me. I prefer the feed (no commercials)

 

[dashaund]

The previous post are correct. There's a HUGE difference between the raw HD feeds versus DirecTV/DISH. Your average consumer won't notice a difference considering they've never seen what a master HD feed looks like. Actually, they'll say that DirecTV looks better than their cable company's HD It's all about managing their bandwidth. If they allocated an entire transponder to one HD channel like the network's do when they're feeding to their stations, then it would look just a good, but you wouldn't have but a handful of channels (or a BUNCH of satellites which is expensive). So, it makes sense to compress it. However, with the HD craze of late, they're trying to load hundreds of national and local HD channels, and they've compressed it to the point to where it's almost nauseating to watch. I have DirecTV as well, and the picture is soft and the color is washed out pretty bad on most things. I can switch to OTA and see an immediate difference. And then switch to the master HD feed and, well, it's amazing. To be honest, my local affiliates do a pretty good job of maintaining respectable quality OTA, with the exception of my CBS affiliate...especially on sports, it pixelates pretty bad.

As far as the 1080p vs 1080i vs 720p debate, it's been going on for years. 1080p is the optimal source, considering you've using the full 1920x1080 resolution and it being progressive scan, however the bandwidth needed to broadcast it terrestrially and via cable systems is a large demand. Remember when the progressive scan DVD players came out and it was the holy grail of movie watching when you have a 480p TV and a 480p DVD player? From the little bit of research I have done on this, and don't hold me to it, it's approximately double the bandwidth comparable to 1080i/720p. 1080i is the full HD resolution of 1920x1080, however it is interlaced, so it isn't as smooth. 720p is only 1280x720 resolution, but it is smoother since it is progressive scan. So the decision was made for fast motion feeds, such as sports, 720p is more desirable. For slower motion feeds, such as TV shows and movies, 1080i is more desirable. From what I understand (and others can correct me on this), CBS, NBC, and PBS do 1080i, while Fox and ABC (and ESPN) do 720p. This may explain why CBS's sports feeds when compressed look crappy to me, because of the fast motion and an interlaced picture.

 

[SpiffWilkie]

Thanks for the replies. I just did a quick survey of my locals and CBS, NBC, PBS, and CW are 1080i. FOX and ABC are 720p.
The SEC network football feeds are 720p and I always thought it was strange that my local CW affiliate broadcasts it in 1080i. I failed to considered the fact that a lot of the syndicated programming on that channel is upconverted, actually.

I need my t.v. to spontaneously combust so I can get a new one. :

 

[tvropro]

A 1st generation master HD or SD with plenty of bandwidth will always look the best. Little dish, Cable and the like compress to sell more. OTA is following suit with too many sub channels. Having a big dish and access to the master feeds will always look better than any compressed second generation.

 

[qwert1515]

I have seen some HD feeds on FTA have a video bitrate of 36Mbps and the same feed on the local OTA channel had a bitrate between 12 - 15 MBps.

In DVB-S most single HD feeds use a symbolrate between 25000 - 30000 have a bitrate of 34.6 - 41.5 Mbps.
In DVB-S2 the highest bitrate I have seen for an HD channel is 60 Mbps (52 Mbps video) with a symbolrate around 25000.

 

[gardo403]

Don't get me wrong I love watching the high bitrate hd super clean feeds..... but I wonder why the overkill if the providers and your ota locals are going to compress it so much? I mean, who benefits.. besides us FTAers.. Just the one of the things I wonder about when I can't sleep

 

[Anole]

I often wonder the same about beautiful 4:2:2 video delivery?
If you're running a projector in a theater, I get it. Otherwise . . .

Don't get me wrong.
I'd love to see two TV sets in your local store window, one showing regular OTA HD, and one showing Super HD.
That would finally show the consumer the difference.
Sort of like when TVs first got color. -

But the sat guys won't carry it, the cable guys don't have the bandwidth, and the OTA stations were just finally forced to run the old ATSC HD standard!
So, for the next 20 years (?), will only FTAers be seeing the best quality TV has to offer? -

 

[Tron]

Don't get me wrong I love watching the high bitrate hd super clean feeds..... but I wonder why the overkill if the providers and your ota locals are going to compress it so much? I mean, who benefits.. besides us FTAers.. Just the one of the things I wonder about when I can't sleep

Because if the quality is that high from the source, it MAY just be acceptable to the masses by the time it is re-compressed multiple times and "Dished" out ...

Any processing that is done to the original feed requires that it be decompressed, processed, and re-compressed. They send the original feed at highest possible quality in the hopes that it won't look too bad by the time it reaches the consumer.

So, for the next 20 years (?), will only FTAers be seeing the best quality TV has to offer? -

Isn't FTA grand?

