[vlc-devel] Dropped frames despite ample CPU idle time?

[Finn Hughes]

I'm trying to play an MPEG2-TS with yadif2x deinterlacing and subtitles, 
but keep on dropping frames with the following warning
"picture is too late to be displayed (missing 21 ms)"
My busiest core was 60% idle at it's busiest (I've pasted a sample from 
top below). I'm using VLC 2.1 and xvideo output on Fedora 18.

I've tried setting "--file-caching 60000" in the theory this gives a 
longer window for the decoding to occur but I see no change. I also 
tried upping "VOUT_MAX_PICTURES" from 20 to 200 but again no improvement.

I'm not familiar enough with the vlc chain to know what's going on, the 
decoder isn't reporting dumping any frames so I assume all frames are 
being decoded and it's just that there is too much jitter in the 
"decode" chain?

Any thoughts of what I can poke next?

Finn


More details:
I've described one specific test case however I've had similar problems 
in lots of other situations.

CPU is an Atom D525 1.8GHz (dual core hyperthreading).

Source video is MPEG2-TS (MPEG2 2.5Mbps 720x576 at 25), captured from a DVB 
stream.

output from top whilst dropping frames
top - 15:45:39 up  6:14,  3 users,  load average: 0.77, 0.43, 0.39
Tasks: 126 total,   1 running, 125 sleeping,   0 stopped,   0 zombie
%Cpu0  : 24.6 us,  4.7 sy,  0.0 ni, 70.7 id,  0.0 wa,  0.0 hi,  0.0 si, 
  0.0 st
%Cpu1  : 25.2 us,  3.4 sy,  0.0 ni, 71.4 id,  0.0 wa,  0.0 hi,  0.0 si, 
  0.0 st
%Cpu2  : 20.9 us,  3.4 sy,  0.0 ni, 75.7 id,  0.0 wa,  0.0 hi,  0.0 si, 
  0.0 st
%Cpu3  : 21.9 us,  3.7 sy,  0.0 ni, 74.1 id,  0.0 wa,  0.0 hi,  0.3 si, 
  0.0 st
KiB Mem:   1017804 total,   765140 used,   252664 free,      320 buffers
KiB Swap:        0 total,        0 used,        0 free,   593728 cached

   PID USER      PR  NI  VIRT  RES  SHR S  %CPU %MEM    TIME+  COMMAND
12516 lincor    20   0  289m  70m  41m S  82.4  7.1   0:55.89 vlc