[MPlayer-users] Inconsistent playback speed

[David Middleton]

Hi 

I am getting inconsistent results when using mplayer to view some videos
at high speeds (4x to 8x).  For example, playing a 30 minute video at 4x
speed can take 16 minutes:

$ time ../mplayer.exe -speed 4 V0329001x2.AVI
MPlayer 1.0rc2-3.4.5 (C) 2000-2007 MPlayer Team
CPU: Intel(R) Core(TM)2 CPU         T7400  @ 2.16GHz (Family: 6, Model:
15, Stepping: 6)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
Playing V0329001x2.AVI.
AVI file format detected.
[aviheader] Video stream found, -vid 0
AVI: No audio stream found -> no sound.
VIDEO:  [FMP4]  640x544  24bpp  34.000 fps  1579.4 kbps (192.8 kbyte/s)
Clip info:
 Software: MEncoder 1.0rc2-4.2.1
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg MPEG-4)
==========================================================================
Audio: no sound
Starting playback...
VDec: vo config request - 640 x 544 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.18:1 - prescaling to correct movie aspect.
VO: [directx] 640x544 => 640x544 Planar YV12
V:1800.5 61217/61217  0%  0%  0.0% 0 0 4.00x
Exiting... (End of file)
real    16m0.078s
user    0m0.015s
sys     0m0.046s


On other occasions, however playback speed is as expected:

$ time ../mplayer.exe -speed 4 V0329001x2.AVI
MPlayer 1.0rc2-3.4.5 (C) 2000-2007 MPlayer Team
CPU: Intel(R) Core(TM)2 CPU         T7400  @ 2.16GHz (Family: 6, Model:
15, Stepping: 6)
CPUflags:  MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
Playing V0329001x2.AVI.
AVI file format detected.
[aviheader] Video stream found, -vid 0
AVI: No audio stream found -> no sound.
VIDEO:  [FMP4]  640x544  24bpp  34.000 fps  1579.4 kbps (192.8 kbyte/s)
Clip info:
 Software: MEncoder 1.0rc2-4.2.1
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg MPEG-4)
==========================================================================
Audio: no sound
Starting playback...
VDec: vo config request - 640 x 544 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.18:1 - prescaling to correct movie aspect.
VO: [directx] 640x544 => 640x544 Planar YV12
V:1800.5 61217/61217 31%  0%  0.0% 0 0 4.00x
Exiting... (End of file)
real    7m32.680s
user    0m0.015s
sys     0m0.062s


There is no obvious reason for the difference: on both occasions the
machine was not loaded with other user processes.  Other than the
playback speed, the only other difference in the mplayer output is in
the reported video codec CPU usage, which is much lower (0% vs 31%) when
playback is slower. This is on an HP laptop running windows XP with
Mplayer 1.0rc2, on mains power.  The 16 minute times were consistent
earlier today, but now it happily plays in 7.5 mins.

I am keen to diagnose this problem and hopefully ensure consistent
playback speeds - any suggestions on how to solve this would be
appreciated.

Thanks

David