Dropped frames/inconsistent frame rates

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nevfaith

6 posts

Wannabe Geek

#23476 30-Jun-2008 14:27

I'm using MediaPortal with software decoding (PowerDVD 7.3) to view dvb-t channels, and on the most part it's working fine, with a good quality image and nice smooth video.

Problem is, on channel 6 and 7, the framerate regularly drops from 25fps (measured using fraps) to around 15-19fps causing noticable jerkiness.

I doubt it's the cpu because it isn't anywhere near max - channel 3 averages 50-60%, but all other channels are around 10-30% cpu usage, and cpu usage is consistently around the 20% mark on channels 6 and 7, whether it's running at the full 25fps or the lower jerky framerates.

I saw on a thread somewhere that it may be caused by audio/video sync issues, where the video drops frames to stay in sync with the audio. Not sure if this is the cause or how to fix it if this is the cause, but any help on this issue would be greatly appreciated.

Thanks,
Nev

Fossie

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#141507 30-Jun-2008 14:45

Channel 6 and 7? tvnz 6 and 7?

nevfaith

6 posts

Wannabe Geek

#141519 30-Jun-2008 15:01

Yip, just TVNZ 6 and 7 that I've noticed. Usually on channel change it takes a couple of seconds to get up to max fps (usually 50fps on TV1, TV2, FreeviewHD, and 25pfs on 3, c4, maori, tvnz6, tvnz7 and tv central). Once up to max fps, it sits there nicely except for TVNZ 6 and TVNZ 7 where the problem above occurs. Maybe it's the TVNZ interlaced signal or the way the audio is encoded on the TVNZ interlaced signals?

Fossie

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#141522 30-Jun-2008 15:05

If it was a problem with interlaced SD content then you would be having problems with C4. But C4 is fine for you?

sbiddle

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#141528 30-Jun-2008 15:10

I've noticed a jerky ticker bar on TVNZ7 using GB-PVR as well. I haven't looked at the frame rate but it doesn't affect any other channels.

heppy

3 posts

Wannabe Geek

#141590 30-Jun-2008 17:11

Reinstall the 75.16 drivers if you have updated to the 75.19 drivers, as I had the same problem after installing them.
Vista ones here.
http://www.pixelrage.ro/downloads/Nvidia-Geforce-175.16-WHQL-driver-download-vista-32-3714.html

aucklander

477 posts

Ultimate Geek

#141773 1-Jul-2008 08:41

just install the "old" driver on top of existing, or uninstall graphic card, restart, (Vista will install some drivers), and then update to the version you need?

mobo Intel DH55PJ, RAM: 4GB RAM, Nova-T 500 HD + Avermedia Trinity tuner card, Geforce 520 video, 120GB SSD Sandisk + 640 WD + 1000SG, Win7 Home Prem 64-bit, Media Portal 1.15.0; BTC 9019URF Cordless Keyboard, Panasonic 55" (HDMI cable), HTPC Case Silverstone Grandia GD05B.

nevfaith

6 posts

Wannabe Geek

#142237 2-Jul-2008 14:49

Sorry, for some reason my sig never showed. I've got a AMD 64 x2 5600+ running on an Asus M2N VM HDMI (7050pv), Pixelview B1000 analogue/dvb-t tuner, OS is Win XP Pro SP3.

After having no luck getting hardware h.264 decoding using the onboard 7050PV gpu, I got a Sapphire 3450. After having no luck with that either (should have read this msg board earlier), I went back to software decoding. I'm not sure why but software with the 3450 was better than software with the onboard gpu, eg less tearing and smoother deinterlacing (ATI drivers better than nforce drivers maybe). So now it's pretty sweet other than the framerate issue on 6 & 7, although ideally I'd prefer to get hardware decoding on the 3450.

Fossie:
I haven't watched C4 much, just a few minutes at a time to check that it's working ok and it seemed to be. Thought maybe it was the way the sd interlaced content was encoded in the TVNZ mux, as mediaworks channels seemed fine.

Re suggestions of rolling back to older drivers, I'm using the catalyst driver for the HD3450 not the nVidia drivers. Also I just upgraded from the older catalyst drivers to the newer one's (can't remember version no's) in the hope that my hardware acc would work so it's not related to this version of catalyst driver.

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

Fossie

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#142242 2-Jul-2008 15:03

As of yesterday, you'll need a minimum of 10 posts before your signature will show.

I used to have problems with the TVNZ 6 and 7 channels with a shaking picture and inconsistant frame rate, I ended up doing a full reinstall of windows. This was in Vista.

aucklander

477 posts

Ultimate Geek

#142489 3-Jul-2008 12:09

nevfaith,

I used to get a "low frame" effect on TV3 only, after switching to Media Portal (from Powercinema, where after many trials and adjustments, I finally got it working). All good on the other channels and honestly, I do not watch too much on TVNZ 6 and 7...

The "low frame" effect existed even when FRAPS showed 50fps on all channels (except TV3, where it used to go up and down 47-50fps). I think this is related with the audio codecs somehow, as it improved a lot after changing some setting: MP Configuration -> TV Client -> Audio Settings tab. There, at the bottom of the window is a "tick" on something to do with AC3 or AA3, don't remember and I am not near the computer. That used to be checked, as per the installation instructions. In fact, it was ticked by default. there are two options there, I am talking about the one on the left. The effect I am talking about did not go away completely but now it is minimal and I can live with that. Maybe I see it because I know is there and other people think the picture is just fine because they do not know what to look for??

I un-checked that option, restarted MP and the image is better on TV3, no sound quality / performance changes noticed. While I used to get that "low frame" effect, the recording was very smooth, with no defects, it was only on the screen. I did that 4-5 days ago and all good since then, including recordings. MP crashed only once during ffwd 32x of a recording (by the way, the 32x ffwd jumps every 20sec and it takes 2-3 sec in between steps, it doesn't look like 32x, where you are supposed to skip 1min every 2 sec, right? - maybe I need to play with the settings for the skipping steps.... I saw that somewhere in the menus...);

I have the Cyberlink drivers supplied with Powercinema and the PDVD8 drivers as well, unsure which of them are selected in MP configuration. If is important, I will post back.

nevfaith

6 posts

Wannabe Geek

#142502 3-Jul-2008 12:49

Thanks. I tried changing the codecs/renderers around but never changed the options you mentioned (although I remember then now from the setup). I will check it out tonight and post my results.

Out of intrest I watched 10 mins of c4 this morning and it played consistantly smooth at 25fps. On channel 6, within two minutes it dropping to between 15 and 19 for a few seconds, and did it again about a minute later.

It's still watchable but the mrs is asking why the approx $500 of equipment is worse than plugging the aerial directly into the tv :-0

nevfaith

6 posts

Wannabe Geek

#143746 7-Jul-2008 13:24

Well I ticked the option as suggested and all seems well - still can't see why it worked so half expecting the problem to rear it's ugly head in the future but for now it looks good.

So I've can finally put the lid on the HTPC case, put it in the entertainment cabinet and route all the cables behind the cabinet and have a nice and tidy TV/AV area. YAY!!

Thanks for all your suggestions.