MPEG 2 decoder troubles

[dooferlad]

Hello all,

I am a Hauppauge user (PVR350) so I have been using the non-css decoder as provided by Hauppauge. This decoder mostly works OK, but sometimes the picture stutters while the sound keeps going. If you pause the playback and resume a few seconds later all seems well. I have no idea if something is happening in the background, but it doesn't happen when watching DVDs so I figure it shouldn't happen when watching TV. It appers to be happening more of late, so I need a fix. With that in mind I went off in search of a solution. I have all ready got the registry hack going for the Hauppauge decoder, so I am not expecting any speedups from that. On to the other options then.

I heard that the cinemaster MPEG 2 decoder was very good so I gave it a try last night. It appears to want to display the video in a different window. Hardly ideal. I have to use VMR 9 because for some reason my overlay picture contains errors (I have turned off tiling to get my Radeon 9000 to output 50Hz RGB interlaced to my TV, which I think is the cause - was fine before). I don't know if it has this problem with VMR 9.

Frustrated I went on to try FFDSHOW using both libmpeg2 and ffmpeg decoders. If memory serves me correctly (which it oftern doesn't) then ffmpeg got the audio sync right, while libmpeg2 did not. It didn't matter though because I was getting picture errors (the picture wobbled vertically - it is as if it was correctly decoded, but then x shifted in a sine wave in places). This was with both decoders. Maybe I need to stop using the alpha releases.

I then tried a trial of the bitcontrol MPEG2 decoder, but could not select it from within SageTV. It may be that Sage only displays filters it knows about in the list, so maybe I just need to tweak something, or ask someone to update the list. Either way advice is welcome.

So all you people who have got this sort of thing working. May I ask how?

Thanks!

[kny3twalker]

not sure why you have to use VMR9 but it is not the easiest for any video card
and you might want to use VMR7 (default video render on Windows XP)

this is defintely a slow video card issue though

if the video stutters
the video card is unable to keep with the video being rendered

have you considered using the pvr 350's TV out as well?

the best decoder for VMR9 is nvidia video decoder with post processor

you can try to disable DXVA in the decoder and it should help smooth the video but VMR9 is the problem

[dooferlad]

It isn't a graphics card problem - the same clip can be played back if I rewind it. If my graphics card could not keep up then it would never be able to keep up. Sorry about not making that clear. It is a stutter that appears at random, lasts about 20 seconds and then goes away.

Mostly I just want to get a better decoder working, so I don't care about what the problem is with the Hauppauge decoder.

[mlbdude]

I would say it is a graphics card problem as well - ATI 9000 is not even close for VMR9. To confirm try using the Default renderer. VMR9 underpower issues will not be consistant and cannot be repeated by watching the same frames.

[stanger89]

Are you having the "interlaced overlay" problem? Where overlay is stretched vertically (you only see half the picture). If so try newer drivers for your 9000.

[dooferlad]

OK OK this has all got a bit confused. I will try and clear things up.

When using overlay in SageTV and the Hauppauge decoder the picture has a rather strange interlcing artifact; instead of the normal interlacing where two fields are out of sync (as they should be down the TV) it is happening in, I would guess, 32 pixel high stripes. This problem was not present when I used the s-video out, but the picture quality is much better with VGA --> SCART so I am not going back. The problem goes away when I use VMR 9. I don't have the option of using VMR 7 - my only two options are overlay and VMR9.

When playing back videos in WinDVD (essentially the same decoder, but with CSS decode) I don't get this problem. I also don't get the problem in any other application and I have not gone to each one and told them to use VMR9, so I am guessing it is something to do with the Hauppauge decoder. For this reason I wanted to try another decoder, which is why I was asking for help with them. I hear the Cineplayer is very good and also ffdshow can give picture quality improvements. Mostly I just want video playback that is reliable.

I did try Cineplayer tonight using the Overlay and while it did exhibit the stripe problem initially it went away. Of course with overlay I don't get the nice transparent menu system and sometimes I get errors where the screen doesn't redraw when going through menus, so VMR9 would be nice. I can run Cineplayer in VMR9 but it displays in an external window, so that isn't much good.

I haven't got around to trying ffdshow with any more settings.

Why is VMR9 such a strain? Isn't it basically rendering to a texture and getting the card to alpha blend between various ones to produce the menu on top of the video? Should be very easy! Of course I am sure there is lots of interesting API sitting on top of it.

[dooferlad]

You may want to know I disabled tiling to get the RGB out working. This does decrease memory performance, but this doesn't appear to be an issue other than the stated overlay problem.

[stanger89]

Is that Cineplayer or Cyberlink? CP shouldn't pop up an activemovie window with VMR9.

As for decoders, the best ones right now are probably the nVidia 1.00.58 decoders (with the provision that the audio decoder doesn't work with Sage for some reason).

With regard to the "interlacing" I know what you're talking about, but I've only seen that with wierd AVI files.

[dooferlad]

It is Cineplayer that popped the window up. I may give the nVidia filters a go though if they are the current favourite.

[kny3twalker]

in SageTV 2.1
Cyberlink PowerDVD does VMR9 fine now

[dooferlad]

Aha! Well, I may just have to give 2.1 a go :-) I was going to wait until peoples tuner toubles had calmed down, but it is worth a shot.

Normally I am the first to try Beta software. Don't know what has come over me!