Matrox P750 first impressions

[greinedo]

Hello,

I received the Matrox P750 a few days ago and here are my first impressions :

2D : Excellent picture quality on the NEC Multisync HR 17. At 1600x1200, the GF4200 and the Radeon 9200 I own have a blurry picture and washed out colors, while the picture of the P750 is simply perfect : sharp and crisp image, consistent colors. I thing this P750 has a better picture quality on the PC monitor than my G400, wich is not bad.

3D : Ok, it’s not a gamer card, but I’m not a gamer too. I tweaked the P750 with Powerstrip and increased the clocks from 250Mhz to 280Mhz without any problems. That way the 3Dmark2001 SE rised from 4400 to 4994. With that settings, X2 Rolling demo=31FPS, Aquamark3=12000 (all Bench default settings). It’s enough for me. But while playing the Benchs, I noticed the good 3D picture quality over ATI and NVIDIA wich are cheating...

TV-out : Big deception. The P750 S-VHS TV-out is not good for me. Ok it’s better than ATI and NVIDIA S-VHS TV-out. But the TV-out of my G400 (even in S-VHS) is better. This is a surprise for me because Matrox claims the superior 10 bit DVD Playback of the P series. The picture on TV is a little blurry, and has some artifacts in the dark areas of the pictures. I’s like a low bitrate movie. But I know my DVDs and have seen them with the G400 in RGB TV-out and with the tweaked Radeon (SCART RGB DRIVE).

Powerstrip : The P750 is only partially supported by Powerstrip. The clocks can be tweaked. But the most important function for my purpose is greyed out : interlaced res and composite sync. Aarg ! I suppose it’s not because a hardware limitation, but because of the Matrox policy regarding the chip programming specs. I saw at Powertrip forum a Parhelia owner requesting that feature. But with no result. With interlaced resolution support, the P650/P750 could be very good cards for home-theater setups.

In this PC, right now, I’m using the P750 AGP for the main monitor, but I’m still using the Radeon PCI, tweaked with Powerstrip, to drive the TV in PAL RGB mode. I hope that in later releases Powerstip will enable interlaced resolutions and composite syncs for the P series, so that I can drive drive the TV with the second head of the P750.

Regards

[greinedo]

sorry for this "double post"

made something wrong with my browser

[dZeus]

There might still be a chance that Matrox enables SCART-RGB support for tv-out on the P-series cards, as they claim 'SCART' support on one of their other cards which is based around the Parhelia LX chip.

BTW. does it support field based scaling for dvd-max on the P750? Which is needed to output interlaced contents to interlaced output while maintaining correct field order and non-blended fields/frames.

[greinedo]

I didn't play interlaced material so far (and I don't have a lot), but I just tried one to see.

With Powerdvd and the Geforce 4200 I had to play this movie it in bob mode to have a correct ouput to TV. With the P750, I can play it in weave mode. It appears correct on TV. It seems the P750 does additionnal job, that was done softwarewise before.

But I don't know if I have aswered to your question.

[dZeus]

can you try playing back interlaced material in weave mode that's not the same as the vertical res. of the tv-out standard you use? (i.e. if you watch pal tv-out, play back NTSC video material).

If you can't get hold of interlaced NTSC material, please play back the PAL interlaced contents, and press pause a couple of times to see if the field order changes on the tv-out.

[gangster]

I emailed entech about the lack of features in powerstrip (with my Parhelia) several months ago. Entech said that matrox charges for the detailed info necessary to enhance there drivers! So, since there haven't been alot of requests for matrox card enhancements, they can't justify and therefore purchase the info from Matrox.

[dZeus]

SCART-RGB pinout for Parhelia QID:

http://forum.matrox.com/mga/viewtopic.php?t=5479

I wonder if/when the driver code for SCART-RGB will be incorporated for the P-series cards as well...

[Che Guevara]

Does the P750 really clock @250Mhz?
More than Parhelia?
Why didn't they clock my P @250 too...


@greinedo:
It was said that the FAA-16x is fixed in Parhelia LX cards. Can you say anything about it?
No more problems with antialiased objects behind fogs for example?

[greinedo]

Hi,

@Che Guevara:
Powerstrip says 250Mhz, it's perhaps not true. But the overclocking works...

Sorry, but I'm really not a gamer, so I cannot answer your expert question abour FAA-16X.

