Here are some HDTV Performance tweaks I posted about a month ago:
Things to check for best HDTV performance:
a) Right drivers for card with your kernel
b) Proper AGP bus speed and AGP interface driver in use
c) Proper user of openGL sync for retrace
d) Proper settings for deinterlace and, if used, xvmc
e) Proper sound settings and handling of 5.1 sound and multiple streams
f) Real time scheduling of playback thread
g) Making sure disk or network speed is adequate
h) Nothing else sucking up CPU on the machine
a) Right drivers for card with your kernel
Check /var/log/<xservername>.0.log. Excerpt from my
/var/log/Xorg.0.log which shows nVidia driver version 7174:
(II) LoadModule: "nvidia"
(II) Loading /usr/X11R6/lib/modules/drivers
/nvidia_drv.o
(II) Module nvidia: vendor="NVIDIA Corporation"
compiled for 4.0.2, module version = 1.0.7174
Module class: XFree86 Video Driver
b) Proper AGP bus speed and AGP interface driver in use
[EMAIL PROTECTED] ~]$ cat /proc/driver/nvidia/agp/status
Status: Enabled
Driver: AGPGART
AGP Rate: 8x
Fast Writes: Disabled
SBA: Enabled
c) Proper user of openGL sync for retrace
Start mythfrontend with the "--verbose playback" option and redirect
output to a file. Check for Open GL Sync messages (SGI OpenGL)
when a recording or live tv is played back.
mythfrontend.log:
2005-04-25 22:29:36.515 Video timing method: SGI OpenGL
d) Proper settings for deinterlace and, if used, xvmc
These are set via mythtv in the settings->tv->playback screens
(deinterlace on the first and xvmc on the fourth or fifth, IIRC). If
xvmc is set properly, the OSD will be black and white. If xvmc
doesn't show up on the options screen, then it wasn't compiled into
the program. If xvmc is used, the "filters" field (which can also be
used to set deinterlace) isn't used. My personal opinion is that
kernel deint appears to give a better picture (in terms of motion
artifacts) than the others (including BOB).
e) Proper sound settings and handling of 5.1 sound and multiple streams
I am using ALSA:digital for sound (via the Digital Sound HOWTO on mythtv.info)
and I can confirm that it works since my DD receiver switches to digital mode.
Not sure what exactly to check here, but you can use "aplay -L" to get a listing
of the ALSA devices set up for your card / .asoundrc file. Testing
individual devices can be done with "aplay -D <device> <soundfile>".
f) Real time scheduling of playback thread
Need to do a couple of things to get this working:
1. chmod u+s mythfrontend
2. Need to modify /etc/sudoers to add your mythtv user
(use ALL option and NOPASSWORD; example in sudoers file)
3. Start mythfrontend with sudo: "sudo mythfrontend &"
At this point the mythfrontend logs should say something like "using realtime priority"
h) Nothing else sucking up CPU on the machine
Check using "top" and confirm that mythfrontend and X are the top two
items (X may be lower if XvMC is used). Remaining items should be
substantially less (not sure how to define "substantial"...).
I tried several different settings and the best performance I get is with the following:
xorg.conf
NvAGP = 3 (I couldn't get NVAGP to work, so AGPGART is what I'm using)
mythtv
OpenGL enabled (compiled from CVS)
Kernel deinterlace
libmpeg2 enabled
realtime priority enabled
video for timebase enabled
extra audio buffer enabled
xvmc *not* enabled
On my AMD XP 3200+ system with an NVidia GF4 5500, using FC3 (kernel 2.6.10.770), Nvidia driver 7174, and mythtv v0.18 (compiled), frontend and backend on one box, I get the following performance results:
glxgears: 2962
SDTV:
Idle: 83%
mythfrontend: 12%
X: 2%
FPS: 30.42 (no frames dropped)
HDTV (720p):
Idle: 42%
mythfrontend: 37%
X: 14%
FPS: 60.85 (no frames dropped)
HDTV (1080i):
Idle: 12%
mythfrontend: 61%
X: 17%
FPS: 30.42 (no frames dropped)
Hope this helps!
phlepper
-- (II) Module nvidia: vendor="NVIDIA Corporation"
compiled for 4.0.2, module version = 1.0.7174
Module class: XFree86 Video Driver
b) Proper AGP bus speed and AGP interface driver in use
[EMAIL PROTECTED] ~]$ cat /proc/driver/nvidia/agp/status
Status: Enabled
Driver: AGPGART
AGP Rate: 8x
Fast Writes: Disabled
SBA: Enabled
c) Proper user of openGL sync for retrace
Start mythfrontend with the "--verbose playback" option and redirect
output to a file. Check for Open GL Sync messages (SGI OpenGL)
when a recording or live tv is played back.
mythfrontend.log:
2005-04-25 22:29:36.515 Video timing method: SGI OpenGL
d) Proper settings for deinterlace and, if used, xvmc
These are set via mythtv in the settings->tv->playback screens
(deinterlace on the first and xvmc on the fourth or fifth, IIRC). If
xvmc is set properly, the OSD will be black and white. If xvmc
doesn't show up on the options screen, then it wasn't compiled into
the program. If xvmc is used, the "filters" field (which can also be
used to set deinterlace) isn't used. My personal opinion is that
kernel deint appears to give a better picture (in terms of motion
artifacts) than the others (including BOB).
e) Proper sound settings and handling of 5.1 sound and multiple streams
I am using ALSA:digital for sound (via the Digital Sound HOWTO on mythtv.info)
and I can confirm that it works since my DD receiver switches to digital mode.
Not sure what exactly to check here, but you can use "aplay -L" to get a listing
of the ALSA devices set up for your card / .asoundrc file. Testing
individual devices can be done with "aplay -D <device> <soundfile>".
f) Real time scheduling of playback thread
Need to do a couple of things to get this working:
1. chmod u+s mythfrontend
2. Need to modify /etc/sudoers to add your mythtv user
(use ALL option and NOPASSWORD; example in sudoers file)
3. Start mythfrontend with sudo: "sudo mythfrontend &"
At this point the mythfrontend logs should say something like "using realtime priority"
h) Nothing else sucking up CPU on the machine
Check using "top" and confirm that mythfrontend and X are the top two
items (X may be lower if XvMC is used). Remaining items should be
substantially less (not sure how to define "substantial"...).
I tried several different settings and the best performance I get is with the following:
xorg.conf
NvAGP = 3 (I couldn't get NVAGP to work, so AGPGART is what I'm using)
mythtv
OpenGL enabled (compiled from CVS)
Kernel deinterlace
libmpeg2 enabled
realtime priority enabled
video for timebase enabled
extra audio buffer enabled
xvmc *not* enabled
On my AMD XP 3200+ system with an NVidia GF4 5500, using FC3 (kernel 2.6.10.770), Nvidia driver 7174, and mythtv v0.18 (compiled), frontend and backend on one box, I get the following performance results:
glxgears: 2962
SDTV:
Idle: 83%
mythfrontend: 12%
X: 2%
FPS: 30.42 (no frames dropped)
HDTV (720p):
Idle: 42%
mythfrontend: 37%
X: 14%
FPS: 60.85 (no frames dropped)
HDTV (1080i):
Idle: 12%
mythfrontend: 61%
X: 17%
FPS: 30.42 (no frames dropped)
Hope this helps!
phlepper
I hear and I forget. I see and I remember. I do and I understand. -- Confucius
_______________________________________________ mythtv-users mailing list [email protected] http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