 

[tvropro]

Don't get me wrong I love watching the high bitrate hd super clean feeds..... but I wonder why the overkill if the providers and your ota locals are going to compress it so much? I mean, who benefits.. besides us FTAers.. Just the one of the things I wonder about when I can't sleep

There are good points brought up here. In digital they can pass along the original bitrate, bandwidth etc, but they won't. It all boils down at the end as a money thing. They would rather turn tall $$$ by giving more content (as poor as the quality is) vs giving a beautiful picture. They force feed and program the masses with crappy SD video so when they use a slightly higher bitrate for HD it looks great to them. If they ever saw the backhaul they would see how bad that HD lite crap there pushing is.

Case in point with the 4DTV. Some of the SD digital masters are really beautiful and beat out the quality of most of the HD the consumer see's. Now why does a SD master signal look better than consumer HD. It's because the bitrate and bandwidth is there.

We are lucky we get to see the stuff we do. 99% of the public never will. Enjoy our hobby and the benefits that come with it

 

[Tron]

All true, TVROPro. Joe Sixpack doesn't pay all that much attention to PQ. I think poor quality web-based video has desensitized much of the public to picture quality. I have a friend who, when I tried to explain the benefits of Blu-Ray, said, "Who cares how good the picture looks? I'm just interested in the movie itself." Unfortunately, that kind of thinking is predominant, and the result is more channels with crappier PQ.

 

[toucan-man]

All true, TVROPro. Joe Sixpack doesn't pay all that much attention to PQ. I think poor quality web-based video has desensitized much of the public to picture quality. I have a friend who, when I tried to explain the benefits of Blu-Ray, said, "Who cares how good the picture looks? I'm just interested in the movie itself." Unfortunately, that kind of thinking is predominant, and the result is more channels with crappier PQ.

Poor Joe. I remember when DVDs first came out, the store where I first saw them had their demo units hooked up in such a way to get crappy quality, and put that on public display, and I'm not sure many really cared. They were DVDs!

S-VHS never sold well, I still have my S VCRs, and they do a great job on SD network stuff today, but I've never seen a pre-recorded tape on one, it was an orphan format almost from the get go.

I think people buy HD sets because they are skinny, not because of the PQ. Finally WalMart locally has hooked up some content that displays HD, previously they had rows of ugly PQ on display for an uncaring public. Strange.

I had thought about helping someone here get the locals only package for $9.95 from Dish, and was astonished at how awful the SD PQ was. You couldn't pay me $9.95 a month to watch that.

The local cable service here will win no awards for PQ either, yuck, why do people watch tv at all? Why not just pour maple syrup all over your screen and watch tv through that?

 

[SpiffWilkie]

Poor Joe. I remember when DVDs first came out, the store where I first saw them had their demo units hooked up in such a way to get crappy quality, and put that on public display, and I'm not sure many really cared. They were DVDs!

S-VHS never sold well, I still have my S VCRs, and they do a great job on SD network stuff today, but I've never seen a pre-recorded tape on one, it was an orphan format almost from the get go.

I think people buy HD sets because they are skinny, not because of the PQ. Finally WalMart locally has hooked up some content that displays HD, previously they had rows of ugly PQ on display for an uncaring public. Strange.

I had thought about helping someone here get the locals only package for $9.95 from Dish, and was astonished at how awful the SD PQ was. You couldn't pay me $9.95 a month to watch that.

The local cable service here will win no awards for PQ either, yuck, why do people watch tv at all? Why not just pour maple syrup all over your screen and watch tv through that?

I haven't spent much time shopping for HD sets or watching them at people's houses, although I saw Taken on BluRay at a friend's and was relatively impressed. My local Costco usually has some pretty decent demo video running on their machines, though. I have had a friend who worked at a big box retailer tell me that they would purposefully tweak the highend (read: expensive) sets to look gorgeous and then would either leave the lower end ones on default settings or purposefully mess with the picture a bit in order to move to expensive ones faster.

 

[tvropro]

Most tv's on display nowadays are in torch mode (everything cranked) There is also a store mode they put them in that returns the tv to torch mode after 20 minutes or so if it's been messed with. They have everything cranked to overcome the lighting in the stores etc. That mode would burn you eyeballs out especially on an LCD at home

 

[B.J.]

I'm getting into this late, so I'm just going to make a few comments on some of the issues above, some of which were already addressed.

First of all, where I live, the over the air (OTA) HD is quite good, mainly because the channels around here don't try to squeeze all sorts of other channels into the same bandwidth. Two of the networks do add a low bitrate weather channel, the third doesn't have any extra signals. So I'm not really able to see a whole lot of difference between the network sat feeds and the OTA signals, even though the network feeds are much higher bitrates.

My very qualitative comparison of the various sources is that the network sat feeds (including ESPN, etc) are the best. HDNET is probably next best in quality (when it's FTA), PBS is next and OTA is just slightly behind that but I really don't notice much between any of these. All are quite good.

