[mythtv-users] Recent DVD problems with video and audio drops

[HP-mini]

On Sat, 2013-01-19 at 13:48 +0100, Richard wrote:

> >
> > The problem was seen with both VDPAU and OpenGL.  I had 'top' going in
> 
> Ok, so it doesn't appear to have anything to do with any special 
> handling required for the presentation method.
> 

> > What I am curious about is:
> >
> > 2013-01-18 17:27:17.976224 I  Trying to match best refresh rate 29.970Hz
> > 2013-01-18 17:27:17.976279 I  Trying 1920x1080 59.939 Hz
> > 2013-01-18 17:27:18.030063 I  Dynamic TwinView rate found, set
> > 59.9394Hz as XRandR 54
> > 2013-01-18 17:27:18.175301 I  SwitchToVideo: Video size 720 x 480:
> >      Switched to displaying resolution 1920 x 1080, 487mm x 274mm
> >
> > Ok, so is this upconverting to 1080p?  The DVD is 29.970Hz then it's
> > doubling the frame rate to 59.939Hz and going from 480p to 1080p?
> 
> Yes.
> 
> > Once it starts playing and the judder starts we see this:
> >
> > 2013-01-18 17:28:24.160577 D  DVDRB: DVDNAV_NAV_PACKET
> > 2013-01-18 17:28:24.233484 I  Player(0): FPS:   24.18 Mean: 41354
> > Std.Dev:  9959 CPUs: 20% 19% 18%
> > 2013-01-18 17:28:24.802166 D  DVDRB: DVDNAV_NAV_PACKET
> > 2013-01-18 17:28:25.451091 I  Player(0): Waiting for video buffers...
> > 2013-01-18 17:28:25.486048 D  DVDRB: DVDNAV_NAV_PACKET
> > 2013-01-18 17:28:25.521649 I  Player(0): Waiting for video buffers...
> > 2013-01-18 17:28:25.577362 I  Player(0): Waiting for video buffers...
> > 2013-01-18 17:28:25.683569 I  Player(0): Waiting for video buffers...
> > 2013-01-18 17:28:25.822837 I  Player(0): Waiting for video buffers...
> >
> > Why is it playing at 24.18 FPS when before it was reported at 29.970 FPS?
> 
> A DVD can either be 29.97 or 25 fps depending on whether it's NTSC or 
> PAL.  If it's an NTSC disc and should be played at 24fps (or 23.96 or 
> whatever the actual value is) it performs a pull-down.  To be honest, I 
> have very little experience with this and nearly all my DVDs are PAL.
> I just tried one of the region 1 DVDs I have and that reported ~23.97fps 
> too.  Also there are chunks of your logs where there is apparently no 
> playback problem and it's still reporting around the same frame rate.
> 
> The frame rate shown is more the actual framerate rather than the 
> intended framerate, which is why it sometimes jumps around a bit when 
> you get playback issues.
> 
> > There are lots of "Waiting for video buffers".  No idea what is going on!
> 
> That's what we to eliminate but I'm not sure what's causing it either.
> 
> Could you try again with -v playback,timestamp --loglevel=debug? 
> That'll spew out an awful lot of messages but may help identify timing 
> issues.  It's probably not necessary to post the entire log (it's 
> possible you hit pastebin's limits) but a section starting before the 
> playback issues occur would be good.
> 
> It's tricky trying to pin these things down.  
> 
There's been a lot of activity on the libdvdnav mailing list
http://lists.mplayerhq.hu/pipermail/dvdnav-discuss/
There have been loads of patches & talk/complaints about getting the svn
repository up-to-date..
Seems to be reported problems being relayed in from VLC etc..