Combing or pulldown artifacts with extender on standard digital channels

[brzez]

HDTV with the HD100 extender looks great. My wife watches Bravo and Food network occasionally and while she is not very critical of picture quality, she has mentioned that the extender looks terrible for some of her shows. Much worse than the Dish 411 receiver she watched things on before. I took a look at some of the shows and noticed a lot of combing artifacts (especially during motion). This occurs both on my local over the air standard definiton digital broadcasts (non HDTV PBS for example) as well as many Dish standard definition broadcasts.

So is the extender not doing 3:2 pulldown correctly? I see a lot of jagies and motion artifacts as shown in http://www.hometheaterblog.com/homet...s_pulldow.html The broadcasts are in 480i so I was wondering if there are settings/tweaks on the extender or sagetv server that can be done to fix this? 1080i programming works fine as does any progressive programming.


My system and setup is as follows:

SageTV 6.3.8 running as a service on a WinXP SP2 machine using NextComm R5000 modded Dish 411 receiver and an HDTVFusion ATSC PCI tuner for local HDTV
2 HD100 Media Extenders
2.2 Terabyte Linux Ubuntu Samba Server running ZFS RaidZ2

Thanks..

-- John

[autoboy]

I also found that the extender did not do a stellar job at improperly flagged SD content. Some shows looked great, others did not. You can try to bypass the scaler in the extender by setting the output to native in the sagetv detailed setup. Make sure you have all the supported resolutions of your TV checked in the sage extender setup. In native mode it will pass the native show resolution as long as it is a standard rez (if non standard it will scale to highest allowed resolution) Your TV will then do all the scaling and you can compare. I got a receiver with a high end HQV Reon scaler (Onkyo 875) and it does a great job with SD and HD material. My TV, a Sony KDS60A3000 was no better than the HD extender. Your results may be better than mine.

[mrwolf]

I just received mine this evening and I noticed some of this on a couple shows. The worst was a basketball game on ESPNHD (I'm using composite video into my SageTV server). Most other shows are quite incredible, though. My OTA HD never looked better. I think I'm willing to deal with it until the HD-PVR comes out.

[Slipshod]

Ahhh. Just had to go further back in the archives to see somebody else having the same issue.

I wonder if the deinterlacer is even on, it really doesn't look like it is.

[autoboy]

Mr Wolf.

The problem is not with the extender but with your setup of the extender. ESPNHD is in 720p which means that there is no deinterlacing going on in the extender to play the file.

There are many ways that you can get strange results from progressive scan sources.

1. The show is shot in interlaced format (480i or 1080i) and the station did a terrible job at deinterlacing the original show and scaling to the 720p format. You will see this most often in commercials. You will also see this with 1080i stations that use upscaled 480i content like Food Network. There is nothing at all that you can do since it has nothing to do with you. Call the station and complain is about all you can do.

2. Your setup is all wrong. You said "I'm using composite video into my SageTV server" and this makes no sense. Composite is limited to 480i and has been in use for 30 years. It sucks. Also, are you recording HD content with the composite input? You will not get HD out because composite is limited to 480i. I am going to assume you misspoke and really mean you are using component to the TV which could also be your problem. Component, while capable of carrying 1080p, is mostly limited to 1080i. I am going to assume that you are using 1080i component output from the extender and that your TV now has to deinterlace the 1080i from the extender. This could be were your problem is because your TV likely sucks, like 95% of the TVs out there, at deinterlacing 1080i. So you took that 720p ESPNHD signal that was perfectly fine and scaled it to 1080i with the extender, then let the TV deinterlace it and there are your problems. If you had set your extender to output 720p as 720p, you would likely not have run into problems.

Please set your HD extender to the resolution of your TV. If you have a 720p which you likely do, then set your extender to 720p resolution so your TV doesn't have to do anything to the signal. If you have a 1080p TV, get a HDMI cable from monoprice cable and set your extender to 1080p. If you would rather have the TV do all the scaling (which if you are limited to 1080i output is a good idea anyways) then set the extender to all your supported resolutions, and enable native mode switching. Now, 480i will be 480i (not some crappy double scaled 1080i) 720p will be 720p without TV introduced artifacts, and 1080i will be 1080i with all the deinterlacing problems that you had before.