[MEncoder-users] performance with large files

[Tobias Brockamp]

Hi,

i now have tried different options, first of all i used huffyuv encoded  
material
as input instead of raw avi.

Here the encoding times:

INPUT		ENCODE
raw 		01:03:57
huffyuv		00:37:54

Again my command line:

mencoder-of avi -ovc xvid -ofps 25 -oac mp3lame -srate 44100  
-audio-preload 1.5 -mc 0 -vf  
scale,format=rgb24,scale,format=yv12,pp=lb,harddup -xvidencopts  
"threads=2:par=1/1:max_key_interval=250:nopacked:closed_gop:rc_reaction_delay_factor=16:rc_averaging_period=100:notrellis:bitrate=1500:min_iquant=1:max_iquant=31:min_pquant=1:max_pquant=31:min_bquant=1:max_bquant=31:max_bframes=2:bquant_ratio=150:bquant_offset=100:me_quality=6:lumi_mask:chroma_me:qpel:gmc:vhq=4:bvhq=1:quant_type=h263"  
-lameopts "cbr:preset=128:mode=0" -o OUT.avi IN.avi

Then i followed the tipps from Reimar adding leaving out the  
-audio-preload, -mc 0 and adding a cache value.
(For all options i only added the mentioned command to my original line  
and not in combination).

			ENCODE
no -audio-preload	00:31:16
no -mc 0		00:35:24
-cache 102400		00:29:31

Which value for cache is optimal? The thing is i want to make a very  
reduced mencoder frontend programm and so the command line
must work on different hardware configurations.

I'm also playing with other options like the threads value in the  
xvidencopts, threads for -lavdopts and thread priority.
All the options doesn't make a great effect on my CPU Usage but encoding  
speed was increased

			ENCODE
-threads 18		00:31:53
-threads 36		00:31:51 (no great differenc to 18)
-lavdopts "threads=8"	00:31:57
-priority high		00:38:30 (no great effect here)


Here again my question, which values are reasonable for variable hardware  
configurations?

And why does Virtual DUB make such a good job with my files? For both raw  
and huffyuv it only takes
about 25 minutes.

Am 22.09.2007, 09:34 Uhr, schrieb Reimar Döffinger  
<Reimar.Doeffinger at stud.uni-karlsruhe.de>:

> Hello,
> On Mon, Sep 17, 2007 at 05:59:01PM +0200, Tobias Brockamp wrote:
>> mencoder -of avi -ovc xvid -ofps 25 -oac mp3lame -srate 44100
>> -audio-preload 1.5 -mc 0 -vf
>> scale,format=rgb24,scale,format=yv12,pp=lb,harddup
>
> -mc 0 normally isn't good idea.
> Most likely your problem is with -audio-preload 1.5, since that means
> that a lot of video data must be buffered. Try -nocache, a -cache value
> that is enough for at least 5 seconds of the raw video and -ni and -nini
>
> Greetings,
> Reimar Döffinger
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> MEncoder-users mailing list
> MEncoder-users at mplayerhq.hu
> http://lists.mplayerhq.hu/mailman/listinfo/mencoder-users



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