Nebula and the rugby

sneaky

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Hi all,

I have been using the nebula for a few days now. I have watched alot of programs through my hs20 onto a 6ft screen and the quality has been very good.

I have sat down this afternoon for an afternoon of sport and first up is Scotland v Italy in the rugby. The closeups are good a nd when static it is good but when there is movement I see alot of artefacts and the general quality is rubbish.

Any ideas of how I can improve the PQ. Im hoping to watch England v Ireland and Arenal v Porstmouth later so help would be greatfully received.

Chris
 
Have you got deinterlacing set to "bob"? If not then this will improve the motion artefacts a lot. The option is on the video page of settings. If this is already done then I'm afraid the poor quality comes from the MPEG compression used on the channel, not much you can do about that I'm afraid.

HTH
Owain
 
Deinterlacing is poor on the Nebula isn't it?
 
Thanks Guys,

I had tried the three options for de-interlacing and it seemed to make little difference.

One thing I did notice was the second game - england v Ireland was a lot better than the first one (Both on BBC).

I have connected a portable tv into the multicable on the PJ and everything is good.

Another thing I have noticed, like you say, there is a lot of different qualities of program being pumped out.

The best quality seems to come from ITV adverts.

Thanks

Chris
 
Originally posted by Jeff
Deinterlacing is poor on the Nebula isn't it?
Compared to what Jeff?

I find de-interlacing is pretty good in the recent software releases, still not quite up to dscaler standards, but I find it quite acceptable for viewing on a big screen. It's certainly dramatically better than the Hauppauge card!
 
I was thinking compared to Dscaler or most of the hardware based deinterlacer chips, but yes, I'm sure there are some product that are even poorer.
 
Pootle - I can confirm that the nebual PQ showing of the rugby this afternoon was shocking, the football slightly better, motor racing ok but not great.

It obviously depends on what you are watching as to what quality comes out of it, some of that will be the TV companies programming and some of it will be that the Nebula just isnt good at some stuff but just because you maybe have one dont try and defend the indefensible.
 
I wouldn't be too quick to blame the nebula as you are seeing such variable results: sounds more like compression.

The bob deinterlace is actually very solid looking with fast motion , the blend less so. I've watched footie and other sports no problem on the nebula. Most 100Hz TVs do a far worse job than even the blend as does the native processing in my panny plasma.

As to it not being very good at deinterlacing well... the bob is about as good as you'll get without motion based solutions. As Bobs go it looks to me like quite a good one...minimal jumping on horizontal detail for a bob deinterlace. Slight judder always present with the nebula but I am running at 60Hz as a matter of course ( it does feature a frame smoothing option which introduces pulldown though to help with judder although its a compromise as always)

Switching it to off gives a simple weave which is ideal for frame based material ( films for examples).Pretty smooth not any worse than theatertek for films at the 60Hz refresh. The video mode in theatertek is still way worse than even the blend in the nebula for example.

Dscaler is slightly smoother with regard to display but the nebula is noticably sharper , has more contrast and has better colour and thats comparing it to a sweetspot fed RGB.

Considering they don't exactly trumpet about its deinterlacing capabilities they've done about as good as they can without incorporating something along the lines of Dscaler.
If they get it together with a decent motion based system ( which they have plans for) it will be something pretty special for a £100 card.
 
I'm not trying to defend it, I was just wondering what Jeff was comaring it with.

I'm with Mr D. here - still PQ is streets ahead of anything that involves goiing through a restricted bandwidth analogue stage like RGB or s-video - even STB straight into my projector is very obviously loosing a lot of detail.

Since release3 06 (I think it was), when the de-interlacing really started to work with the nebula, it has become (for me) quite acceptable for motion as well.

Maybe I should post some picces of the display quality? - although these will obviouisly only be stills.
 
Pootle sorry to go of on one yesterday but frustration had set in by then.

Take your points guys.

Ive just installed the Nebula so I probably need to check which version of the software software I am using. Like I said yesterday the Nebula has been fantastic for watching normal tele (I love it) - but what I saw yesterday wasn't good. I certainly take the point that it can depend on what the TV are pumping out - I saw that with my own eyes.

Mr D. You mention TT (Only use it for Film based stuff) - I have found that to be excellent everytime I have used it, far better than the sweetspot and XCard combination which I found to be very very variable with its performance. Unless I am missing something with sweetspot.

Again with the XCard I tried the SPDIF out and foud it to be very very tinny, Changed it for a 3 year old SB Platinum with front panel and the sound quality improved drastically.

Thanks

Chris
 
Deinterlacing film based material off dvd is about as easy as deinterlacing gets.
Theaterteks video deinterlacing is unfortunately garbage. ( software or hardware although hardware isn't really TTs fault)

I never use theatertek with video based material because of this : an off board dvd player feeding RGB into a sweetspot capture card and being dealt with by Dscaler is my preffered option for video material ( or badly mastered film discs) at the moment although I assume an Xcard solution would be as good if not better. Theatertek is used only for film based material in my seup.
 
Sneaky, just a note about the newer releases of nebula software; yes the de-interlacing (and other things) are very much better in the later 3.x releases, but they also require a lot more processing power. After the last big improvement in de-interlacing (around 3.06 I think), I found things were definitely on the jerky side, and processor utilisation was often up around 100%.

I upgraded to Athlon Barton 2500 with dual channel DDR memory and it has improved things greatly. Even DVD playback (PowerDVD) is slightly improved.

Previoulsy I had an Athlon 1200.
 
