WMC picture quality - jaggies, moire, shimmering

[richard1980]

I'm pretty sure video drivers for all 3 popular chipset families (AMD/NVidia/Intel) have some setting that effectively makes them not have the flag fluctuating issue with the corresponding DXVA codecs.

For example, some of the HD HBO channels have this issue on FIOS (curiously none of the SD ones or other premiums do), and turning off dynamic contrast in the Intel integrated graphics settings seems to fix it for some bizarre reason (I don't get how the 2 are related).

The flags are embedded in the MPEG stream. Making changes to the GPU driver (or anything else for that matter) doesn't affect the flags...it affects what the GPU does during processing.

If I'm following Richard's explanation correctly of this being an interlacing issue, turning off the honoring of the progressive_frame flag (even when progressive_sequence 0 is seen) and treating interlaced fields as progressive should not have the shimmering effect, but instead cut your effective vertical resolution in half

The terms "interlaced" and "progressive" can't be used to describe a field. A field is simply half of a reconstructed frame (either all of the even lines or all of the odd lines). It's the reconstructed frame that is either interlaced or progressive. It doesn't matter which way you treat the frame...all lines will still be displayed.

[tzr916]

My Tivo was setup to always output 1080i. Is it possible to force WMC to play WTV files in 1080i then let my AVR or Tv do the deinterlacing? If the desktop is set to 1080p, will the video card override or does it obey WMC? Would doing this even affect my situation? I am tempted to try...

[richard1980]

Switching to interlaced output won't solve anything. The mismarked frames will still be processed incorrectly. It's easy enough to try it and see for yourself. You'll actually probably notice a slight improvement in picture quality.

[nullmindset]

I recently switched to two HDHomerun Primes from a PCI Ceton Infinitv 4. In the past I can't say that i noticed the jaggies and overall shakiness of the picture on certain channels, but in the past day or two they are extremely apparent. I've tried playback on host machine, Linksys, HP extenders and an Xbox 360 and the issue is still there. Is it possible the issue didn't present itself on the Ceton, but does on the HDHomerun?

Any thoughts or feedback would be appreciated.

[richard1980]

Is it possible the issue didn't present itself on the Ceton, but does on the HDHomerun?

It is possible that you did not watch any incorrectly-flagged content on the infiniTV, but you are watching incorrectly-flagged content on the HDHRP. It is not possible for the tuner to affect the flags.

[nullmindset]

I quick google yielded some forum posts on avsforum that Ceton implemented a software fix for the 29/59 bug on their InfiniTV, which doesn't seem possible, but then again they fixed the 6-tuner cable card issue that Tivo has still yet to "fix".

The same program was being recorded. So unless my content provider changed the flag overnight, it must be doing something different. It's apparent on every single episode of Family Guy on Cartoon Network HD. I reviewed an episode that recorded the day before on the InfiniTV the night before and it was fine. It will be a pain in the ass, but perhaps I'll grab another cablecard and re-install the Ceton to test.

[richard1980]

Whatever you think you read, you misread it. Either that or someone is making false claims.

[barnabas1969]

Is it possible the issue didn't present itself on the Ceton, but does on the HDHomerun?

It is possible that you did not watch any incorrectly-flagged content on the infiniTV, but you are watching incorrectly-flagged content on the HDHRP. It is not possible for the tuner to affect the flags.

It is also not possible for a digital tuner to affect the picture quality, other than the fact that one tuner can be more sensitive and therefore work better with a weak signal. But if it was a weak signal problem, you would see dropped frames, or pixellation.

[woodchuck]

Hey Richard-

So in your experience, are there any hardware/software configurations that noticeably help in 7MC? I remember talk of certain GPUs doing a better job than others - and then additional talk about turning off all the video card "enhancements" for better performance. Are these all untrue in hindsight?

[barnabas1969]

Hey Richard-

So in your experience, are there any hardware/software configurations that noticeably help in 7MC? I remember talk of certain GPUs doing a better job than others - and then additional talk about turning off all the video card "enhancements" for better performance. Are these all untrue in hindsight?

No, they are true for certain things. Certain GPU's do a better job with the 29/59 issue. If you have cable TV content that fluctuates between 29/59 fps, then you need a GPU that can handle it. This same problem affects people in the UK... I believe even with OTA (terrestrial broadcast) channels, where the frame rate alternates between 25 and 50 fps.

The enhancements also relate to the 29/59 issue.

[nullmindset]

Is it possible that if I obtain the GPU that does a better job with the 29/59 issue that the "fix" will also work on extender picture quality as well? I would imagine that the image would only look better on the source PC and wouldn't affect extenders, but I'm reaching here.

Also, is there a list anywhere? I personally have an Intel 4000 and Nvidia GTX 670.

[barnabas1969]

No, the GPU in the PC doesn't affect extenders. Extenders have their own graphics processor.

More information (and a partial list of GPU's that work) can be found in the wiki:
http://www.thegreenbutton.tv/wiki/index ... Rate_Issue

[nullmindset]

I've at least confirmed that I am indeed exhibiting signs of the 29/59 issue on my setup after reading the wiki. Oddly enough, I used my HDHomerun Prime to playback Cartoon Network HD via LG TV (using DLNA) and playback is perfect, quality is as good or better than the Tivo Roamio (which as a sidenote, is being cancelled and shipped back).

Does any particular extender handle the 29/59 issue better than the others? 411-Info button doesn't give me relevant information on any extender.

[tzr916]

...Does any particular extender handle the 29/59 issue better than the others?

At my house, echos and xbox handle incorrectly flagged material exactly the same. My two echos have a lot of other picture issues- combing, tearing, stuttering, pixellation...

[Hisma]

I found this thread on a google search recently because I was having similar issues to the OP.

I found a solution, but it requires using a different video player (but not having to ditch wmc completely).

I fixed the issue by using alternative de-interlacing to DXVA de-interlacing. I am guessing that because WMC uses DXVA decoding, it also uses DXVA de-interlacing if it's available. I isolated the issue by playing around with different de-interlace settings in XBMC, since I found that the jaggies/shimmering only occur when de-interlaced content is showing.

You can use serverwmc as a backend for XBMC, and watch your live TV via XBMC. Then in your video settings, you can use any combination of settings you prefer, but in the "accelereation" section of "video settings", do NOT enable DXVA2 decoding. Leave that unchecked.

Then inside the video player when you are watching TV, go to the video settings inside the player, set "deinterlace = auto", "de-interlace method = de-interlace". This will allow the video player to properly de-interlace the content without jaggies/shimmering. Well, jaggies are 100% eliminated, shimmering is about 85% eliminated. Still see it, but only on rare occasions. The quality is totally acceptable at that point.

To test the difference, change "de-interlace method" to "DXVA Best" or "DXVA Bob". You will see the jaggies and moire come back.

If anyone needs more details, let me know. I know this is a WMC forum, so using an alternative media center may not be acceptable for some... but I think it's a good compromise, since this issue is so bad, this is the only way I have found to almost completely eliminate it without replacing the video card or any other hardware.

Hopefully this will help someone else out there having this problem, since I had this problem for months and could never figure out the cause, even with hours of google searching. Even though many others have had this issue, I have yet to find any solutions that involved changing the de-interlacing method.