[mythtv-users] Frame rate problem when watching live TV

Mark Smit mark at miracle-online.nl
Wed Jan 2 19:18:51 UTC 2008

I am just starting with MythTV, and have set up a system primarily aimed at 
watching and recording TV, including HD. The system consists of:

- GigaByte MA69GM-S2H mainboard with onboard ATI Radeon Express 1250
- Athlon 64 X2 4200+
- Kingston ValueRAM 2 GB DDR2-667 Kit
- Samsung SpinPoint T166 SATA II 500GB harddisk
- Samsung SH-S203B SATA DVD writer
- Terratec Cinergy 1200 DVB-C tuner

I have installed MythBuntu, i.e. Ubuntu Gutsy 7.10 with a pre-installed 
stable MythTV version. I am using fglrx 8.42.3.

Now I have the problem that the frame rate is low when watching live TV. I 
can watch recordings however at full frame frame rate. It makes no 
difference if it is an HD or SD channel.

I am aware that my driver does not support XV, which can cause slowdowns. 
For this reason, I have tried the following to no avail:

- Using the latest fglrx driver (7.12) produces a slightly lower frame rate 
(but difficult to tell the difference);
- Using the standard vesa driver, which produced no image at all.
- Building and installing an SVN version of the RadionHD driver, which 
seemed to produce a similar frame rate, so didn't solve the problem;
- Building and installing an SVN version of mythtv-vid, but I was unable to 
find a combination of MPEG decoder and renderer that would solve my problem.

I have the following questions:
- Given the fact that it is possible for me to view recordings or DVD's with 
no frame rate problems, is the lack of XV support from any currently 
available drivers still a likely cause?
- How can I monitor the frame rate in MythTV?
- Since Myth always records live TV, could the problem be caused by a 
possible problem in the Linux support for SATA?
- Can the above possibility be checked by turning off the recordinfg when 
watching live TV?
- Is mythtv-vid still a branch? Has there ever been a stable version? I have 
read somewhere in this list that part of the code has been merged to the 
trunk. Would it make sense to try an SVN version of MythTV (trunk)?

Thanks for any help!

More information about the mythtv-users mailing list