Big Picture Quality?

[dkardatzke]

What chipset does the PlayTV PVR card use. Currently we only support hardware based MPEG-2 encoding cards like the PVR-250 from Hauppauge.

[Funky D]

I'm pretty new to Sage myself, and I'm having the exact problem that is being described here....

I'm projecting onto a 100" screen, and some channels (usually ones with fast movement, like sporting events) look downright awful. The pixelation and blur effects are miles away from what the standard cable feed on a CRT look like. I'm sure this is because the MPEG encoding is working double time (hard to encode effectively, possibly hard to decode, but CPU usage is still minimal).

So many places to try to improve this....

Try a new decoder? (any suggestions?)
Use Dscaler? Will this solve all my problems?
Just can't be done?

I'd love to hear more about people's success/frustration with dscaler. It's integration into Sage's fairly spartan configuration options makes me think it's likely a good move....

On a related subject, I'm pretty sure I have more than enough horsepower for all the things I'm trying to do, but with the timeshifting, changing channels still takes a second or two. Shouldn't this be seamless, or you I need to start troubleshooting my setup?

Mucho Thankso,

Funky D

[jmeeks]

What do you have your recording quality settings set to?

Sporting events quite often are not very good quality broadcasts.

I wouldn't expect a 100" projection to ever look like a 27" TV. You just get to see all the poor quality of the broadcast. The hardware MPEG2 encoding can match DVD quality.

The channel changing will not be instantaneous. The playback is always recorded to the hard disk first and then played back from there. This buffer required is small, but that's why you won't get instant channel changing.

[mlbdude]

Don't forget that Sage is using the VBR capabilities of the Hauppauge drivers as well. So it is recording at the lowest bitrate it can for the quality setting. Then, as it detects that more bits are needed, it starts to rasie to the maximum allowed. It can take a seceond or two for this to happen. I notice this on fast moving scenes (rain, water expecially) but it usually cleans up quickly.

[Funky D]

Well, I have the recording quality set to 2gb/hr, so I'm pretty sure the bitrate is high enough.

No, no.... sporting events are usually broadcast just fine... you've never heard millions upon millions of people complaining about them, have you?

Hmmm, mlbdude's and jmeek's comments contradict each other. Fast motion is where I usually see a lot of pixelation, and blurring in other parts of the video. Constant changing motion (like football, basketball) seem to distort the picture quality all over the screen.

I've tried dscaler (with the elecard mpeg2 decoder) but no great change.

Maybe I'll start re-examining my cable feed to that computer....

D

[jmeeks]

I don't see the contradiction. Although I wasn't taking into account the possibility of VBR causing the pixelation of fast motion on a temporary basis.

I thought there was a way to specify CBR vs. VBR. I'll have to look that up.

Millions and millions of people do not view NTSC broadcasts on a 100" size screen. They just don't see what your seeing, but it's there. I've seen large fluctuations in quality and quite often some sporting events are terrible. In fact, I can see these quality variations a lot easier using SageTV on a 21" monitor than on the 27" tv.

I agree with you on verifying your input feed as well. I know I had a problem with that. (because of too many splitters) and after resolving that, and improving the signal, our reception even on a regular tv was greatly improved.

[jmeeks]

Ok, I figured out how to check and change if you are recording VBR or CBR.

Go to Detailed Setup, Multimedia, click on Video Capture Settings (Advanced). Click the Video Properties tab. There you will see a box for bitrate mode. Select Constant Bitrate or Variable Bitrate as desired. (I have mine set to Constant Bitrate)

[Narflex]

For sports, 2GB/hr is not really sufficient. I recommend the 3GB/hr setting (Best) for recording sports. At that level, there's almost no discernable artifacts introduced.

[Xleon]

mn3kgtvr4, your'll want to run the Cube straight to the projector and not put things in it's signal path. That really goes for most things. If you can avoid it, don't go through the PC.

I have a RGB SCART switcher so the Sky Digi, HTPC, GameCube can use the RGB cables to my Sony VPL-VW10HT projector and it makes a big difference. This also means you only need one set of RGB leads.

I've not actually tried Sage on the projector, even though it's connected, so I'll give it a try. Though, I have a Provideo 256T (very good compression quality) and the Sigma Xcard which is ideal for the projector as it can to progressive, SVHS, RGB and HD.


Funky D, I'd recommend 4Mbs as drive space is chepa now and that equates to about 2.3Gb ish used per hour with a 120Gb drive gives you 75 hours approx.
If you burn that to a DVD, it gives you 2 hours per DVD.

[Funky D]

Wow, thanks for the help guys... I'm really looking forward to getting this picture as clear as possible.

4gb/hr. Whoa. I have the space for it, but still, that's pretty steep.

I have plenty of processor power available. Has anyone tried a different codec (Divx, Xvid, etc) or even 2gb/sec at a lower resolution? Honestly, I'm using a basic cable feed, so am I really gaining that much from 720x480?

Very slight gains with dscaler. I'm still on the hunt it appears.

D

[Xleon]

Funky D, 4Gb/hr is quite a lot. Try using something lower, such as 4Mbs which eats us about about 2.3Gb/hr (ish) and work from there!

[Funky D]

Xleon, the presets in Sage are geared (though config) to GB/hr. Not mbs.

I had been using 2... but people are making me think that might not handle sports and the like.

D

[Funky D]

A-HA!

FINALLY, I have found the reason my recordings look so horrible...

It has something to do with the way Sage is decoding the mpeg2.

Most players (WMP, Zoomplayer, etc) Rely on internal calls to display video through software decoding. I think something is wacky with the mpeg decoder. Playing my recordings through ZP has them looking GREAT.

I looked in the settings to see if there was a way to enable pure software decoding, but no luck. Perhaps it's because I'm using 1.3.8 instead of the 1.4 RC2. Is that what everyone else is using?

Odd, as I tried a few different decoders, but maybe it was always hitting the hardware instead. It's funny that every windows app that displays video has these recordings looking amazing, yet Sage (the creator) can't seem to stream it out without pixelation.

If anyone knows what the problem might be, please feel free to give me a smack with the 2x4 of knowledge.

D

[Narflex]

Set your Video & Audio Decoders to be Default. That's what everything does for playback. I also highly recommend an ugrade to 1.4 (it's released now).

[Funky D]

Hmmmm, no dice. Viewing live tv and recorded shows is still showing a good deal of pixelation that doesn't appear when used with another viewer.

I'll try the RC2 next... possibly it has something different in this arena?

D

[Funky D]

Well, 1.4 isn't the huge change from 1.3.8 I was hoping.

I'm still getting the bad pixelation. Not sure if FDDSHOW is cleaning up the signal from the other players, or if Sage just isn't making the same calls.

All my filters are set to default.

Sigh... I'm running out of options, as I can only reproduce this problem within SageTV. No other player is distorting the picture. I'm on a fresh machine build here, so it's odd that nobody has run into this issue before. Can't think it's anything to do with the hauppage drivers, as the encoding is being done just fine. It's Sages playback that's the real burner.

D

[Narflex]

Playback a file in WMP. Then go to File->Properties. That'll tell you what Video & Audio decoders you're using to play it back. Select the same ones inside SageTV. Also, select Overlay for the video renderer.

[Funky D]

Thanx Nar, that did it... although I couldn't use the same audio decoder without it crashing.

It makes me wonder what Sage is doing when you set it to "Default". I would have guessed that it means windows default, but no dice.

Also, perhaps a suggestion (hopefully saving someone from doing as much troubleshooting as I had to do): After changing the mpeg2 decoder, a msgbox should display that these settings will take effect the next time you start SageTV.

D