Hello all,

I realize that this may simply be an IVTV driver issue, but I'm wondering if anyone else has run into this problem before I spend too much time troubleshooting.

I have a 2.6 Ghz Celeron-based system with three tuners (one PVR-350, and two tuners on a PVR-500). I'm currently only using the tuners on the PVR-500. This system was previously running MythTV 0.19 on top of CentOS 4, and it worked great, but with the recent changes to scheduling I decided to give KnoppMyth a try.

While the install went very smoothly, I've ended up with some serious video problems -- most recordings are jumping, with stuttering video and audio, poor vertical hold, etc. Given that this was all working smoothly under earlier versions of the software I'm confident this isn't a hardware issue.

I'm currently looking at what's involved in bringing my KnoppMyth install up to kernel 2.6.22, which has the most recent version of the IVTV drivers. This looks like it going to involve pulling a large number of packages from unstable to satisfy the dependencies for TV-out on the PVR-350, so before I pursue that solution:

- Has anyone else with a PVR-500 run into problems with R5F27?

- Do you have any ideas for resolving these issues? I've tried the obvious (make sure DMA is turned on for the drive, disable VBI, make sure capture resolution = NTSC resolution, etc).

There aren't any obvious errors in the mythbackend log.

hello larsks,

i am having what seems to be the same problems on a p4 3.06 ghz based system with one pvr-150. i am connected to a dish network stb via the coax connection, using svideo to tv by way of a nvidia 5200 based video card. all was well using R5E50, trouble started when i did a fresh install of R5F27. the problem is most pronounced whenever there is any kind of graphics on the screen.
my other system is a amd64 3200 based system with the same video and pvr card as above. this one is connected svideo from the stb and svideo to the tv. there is no video problems on this machine, also running R5F27. the problem here is terribly tinny audio, to the point of ruining the recordings it occurs on. this machine was fine under R5E50.
i hope to resolve the issue by trying the delayed settings script i read about on this forum. if this works i will use svideo on both machines.

I am also having this problem with a PVR-500 connected to a DirecTV receiver. So far, I have not spent any time trying to fix it. Once I spend some time debugging, I'll post. My first step will be to check that the capture resolution is 720x480 and such. What have you done so far?

larsks,
How did you disable VBI? I haven't been able to find that info.
Thanks.

As I said in the original post, I've checked the capture resolution, disabled VBI, and verified DMA settings on the drive. That's about as far as I've gotten -- there are no errors in the logs, and the problem seems somewhat sporadic.

Run mythtv-setup. Select General, then Next twice to reach the "Global Backend Setup" screen. The second option down is VBI Format, set this to None.

Thanks Larsks.
If this is also the screen where you set your "capture resolution = NTSC resolution", that's ok, but for completeness's sake, at the risk of stating what you may already know, resolution needs to not be set to 480 x 480. 720 x 480 is recommended to clear this problem up and it needs to be set under Utilities/Setup > Setup > TV Settings > Recording Profiles > MPEG-2 Encoders. You need to change it in all the profiles, including Default and Live TV. You can also adjust your bit rates here for the higher resolution. If this was already obvious, my apologies.

I had this problem. Changing to 720x480 seems to have cleared it up. Thanks for the help!

amd x64 2800+
PVR-150
2 hd tuners

Very well put. I've hijacked this for the hints. Thanks!

No problem. The Hints are an excellent resource. Every time I read them, I pick up on more stuff!

I also had this problem after upgrading from R5E50 to R5F27.

Problem 1: The new PVR500 firmware was not loaded. In my haste I neglected to power down after the upgrade to ensure the new firmware loaded on restart. However, the problem persisted.



Problem 2: Encoder MPG stream buffers are full and dropping data. Look for the following in the kern.log and syslog.



Fix: Increased the buffer size to 16mb from the default 4mb by adding the following option to /etc/mythtv/modules/ivtv then rebooting.



Now recordings are smooth again.

Hey thanks for pointing this out. I've noticed this message since my R5F27 upgrade, but I thought it was just me doing something wrong in the foreground. My box is rebooting now ... let's see if this is a cure.