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Raccoon1400

Member

From: Ontario, Canada

Registered: 2008-04-14

Posts: 853

compress video for youtube

I have some 500MB .mov files that need to me <30 MB so I can put them on youtube. How can I do this with mencode? I've looked around, but haven't been able to figure it out.

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rebugger

Member

From: Germany

Registered: 2007-10-28

Posts: 229

Re: compress video for youtube

mencoder input.avi -o output.avi -oac lavc -ovc xvid -xvidencopts bitrate=1500
should be a good start.
But there are more options for scaling, etc - have a look at
http://davidmalin.blogspot.com/2007/08/ … -with.html
or have a look at avidemux for a gui.

Last edited by rebugger (2009-06-02 00:14:31)

Raccoon1400

Member

From: Ontario, Canada

Registered: 2008-04-14

Posts: 853

Re: compress video for youtube

sound doesn't seem to work on output file.

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Fustrated Windows users have two options.
1. Resort to the throwing of computers out of windows.
2. Resort to the throwing of windows out of computers.

rebugger

Member

From: Germany

Registered: 2007-10-28

Posts: 229

Re: compress video for youtube

you could change "-oac lavc" to "-oac copy"
or check what's available on your system by running
mencoder -oac help

ahaslam

Member

Registered: 2007-05-11

Posts: 119

Re: compress video for youtube

This'll do the trick, just a stripped down version of one of my other scripts:

#!/bin/sh

#script to calculate bitrate, scale & encode to mp4
#uses ffmpeg presets within ~/.ffmpeg (-vpre fast/-vpre vhq)
#examples: http://svn.mplayerhq.hu/ffmpeg/trunk/ffpresets
#depends: faac, ffmpeg & x264 (>20081002 recommended)
#use: ./2mp4 sourceVideo requiredWidth requiredSize(MB)

VID="$1"
WID="$2"
MB="$3"
DEST="${1%.*}.mp4"

#info    
ffmpeg -i ${VID} 2> /tmp/$$
TH=`grep Duration /tmp/$$ | cut -d":" -f2 | cut -c 2-3`
TM=`grep Duration /tmp/$$ | cut -d":" -f3`
TS=`grep Duration /tmp/$$ | cut -d":" -f4 | cut -c 1-5`
SEC=$(echo "( ${TH} * 3600 ) + ( ${TM} * 60 ) + ${TS}" | bc)
RESX=`grep Video: /tmp/$$ | grep -o ....x | tr -d 'x '`
RESY=`grep Video: /tmp/$$ | grep -o x.... | tr -d 'x,'`
rm /tmp/$$ && echo ${RESX} ${RESY} ${SEC}

#height
ASPECT=$(echo "scale=3; ${RESX} / ${RESY}" | bc)
HEIGHT=$(echo "${WID} / ${ASPECT}" | bc)
MOD16=$(( ${HEIGHT} / 16 * 16 ))
echo ${MOD16}

#bitrate
RATE=$(echo "(( "$MB" * 1024 ) / ${SEC}) - 16" | bc)
R8=$(echo "(( ${RATE} * 8 ) * 1.02)" | bc)
KBPS=`echo "tmp=${R8}; tmp /= 1; tmp" | bc`
echo ${KBPS}

#encode
ffmpeg -i ${VID} -pass 1 -s ${WID}x${MOD16} -vcodec libx264 -vpre fast \
-b ${KBPS}k -threads 0 -rc_eq 'blurCplx^(1-qComp)' -level 41 -an "$DEST"
ffmpeg -i ${VID} -acodec libfaac -ac 2 -ab 128k -async 2 -pass 2 \
-s ${WID}x${MOD16} -vcodec libx264 -vpre vhq -b ${KBPS}k -threads 0 \
-rc_eq 'blurCplx^(1-qComp)' -level 41 -psnr -y "$DEST"
echo "Finished! Saved as ${DEST}"

You'll need some decent ffmpeg presets in ~/.ffmpeg/, I recommend you start with these. Usage is explained at the top of the script & the repo versions of said dep's are fine.

Hope it helps.

PS. Sorry, I missed the mencoder part... I only use it for its filters, ffmpeg seems more efficient with straight encodes.

Last edited by ahaslam (2009-06-06 18:30:26)