Pootle,

I already have 2500 and 2 * 256 ddr memory so I will have a look at the software.

Have you tried the 3.10 software that is on teh nebula site.

Chris
 
Any of you guys trying Showshifter with your Nebula card as it now support DVB cards.

I found it to be very good with an easy to use interface.

You can download different deinterlacing plugins to use with showshifter.

See what you think.

Steve.
 
Sneaky, I'm running 3.10, although the web server keeps crashing, so I'm ignoring that bit :rolleyes:

rest seems fine though...

Your PC certainly sounds to have enough va va zoom in it
 
What disappoints me about the Nebula software is the temporal jitter is displays. I know they had a stab at improving it a couple of point releases ago but the results still don't cut it in my mind.

What sucks is that I get incredibly stable playback if I take an mpeg recording from their card and play it back using Zoom Player with a custom graph and ReClock. (BTW I'm using RGB SCART direct drive from a Radeon). If you use an MPEG2 decoder that does not deinterlace (Elecard is good) and don't scale the video frame then you can get field-accurate interlaced presentation back on your TV and that, trust me, does look sweet.

Watching the same material live through their TV viewing software is appalling in comparison. It's like the rendering engine in DigiTV does its thing and the video card's raster scan does its thing without syncing to each other - duh.

I thought they were developing an API so other people could write DirectShow apps to use their card but all I can see is something they'll only release under NDA.

Noticed that ShowShifter now supports the Nebula it in their DVB release. No suprise to find a bunch of DirectShow filters bundled with it that look like they would provide an MPEG2 program stream from the card. You can play with them in GraphEdit but I couldn't get them to connect to any decoders.

Anyone noticed or even cares about this except me?

James
 
Originally posted by jwexqm

Anyone noticed or even cares about this except me?
I certainly care. I'd love for them to release an SDK that I could write a replacement front end for. BDA drivers would be even better.

They seem to want to write their own version of media centre for some reason instead of just getting on with making hardware.

John
 
I'm guessing they must have that 'teeth-chattering' corporate control freak mentality going on.

Presumably they think they won't get sales unless their bundled software does 'everything'.

I mean even if some freeware author did come up with something that whipped their software offering then do they really lose out?

Judging by their DigiTV update history I guess it's an under-resourced team of coders doing what they can to balance DigiTV ehancements and updates to with work for future projects.

I have an Archos 20GB MP3 Jukebox and run an open source replacement firmware on it called RockBox. It is easily twice as good as the official firmware but I don't see how Archos loses out with this arrangement, other than having their pride dented. Maybe that's enough.

James
 
It is a shame that they won't do this. And it does seem stange to me, as they're only a small company, and they do seem really helpful when I've spoken to them (apart from not even getting an acknowledgement to me email about my MPEG audio headers problem).

Matt. :)
 
Originally posted by jwexqm
What disappoints me about the Nebula software is the temporal jitter is displays. I know they had a stab at improving it a couple of point releases ago but the results still don't cut it in my mind.

I'm not with you here James - before upgrading my hardware I had jitters, but since I put a more powerful PC behind it, it is much better. I still get a marginally more readble fast scrolling text if I plug a STB straight into my PJ using s-video, but the rest of the PQ is so much lower that I never actaully watch like that.

If I use PowerDVD to watch a recording it is pretty much the same as the live broadcast.

Mind you I have to run the PJ at 100Hz to get this quality - no other frequency works as well (the PJ won't go down to 50Hz on VGA input)

I am right with you when it comes to what Nebula spend their development resource on. I'd like them just to do a really fantastic live TV machine. Mind you if they are under resourced I don't know what that makes Hauppauge on the Nova-T team - one dog part time on Tueday afternoons I think.:blush:

Trying to be a media centre is like lying down in front of a road roller. Microsoft media centre is getting closer every day, and there are already people making it work with Nova-T cards.
 
Microsoft media center uses the mpeg2 codec that's installed on your PC with a software dvd player, Nebula does the mpeg decoding and deinterlacing by itself, I agree there's still a bit of jitter with video playback compared with say, power dvd, but once you've recorded something you can play it back with whatever mpeg2 player you want.
 
pootle: I think you're 2x (or maybe 4x) better off than I am running at 100Hz progressive. I'm stuck at 25Hz interlaced (50 fields/s). If the Nebula software 'misses' a Video card retrace at 100Hz then the next one comes along much sooner than it does for me. Plus, as it's oversampled it won't drop frames/fields if the threads get out of sync. BTW, the machine is a 2.54GHz P4.

Don't get me wrong though, I like Nebula and fully support them. After years of putting up with poor software from Hauppauge I sincerely do hope they up the standard.
 
I'm stuck at 25Hz interlaced
Therein lies the problem, I guess. At 60Hz (interlaced or progressive) I see no jerkiness at all. PowerDVD is identical. I'm using bob deinterlace (none for films), and no frame smoothing, on an AMD 2400 XP. CPU around 30%. Scrolling text is fine, although I don't have an STB to compare (but it is significantly better than early DigiTV versions). I get minor deinterlacing artefacts on a couple of music channels, but otherwise I don't see any.
 
3.11 looks a bit smoother, look at the scrolling text on bid up tv for a good test.
 
I see less judder when I engage frame smoothing.
Into my panny 37pw5 plasma at 856x480 at 60Hz its a huge improvement in every area over raw svideo into the panel.

I agree thats the judder improved no end in the last few versions.

I can't wait for the dual card support although I suspect I'll need to upgrade my 1.4 p3 for the motion estimation based deinterlacing when it arrives.
 

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