[MEncoder-users] performance with large files

[Tobias Brockamp]

Hi everybody,

i'm encoding large raw-avi files f.e. 11 GB in size to xvid/mp3 avi.
I've recognized that mencoder went very slow:

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 output.avi input.avi

For a 5:44 min Video i need about 40 minutes encoding. I made another test  
with Virtual Dub, the encoding time
was there about 20 minutes.

Then i tried to encode video and audio separatly with two mencoder lines:

mencoder -of avi -ovc xvid -ofps 25 -oac copy -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"  
-o dummy_output.avi input.avi

mencoder -of avi -ovc copy -ofps 25 -oac mp3lame -srate 44100  
-audio-preload 1.5 -mc 0 -lameopts "cbr:preset=128:mode=0" -o final_output  
dummy_output.avi

Then the encoding time was also about 20 minutes.

How is your video workflow do you also encode video and audio separatly?  
Is there a way to do it without a dummyfile?
Anybody an idea how Virtual Dub does it?

I'm open to all suggestions to optimize my workflow.

I have read in the mplayer doc that using "-ovc copy" makes the file only  
play with mplayer correctly, i have no problem
with VLC and media player 2 here.

kind regards,

tobias brockamp

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