[mythtv-users] Live TV Pauses

[David]

Kevin Stussman wrote:

>Followed the instructions here http://wopr.yi.org/mythtv.html and so far
>everything has worked except for two items:
>
>1. I could not get the OSS audio to work properly, but ALSA worked fine.
>So I changed the MythTV audio device to "ASLA:Default" and the sound now
>works fine.
>
>but the part that is driving me crazy is:
>
>2. The live video pauses/jitters/slows down approx every 10 to 20
>seconds. My gut feeling is that either the decoder is somehow not
>keeping up with the video stream or the process of putting the images
>onto the TV is somehow too slow.
>
sounds likely - sorry - been trying to knock the XFS FUD on the head
Wouldn't want you wasting a time reformating etc

> Here's what I have tried but have had
>no success so far:
>
>- I am using XFS for the main partition and get 56.62 MB/sec with hdparm
>  
>
Good choice;) Good throughput.
[I use :
  dd if=/dev/zero of=/myth/delete.me bs=8k count=64k
newer dd's will give you a transfer (in this case write) rate
Don't forget to rm the delete.me file.]

>- Updated the Hauppauge firmware drivers for ivtv to the latest I could
>find. (the drivers on the HOWTO are a bit outdated)
>  
>
Do you mean firmware?
or are you using one of ck's bleeding edge ivtv drivers.
If so then try #71d it's reasonably stable.

>- Tried to update the nvidia-kernel drivers to the latest gentoo build.
>Also tried to use the latest from nvidia.
>  
>
And did this work?
If you're not using the nvidia hw accel then you will be stressing the CPU
That's what it sounds like.

>- Nice'd mythfrontend to 15 (as per a suggestion to help someone with a
>similar problem)
>  
>
>- I have audio buffers and interlace set to on and XvMC off (also per
>the guide)
>  
>
Try with  interlace turned off (I'm guessing here - someone correct me - 
but you're outputting to a TV so it won't make any difference and it may 
well cause extra processing and bypass HW accel ???)

>- Tried setting the mythtv video device to /dev/video16 and /dev/video32
>  
>
why?

>- The load average is between 1 and 3 when watching live tv, with X
>leading the pack in CPU usage, but the cpu is only at 20-40% used.
>  
>
no HW accel for XV

>- I tried to increase the buffers for the ivtv module, but i'm not sure
>it did anything: options ivtv ivtv-debug=0 mpg_buffers=100
>dec_mpg_buffers=100 yuv_buffers=100 dec_mpg_qlen=100
>  
>

>A couple of observations/suggestions:
>- I am using the svideo out on the nvidia card, but am not sure if my
>settings are correct...could that have an effect in something like this?
>  
>
If it displays on the TV then it's working OK.

>- When I switch channels, there is a noticeable pause,
>
normal

> then the first
>few seconds are jittery/slow,
>
yeah,  I've had that.

> then smooth sections and the 10-20 second
>pause/jitter/slowdown start. But recorded shows seem to play back
>without the pauses (still verifying this).
>  
>
So the captures are good.

I don't think you are using XV properly

Since I RMA'd my nvidia motherboard today I can't check any settings :'-(

David