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VDPAU artifacts with mpeg-2 content

post #1 of 15
6/11/10 at 8:22pm
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I keep getting bad artifacts with my mpeg-2 recordings when playing back using any VDPAU profile on my ION and my 8400GS frontends (Haven't tested my GS210 too much). I noticed on my ION when I turned off VDPAU and used the CPU++ profile most of the artifacts are gone, so it's not the recording. Looking at the mythtv wiki I tried adding vdpaubuffersize=32 to my filters but didn't help. Any ideas?

It seems to work fine on x264 material. Only seem to have problems with mpeg-2.
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post #2 of 15
6/12/10 at 6:49am
Is it perhaps a 1080i video? Not sure what you are seeing but perhaps you are not deinterlacing at all with VDPAU. If the video was 1080i and without deinterlacing you would see horizontal lines especially in quick scene changes.

In my mplayer config I add:

vo=vdpau:deint=1

where the deint=1 is a pretty basic deinterlacer (sorry forgot which one). There are others you can use but I found that my 8400GS cards only can handle this simple one.

In the myth UI you should be able to set the deinterlacer - I would say just experiment.

Of course this might not be your problem but I thought I would mention it anyway. When you say the x264 video looks fine - most of that usually is progressive video so no deinterlacing needed when displaying it.
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post #3 of 15
6/12/10 at 7:38am
Thread Starter 
Quote:
Originally Posted by djb61230 View Post

Is it perhaps a 1080i video? Not sure what you are seeing but perhaps you are not deinterlacing at all with VDPAU. If the video was 1080i and without deinterlacing you would see horizontal lines especially in quick scene changes.

In my mplayer config I add:

vo=vdpau:deint=1

where the deint=1 is a pretty basic deinterlacer (sorry forgot which one). There are others you can use but I found that my 8400GS cards only can handle this simple one.

In the myth UI you should be able to set the deinterlacer - I would say just experiment.

Of course this might not be your problem but I thought I would mention it anyway. When you say the x264 video looks fine - most of that usually is progressive video so no deinterlacing needed when displaying it.

No it's not related to deinterlacing. It happens with all mpeg-2 content (480i, 720P, 1080i) and not on any x264 content. It's not horizontal lines. it block artifacts, and it's not tied to motion (panning or screen changes).

I'm pretty sure it's related to:

http://www.nvnews.net/vbulletin/show...=136817&page=4
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post #4 of 15
6/12/10 at 7:40am
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For an example of the artifact I'm talking about take a look at this post:

http://www.nvnews.net/vbulletin/show...06&postcount=3
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post #5 of 15
6/12/10 at 7:42am
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From what I can tell from searching it is due to corruption in the mpeg-2 stream that is not handled well by the VDPAU hardware decoding, but is handled well by the software decoders.
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post #6 of 15
6/12/10 at 10:19am
Ahh I see. I don't see that happening here at all. Some people mentioned mplayer was OK, have you verified that with your system?

How are you getting your mpeg2 video? OTA? QAM? Or is it any mpeg2, like from a DVD that should be "pristine", that displays incorrectly?

Is there a possibility that you are just not getting a solid signal? I guess if mplayer plays it correctly then that would eliminate that possibility.

You probably thought of all this but it doesn't hurt to mention it.
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post #7 of 15
6/12/10 at 10:38am
Take a look at this, from Ubuntu forums:

http://ubuntuforums.org/showpost.php...60&postcount=2

You may need to specify what you want in more detail.
Code:
mplayer -vo vdpau:deint=2 -vc ffmpeg12vdpau
The 2 is for BOB deinterlacing.
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post #8 of 15
6/12/10 at 12:46pm
Thread Starter 
Quote:
Originally Posted by djb61230 View Post

Ahh I see. I don't see that happening here at all. Some people mentioned mplayer was OK, have you verified that with your system?

How are you getting your mpeg2 video? OTA? QAM? Or is it any mpeg2, like from a DVD that should be "pristine", that displays incorrectly?

Is there a possibility that you are just not getting a solid signal? I guess if mplayer plays it correctly then that would eliminate that possibility.

You probably thought of all this but it doesn't hurt to mention it.

Yes, mpeg-2 from a dvd displays fine, but if there is any corruption (such as I get from time to time with my QAM or OTA recordings I get the artifact above with VDPAU (but at most a minor glitch when using software decoding). mplayer using VDPAU behaves the same way. Mplayer using software decoding works fine. So I'm fairly certain it is how the hardware is handling the corruption.

Basically, as long as I am not using VDPAU, it is fine, mplayer or myth's internal player.

