Certain HD programs stutter but others don't.

[wtsitmn]

Has anyone out there noticed stutter on certain televised (OTA) HD programs and not on others? I first noticed this when ABC televised Pirates of the Caribbean a few months back. Using Sage, the video throughout the movie wasn’t smooth like all the other HD programs I’ve watched. Since then I’ve noticed it elsewhere but haven’t been able to identify a totally consistent pattern. There seems to be more of a problem with programs which were converted from an analog source, such as film. I notice little if any issues with network TV programs like CSI.

As a test, I tried playing some files with Windows Media Player. The ones which stutter using Sage are a complete disaster with WMP. The ones which are smooth using Sage stutter slightly using WMP.

Can anyone explain what’s going on?

The sizes of various HD files are all comparable. I use the latest nVidia PureVideo decoder. I’ve tried totally reinstalling everything from scratch, but it makes no difference. I even tried temporarily installing Sage on a different computer with totally different hardware, but the results were the same. I even dug out an old tuner I don’t use anymore to see if that would make a difference, but it didn’t. FYI, Programs which are not broadcast in HD are not affected, and all my tuners are digital.

At this point I can make do with the stuttering, although it’s a bit annoying. What I’d really like is a viable explanation more than anything else. What the heck is going on?!!

[GTwannabe]

Please list the following so that we can help you:

- OS
- CPU type/speed
- Video card model and driver version
- SageTV rendering mode (VMR7, VMR9, or Overlay)
- SageTV 3D mode on/off
- SageTV FSE setting on/off
- PureVideo tray icon settings

[wtsitmn]

Originally Posted by GTwannabe

Please list the following so that we can help you:

- OS
- CPU type/speed
- Video card model and driver version
- SageTV rendering mode (VMR7, VMR9, or Overlay)
- SageTV 3D mode on/off
- SageTV FSE setting on/off
- PureVideo tray icon settings

Feel free to look at my public profile. But as I said, the exact same thing happens with a totally different machine. There seems to be something significantly different in the encodings of some HD programs (mpegs). I'm interested in knowing if anyone else has noticed similar issues. As far as Sage settings go, they have no effect on this issue.

Just to reiterate, some HD programs play perfectly and others stutter a bit. The problem is more pronounced when using Windows Media Player. I can transfer these files to any other computer and get the same result with WMP. This does not appear to be a Sage problem at all. However, I've searched the net for answers and so far can find none. Since many Sage users on this forum are very experienced, I thought one might have some idea what might be in the encoding of some mpegs which could cause this. On the other hand, if no one else has this problem, that would be interesting to know, too.

[dvsing]

What video decoder are you using? Which HD channels stutter (is it the same channels?) Check the recording details of your HD recordings.. I'd be willing to bet you that your 720p recordings play back fine, but your 1080i recordings stutter. I have this issue using the Nvidia PureVideo decoder in hardware accellerated mode. There seems to be an issue with the decoders ability to detect film or video content with 1080i. If you disable hardware acceleration for Nvidia's decoder, it works ok (although it does chew up more CPU cycles to decode).

-Dan

[wtsitmn]

Originally Posted by dvsing

What video decoder are you using? Which HD channels stutter (is it the same channels?) Check the recording details of your HD recordings.. I'd be willing to bet you that your 720p recordings play back fine, but your 1080i recordings stutter. I have this issue using the Nvidia PureVideo decoder in hardware accellerated mode. There seems to be an issue with the decoders ability to detect film or video content with 1080i. If you disable hardware acceleration for Nvidia's decoder, it works ok (although it does chew up more CPU cycles to decode).

-Dan

Thanks for those suggestions, Dan. Those were good. Too bad I already checked for those things.

I'm using PureVideo, but the problem occurs when using the Sage decoder as well. Although it's much more pronounced when using the Sage decoder, and all programming is a bit jittery at times.

FYI: As far as I can tell, all televised (OTA) HD programming is 1080i. At least it is here in DFW.

The more I think about it, the more I wonder if it's mainly programming that's been converted into digital HD from film. I think about all the HD movies I've recorded have been less than smooth, and yet about all the made-for-TV HD programming seem to work fine. There may be exeptions, but of course it's impossible for me to know for certain when I'm watching a program which has been converted in some way. I believe Letterman and Leno are recorded directly in HD using HD cameras in the studios. I've never had any problem with those. And like I mentioned before, network HD made-for-TV programming seems to be fine.

So it sounds like you may have a point with the decoder not being able to detect film.

The mystery continues...

[sandor]

abc sucks in philly. prime time shows are constantly stuttering (via sage and a set top ATSC tuner). All the other channels are fine, and all day ABC seems fine.

as far as i remember, ABC and Fox are both 720p and CBS and NBC are both 1080i broadcasts.

[cbryan27]

wtsitmn -

I haven't experienced any problems in DFW, but I can't remember the last time I recorded an HD movie OTA. If you want to coordinate a test, I'm game.

[Polypro]

Originally Posted by sandor

abc sucks in philly. prime time shows are constantly stuttering (via sage and a set top ATSC tuner). All the other channels are fine, and all day ABC seems fine.

as far as i remember, ABC and Fox are both 720p and CBS and NBC are both 1080i broadcasts.

Add Detroit to that list. ABC-HD doesn't work well in Sage, all others are fine. I've sent files, played with different media players, decoders, tried different computers...no joy, ABC-HD and Sage (Vista) don't play well in my house.

P

[wtsitmn]

Originally Posted by cbryan27

wtsitmn -

I haven't experienced any problems in DFW, but I can't remember the last time I recorded an HD movie OTA. If you want to coordinate a test, I'm game.

I'd be willing to give that a try. Since I always seem to have trouble with HD movies, that seems like a good test case. Unfortunately there aren't any of those scheduled in the foreseeable future.

[Polypro]

Just discovered this, this morning, after doing a "Repair Install" of SageTV:

nVIDIA & Cyberlink Audio Decoders give me judder on my ABC-HD channel.

After doing a repair install of Sage, I forgot, and left AC3Filter as the preferred decoder (I normally set it to "Prefer Other Decoder" and use either NV or CL). My problem channel played smoothly. I switched back to both NV and CL and the judder returned. Looks like AC3Filter is doing something that the others aren't. Try AC3Filter.

P

[cbryan27]

PM sent to OP.