[pug_]

Hi folks,

I'm having a bit of a problem with watching TV on my Mythbuntu set up. It works in that I can watch TV programs, but the picture is very jerky and every 10-15 seconds it'll pause for a second and then come back a second later.

Everything else works perfectly I can watch avi's even hi-def ones without a glitch, but it's just the TV part that's causing a problem.

I've tried using both tuners on the pvr500 in case it was a problem with one of the hardware encoders, and I've tried using the standard coax cable as well as scart to composite with the same results for both.

I'm thinking it might be some kind of buffer that might need increasing on the pvr500, but I'm new to all this and haven't found any kind of buffers I can adjust yet.

I'm using an old compaq with a p4 2.2Ghz processor and 1Gig of ram.

Any help appreciated.

[adrian.s]

Originally Posted by pug_

Hi folks,

I'm having a bit of a problem with watching TV on my Mythbuntu set up. It works in that I can watch TV programs, but the picture is very jerky and every 10-15 seconds it'll pause for a second and then come back a second later.

Everything else works perfectly I can watch avi's even hi-def ones without a glitch, but it's just the TV part that's causing a problem.

I've tried using both tuners on the pvr500 in case it was a problem with one of the hardware encoders, and I've tried using the standard coax cable as well as scart to composite with the same results for both.

I'm thinking it might be some kind of buffer that might need increasing on the pvr500, but I'm new to all this and haven't found any kind of buffers I can adjust yet.

I'm using an old compaq with a p4 2.2Ghz processor and 1Gig of ram.

Any help appreciated.

I'd need to see some log output from myth in order to properly help you. Is there anything standing out in the log file (usually /var/log/mythtv/mythbackend.log), particularly anything from ivtv since you are using the 500 card. You might something in there with "prebuffer" or "timeout", so that info would be useful.

Other thing to look at is that your frontend is setuid root (chmod +s <your frontend exec) so that it's able to get realtime capabilities when displaying TV.

One thing I have occasionally noticed on my box is that playing live tv can be jerky, but recording the same program, then viewing the recording is perfect, maybe try that.

Adrian.

[pug_]

The recorded program is also jerky, and the jerks happen in the same place as the live TV when watching it back if you get me. I meant to put that in the original post but forgot.

I'll check the ownership, and logs for anything useful when I get home.

[stiofanD]

PVR 500 does not do TV-out, so I wouldn't automatically assume that it is the problem. Try playing back one of your recordings using a different player (xine/mplayer) or even copy one to a windows PC and see how it plays there. If the recording is fine, then the problem is with the Myth player settings.

Go to Setup->Tv settings->Playback. What do you have selected for your preferred MPEG2 decoder? Also, what graphics card are you using to output to your TV?

[pug_]

@adrian.s Had a look last night, and the owner, group, permissions all look to be good for the frontend.

The logs are kind of interesting though, the same lines appear over and over again I don't know what it means but any time I see the word error I get the feeling I'm onto something The first line in particular is interesting to me, if it can't parse the stream properly could that be a problem?

There is nothing else in the logs though, it's literally just full of these lines over and over again.....

Parser not found for Codec Id: 94210 !
0: start_time: 6480.295 duration: 323.968
1: start_time: 1504.417 duration: 323.919
2: start_time: 6480.258 duration: 323.961
stream: start_time: 16715.746 duration: 58887.174 bitrate=315 kb/s
2008-02-16 07:04:35.345 AFD: Opened codec 0x8229820, id(MPEG2VIDEO) type(Video)
2008-02-16 07:04:35.374 AFD: Opened codec 0x8227a20, id(MP2) type(Audio)
2008-02-16 08:04:34.682 TVRec(1) Error: GetProgramRingBufferForLiveTV()
ProgramInfo is invalid.
ProgramInfo: channame() startts(Sat Feb 16 08:04:34 2008) endts(Sat Feb 16 08:04:34 2008)
recstartts(Sat Feb 16 08:04:34 2008) recendts(Sat Feb 16 08:04:34 2008)
title()
2008-02-16 08:04:34.804 Finished recording : channel 4294967295
2008-02-16 08:04:34.925 TVRec(1): Enabling Full LiveTV UI.

@stiofanD Yes you're right, I shouldn't make assumptions. I guess I was blinded by the fact that avi's and mp4's play flawlessly even hi-def ones leading me to look elsewhere first. I'll try playback on a windows machine when I get home just to be on the safe side.

I don't know if it's relevant or not, but for my setup I don't have a hi-def TV and everything is played from s-video to a scart port on my TV that supports s-video. So when I say hi-def plays flawlessly what I mean is it plays without a glitch on my TV not in true high definition though.

With that in mind my graphics card is pretty meagre I'm afraid. An nvidia GeForce4 MX 440 AGP 8x with 64Meg ram to be exact. The problem is it has to fit in a half height slot, it has to be agp, and it can't be very long as it's only a desktop type chassis and a small one at that. I couldn't buy one of those, so I hacksawed the top of the slot of a half height size card I already had lying around.

It takes everything I've thrown at it so far, and it doesn't have to do very high resolutions or anything so is should be fine... Shouldn't it?

[adrian.s]

Originally Posted by pug_

@adrian.s Had a look last night, and the owner, group, permissions all look to be good for the frontend.

The logs are kind of interesting though, the same lines appear over and over

I know this isn't going to be much help to you, but there doesn't appear to be anything going wrong in that snippet of error log you sent me. I'd like to rule the capture by getting you to play some of the recorded material using mplayer for example and see does it play flawlessly. If so, then it's probably something on the mythfrontend side of things. Things you could check are the playback profiles and make sure that XDMCP is enabled as a possibility.

Sorry I can't be more help.

Adrian.

[10-10-20]

Ensure that DMA is enabled for all IDE devices.

[subway]

Originally Posted by 10-10-20

Ensure that DMA is enabled for all IDE devices.

seconded

[pug_]

Right I've only managed to start looking at this properly this evening.

It's good news and bad news. It seems to be working OK now, but unfortunately I have no idea what was at fault. I exited out of myth, all psyched up to do all kinds of good things and saw there were updates ready to be installed. Clicked on the little icon and there were 53 of them ready to install including a new kernel and a newer version of mythtv. I figured I've nothing to loose so I went ahead and installed them.

Rebooted with the new kernel and I tried the TV, it was playing flawlessly not a glitch. Picture quality was poor, I'm hoping that's down to my messing around trying to get it to play smoothly, but otherwise it was perfect. I guess it must have been a bug somewhere with something, but I guess I'll never know now, and hopefully it'll never happen again so I won't ever have to know

Cheers for all the advice, I've a feeling I'll be back for more in a couple of weeks though cos there are plenty of other things that are puzzling me like how in the name of jebus can I get the OSD to work, and I'm also not getting recordings to behave. I'll give it a proper bash myself first though hopefully I'll figure it out.