[mythtv-users] Odd video playback behavior

[Johnny Walker]

On Tue, Jun 22, 2010 at 8:28 AM, Jason Ward <jasonfward at gmail.com> wrote:
> When I watch HD MKV's through MythVideo everything is fine for a few short
> minutes.
>
> Then artefact's and stutter appear and this just gets worse until I stop
> play back.

What is your playback profile for this media? Are you using VDPAU?

>
> This seemed odd to me, both as I have played HD content using other methods
> flawlessly, and because of the degregation (although I have no HD tuners so
> can't test HD MythTV recorded content).
>
> So I loaded System Monitor and watched what happens.
>
> When the video starts to play CPU usage goes to between 60% and 80%,
> outbound network traffic is near zero and inbound jumps up to 4mb and down
> to near zero in a stop start fashion.
>
> However, slowly the outbound network traffic builds, eventually reaching a
> steady 4mb, at the same time CPU usage creeps up to 90% plus and thats when
> the stutter starts.
>
> When I stop playback the outbound traffic falls slowly, taking a minute or
> two to fall back to near zero, whereas inbound traffic behaves as expected
> and falls to near zero as soon as play back is stopped.
>
> When I watch recording made by MythTV everything works pretty much as
> expected, the one thing that does seem a little odd to me is CPU usage
> always sits at between 60% and 80% during playback of any kind (i.e. any bit
> rate), however outbound traffic does nothing in particular and inbound
> traffic arrives in a steady fashion rather than the stop start fashion when
> playing through MythVideo.
>
> One difference between the two streams that might have something to do with
> this, is that the videos are directly accessible on a mounted share to the
> Frontend (in fact the only way I've been able to make it work) whereas the
> recorded TV is not and must be stream through backend.
>
> I'm not at all sure what is going off, it's not I'm sure a network problem,
> I have a wired 1Gb network throughout.  However, why so much outbound
> traffic when playing?  And why the stop start nature of the incoming stream?
>
> My backend is Mythbuntu 0.23 + fixes
> My frontend is Ubuntu with MythTV installed from the Mythbuntu website 0.23
> + fixes
>
> Jason
>
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