@dZeus :
I'm confused. I tried other interlaced material, and it doesn't work correctly on TV. In fact, it seems to react differently if the file is played with WinDVD or with PowerDVD (both in weave mode). Also, some movies are better than others. The way the stream is encoded has certainly an importance. As soon I have more time, I'll dig into that.

If the file attachment works, I post here my complete setup.
I still work on improving DVD playback with zoomplayer and FFDSHOW filter, combined with the P750.

regards

[dZeus]

Well one explanation for it only working some of the time would be that you're playing back interlaced PAL material to PAL tv-out. In that case, no vertical scaling has to be done, so field order might show up just right on the tv-out. Though if there's no mechanism to check field parity, the field order may just change when you press pause a couple of times, use different players, etc.

That's why you should try to play back interlaced NTSC material (like a TV series released on DVD, or even better, footage shot on camcorder by someone). In that case, the card will HAVE to rescale the image vertically to reach the 576 lines of resolution used for PAL. If there's no field-based scaling (which the Matrox G-series provide in the DVD-MAX setting panel through a checkbox), the fields will be blended together, and look horible on the tv-out, under all circumstances

anyway, if there's no 'field based scaling' checkbox in the Parhelia/P-series DVD-MAX panel, then I doubt there's any way to detect interlaced overlay from progressive ones, independant of the videoplayer used.

[greinedo]

Hello,

@dZeus :

I hope I have now an answer to your question :

First, I discovered that PowerDVD and WinDVD don't have the same behavior even in weave mode. WinDVD is known to have a build-in sharpness filter, that you cannot remove. That's why I choose this filter in my HTPC setup, because the picture is more detailed. But this filter is certainly interferring when it comes to play interlaced material and don't want to change it with bob option.

I choose a camcorder video (native PAL DV, but converted into interlaced PAL MPEG with Pinnacle Studio 8).

I played that file with PowerDVD in weave mode : excellent on monitor and on TV. P750 is certainly here deinterlacing hardwarewise.

I played it with WinDVD in weave mode : some problems on monitor and on TV (like horizontal waving bars). WinDVD is here certainly modifying the video stream.

In order to test the scaling, I played that file with Zoom Player, combined with FFDSHOW filter. I only selected the "crop" option in the FFDSHOW filter. This "crop" option processes the incomming video stream and outputs a cropped video stream. The P750 detects that cropped stream and scales it in hardware to a PAL res. You can adjust cropping from 0 to 100%. At 0% (PAL res) , the video played in weave mode is perfect on monitor and on TV. But if I increase cropping parameter (this decreases resolution of the video stream and forces the P750 to scale) then the output becomes ugly on monitor and TV (exactly the same effects as with WinDVD).

So I think you are right : the P750 certainly doesn't support field based scaling.

regards

[dZeus]

yeah, looks like only the Matrox G-series supported field based scaling.

btw. sharpness filter (aka edge-enhancement) doesn't really make the image more detailed. It just artificially increases the contrast of edges, and imho doesn't look better at all.
Most tv sets have this enabled as well by default, and it's one of the first thing to be turned off if you care about watching video like it's intended to be

[greinedo]

I know that, and disabled completely the basic sharpness filter on my TV. But there are many ways to enhance sharpness, and even really complex ways to do that. They give fantastic results, but you have to spend a lot of hours to understand and try. I tested the Resize-Sharpen method with sucess, but it needs a lot of CPU time.

Please have a look at FFDSHOW FAQ in the AVSFORUM :

http://www.avsforum.com/avs-vb/showthread.php?threadid=246752&highlight=FFDSHOW+FAQ

Somewhere in the middle of this page (in French) you can also find comparative pictures With and without sharpness filters. For me it's worth to try, I had very good results, even with a normal TV :

http://perso.wanadoo.fr/nicolas.phil/fr/DPCHC.html

regards

[Che Guevara]

@greinedo:

Thanx anyway

Anybody else using a P750 with games (the FAA-bug is visible also in farcry, just look at the ground of the sea...)?

[greinedo]

Hi

@Che Guevara :

I downloaded the FarCRy demo (500MB!!!) and tried to play, but I experience problems with the P750. With and without FAA-16X, High-medium low quality levels,.. I always have the same problems :

FarCry stops loadind at 95% approx, or playing begins but problematic rendering. I ran all the 3D benchs described above with no problem. But I never really played 3D game with this HTPC. I am using the latest beta drivers 1.6.0.78 Is this a P750 specific problem ?

See thet picture

regards