[MPlayer-users] System pauses when replaying

[Geoffrey Leach]

On 11/20/2012 01:11:53 PM, Reimar D=F6ffinger wrote:
> On Tue, Nov 20, 2012 at 12:03:02PM -0800, Geoffrey Leach wrote:
> > Configuration. Host is a Puget Systems Echo I, built on the Intel 
> > DH77DF MB. It uses an Intel i7 3.1 GHz with 2 x Patriot Signature 
> > DDR3-1333 8GB. There is a 100MHz connection to a Silicon Dust dual 
> > tuner.
> 
> What do you mean by "100MHz connection"?? Is that a USB device?
> What drivers does it use?
> 
> > What's going on. While the tuner is decoding and downloading OTA TV
> and 
> > mplayer is replaying an MP4. the replay pauses for a second or so, 
> > repetitively. As far as I can tell, there's no loss of playback.
> 
> What pauses? Audio and video together, at the same time?!
> I'd consider that "impossible", it would have to somehow block the
> whole
> audio driver chain to pause audio (MPlayer feeds usually the whole
> upcoming second of audio data to the driver).
> That is, unless it is actually the audio output that hangs and 
> MPlayer
> reacts to it by suspending the video.
> Which could for example happen if a kernel driver hangs while holding
> a lock.
> A similar, but in the details different effect happens if your hard
> disk
> is getting swamped, you should be able to see this by the cache
> getting
> empty (assuming you run with cache enabled).
> Whatever it is, since processes should not be able to influence each
> other directly there should be going something wrong with a shared
> resource -
> which might be a lock, disk bandwidth, memory bandwidth, DMA buffers,

Connection is gigabit ethernet, Intel chip. (Not supprisingly, 
everything is Intel)

Yes, audio and video pause together.

The disk is a 750GB Western Digital WDC WD7500BPKT-7, 7200 RPM

Your mention of (disk?) cache is interesting. I have no idea whether 
cache is enabled or how to check its state.  Can you point me to some 
doc? Given that I'm writing and reading at (presumably) high data 
rates, this could well be a source of my problem.