how do you tell if a channel is being down converted? Just a simple(hopefully) question

Generally, there are two ways. One is by measuring the resolution or bandwidth of the channel. Depending on the source, this may not always be possible. Two, is by knowing what a reduced resolution or bandwidth channel looks like, based on previous experience.

Or, by comparing a source that you know is HD and generally regarded as a high quality source (i.e.: HDTheater or HDNet) and looking at the quality of the image, look at it's crispness or sharpness and the dynamic range of the picture. A down-coverted image tends to look much less crisp, I use the word, smeary. Even though you don't have the ability to compare the same source material, I think the differences that I've described can be seen even by people who are not experienced in such observations.

well, I am currently an E* sub, and was just trying to figure out which channels are HD lite and which are not. is there a list anywhere?

well, I am currently an E* sub, and was just trying to figure out which channels are HD lite and which are not. is there a list anywhere?

I've always followed the simple rule that if it looks great to me, then I can care less if the channel's being downrezed or not.

An example of this with D* is that IMO, ESPN (an MPEG2 channel that's been bitstarved more times than not) has looked much, much better over the past 30-45 days and has actually gotten to an acceptable PQ level with me. I never posted here about it because I'm not really concerened about the numbers to back it up. It looks better to me and I'm not needing confirmation with numbers to prove it.

Ofcourse this doenst work for everyone, so YMMV. :D

I'm just a little curious. At times TNT looks bit starved, at times it looks terrific. My local RSN looks bit starved everytime it is on however.

HD-Lite is bull. It implies that there is an "on" and "off" determination, whereas actually it is a spectrum.

When D* was waiting for its satellites to launch, it ended up not having enough bitrate for a good quality HD picture. To less the effects of excessively low bitrate, it lowered the resolution, so each frame required less bits.

But the cause of the poor quality picture was insufficient bitrate - lower resolution was a symptom, not a cause.

The extent to which you can see any artifacts due to lowering of bitrate is entirely dependent on two factors - TV size and viewer distance.

If your screen is larger than 52 inches, you need either Blu-Ray or an OTA antenna - everything else is designed for an average 37 inch HD TV set.

well I use a 23" LCD and sit right by it. that is probably why I notice a ton of artifacts. However, when the next Dish satellite launches, won't the bandwith be better, and channels will get better PQ?

HD-Lite is bull. It implies that there is an "on" and "off" determination, whereas actually it is a spectrum.

When D* was waiting for its satellites to launch, it ended up not having enough bitrate for a good quality HD picture. To less the effects of excessively low bitrate, it lowered the resolution, so each frame required less bits.

But the cause of the poor quality picture was insufficient bitrate - lower resolution was a symptom, not a cause.

The extent to which you can see any artifacts due to lowering of bitrate is entirely dependent on two factors - TV size and viewer distance.

If your screen is larger than 52 inches, you need either Blu-Ray or an OTA antenna - everything else is designed for an average 37 inch HD TV set.
I don't understand what you are saying. I have a 42" RPTV and I can see the motion blocking at 15 ft away.

HD-Lite is bull. It implies that there is an "on" and "off" determination, whereas actually it is a spectrum.HD Lite is not bull. It is a documented issue. For the last time, here is the definition we use for HD Lite:

HD Lite
A 19.3mbps 1280x720p or 1920x1080i HDTV source, transmitted with either a lower bitrate, a lower resolution, or both. This is sometimes done by satellite or cable providers to save bandwidth, and by over-the-air broadcasters when multicasting. Typically the term is used when the reduced bitrate and/or resolution results in a noticeable degradation in picture quality.

There is no implication whatsoever that HD lite is an "on" and "off" determination.

hmm well I just turned on MHD on E*, and it looks disgusting. However, Showtime East looks great in HD showing Casino Royale in OAR.

well I use a 23" LCD and sit right by it. that is probably why I notice a ton of artifacts. However, when the next Dish satellite launches, won't the bandwith be better, and channels will get better PQ?They will have more bandwidth, the question is, what will they do with it.

HD Lite is not bull. Claiming you can measure effective resolution visually is bull. :)

H
If your screen is larger than 52 inches, you need either Blu-Ray or an OTA antenna - everything else is designed for an average 37 inch HD TV set.

Did you make up this absurd statement or did you read it somewhere?

HD Lite is not bull. Claiming you can measure effective resolution visually is bull. :)

I don't think anyone is claiming to measure resolution visually. The concept is simply knowing when HD image quality is being reduced, by what it looks like. The measurements, when available, confirm what viewers are seeing.

