Mplayer output on n900:
MPlayer UNKNOWN-4.2.1 (C) 2000-2009 MPlayer Team

Playing Full metal alchemist - 01.mp4.
libavformat file format detected.
[lavf] Video stream found, -vid 0
[lavf] Audio stream found, -aid 1
VIDEO: [avc1] 480x272 24bpp 23.976 fps 0.0 kbps ( 0.0 kbyte/s)
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Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffh264] vfm: ffmpeg (FFmpeg H.264)
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Opening audio decoder: [faad] AAC (MPEG2/4 Advanced Audio Coding)
FAAD: compressed input bitrate missing, assuming 128kbit/s!
AUDIO: 48000 Hz, 2 ch, s16le, 128.0 kbit/8.33% (ratio: 16000->192000)
Selected audio codec: [faad] afm: faad (FAAD AAC (MPEG-2/MPEG-4 Audio))
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[AO OSS] audio_setup: Can't open audio device /dev/dsp: No such file or directory
AO: [alsa] 48000Hz 2ch s16le (2 bytes per sample)
Starting playback...
VDec: vo config request - 480 x 272 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.76:1 - prescaling to correct movie aspect.
VO: [xv] 480x272 => 480x272 Planar YV12
[AO_ALSA] Write error: Broken pipe 0.000 0/ 0 ??% ??% ??,?% 0 0
[AO_ALSA] Trying to reset soundcard.
A: 3.0 V: 2.3 A-V: 0.696 ct: -0.017 0/ 0 106% 13% 13.6% 50 0

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**** Your system is too SLOW to play this! ****
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Possible reasons, problems, workarounds:
- Most common: broken/buggy _audio_ driver
- Try -ao sdl or use the OSS emulation of ALSA.
- Experiment with different values for -autosync, 30 is a good start.
- Slow video output
- Try a different -vo driver (-vo help for a list) or try -framedrop!
- Slow CPU
- Don't try to play a big DVD/DivX on a slow CPU! Try some of the lavdopts,
e.g. -vfm ffmpeg -lavdopts lowres=1:fast:skiploopfilter=all.
- Broken file
- Try various combinations of -nobps -ni -forceidx -mc 0.
- Slow media (NFS/SMB mounts, DVD, VCD etc)
- Try -cache 8192.
- Are you using -cache to play a non-interleaved AVI file?
- Try -nocache.
Read DOCS/HTML/en/video.html for tuning/speedup tips.
If none of this helps you, read DOCS/HTML/en/bugreports.html.