[MEncoder-users] capture: synchronization problems

[Kyle Schmitt]

--- RC <rcooley at spamcop.net> wrote:
> I did just that, and MPEG2 is faster than both MPEG4
> and MJPEG (though not by too much).  I am actually
> surprised that MPEG2 isn't faster, as my normal
> encodings show MPEG2 to be noticably faster than
> MPEG4...  Perhaps with mbd=2 and trell the
> differences are more significant.
Until you printed your test results I hadn't even
thought about going back and running my own tests
again (I havn't tested it in two years just been going
with my old settings)

My results follow below, and they show a slightly
different picture, mjpeg faster than mpeg2 or mpeg4,
with mpeg2 and mpeg4 being very very close in speed. 
I timed it going to /dev/null and going to an avi.
That said upon viewing simple scenes (the roaring MGM
lion, text credits etc.) mjpeg had significant
artifacting where the mpeg2video and mpeg4 did not. 
During the high motion scenes they were
indistinguishable except when the image was
dark/gritty.  I expect most of the artifacting would
go away with a smiple blur filter before encoding,
which isn't a bad idea anyway.

I suppose its time I adjust my tv-capture scripts.

Anyway tests run in linux on a dual athlon 1800xp
(1.533ghz/proc and yes it is xp not an mp, no I'm not
on crack, this isn't the right forum to talk about
hardware anyway) with mplayer monopolizing one
processor.

mpeg2video to /dev/null
real    4m57.503s
user    4m52.249s
sys     0m2.852s

mpeg2video to mpeg2video.avi
real    5m7.912s
user    4m51.821s
sys     0m5.447s
Most frequent FPS       59
Average FPS             66.26
Max FPS                 90
Min FPS                 59

mpeg4 to /dev/null
real    4m51.011s
user    4m45.384s
sys     0m2.440s

mpeg4 to mpeg4.avi
real    5m28.429s
user    4m47.625s
sys     0m5.879s
Most frequent FPS       56
Average FPS             62.63
Max FPS                 83
Min FPS                 47

mjpeg to /dev/null
real    3m19.550s
user    3m12.945s
sys     0m2.382s

mjpeg to mjpeg.avi
real    3m51.182s
user    3m14.743s
sys     0m5.571s
Most frequent FPS       79
Average FPS             86.05
Max FPS                 102
Min FPS                 65

--Kyle


		
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