[mythtv-users] HD, XvMC, and realtime

Sat May 6 08:33:31 EDT 2006

On 5/5/06, Gary Dezern <gary at garyndenise.org> wrote:
>  Top is running with -d 1.  (1 second delays)
>
>  Here's a sample of the "top 10" (see below) while my wife is watching
> something recorded the other night in 1080i _and_ the BE is recording
> something else in HD (not sure what format)  Notice that thread 13136 is
> running with a priority of -2.  That's a realtime priority.  Thread 13133 is
> doing something I have no clue about.  Here's the fun one:  thread 6097
> belongs to X and is eating 70% of a single CPU.  The _only_ thing running
> under X on this machine is:
>
>  1)  fvwm
>  2) mythfrontend
>
>  That implies that mythfrontend is dumping a ton of load on X, but I have no
> idea why.  The FE is running at 720p resolution, BOB deint is turned on,
> along with XvMC, and RTPRIO is working.  Audio is being sent to ALSA:spdif.
> I'm getting tons of prebuffering pauses.
>
>  Tasks: 203 total,   4 running, 199 sleeping,   0 stopped,   0 zombie
>  Cpu0  : 24.5% us,  1.0% sy,  0.0% ni, 68.6% id,  5.9% wa,  0.0% hi,  0.0%
> si
>  Cpu1  :  7.8% us, 64.7% sy,  0.0% ni, 25.5% id,  0.0% wa,  2.0% hi,  0.0%
> si
>  Mem:   1027816k total,  1017800k used,    10016k free,    10132k buffers
>  Swap:   977248k total,      192k used,   977056k free,   630156k cached
>
>    PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
>   6097 root      14  -1 76868  46m 4080 R   70  4.6   2:23.38 X
>  13133 mythtv    17   0  270m  67m  31m S   26  6.7   0:52.64 mythfrontend
>  13136 mythtv    -2 -19  270m  67m  31m S    2  6.7   0:03.21 mythfrontend
>  13350 root      16   0  9588 1392  964 R    2  0.1   0:01.05 top
>   4984 root      10  -5     0    0    0 S    1  0.0   0:24.66 saa7133[0] dvb
>      1 root      16   0  2572  576  488 S    0  0.1   0:01.08 init
>      2 root      RT   0     0    0    0 S    0  0.0   0:00.40 migration/0
>      3 root      34  19     0    0    0 S    0  0.0   0:00.01 ksoftirqd/0
>      4 root      RT   0     0    0    0 S    0  0.0   0:00.60 migration/1
>
>
>
>
>  glen martin wrote:
>
>  What is your top delay (press D while top running, or start top with -d
> flag). Default is 3 seconds, so the load is averaged over a 3 second
> period. I noticed this when I was testing an Athlon XP 3200, with a high
> bitrate HD stream the load was only around 40-50%, peaking to 60% when
> popups were being inserted. No problem, right? However, setting the
> delay shorter to 1 second showed a different picture, in which the cpu
> load was spiking to 100% when a popup was displayed. No doubt shortening
> the period further would show more of the impact.
>
>
>
>  XvMC is being used, storage is local on a dedicated XFS
> formatted SATA drive.
>
>
>  <snip>
>
>
>  Please. And, let's keep this thread going. I too have plenty of CPU
> power, XvMC, blah blah... and I get lots of NVP pauses. Seems media
> dependent.
>
>  This is what I've noticed ... some streams I'm playing are high bit rate
> (~17000 kb/s for some HD channels) and some much lower (SD or recorded
> from analog are 3,000 - 5,000), and the high bitrate are somewhat of a
> problem.