Now, for signals that I CAN notice some difference, DN network feeds are not quite as good as OTA, and I assume it would be similar to DTV. I'm not sure what the difference is with the DN video, it's a bit washed out, and has some motion artifacts, and just generally doesn't look quite as good, to me at least. There are a few other low bitrate HD feeds, that are significantly lower in quality

In the past, I've tuned in all the various HD signals, and noted the bitrates they use to compare them. Usually I'd be quite happy with 4.2.0 feeds with bitrates of 15 mbps and above. However it's getting harder and harder to to compare things via bitrates. Now, the various signals are all in different formats, such as 4.2.2, 4.2.0, MPEG4 and MPEG2, so it's really hard to compare them. Also some muxes have channels using a variable bitrate mode, so that the bitrate depends on the content, while other muxes have a constant bitrate regardless of content, so it is just very hard to compare. However this morning, I went through about a dozen different random signals, and wrote down the bitrates (mbps) they were using.

CBS Synd feeds 4.2.0-1080i 40
CBS-4.2.2 -1080i 33
ABC MPEG4 720p 23.5
HDNET 1080i 18
PBS-AMC21 1080i 17
OTA ATSC CBS 1080i 14-15
OTA ATSC ABC 720p ~13
Nebraska PBS HD 1080i 12
DTV ESPN 720p 13.6
DN ESPN MPEG4 720p 7
DN 1440x1080i DHDT MPEG4 6.3
DN CBS local 1440x1080i MPEG4 5.3
DN ABC local 720p MPEG4 4.1
DN FOX local 720p MPEG4 3.85

Note, the above are just random channels I selected, some were FTA, some were scrambled at the time. I've read that there is some rule of thumb that network sat feeds are supposed to have at least twice the bitrate of OTA channels using that feed. I don't know what the theoretical relationship between equivalent quality MPEG2 and MPEG4 is, but it seems to be approximately a factor of 2, so you could probably double the numbers above for the MPEG4 channels. Also, some of the network channels had SD programming on at the time, which affects the bitrates of some channels, but doesn't affect the bitrate of other channels, and I'm not sure if it would change things if they had HD on all channels or not.

One comment though.... Most of the above looked EXCELLENT resolution wise, on programming that had negligible motion. The problems with the video was generally when there was motion, where all sorts of compression artifacts appear. Also the high quality feeds seem to have much better color, whereas the low quality video generally looks washed out, where you can't distinguish subtile differences in color and brightness. Those differences are much more subjective, where some people might actually prefer video that other people consider inferior. I've noticed that some low quality sources try to make their video look good by increasing the contrast.

This week I tuned in a low quality (not one of the above) HD feed that I was hoping to watch an NFL game on. I looked at some HD content on this channel prior to the game, and it looked quite good, despite the relatively low bitrate. Once the game began, when it was just the relatively static view of the field between plays, it looked OK, however once the play began, the video deteriorated into a bunch of large blocks along the edges of moving objects caused by the compression, and the game was not watchable. I ended up switching to a SD DTV Sunday Ticket feed, which was MUCH better than the low quality HD. I could have watched the CBS 4.2.2 HD, but I can't delay that, which is important to me.

I tend to judge video by how good it looks on fast moving programming. For this, even though slightly lower in bitrate, the 720p is really MUCH better than the 1080i programming. For slow moving scenes, though 1080i is better. I've taken freeze frame images from both 720p and 1080i, and virtually EVERY image taken from 1080i with any motion comes up blurry, whereas almost every image taken from the 720p is clear. You can de-interlace the 1080i images and get clear images, but then it's basically a 1920x540 image.

Anyway, I thought that the list of observed bitrates might help the discussion. If by nothing else, you can see how much bandwidth they are devoting to these signals, which has to be related to the resulting quality even if you can't distinguish the differences.

 

[zamar23]

I wonder what is the advantage of having a variable bitrate in a channel mux? It might be lower total on average statistics wise, but the provider must keep some extra capacity to compensate for higher bitrate needed periodically. Do they pay for bandwidth actually used, or just for rented bandwidth "capacity"?

 

[whatchel1]

For mux

I wonder what is the advantage of having a variable bitrate in a channel mux? It might be lower total on average statistics wise, but the provider must keep some extra capacity to compensate for higher bitrate needed periodically. Do they pay for bandwidth actually used, or just for rented bandwidth "capacity"?

VBR is for muxed channels so that it can pull bits from the other channels that don't need them and move bits back & forth to which stream needs it the most. So the VBR is constantly moving the bits back and forth between the streams.

 

[tvropro]

VBR is for muxed channels so that it can pull bits from the other channels that don't need them and move bits back & forth to which stream needs it the most. So the VBR is constantly moving the bits back and forth between the streams.

Until there is such a high demand then the video locks up or misses frames on the bit starved channels

 

[Comptech]

Tonights Dodger game is a good example of bit rates being variable. It is in 4.2.2. and when they are showing the anouncers it hovers around 40mbs, when they show action it shoots up to 56mbs. What a picture! P.S. this is in 1080i. Actually 1920x1088.