[mythtv-users] Where's the playback bottleneck?

[Kevin Kuphal]

Jerry Rubinow wrote:
> On 1/24/06, Robert Johnston <anaerin at gmail.com> wrote:
>   
>> On 1/24/06, Jerry Rubinow <jerrymr at gmail.com> wrote:
>>     
>>> If I playback an HD resolution file, I get stuttering, pick a codec, any codec.
>>>
>>> If I play it back with mplayer (-vo xv -vc ffmpeg12), also stuttering.
>>>  If I play it back with mplayer (-vo xvmc -vc ffmpeg12mc), plays back
>>> pretty much ok.
>>>
>>> In all cases, myth and mplayer, CPU is between 20% and 50% (this is on
>>> a combined front/backend, P4 2.8 Pundit, with onboard VGA disabled,
>>> using a PCI FX5200).
>>>
>>> The fact that I can playback the file in mplayer with xvmc, tells me
>>> it's not a disk issue, and the fact that mplayer cannot play it back
>>> smoothly with xv tells me it's probably not a myth issue.
>>>
>>> Is it a bandwidth problem in the video card or the bus?  Some BIOS
>>> setting incorrect?  Does anyone have any suggestions for how to narrow
>>> it down and tell for sure where the problem might be?
>>>
>>> Is anyone using an original (sis-based) Pundit for HD playback successfully?
>>>       
>> If you can play back using mplayer (and XvMC), it means you can enable
>> XvMC in Myth and have smooth HDTV playback.
>> --
>> Robert "Anaerin" Johnston
>>     
>
> Theoretically, yes, but I've tried many different combinations of
> options (vsync, vblank, audio buffering, etc) and it's just not quite
> good enough for useability.  Sometimes I get a lockup when starting to
> play, sometimes it gets a stutter, sometimes it gets out of sync with
> sound.  Nothing consistent, but perhaps indicative of getting near the
> same bandwidth limit I'm hitting consistently without xvmc.
>   
What video card and driver version?

I have trouble with anything other than Nvidia 7676

Kevin