Another thread on PQ of DirecTV HD channels

[TheForce]

This is not an HD Lite thread.

With all the claims that DirecTV is about to launch a hundred HD channels, I decided I should once again revisit what they are doing with their PQ. Many have claimed they improved it. My method is to compare equal channels with Dish Network.

I looked at HDNet, HDNET Movies, and Discovery HD Theater for starters. I did this A/B comparison over the past 6 days.

All three channels on DirecTV appeared sharper and brighter than Dishnetwork, which could be said to be "softer" than DirecTV.
On a quick glance this is what one sees, even a blind test- which is a better picture, the call would go to DirecTV.
However, upon closer look, I discovered DirecTV's channels were actually white clipped and black stretched. The Dish channels were properly balanced in the upper and lower luminance regions. Both appeared to have the same amount of detail in the middle of the luminance spectrum.
What this clipping and black stretch does is make the image "brighter" with more luster, however, it also causes a suffer of lost detail in the shadows and lost detail in the whites that Dish Network retains.

If this were just one channel, I would have said something is out of adjustment, but since this was on three channels and over several days period of time, I have to credit DirecTV with making this mis-adjusted picture intentionally as a policy or they have some newbie in engineering who just needs to be watched over. I hope DirecTV can fix this. Meanwhile I will be looking at other channels PQ with not just detail but also the level of white clip and black stretch being added.

Another thought is that DirecTV is using the same logic as monitors are set at for in store sales vs in home viewing. The brightness and contrast is cranked way up for in store viewing. Since D* cannot adjust my monitor in the my home they have adjusted the picture before sending. Unfortunately when it is adjusted before airing, I can't pull that detail in those clipped and stretched regions back to normal. It is lost.

 

[paulman182]

Thank you so much for the comparison.

I hope D* pays attention to your work and examines this situation.

I can't comment on your findings as I don't currently have E*.

 

[rad]

Why bother with this tread at this time? In a few short weeks D* will be firing up their nation HD MPEG4 channels, wouldn't that be the time to start this subject again vs the old technology? Or, are you just looking to start up another D* vs. E* thread

 

[gadgtfreek]

Are any of D*'s current HD channels MPEG4? Im asking because I honestly dont know.

 

[Brewer4]

Are any of D*'s current HD channels MPEG4? Im asking because I honestly dont know.

The HD LIL's and RSN's.

 

[gadgtfreek]

The HD LIL's and RSN's.

Thanks Brewer.

So technically, when the sat goes live they will move their current stuff to mpeg4 along with the additions?

If so, very good.

 

[Brewer4]

To get you up to speed, here are some observations and thoughts what is going to happen.

1. The stuff on the spaceways (99 and 103) is using MPEG4 and is only viewable using HR20 or H20/H21 and 5 LNB dish. The content is only local HD channels and some RSN's.

2. All the new HD channels are going on D10 (103) which is weeks if not days away from lighting up. All the channels will be MPEG4. More HD LIL to follow using this bird.

3. When D11 is launched, expect a ton more HD LIL and most if not all markets covered within a year or so of D11 activation.

4. The current MPEG2 HD channels on 101, 110, and 119 are expected to be MPEG4 too mirrored with the current ones keep active for legacy receivers like HR10-250. At some point the MPEG2 ones will be shut down and will require all folks with MPEG4 capable hardware. We dont know the cutover date.

5. Sunday Ticket HD games should be MPEG2 and existing sats for lots of reasons for at least this season. ST is a massive money maker and there has been no official switching or announcements getting folks off non-MPEG4 hardware.

6. Most folks that get the HD LIL on Directv have compared the channels to OTA versions and think the MPEG4 quality look as good as the OTA ones they are getting. So most are excited by the prospect of Directv using MPEG4 for all HD channels going forward.

 

[gadgtfreek]

Thanks, very helpful info.

Itll be interesting to see how the mpeg4 nationals look soon.

Is there any input yet on whether the HD nationals on the new bird will be 1280,1440 or 1920?

Doesn't much matter to me as I only have a 1280x720p tv

Last question(I think), is there a "uplink activity report" like we see on E*?

 

[Brewer4]

Thanks, very helpful info.

Itll be interesting to see how the mpeg4 nationals look soon.

Is there any input yet on whether the HD nationals on the new bird will be 1280,1440 or 1920?

Doesn't much matter to me as I only have a 1280x720p tv

Last question(I think), is there a "uplink activity report" like we see on E*?

You are welcome. Thought it would be easier to summarize then dig through pages of babble and misinformation.

Nobody knows the bit rates or dimensions yet. We are all wishing and hoping that it matches the source. Keep in mind, not all channels are 1920 which is a general misconception. We are hoping that the quality is on par with the source feed. I am sure there will be a boat load of discussion around this and even some unfair bashing of Directv for some providers that are going to cheat and skimp on their HD. Prepare yourself for lots of SD stretch o vision content on some channels until they can get more HD content. Not all HD channels will be equal.

No uplink report. We are all waiting with baited breath on an announcement from Directv real soon. We are literally days or week/s away from something coming in either announcement or possible channels. This is going to be a massive momentous moment in TV and HD history. You dont have to be a Directv subscriber or fan to realize the ramifications of this new satellite.

 

[gadgtfreek]

I can see why everyone is excited, the potential is huge and its a long time coming.

I bet the day it goes online and the channels do come, cable co's are gonna produce a large brick if they dont have a plan.

I personally feel the 1440x1080i on E* looks great, but many would stone me over that.

Im fairly confident that D* will up the ante with this fancy new sat.