This is not to say some viewers become disappointed in what they see after hearing about measurements, and not because of what they are actually seeing. The power of suggestion is always in effect, especially with lay person perception.

As I have pointed out in the past, the usual pattern is as follows:

1) Viewer(s) note a change, not for the better, in HD image quality.
2) Other viewer(s) also note the same issue, as discussed on the forum.
3) Some technically oriented viewer(s), most with TV / video industry experience, attempt to verify what they believe they see by using computer software tools.
4) The data bares out the viewer(s) perceptions.
5) Forum members say 'Ah Ha! I knew it!'
6) Mass provider defections are threatened.
7) Life goes on.

A slight deviation to the above pattern occurred when AVS member bfdtv posted his results regarding Comcast's recent decision to reduce HD image quality by ~1/3, on some Cable/DBS HD channels. His research was widely discussed in the general press. And then life went on.....

I don't think anyone is claiming to measure resolution visually. The concept is simply knowing when HD image quality is being reduced, by what it looks like.However, image quality could be degraded due to a number of reasons, many of which could have multiple sources.

HD Lite is not bull. It is a documented issue. For the last time, here is the definition we use for HD Lite:

HD Lite
A 19.3mbps 1280x720p or 1920x1080i HDTV source, transmitted with either a lower bitrate, a lower resolution, or both. This is sometimes done by satellite or cable providers to save bandwidth, and by over-the-air broadcasters when multicasting. Typically the term is used when the reduced bitrate and/or resolution results in a noticeable degradation in picture quality.

There is no implication whatsoever that HD lite is an "on" and "off" determination.

By that definition, all sources of HD channels in 2010 will be "HD Lite" - other than some OTA and maybe FIOS...

Also that definition doesn't take into account MPEG2 sources that are transmitted in MPEG4.

And it certainly is "on" or "off", because by that definition, while 19.3mbps is "not HD Lite", 18mbps is "HD Lite" and 3mbps is "HD Lite".

hmm well I just turned on MHD on E*, and it looks disgusting. However, Showtime East looks great in HD showing Casino Royale in OAR.

Ironically, one example of poor quality does not mean that the channels's overall quality on that provider is poor - because you don't know whether it is the channel or just the program.

Many times I have remarked about poor picture quality, only for it to improve greatly when a different program aired.

(In fact, sometimes the commercial is so much better quality than the program, that you can instantly tell that the program's quality is poor.)

I will agree that to an extent HD-Lite is an over simplification. For instance, if Discovery HD is reduced from 1920 to 1440, is that HD-Lite when the source material itself is 1440? If 1440 is reduced further to 1280, is that difference visible? If a 1080i 19 Mb/s MPEG2 source is re-encoded to 19 Mb/s 1080i, is that HD-Lite? By the definition it would not be, but re-encoding at the same low bitrate will usually degrade the image as the artifacts from the first will compromise the encoding efficiency of the second. MPEG artifacts are intentionally made to be in in the higher frequencies due to the typically coarser values in the upper frequencies of the DCT quantizing matrix. This also reduces or eliminates fine detail at higher frequencies. The second encoder may sacrifice actual lower frequency detail to preserve the artifacts. In fact, filtering down to a lower resolution may help to reduce blocking effects and mosquito noise.

Another example is ATSC. Aside from Fox, networks use a mezzanine approach with a higher bitrate on the network fronthaul than the transmitted ATSC. Are all stations using this HD-Lite as they degrade the network feed? While it's not practical to relay the network bitrates, at what point does a station become HD-Lite? 17 Mbs? 15Mbs? 11Mbs? It is in fact a sliding scale based on the bitrate and the encoder efficiency. One encoder may look better at 16Mbs than another at 18Mbs.

What HD-Lite attempts to define is the degradation of the path to the viewer, and does qualify whether the degradation is noticeable which can be subjective. In cases where the distribution is already a low bitrate source in the ATSC range, subsequent processing becomes significantly more difficult due to the artifacts already introduced. D*'s MPEG4 LiL's have been mentioned to have reduced degradation. Is a determining factor whether it remains at the same pixel count or the same bitrate? If so then it doesn't take into account the dynamic nature of resolution loss in compression, or the differences in encoders and codecs.

The bottom line I guess is whether the degradation is noticeable, so HD-Lite is in the eye of the beholder.