[mythtv-users] MYthTV Playback is Choppy

Brian Schmidt firehawk78 at gmail.com
Wed Apr 8 03:18:49 UTC 2009


Here is the additional detail on the hardware:
AMD Athlon(tm) XP 2100+ (~1730MHz)
256MB RAM
10GB boot drive
200GB video storage drive

Installed packages:
mythtv-0.21-17.fc10.i386
mythtv-frontend-0.21-17.fc10.i386
kmod-nvidia-96xx-2.6.27.5-117.fc10.i686-96.43.11-1.fc10.1.i686
akmod-nvidia-96xx-96.43.11-1.fc10.1.i686
xorg-x11-drv-nvidia-96xx-96.43.11-1.fc10.i386
xorg-x11-drv-nvidia-96xx-libs-96.43.11-1.fc10.i386


`top` output without mythfrontend even running (top 4 processes on the
list):

top - 23:11:25 up 48 min,  2 users,  load average: 1.20, 5.24, 5.29
Tasks: 135 total,   2 running, 132 sleeping,   0 stopped,   1 zombie
Cpu(s): 20.7%us,  1.7%sy,  0.0%ni, 76.0%id,  1.3%wa,  0.0%hi,  0.3%si,
0.0%st
Mem:    221612k total,   192532k used,    29080k free,     1136k buffers
Swap:   524280k total,   222956k used,   301324k free,    53728k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+
COMMAND
 3104 myth      20   0  194m  50m  11m S 11.6 23.4   1:50.86
firefox
 2467 root      20   0 85908  12m 2476 S  9.3  5.7   0:57.58
Xorg
 1441 root      15  -5     0    0    0 S  1.3  0.0   0:33.72
lirc_dev
 2317 root      20   0  213m 6448 2812 S  1.3  2.9   0:30.63 mythbackend


`top` output while trying to playback a recording (top 6 processes on the
list):

top - 22:53:08 up 30 min,  2 users,  load average: 6.79, 4.93, 2.98
Tasks: 136 total,   1 running, 134 sleeping,   0 stopped,   1 zombie
Cpu(s):  3.7%us,  5.6%sy,  0.0%ni,  0.0%id, 89.7%wa,  0.3%hi,  0.7%si,
0.0%st
Mem:    221612k total,   217580k used,     4032k free,      252k buffers
Swap:   524280k total,   312296k used,   211984k free,    69712k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+
COMMAND
 2961 myth      20   0  159m 2024 1464 S  3.3  0.9   0:01.33
pulseaudio
 3211 myth      20   0  441m  78m  57m S  2.0 36.5   1:37.57
mythfrontend
 2467 root      20   0  201m 7828 3064 S  1.3  3.5   0:36.90
Xorg
 1441 root      15  -5     0    0    0 S  1.0  0.0   0:20.44
lirc_dev
  242 root      15  -5     0    0    0 S  0.7  0.0   0:02.85
kswapd0
 2317 root      20   0  213m 5476 1996 S  0.7  2.5   0:16.47 mythbackend


Brian

On Tue, Apr 7, 2009 at 10:59 AM, Brian Schmidt <firehawk78 at gmail.com> wrote:

> Thanks Brian. Sorry I didn't have more detail. I'll add what I can now, and
> then I'll send more later (directly from the system).
>
> The video chipset is an Nvidia GeForce4 MX 440. I have a separate IDE
> (PATA) drive dedicated to storing the recordings. The database, OS, and Myth
> program files are all on the primary drive in the system and thus separate
> from the recording drive. I'll check on the CPU and mem usage and get back
> to you later today. (I'm away from the system right now).
>
> I've tried to switch desktops but I've been unsuccessful. I've tried using
> switchdesk but Gnome just won't go away. Previously I had used mwm or twm
> before rebuilding with FC10. I've been trying to use WindowMaker but can't
> seem to get switched over.
>
> Thanks again,
> Brian
>
> On Tue, Apr 7, 2009 at 10:23 AM, Brian Wood <beww at beww.org> wrote:
>
>>  On Tuesday 07 April 2009 08:04:57 Brian Schmidt wrote:
>> > I'm running the latest stable MythTV updated via yum on a Fedora Core 10
>> > box. The machine is a Shuttle PC that is multiple years old. It has the
>> > nForce2 chipset. I'm running the latest 96.43 Nvidia drivers also
>> updated
>> > via yum. The TV output is functional and is using the Nvidia drivers
>> (the
>> > Nvidia logo appears as X starts). I'm running Xorg and Gnome. I have a
>> > Hauppage HVR-1600 installed and I'm receiving over-the-air ATSC digital
>> > broadcasts in NTSC format.
>> >
>> > At first I thought the issue was the CPU and memory of my older system.
>> > However, I can record shows without issue and I can play them back
>> without
>> > issue using mplayer. The only time my playback is choppy is when I use
>> Myth
>> > to play the recorded TV show back. I've been searching through the
>> mailing
>> > list archives and other forums for a few weeks, but I haven't been able
>> to
>> > resolve the issue. My best results have come when having Myth configured
>> to
>> > use libmpeg for decoding and chromakey for the OSD. I've tried different
>> > deinterlacers and I've had mixed results. I've also followed the
>> Optimizing
>> > Performance on the Myth wiki along with the "Hacking MythTV" book.
>> >
>> > Another thing to note is that I can't seem to set any resolution other
>> than
>> > 1024. This box is for my parents and they do not have an HD TV, so I'm
>> fine
>> > with running a lower res and was hoping that might help, but X refuses
>> and
>> > keeps automatically switching back to 1024.
>> >
>> > I appreciate any help that anyone can offer me. Previously, this system
>> was
>> > up and running using an older version of Myth and a Hauppage analog-only
>> > card.
>>
>> You didn't mention what your hardware actually is, beyond the mobo
>> chipset.
>>
>> Playing back with Myth requires more resources than doing so with mplayer,
>> and
>> it's possible you are on the edge. What is your CPU usage when playing
>> back?
>> Are you swapping?
>>
>> There are things you can do to reduce load, such as running a lightweight
>> window manager (or no window manager), Gnome is pretty resource intensive.
>> Putting your OS and database on a separate drive from your video storage
>> can
>> also help.
>>
>> It certainly sounds as if you are running into some limiting factor in
>> your
>> system performance, you need to identify what it is.
>>
>> --
>> beww
>> beww at beww.org
>> _______________________________________________
>> mythtv-users mailing list
>> mythtv-users at mythtv.org
>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>>
>
>
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