My quest for smooth DVB-TV and video playback

[Pob]

Like many users, I had become quite obsessed with trying to get smooth TV and videos. Not especially smooth - but as smooth as a £10 freeview box or £15 DVD player.

After many, many hours trying all sorts of different drivers, decoders, deinterlacers etc. I decided to bite the bullett and reinstall windows:eek: . This is not something I took lightly. Many will be dismayed that I have upgraded windows versions for years - upgrading to ME from Win98, then upgrading to XP Pro. So I have not done a clean install since 1998! Have been through many motherboards, Cpu's, video cards and hard drives in that time, but using my trusted tools of Ghost (dos), regcleaner, and repair installs of windows I have never had an issue. So this shows how annoyed I was getting!

So now I had a clean install of XP, and the following:
Athlon 2600+
Hauppage Nova-T 9003
Nvidia FX5900
Nvidia 91.31 drivers
GBPVR 99.12
Dual monitors in clone mode - Primary 32" LCD running 720p @50Hz, secondary CRT@75Hz

For the purposes of testing I did not want to install anything else, so used the Intervideo Non-CSS decoders for video and audio, and the dvrms BDA multiplexor.
I then tried all possible settings in GBPVR, plus all the settings in the Hauppage primary tool.
What I found is that the only two combinations that gave acceptable (to me) performance were Overlay, or VMR9 FSE with DXVA and HWMC turned on. VMR 7, VMR9, and VMR custom gave me the same issues I had before (and again the juddering was made worse by turning DXVA on in these modes):confused:
So I used Ghost and reverted back to my usual Windows install, and found that the two working settings still worked the same - but with one exception. In VMR9 FSE the ticker text on the news channels had a horrible combing effect. As I had all settings the same as in the fresh install of Windows, I was puzzled until I remembered that I had changed the version of Quartz.dll as advised by some of the support threads. I changed it back to the newer 6.5.2600 version and the horrible combing was gone.

So the conclusion drawn from my painstaking experimentation is that VMR 7, VMR 9, and VMR custom are crap! And turning on DXVA makes them double crap! For me and my rig, anyway.

So now I am using VMR-FSE. I had been avoiding overlay and this mode - overlay because of the blocky text and the long delay before TV starts, and FSE because of it's quirky behaviour - like not getting the desktop back after quitting GBPVR and problems resuming from standby. But I am now satisfied with the TV and video picture.

Some other observations - once I had the 'good' setting, changing my LCD to 60Hz refresh rate made hardly any difference. I think juddering is often blamed on using 60Hz on LCDs in error.
But I still get much more noticeable judder if I try to use 1:1 pixel mapping on the LCD (1360*768). So I have to put this down to either my PC struggling with the slightly higher resolution, or the LCD itself. However the judder is also present on the secondary CRT so still not sure about 1:1 mapping.
So the ideal compromise for me is to use 720p for GBPVR, and 1360*768 for my desktop - to achieve this I found more usefull info from the support forums and use Reschanger.exe to launch GBPVR in 720p, and when I close GBPVR it goes back to 1:1. I do this from the green button on my remote and an edited Irremote.ini:
;GBPVR------------------------------------------------
GRNPOWER={run(C:reschange.exe -width=1280 -height=720 -refresh=50 "C:\Program Files\devnz\GBPVR\GBPVR.exe")}
Pob

[stustunz]

im surprised you get good playback with intervideo
lcd tv frequency yeah it doesnt fix the judder its more just making sure things work in sync so its one less calculation the pc has to do
so the frequency of the card should match the media if possible

lcd tvs dont have a frequency problem like crts they are always on hence 60hz has nothing to do with how the picture looks

[Pob]

im surprised you get good playback with intervideo
lcd tv frequency yeah it doesnt fix the judder its more just making sure things work in sync so its one less calculation the pc has to do
so the frequency of the card should match the media if possible

lcd tvs dont have a frequency problem like crts they are always on hence 60hz has nothing to do with how the picture looks

I had previously tried all possible decoders such as purevideo and Dscaler. But what none of them could do was compensate for the inherant problems with the non-fse VMR modes.

