[mythtv] Sluggish pause, waiting for a keyframe?
Ed Wildgoose
lists at wildgooses.com
Mon Nov 29 16:14:47 UTC 2004
Doug Larrick wrote:
> Doug Larrick wrote:
>
>> A little more playing around reveals that pause now appears to wait
>> for or reposition to a keyframe. For material that has come in over
>> ATSC, this is not good news, as the keyframes can be several seconds
>> apart (typically 2-3, but I've seen as much as 10).
>
>
> Isaac fixed the jumping around when entering pause (thanks, Isaac),
> but I still get a multi-second delay sometimes between pressing pause
> and it actually pausing.
>
> A little debugging has led to the conclusion that NVP::Pause is
> waiting a long time to acquire the (newish) decoder_lock. I haven't
> fully examined the code yet (gotta go to work), but it seems the loop
> in NVP::StartPlaying holds this lock most of the time.
Having a lock debug flag would be extremely nice. I have a couple of
delays that I would like to debug including the channel change speed
(which I am sure that I can at least half if I could just track down my
bottleneck)
How easy is it to add some code into the lock create/drop code so that
we could switch on a trace flag if required and just see the code point
and exact time that locks are acquired and dropped. This is obviously a
time critical function in many cases, but perhaps there is an efficient
way to generate a "MythMutex" which can optionally spew debugging info...?
Crazy idea?
Ed W
More information about the mythtv-dev
mailing list