1. FFmpeg Performance on a Core I7 920 @ 3.6 Ghz

    Wed 22 April 2009

    The system i'm running is a Core i7 920 @ 3.6 Ghz.

    I am transcoding a DVD (Grave Of The Fire Flies) to iPod format (640x480 x264).

    Thread support is enabled, to FFmpeg uses about 250% CPU. That's 2.5 of the 4 cores available. If possible, I would have liked to see it use all four to the max.

    Any way. I use these settings:

    FFmpeg version SVN-r18628

    ffmpeg -i $1 -pass 1 -acodec libfaac -ab 128k -ac 2 -vcodec libx264 -vpre normal -vpre ipod640 -s 640x480 -b 512k -bt 512k -threads 0 -f mp4 $2

    With these settings, I get an encoding speed of fps=193.

    I don't know how that stacks up against other systems. It seems fast to me though. In effect, the system is playing the DVD at 7.6 times the speed of the movie (25 fps?). So encoding is 88 minutes / 7.6 = 11.45 minutes for encoding a DVD to iPod x264.

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  2. How to Escape File Names in Bash Shell Scripts

    Sun 29 March 2009

    After fighting with Bash for quite some time, I found out that the following code provides a nice basis for escaping special characters. Ofcource it is not complete, but the most important characters are filtered.

    If anybody has a better solution, please let me know. It works and it is readable but not pretty.

    FILE_ESCAPED=`echo "$FILE" | \

    sed s/\ /\\\\\\\ /g | \

    sed s/\'/\\\\\\\'/g | \

    sed s/\&/\\\\\\\&/g | \

    sed s/\;/\\\\\\\;/g | \

    sed s/(/\\\\\(/g | \

    sed s/)/\\\\\)/g `

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