I suspect that now I have confirmed which renderer works best for me, I would find that any of the decoders would work OK.
Because, when I tried purevideo, it did not help with the judders (or the odd line or tear on quick scene changes), I just stopped using it and moved on to the next decoder...

I might try purevideo again to see if it helps with the remaining problem - lipsync. I do find the lipsync is very slightly out using the intervideo and VMR-FSE. It's very slight but now I am not noticing judders my attention has turned to this.

Again the moral of my story is that I wasted a lot of time trying to get smooth video, when it was actually a hopeless task, as the underlying problem was the renderer mode, and not the decoder, multiplexor, flux capacitor nor anything else! It would be like trying to tune my car's performance, despite the engine having dropped out...

You're right about LCDs - they don't have a frequency problem. What I should have said is 'I think juddering is often blamed on using video adaptor refresh rates, that are not divisible by 25, in error'.

I still find it suprising that only the two renderer modes work well for me - my PC is not the latest but nor is it the slowest around and I do have 2gb memory. It makes me wonder how fast the CPU and GPU have to be (and how much you would need to spend) just so you can play a simple mpeg2 perfectly in VMR7 or VMR9!
Pob

[bgowland]

Just one point. If you're watching UK Freeview, you do know that the format is 576i and not 720p don't you?

576i is 720 x 576 interlaced (obviously).
720p is 1280 x 720 progressive.

Other than the various HD trials (1080i - 1920 x 1080 interlaced), I'm not aware of anything broadcast on DVB-T here except the standard 576i format.

Cheers,
Brian

[stustunz]

i hav eposted similar coments about the video card price and i dont think its a money issue i think its a driver issue
yes i know the picture is interlaced when you recieve it
but when its played back the computer deinterlaces it
and a lcd display cant display interlaced media it has to be deinterlaced(progressive) which is either done by the pc or the tv
even when you put a interlaced signal into the tv(lcd) it is dispalyed progressive

[Pob]

Just one point. If you're watching UK Freeview, you do know that the format is 576i and not 720p don't you?

576i is 720 x 576 interlaced (obviously).
720p is 1280 x 720 progressive.

Other than the various HD trials (1080i - 1920 x 1080 interlaced), I'm not aware of anything broadcast on DVB-T here except the standard 576i format.

Cheers,
Brian

Quite aware thank you! The whole point of using a HTPC is to harness it's power to upscale and post-process, and to play all your media. I do use GBPVR to play 720p HD videos, and even my music visualizations are set to 720p resolution! DVD players are best outputting progressive scan. You can get upscaling freeview boxes and DVD players with HDMI connections - there is some dispute as to them being any better than the TV's own upscaling, but the digital HDMI connection certainly helps get a good picture.
The attraction of GBPVR and a media PC is having one box for all your media - DVD, TV, MPEG4, HD video, music...
Surely that's the aim of everyone here?
If I was using only digital TV then sure I could use 576i - but then it would be pointless having a monitor - would be better of using an old TV!
Pob

[Pob]

i have posted similar coments about the video card price and i dont think its a money issue i think its a driver issue...

I just remembered that when DVD's first came out no PC's could play them - but you could buy add-on PCI cards (£100!) that did nothing else but decode mpeg2 video. I think Creative made one - can't remember what it was called. The biggest drawback was that the card had it's own video-out - so you could not play MPeg2 on your desktop you had to output it to a TV.
The cards became a white elephant once display adaptors started to offer HWMC - I think Voodoo cards were the first to offer 'hardware assisted' decoding.
Who'd have thunk after all these years PC's would still be struggling to play mpeg2!
Pob

[stustunz]

yip i was one of those people( hollywood plus card)
the funny thing is on tv the playback was smooth
but that was about where the positives stopped

i have boxes of cards that i have disgarded for the next generation that meant to be better and infact all they seem to do is bring in a new problem you havent seen before with little gain in anything else
although if i plugged one back in im sure i would notice a difference
just a shame they cant get the simple playback working better)