Quote:
Originally Posted by waterhead View Post

Take a look at this, from Ubuntu forums:

http://ubuntuforums.org/showpost.php...60&postcount=2

You may need to specify what you want in more detail.
Code:
mplayer -vo vdpau:deint=2 -vc ffmpeg12vdpau
The 2 is for BOB deinterlacing.

Bob doesn't help. neither does any other deinterlacing I've tried in myth or with mplayer, so long as I am using vdpau.

Based on that nvidia thread I linked and the fact that others experienced the same problem and a patch was needed I'm chalking this up as a bug. Just wondering if there is a patch I can apply to the nvidia driver I'm using, or an upgrade that will help. I posted on the nvidia forum.

I know the easy answer is don't use VDPAU, but with my ION frontend I need it for some of my x264 material (and I prefer the internal player). So right now, when I am watching recordings I use one non vdpau playback profile, and for mythvideo I have to switch the playback profile to use VDPAU to handle my high bitrate x264 material. I guess I could just use mplayer with vdpau for mythvideo, but I prefer the integration and features of the internal player.

Or if my cable company would just send a better quality signal.
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post #9 of 15
6/12/10 at 2:40pm
Well looks like you have to wait for that patch.

Perhaps in the meantime check your connections on your cable. Try to eliminate splitters if you can - try to get the best signal in your house to your tuner that you can. I recently replaced a 4-way splitter with 3 2-way and got much better results. The signal loss should have been the same but some splitters have less signal loss than others I guess. Now all my HDHR tuners are happy and I have very few dropouts.
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post #10 of 15
6/12/10 at 2:49pm
Can't you just install an older version of the nVidia driver? At least until this bug is fixed. I know that nVidia always has many versions of a driver available for download.

http://www.nvidia.com/Download/Find.aspx?lang=en-us

I am currently getting a server overload error from that site.
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post #11 of 15
6/12/10 at 5:14pm
Thread Starter 
Quote:
Originally Posted by djb61230 View Post

Well looks like you have to wait for that patch.

Perhaps in the meantime check your connections on your cable. Try to eliminate splitters if you can - try to get the best signal in your house to your tuner that you can. I recently replaced a 4-way splitter with 3 2-way and got much better results. The signal loss should have been the same but some splitters have less signal loss than others I guess. Now all my HDHR tuners are happy and I have very few dropouts.

Thanks. You know, that's where I started. I originally assumed it was a capture problem since everything worked fine before I upgraded from non-VDPAU myth .21 to .23. I investigated my tuner card drivers, replaced all of my cables, removed splitters where I had them...triple checked connections. Nothing seemed to work. I have 5 tuners in 3 different machines and all the recordings have the problems. That's what led me to investigating playback, which looks fine on my TV tuners and when decoded in software.
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post #12 of 15
6/12/10 at 5:19pm
Thread Starter 
Quote:
Originally Posted by waterhead View Post

Can't you just install an older version of the nVidia driver? At least until this bug is fixed. I know that nVidia always has many versions of a driver available for download.

http://www.nvidia.com/Download/Find.aspx?lang=en-us

I am currently getting a server overload error from that site.

Thanks. I might try that if I don't get an answer about a patch or upgrade fixing my issue. I'd rather upgrade since I do have a workaround.

Honestly, I feel more blindsided than anything else. I kind expected VDPAU to just work - I hadn't heard of this problem.
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post #13 of 15
6/15/10 at 9:32am
Thread Starter 
Sounds like the patch to my problem is in the 256 beta driver. I'm gonna try and install that this week (when I can wrestle away the ion frontend from the family) and see if that fixes it, then upgrade my other VDPAU frontends if it works. The beta driver seems to have a number of VDPAU fixes, and specifically mentions better handling of video corruption.

I'll post back with results.
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post #14 of 15
6/16/10 at 7:39pm
Thread Starter 
Quote:
Originally Posted by newlinux View Post

Sounds like the patch to my problem is in the 256 beta driver. I'm gonna try and install that this week (when I can wrestle away the ion frontend from the family) and see if that fixes it, then upgrade my other VDPAU frontends if it works. The beta driver seems to have a number of VDPAU fixes, and specifically mentions better handling of video corruption.

I'll post back with results.

Well, that made it a little better, but not good enough for me. It's still way better using a software decoder (with any or no deinterlacer). turns out the fixes affect feature set A GPUs, not my ION. Ahh well... back to the drawing board.
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post #15 of 15
6/16/10 at 8:05pm
Thread Starter 
Quote:
Originally Posted by newlinux View Post

Well, that made it a little better, but not good enough for me. It's still way better using a software decoder (with any or no deinterlacer). turns out the fixes affect feature set A GPUs, not my ION. Ahh well... back to the drawing board.

A little more searching on the nvidia forums indicates there is no fix other than obtaining a better quality signal or using a software decoder for vdpau feature set B GPUs.
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