Itll be good watching D* and E* over the next year with the planned sats, cable co's are going to get left behind for a bit, I think. Comcast is about 3-5 mo's behind every E* add which is not good.

As far as SD strecth, many dont consider that. Much of what is on DiscHD and TLCHD that were just added to E* is stretch, but it still looks better than the SD channels :up

 

[harshness]

Keep in mind, not all channels are 1920 which is a general misconception.

Those that aren't in the Disney or Fox camps should be 1080i. In terms of channels that are to be added soon, F/X may be the only 720p channel.

 

[gadgtfreek]

Those that aren't in the Disney or Fox camps should be 1080i. In terms of channels that are to be added soon, F/X may be the only 720p channel.

Really, F/X 720, wasnt expecting that.

Not sure who owns NatGeo, but its 720p.

 

[harshness]

Really, F/X 720, wasnt expecting that.

Being a Fox channel, you really should have.

Not sure who owns NatGeo, but its 720p.

News Corp., parent company of Fox. It is notable that in some other countries, their National Geographic channels are 1080i.

Okay, two 720p channels. I suppose one could count all of the Fox RSNs that go CONUS too.

 

[gadgtfreek]

I always forget that FX is owned by Fox.

 

[vurbano]

Doesn't much matter to me as I only have a 1280x720p tv

I am suspicious of that. I suspect that 1920x1080 = 2.07 million small square pixels converted to 1280 x 720p looks better than 1280x1080 = 1.38 million larger rectangular pixels converted to 1280 x 720p? Just my guess.

 

[gadgtfreek]

I am suspicious of that. I suspect that 1920x1080 = 2.07 million small square pixels converted to 1280 x 720p looks better than 1280x1080 = 1.38 million larger rectangular pixels converted to 1280 x 720p? Just my guess.

Honestly that is what Ive read on AVS, that a display will always look better if you send it more info than it needs.

Now in my situation (720p 46" tv with 10-12ft of view distance), I dont feel Ill see differences. 1080p is another issue, you either need a much larger screen and/or must be sitting closer to really get the effect IMHO.

I wont buy another tv, Im going projector next time, hope to get a 1080p prob late 2008.

 

[FlyingJ]

Honestly that is what Ive read on AVS, that a display will always look better if you send it more info than it needs.

Now in my situation (720p 46" tv with 10-12ft of view distance), I dont feel Ill see differences. 1080p is another issue, you either need a much larger screen and/or must be sitting closer to really get the effect IMHO.

I wont buy another tv, Im going projector next time, hope to get a 1080p prob late 2008.

Dont you know that Vurbano doesn't go by what we see, he can only go by calculations and equations.

 

[TheForce]

I am suspicious of that. I suspect that 1920x1080 = 2.07 million small square pixels converted to 1280 x 720p looks better than 1280x1080 = 1.38 million larger rectangular pixels converted to 1280 x 720p? Just my guess.

My thinking is that this is a hold over from the analog video days. It doesn't hold true for digital video. We always knew that if you shoot a scene with an 850 line camera and record to component analog tape such as Betacam SP and then make a VHS dub of that video it looks much better than if you shot the scene with a VHS camcorder ( 230 line) directly. One would think that since we end up at 230 lines VHS resolution, both would be the same but the fact is shooting with the larger format camera puts the VHS camcorder to shame when comparing both on VHS.

With digital the math is different. In analog we have an infinite number of possible pixels since the analog video is continuous voltage based, not pixel based. The ability to carry the higher resolution along in the transfer to a lower tape format or lower pixel range offers no better picture in the final video. In other words, a camera that shoots 720x1280 image and output to 320x240 will look the same as if that camera shot the image at 320x240 in the first place. With digital your limited by integer math, with analog you have a chance the circuit will respond, so to speak, of the detail that may remain in the transfer but if you use a low format camera that will not be there in the first place.

 

[TheForce]

Back on topic-

To clarify, my test was indeed done with MP2 channels as that is all I can receive now on D*. However, knowing a bit about TV production, I felt the artifact I listed, white clip and black stretch to make the video look brighter, would be upstream of the mp2 or mp4 encoding process. Meaning that this choice to make the picture look this way has little to do with MP4 vs. MP2. Those of you who can receive the same channel on both and know what to look for, can offer your observations. Not sure that is even possible. You would need both MP4 and MP2 receivers and control each on each transmission to tell.

Maybe the real complaint I have is that this practice is not producing a good quality picture but rather a more vibrant one. I thought I equated it to the monitor in store adjustment vs, at home adjustment. The detail is there but lost in the white clip areas. The detail is there in the blacks but at some point in the shadows it is gone compared to the same image on Dish Network's picture. Yes, in this respect it was a comparison of DN to DTV. But the DN image was less vibrant and more regions of the picture with detail. Take your choice!

 

[atp1313]

Maybe the real complaint I have is that this practice is not producing a good quality picture but rather a more vibrant one. I thought I equated it to the monitor in store adjustment vs, at home adjustment. The detail is there but lost in the white clip areas. The detail is there in the blacks but at some point in the shadows it is gone compared to the same image on Dish Network's picture. Yes, in this respect it was a comparison of DN to DTV. But the DN image was less vibrant and more regions of the picture with detail. Take your choice!

Just out of curiosity, when you do these side-by-side comparisons, are you viewing both sources via HDMI, or is it HDMI on one and Component on the other? And even if it is identical inputs, are the various inputs both calibrated the same? My TV allows/requires distinct variations of settings on all inputs, even both HDMI; rather than a "this applies to all HDMI inputs".