Encoding videos for the Aiptek V10

About two weeks ago I felt the need to try out the Aiptek V10 LED Micro Projector and it actually sucks a lot less than I thought. I am still thinking about selling it again but it was a nice thing to play with and it fulfilled its purpose.

What I found to be very problematic is encoding videos for the aiptek with my mac (same problem with linux or other unix-based systems I guess). There are a couple of pitfalls and it took me about 5 hours to figure every detail out so don't waste as much time as I did and try what I came up with!

I used mencoder and ffmpeg to create working mp4 containers. Mencoder is able to add black bars to your movies; the aiptek will not play anything other than a movie which is exactly 640x480 in size, you can not just adjust the width to 640. I use ffmpeg after adjusting the video size to get a correct audio stream. I haven't quite figured out why mencdoers ac3 doesn't play on the v10 but a quick run of ffmpeg to adjust the audio stream works quite well and doesn't take too long. All in all I came up with the following:

Software:

• mencoder using macports ("sudo port install mplayer-devel +faac +x264 +xvid")
• ffmpeg using macports ("sudo port install ffmpeg")

Commands used:

mencoder "$file" -sws 9 -of avi -ovc lavc -lavcopts \
  vcodec=mpeg4:vbitrate=300 -o "$file-temp" \
  -vf scale=640:-2,expand=640:480:0:0:1::,harddup -oac faac -faacopts br=64:object=2:mpeg=4 \
  -srate 44100 -channels 2 -ofps 25 -ffourcc DIVX -noodml

ffmpeg -i "$file-temp" -s 640x480 -b 800k -acodec libfaac -ab 64 -vcodec mpeg4 -vtag divx "$outfile"

 The first command resizes the video stream and changes formats, the second run "fixes" audio. Now I am not sure why this is necessary but it works for me and it is resonably fast. You can also make a small script out of it:

#!/bin/bash

file=$1
outfile=${file%.[^.]*}

mencoder "$file" -sws 9 -of avi -ovc lavc -lavcopts \
  vcodec=mpeg4:vbitrate=300 -o "$outfile-temp-aiptek.mp4" \
  -vf scale=640:-2,expand=640:480:0:0:1::,harddup -oac faac -faacopts br=64:object=2:mpeg=4 \
  -srate 44100 -channels 2 -ofps 25 -ffourcc DIVX -noodml

ffmpeg -i "$outfile-temp-aiptek.mp4" -s 640x480 -b 800k -acodec libfaac -ab 64 -vcodec mpeg4 -vtag divx "$outfile-aiptek.mp4"
rm "$outfile-temp-aiptek.mp4"


This script encodes the video given as first parameter for the aiptek not changing the original and creating a new file with -aiptek as suffix.

Hope this helps someone out there; I'd really love to hear from you if it did or if you have improved my approach!